# State of Arizona

Exceptional Event Documentation

for the Event of August 1 4, 2012

, for the Phoenix PM 10 

# Nonattainment Area

Final Report p repared for

Arizona Department of Environmental Quality

Phoenix, AZ

February 201 3

## This PDF document contains blank pages to accommodate two

- sided printing.

### Cover image depicts windblown dust and haze in the Phoenix area at 2235 LST on August 14, 2012, resulting from

strong winds associated with thunderstorm outflow. This photo was taken by an ADEQ visibility camera near

downtown Phoenix

, facing northeast tow ard Camelback Mountain.



# State of Arizona

Exceptional Event Documentation

for the Event of August 1 4 , 2012

, for the Phoenix PM 10 

# Nonattainment Area

Final Report

STI

- 912097

- 5571

- FR



# Prepared by

Daniel Alrick

Angela Ekstrand

Briana Gordon

Hilary Hafner

Clinton MacDonald

Hilary Minor

Ashley Russell

Sonoma Technology, Inc.

1455 N. McDowell Blvd., Suite D

Petaluma, CA 94954

- 6503

Ph 707.665.9900 | F 707.665.9800

sonomatech.com



# Prepared for

Theresa Rigney

Air Quality Assessment Section Manager

1110 W. Washington Street

Phoenix, AZ 85007

602.771.2274

February 13, 2013

### Exceptional Event, Pho enix

, August 14, 2012 Acknowledgments



## iii 

# Acknowledgments

The authors would like to acknowledge the Arizona Department of Environmental Quality

for helpful discussion and feedback during the preparation of this document.

### Exceptional Event, Phoenix

, August 14, 2012 Table of Contents



## v 

# Table of Contents

Section Page

List of Figures

................................ ................................ ................................ ........................... vii

List of Tables

................................ ................................ .............. Error! Bookmark not defined.

1. Introduction

................................ ................................ ................................ ....................... 1

1.1 Report Contents

................................ ................................ ................................ ...... 1

1.2 Exceptional Event Rule Requirements

................................ ................................ ..... 1

1.2.1 Public Notification that the Event Was Occurring (40 CFR

50.14(c)(1)(i))

................................ ................................ ............................... 2

1.2.2 Place Informal Flag on Data in A QS (40 CFR 50.14(c)(2)(ii))

....................... 2

1.2.3 Notify EPA of Intent to Flag Through Submission of Initial Event

Description by July 1 of Cale ndar Year Following Event (40 CFR

50.14(c)(2)(iii))

................................ ................................ ............................. 2

1.2.4 Document that the Public Comment Process Was Followed for Event

Docume ntation (40 CFR 50.14(c)(3)(iv))

................................ ...................... 2

1.2.5 Submit Demonstration Supporting Exceptional Event Flag (40 CFR

50.14(a)(1

- 2))

................................ ................................ .............................. 3

1.2.6 Documentation Requirements (40 CFR 50.14(c)(3)(iii))

............................... 3

2. Conceptual Model

................................ ................................ ................................ ............. 1

2.1 Geographic Setting and Monitor Locations

................................ .............................. 1

2.2 Climate

................................ ................................ ................................ .................... 5

2.3 Event Day Summary

................................ ................................ ................................ 6

3. Causal Relationship

................................ ................................ ................................ .......... 1

3.1 Di scussion

................................ ................................ ................................ ............... 1

3.2 Summary

................................ ................................ ................................ ................ 12

4. Historical Norm

................................ ................................ ................................ ................. 1

4.1 Analysis

................................ ................................ ................................ ................... 1

4.2 Summary

................................ ................................ ................................ ................. 2

5. Not Reasonably Controllable or Preventable

................................ ................................ .... 1

5.1 Background

................................ ................................ ................................ ............. 1

5.1.1 Control Measures

................................ ................................ ........................ 1

5.1.2 Additional Measures

................................ ................................ .................... 3

5.1.3 PM 10 

## Rule Effectiveness

................................ ................................ .............. 4

5.1.4 Compliance and Enforcement Activities

................................ ....................... 5

5.1.5 Review of Source

- Permitted Inspections and Public Complaints

................. 6

5.2 Forecasts an d Warnings

................................ ................................ .......................... 6

5.3 Wind Observations

................................ ................................ ................................ .. 7

5.4 Summary

................................ ................................ ................................ ................. 7

6. But

- For Analysis

................................ ................................ ................................ ............... 1

6.1 Discus sion

................................ ................................ ................................ ............... 1

6.2 Summary

................................ ................................ ................................ ................. 1

### Exceptional Event, Phoenix

, August 14, 2012 Table of Contents



## vi 

## Section Page

7. Conclusions

................................ ................................ ................................ ...................... 1

7.1 Affects Air Quality

................................ ................................ ................................ .... 1

7.2 Not Reasonably Controllable or Preventable

................................ ........................... 1

7.3 Natural Event

................................ ................................ ................................ ........... 1

7.4 Clear Causal Relationship

................................ ................................ ....................... 2

7.5 Historical Norm

................................ ................................ ................................ ........ 2

7.6 But For

................................ ................................ ................................ .................... 2

Appendix A: Air Quality and Meteorological Data for Maricopa County

................................ . A

- 1

Appendix B: Media Coverage, Videos, and Images

................................ ............................... B

- 1

Appendix C: Historical Fluctuation Time

- Series Graphs

................................ ........................ C

- 1

Appendix D: ADEQ and NWS Forecast Products

................................ ................................ ... D

- 1

Appendix E: Affidavit of Public Notice

................................ ................................ .................... E

- 1

### Exceptional Event, Phoenix

, August 14, 2012 List of Figures



## vii 

# List of Figures

Figure Page

2

- 1. Locations of ai r quality monitors that recorded exceedances of the 24

- hr PM 10 

## NAAQS and NWS monitors primarily used in this report

................................ .................. 2

2

- 2. Location of sites monitoring PM 10 

## in Arizona on August 14, 2012.

................................ ... 3

2

- 3. Drainage system of Phoenix, Arizona

................................ ................................ .............. 4

2

- 4. Average monthly temperatures and precipitation for Phoenix, 1981

- 2010.

...................... 5

2

- 5. Cross

- section of a thunderstorm creating an outflow boundary and haboob

.................... 6

2

- 6. Thunderstorm s over northwestern Mexico and southern Arizona produced outflow

boundaries that propagated northwestward and transported dust to the Phoenix

area on August 14, 2012.

................................ ................................ ................................ 7

3

- 1. Infrared satellite image from 1815 LST on August 14, 2012 (GOES

- West)

...................... 1

3

- 2. Hourly PM 10 

## concentrations at Pinal County monitors on August 14 and 1 5, 2012

.......... 2

3

- 3. Hourly PM 10 

## concentrations at Maricopa County monitors and visibility at KPHX

............. 3

3

- 4. Hourly PM 10 

## concentrations and wind speeds at the West 43 rd 

## Avenue monitor on

August 14 and 15, 2012

................................ ................................ ................................ .. 3

3

- 5. Hourly PM 10 

## concentrations and wind speeds at the Durango Complex monitor on

August 14 and 15, 2012

................................ ................................ ................................ .. 4

3

- 6. Image from an ADEQ visibility camera near downtown Phoenix facing northeast

toward Camelback Mountain

................................ ................................ ........................... 4

3

- 7. Maximum 5

- minute PM 10 

## concentrations, 5

- minute wind speed and direction,

maximum wind gu sts, and minimum visibility observations at Maricopa and Pinal

County monitors between 2030 and 2100 LST on August 14, 2012

................................ 7

3

- 8. Similar to Figure 3

- 7, but rep resenting observations from 2130 to 2200 LST

................... 9

3

- 9. Similar to Figure 3

- 7, but representing observations from 2230 to 2300 LST

................. 10

3

- 10. Similar to Figure 3

- 7, but representing observations from 2330 to 0000 LST

................. 11

4

- 1. 24

- hr average PM 10 

## concentrations at the West 43 rd 

## monitor (2007

– 2012)

...................... 1

4

- 2. Daily maximum hourly average PM 10 

## concentrations at the West 43 rd 

## monitor

(2007

- 2012)

................................ ................................ ................................ ..................... 2

5

- 1. Timeline of Maricopa County fugitive dust rules and ordinances

................................ ..... 5

### Exceptional Event, Phoenix

, August 14, 2012 List of Tables



## viii 

# List of Tables

Table Page

2

- 1. PM 10 

## measurements on August 14, 2012

................................ ................................ ........ 7

5

- 1. Rules and ordinances regulating PM emissions in Maricopa County

............................... 2

5

- 2. Pinal County rules r egulating existing and new non

- point sources in Pinal County

.......... 3

5

- 3. Pinal County rules regulating fugitive dust in Pinal County portion of the Phoenix

PM 10 

## Nona ttainment Area

................................ ................................ ................................ 3

### Exceptional Event, Phoenix

, August 14, 2012 Introduction



## 1 

# 1. Introduction

On August 1 4 , 2012, two air quality monitors in the Phoenix PM 10 

## nonattainment area

recorded 24

- hr average PM 10 

## concentrations in excess of the National Ambient Air Quality

Standard (NAAQS) for PM 10 

## of 150 μ g/m 3 

## . The purpose of this report is to demonstrate that

these exceedances were due to naturally occu rring windblown dust, were not reasonably

controllable or preventable, were historically unusual, and would not have occurred “but for” the

windblown dust and that they therefore constitute an Exceptional Event as defined by the U.S.

Environmental Protecti on Agency’s (EPA) Exceptional Events Rule (EER).



# 1.1 Report Contents

Section 2 of this assessment contains a conceptual model of the windblown dust event

that transpired on August 14, 2012, providing a background narrative of the exceptional event

and an overa ll explanation showing that the event affected air quality. Section 2 also provides

evidence that the event was a natural event.

Section 3 of this assessment establishes a clear causal connection between the natural

event on August 14, 2012, and the excee dances of the 24

- hr PM 10 

## standard at the monitoring

stations. The evidence in this section also confirms that the event in question affected air

quality and was the result of natural events.

Section 4 of this assessment illustrates that the event of Augus t 14, 2012

, produced

PM 10 

## concentrations in excess of normal historical fluctuations.

Section 5 of this assessment details the existing dust control measures and

demonstrates that despite the presence and enforcement of these controls, the event of August

14, 2012, was not reasonably controllable or preventable.

Section 6 of this assessment builds upon the demonstrations made in the previous

sections, showing a clear causal connection between the natural event and the exceedances,

and concludes that the exc eedances of the 24

- hr PM 10 

## standard on August 14, 2012, would not

have occurred “but for” the event.

Appendix A contains time

- series graphs and data tables to supplement Section 3.

Appendix B contains links to videos, images, and media reports to suppleme nt Section 3.

Appendix C contains time

- series graphs to supplement Section 4. Appendix D contains air

quality forecasts issued by the Arizona Department of Environmental Quality ( ADEQ ) and

weather statements and warnings issued by the National Weather Se rvice (NWS)

. Appendix E

contains a copy of the affidavit of public notice concerning this assessment report.



# 1.2 Exceptional Event Rule Requirements

In addition to the technical requirements that are contained within the EER , procedural

requirements must also be met in order for the EPA to concur with the flagged air quality

### Exceptional Event, Phoenix

, August 14, 2012 Introduction



## 2 

## monitoring data. This section of the report lists the requirements of the EER and associated

guidance and discusses how ADEQ addressed those requirements.



# 1.2.1 Public N otification t hat the E vent W as O ccurring (40 CFR 50.14(c) (1)(i))

ADEQ issued Dust Control Action Forecasts and Air Quality Forecasts for Maricopa

County advising citizens of the potential for high wind dust events on August 14, 2012 . More

information on ADEQ’s forecast s can be found in Section 5.2 of this report. The forecast

products that were issued for August 14, 2012 , are included in Appendix D.



# 1.2.2 Place Informal Flag on Data in AQS (40 CFR 50.14(c)(2)(ii))

ADEQ and other operating air quality agencies in Arizona submit data into the EPA’s Air

Quality System (AQS), the official repository of ambient air quality data. This data submittal to

AQS includes particulate matter (PM) data from both filter

- based and continuous monitors

operated in Arizona.

When ADEQ and/or another age ncy operating monitors in Arizona suspect that data

may be influenced by an exceptional event, ADEQ and/or the other operating agency expedites

analysis of the filters collected from the potentially

- affected filter

- based air monitoring

instruments, quality

- assures the results, and submits the data into AQS. ADEQ and/or other

operating agencies also submit data from continuous monitors into AQS after quality assurance

is complete.

If ADEQ and/or other operating air quality agencies have determined that the potential

exists for a monitor’s reading(s) to have been influenced by an exceptional event, a preliminary

flag is submitted for the measurement in AQS. The data are not official until they undergo more

thorough quality assurance and quality control, lead ing to certification by May 1 of the year

following the calendar year in which the data were collected (40 CFR 58.15(a)(2)). The

presence of the flag on the August 14, 2012, data can be confirmed in AQS.



# 1.2.3 Notify EPA of Intent to Flag Through Submission of Initial Event

Description by July 1 of Calendar Year Following Event (40 CFR

50.14(c)(2)(iii))

ADEQ submitted notice to EPA on August 29, 2012 listing all days from calendar year

2012 that ADEQ intends to analyze under the Exceptional Events Rule

. The PM 10 

## exceedances

that occurred on August 12, 2012, in the Phoenix PM 10 

## nonattainment area were included on

this list. This assessment report serves as demonstration supporting the flagging of these data.



# 1.2.4 Document that the Public Comment Process Was Followed f or Event

Documentation (40 CFR 50.14(c)(3)(iv))

ADEQ posted this assessment report on the ADEQ webpage and placed a hard copy of

the report in the ADEQ Records Management Center for public review. ADEQ opened a 30

- day

public comment period on January 1 4

, 201 3 . A copy of the public notice certification, along with

### Exceptional Event, Phoenix

, August 14, 2012 Introduction



## 3 

## any comments received, will be submitted to the EPA, consistent with the requirements of 40

CFR 50.14(c)(3)(iv). S ee Appendix E for a copy of the affidavit of public notice.



# 1.2.5 Submit Demonstration Supporting Exceptional Event Flag (40 CFR

50.14(a)(1

- 2))

At the close of the public comment period, and after ADEQ has had the opportunity to

consider any comments submitted on this document, ADEQ will submit this document, the

comments received, and ADEQ ’s responses to those comments to EPA Region 9 headquarters

in San Francisco, California. The deadline for the submittal of this package is September 30,

201 5

.



# 1.2.6 Documentation Requirements (40 CFR 50.14(c)(3)(iii))

The EER states that in order to justify th e exclusion of air quality monitoring data,

evidence must be provided for the following elements:

1. The event satisfies the criteria set forth in 40 CFR 50.1(j) that

a. the event affected air quality,

b. the event was not reasonably controllable or preventable, an d

c. the event was caused by human activity unlikely to recur in a particular

location or was a natural event;

2. There is a clear causal relationship between the measurement(s) under

consideration and the event;

3. The event is associated with a measured concentra tion(s) in excess of normal

historical fluctuations; and

4. There would have been no exceedance or violation but for the event.

### Exceptional Event, Phoenix

, August 14, 2012 Conceptual Model



## 1 

# 2. Conceptual Model

This section provides a narrative background and summarizes the meteorological and

air quality conditions in place on August 14, 2012, in the Phoenix area. Elements described in

this section include

 A description and map of the geographic setting of the air quality and meteorological

monitors

.

 A d escription of Phoenix ’s climate

.

 An overall description of meteorological and air qua lity conditions on the event day

.



# 2.1 Geographic Setting and Monitor Locations

Phoenix is located in the Salt River Valley in south

- central Arizona. It lies at an elevation

of 1,090 feet above mean sea level (msl) in the northeastern part of the Sonoran Desert. Other

than the mountains in and around the city, the topography of Phoe nix is generally flat. The

Phoenix area is surrounded by the McDowell Mountains (~4,200 ft above msl ) to the northeast,

the foothills of the Bradshaw (~7,900 ft above msl ) and Mazataal (~7,900 ft above msl ) ranges

to the north, the White Tank Mountains (~ 4,500 ft above msl ) to the west, the Sierra Estrella

(~4,450 ft above msl ) to the southwest, and the Superstition Mountains (~5,000 ft above msl ) far

to the east. Within the City are the Phoenix Mountains (~2,600 ft above msl ) and South

Mountain (~2,600 f t above msl ). Current development is pushing north, west, and south into

Pinal County.

A fairly dense network of air quality and meteorological monitors exists throughout the

Phoenix area, with a much less dense network of monitors throughout the rest o f Arizona.

Figure 2

- 1 shows the general geographic setting of Phoenix, as well as the locations of PM 10 

## monitors that recorded exceedances on August 14, 2012. Monitors shown in this map include

AQS monitors, which measure air quality and meteorological d ata, and NWS monitors, which

measure meteorological data only. Some of the AQS monitors in the Phoenix area are run by

the Maricopa County Air Quality Department (MCAQD), while others are run by ADEQ. The

primary NWS site used in this demonstration packa ge was the Phoenix Sky Harbor International

Airport (KPHX) site, because of that site’s high data quality, data completeness, and

representativeness of meteorological conditions in the Phoenix area. Figure 2

- 2 shows the

locations of PM 10 

## monitors statewid e on August 14, 2012.

Figure 2

- 3 depicts the drainage systems or watersheds for the State of Arizona. Many

of the rivers that form Arizona’s drainage system are dry for most of the year and, consequently,

are sources of silt and fine soils that become suspended and add to regional PM 10 

## loadings

during high wind events. Much of this alluvial matter and fine soil is deposited in the low

- lying

areas of central and southern Arizona, with larger depositional areas focused in and around the

confluences of dry river channels.2



## Figure 2

- 1

. Locations of air quality monitors that recorded exceedances of the 24

- hr PM 10 

## NAAQS and NWS monitors primarily

used in this report.

### Exceptional Event, Phoenix

, August 14, 2012 Conceptual Model



## 3 Figure 2

- 2

. Lo cation of sites monitoring PM 10 

## in Arizona on August 14, 2012

.

### Exceptional Event, Phoenix

, August 14, 2012 Conceptual Model



## 4 Figure 2

- 3

. Drainage system of Phoenix, Arizona.

### Exceptional Event, Phoenix

, August 14, 2012 Conceptual Model



## 5 

# 2.2 Climate

Phoenix has an arid climate, with very hot summers and temperate winters. The

average summer high temperatures are among the hottest of any populated area in the United

States ( Figure 2

- 4 ). Temperatures reach or exceed 100°F an average of 110 days annually,

and reach or exceed 110°F an average of 18 days annually. Phoenix receives an average of

7.66 inches of rain per year. The bulk of this rain usually falls during the December through

March and July through August time periods. During the December through March period,

winter storms originati ng from the Pacific Ocean can produce significant rains in southwestern

Arizona. During the mid

- to late

- summer time period, monsoonal moisture originating from the

Gulf of California, Gulf of Mexico, and large thunderstorm complexes over the Sierra Madre

Occidental Mountains in Mexico move northward into Arizona.

Figure 2

- 4

. Average monthly temperatures and precipitation for Phoenix, 1981

- 2010.



## The influx of moisture associated with the monsoon, combined with strong solar heating,

can result in unstable atmospheric conditions that are favorable for the development of

thunderstorms. Heavy precipitation associated with thunderstorms, and the eventual collapse

or dissipation of thunderstorms, can generate wh at are known as downbursts. Downbursts are

the rapid descent of rain

- cooled air in a thunderstorm. Upon reaching the surface, this air

rapidly disperses horizontally away from the storm as the outflow boundary (also called gust

fronts), as shown in Figur e 2

- 5 . The high winds associated with outflow boundaries can

efficiently loft dust into the air and transport the dust over long distances, resulting in dust

storms (also called haboobs) with high PM 10 

## concentrations and low visibilities.

### Exceptional Event, Phoenix

, August 14, 2012 Conceptual Model



## 6 Figure 2

- 5

. Cross

- section of a thunderstorm creating an outflow boundary and haboob 1



## .



## Dust storms associated with these thunderstorms typically occur in the early part of the

monsoon season (July) before subsequent rains moisten the soil and limit potential lofting of soil

into the air. However, depending on the amount and frequency of precipitation received during

the monsoon season, the extremely hot tempe ratures can dry the surface soils very quickly;

thus, dust storms can occur at any time during the year. Specific PM 10 

## source regions are

difficult to determine during thunderstorm

- driven dust storms because the thunderstorm outflow

can carry dust over lo ng distances that encompass many possible sources of dust. Instead, we

consider general PM 10 

## source regions, which are typically identified based on the locations of

the thunderstorms that are believed to have generated the dust

- laden outflow winds.



# 2.3 Event Day Summary

On the afternoon and evening of August 14, 2012, strong winds generated by

thunderstorms southeast of Phoenix transported dust northwestward into the Phoenix area

( Figure 2

- 6 ). The windblown dust resulted in 24

- hr average PM 10 

## concentrat ions in exceedance

of the NAAQS at two air quality monitors in Maricopa County ( Table 2

- 1 ). The PM 10



## concentrations measured at these monitors were in excess of normal historical fluctuations.

The dust was naturally occurring and likely originated over u ndeveloped lands south of

Maricopa County, and wind gusts in excess of 30 to 40 mph overwhelmed reasonable dust

control measures. While only two monitors in Maricopa County recorded PM 10 

## concentrations in

1 

### Image source: Warner T.T. (2004) Desert meteorology , Cambridge University Press, ISBN

- 10: 0521817986, ISBN

13: 978

- 0521817981, February 9.

Cross

- secti on schematic of a haboob caused by the cool outflow from a

thunderstorm, with the leading edge that is propagating ahead of the storm called

an outflow boundary. The strong, gusty winds that prevail at the boundary are

defined as a gust front. The leadin g edge of the cool air is called the nose, and the

upward

- protruding part of the features is referred to as the head. Behind the roll

in the windfield at the leading edge is a turbulent wake. The rapidly moving cool

air and the gustiness at the gust fron t raise dust (shaded) high into the

atmosphere.

### Exceptional Event, Phoenix

, August 14, 2012 Conceptual Model



## 7 

## exceedance of the NAAQS, monitors across Maricopa and Pinal counties recorded elevated

PM 10 

## concentrations during this dust storm.

Figure 2

- 6

. Thunderstorms over northwestern Mexico and southern Arizona produced

outflow boundaries that propagated northwestward and transported dust to the Phoenix

area on August 14, 2012.

Table 2

- 1

. PM 10 

## measurements on August 14, 2012. The exceedance monitors

discussed in this report are shown in bold.

Page 1 of 3



### Mo nitor Monitor

Type Operator AQS Monitor ID 24

- hr

Avg

PM 10 

### ( μg/m 3 

### ) 1

- hr

Max

PM 10 

### (μ g/m 3 

### ) Time of

Max 1

- hr

PM 10 

### (LST) AQS

Qualifier

Flag

Apache County

N/A TEOM WMAT 04

- 001

- 1003

- 81102

- 1 15 49 1300

Coconino County

N/A N/A ADEQ 04

- 005

- 1237

- 81102

- 1 N/A N/A N/A

### Exceptional Event, Phoenix

, August 14, 2012 Conceptual Model



## 8 Table 2

- 1

. PM 10 

## measurements on August 14, 2012. The exceedance monitors

discussed in this report are shown in bold.

Page 2 of 3



### Monitor Monitor

Type Operator AQS Monitor ID 24

- hr

Avg

PM 10 

### ( μg/m 3 

### ) 1

- hr

Max

PM 10 

### (μ g/m 3 

### ) Time of

Max 1

- hr

PM 10 

### (LST) AQS

Qualifier

Flag

Gila County

Hayden Old Jail TEOM ADEQ 04

- 007

- 1001

- 81102

- 3 28 49 1800

Maricopa County

West Phoenix BAM MC 04

- 013

- 0019

- 81102

- 1 106 1251 2200

North Phoenix BAM MC 04

- 013

- 1004

- 81102

- 1 44 77 700

Glendale TEOM MC 04

- 013

- 2001

- 81102

- 1 62 354 2300

Central Phoenix TEOM MC 04

- 013

- 3002

- 81102

- 4 84 916 2200

Greenwood TEOM MC 04

- 013

- 3010

- 81102

- 1 113 1352 2200

South Phoenix TEOM MC 04

- 013

- 4003

- 81102

- 1 125 1624 2200

West Chandler TEOM MC 04

- 013

- 4004

- 81102

- 1 126 1535 2200

Tempe TEOM MC 04

- 013

- 4005

- 81102

- 1 90 978 2200

Higley TEOM MC 04

- 013

- 4006

- 81102

- 1 95 313 2200

West 43 rd 

### Ave TEOM MC 04

- 013

- 4009

- 81102

- 1 254 3574 2200 RJ

Dysart TEOM MC 04

- 013

- 4010

- 81102

- 1 66 651 2300

Buckeye TEOM MC 04

- 013

- 4011

- 81102

- 1 68 283 2300

Zuni Hills TEOM MC 04

- 013

- 4016

- 81102

- 1 44 372 2300

Fort

McDowell/Yuma

Frank TEOM FMIR 04

- 013

- 5100

- 81102

- 3 47 N/A N/A

Durango Complex TEOM MC 04

- 013

- 9812

- 81102

- 1 179 2540 2200 RJ

JLG Supersite BAM ADEQ 04

- 013

- 9997

- 81102

- 3 79 724 2200

JLG Supersite TEOM ADEQ 04

- 013

- 9997

- 81102

- 4 N/A N/A N/A

Navajo County

N/A TEOM WMAT 04

- 017

- 1002

- 81102

- 1 20 47 1900

Pima County

Ajo TEOM ADEQ 04

- 019

- 0001

- 81102

- 3 49 103 2200

Rillito TEOM ADEQ 04

- 019

- 0020

- 81102

- 3 97 485 1900

Orange Grove FRM PCDEQ 04

- 019

- 0011

- 81102

- 2 41 N/A N/A

South Tucson FRM PCDEQ 04

- 019

- 1001

- 81102

- 1 32 N/A N/A

Green Valley TEOM PCDEQ 04

- 019

- 1030

- 81102

- 1 25 63 1800

Geronimo TEOM PCDEQ 04

- 019

- 1113

- 81102

- 1 32 57 1800

Pinal County

Casa Grande

Downtown TEOM PCAQCD 04

- 021

- 0001

- 81102

- 3 132 773 2100

Apache Junction

Fire Station FRM PCAQCD 04

- 021

- 3002

- 81102

- 3 53 267 2100

Stanfield TEOM PCAQCD 04

- 021

- 3008

- 81102

- 3 282 1209 2100 RJ

### Exceptional Event, Phoenix

, August 14, 2012 Conceptual Model



## 9 Table 2

- 1

. PM 10 

## measurements on August 14, 2012. The exceedance monitors

discussed in this report are shown in bold.

Page 3 of 3



### Monitor Monitor

Type Operator AQS Monitor ID 24

- hr

Avg

PM 10 

### ( μg/m 3 

### ) 1

- hr

Max

PM 10 

### (μ g/m 3 

### ) Time of

Max 1

- hr

PM 10 

### (LST) AQS

Qualifier

Flag

Combs School TEOM PCAQCD 04

- 021

- 3009

- 81102

- 3 113 1163 2100

Maricopa TEOM PCAQCD 04

- 021

- 3010

- 81102

- 3 231 1500 2200 RJ

Pinal County

Housing TEOM PCAQCD 04

- 021

- 3011

- 81102

- 3 135 969 2000

Cowtown TEOM PCAQCD 04

- 021

- 3013

- 81102

- 3 481 2859 2300

Santa Cruz County

Nogales Post Office BAM ADEQ 04

- 023

- 0004

- 81102

- 3 40 78 0000

Yuma County

Yuma Supersite TEOM ADEQ 04

- 027

- 8011

- 81102

- 3 81 492 2300

TEOM: Tapered Element Oscillating Microbalance monitor

BAM: Beta Attenuation Monitor

FRM: Federal Reference Method

WMAT: White Mountain Apache Tribe of Fort Apache Reservation, AZ

MC: Maricopa County Air Quality Department

FMIR: Fort McDowell Indian Reservation

PCDEQ: Pima County Department of Environmental Quality

PCAQCD: Pinal County Air Quality Control District

RJ: qualifier flag for high w inds

### Exceptional Event, Phoenix, August 14, 2012 Causal Relationship



## 1 

# 3. Causal Relationship

3.1 Discussion

Meteorological and air quality observations indicate that dust carried by thunderstorm

outflow was directly responsible for the high PM 10 

## concentrations observed in the Phoenix area

on August 14, 2012. On the evening of August 14, a large area of thunderstorms developed

over far northwestern Mexico and southeastern A rizona, south of the Phoenix area ( Figure 3

- 1 ).

Thunderstorms southeast of Maricopa County generated a dust

- carrying outflow boundary that

propagated northward into the Phoenix area. As stated in Section 2.2, thunderstorms

associated with the summer mons oon season can generate strong winds and blow dust across

Arizona. The likely source region for PM 10 

## during the August 14, 2012, event was the desert

region south of Phoenix, most of which lies outside the Phoenix PM 10 

## nonattainment area. This

region lar gely consists of natural, undisturbed desert. In addition, the weeks leading up to the

event were dry in the Phoenix area, with the last measureable rainfall at KPHX occurring on

July 28 and 29. This combination of geography and lack of rainfall precedin g the event resulted

in a large fetch of soils that were particularly vulnerable to particulate suspension.

Figure 3

- 1

. Infrared satellite image from 1815 LST on August 14, 2012 (GOES

- West).

Colder temper atures (blues, purples, and white) indicate tall, convective (thunderstorm)

clouds. Thunderstorms over northwestern Mexico and south

- central Arizona generated

an outflow boundary that carried dust northward into Arizona.

### Exceptional Event, Phoenix, August 14, 2012 Causal Relationship



## 2 

## The thunderstorm outflow and assoc iated windblown dust were first evident at Pinal

County monitors after 2000 LST on August 14, with a sharp increase in PM 10 

## at several

monitors ( Figure 3

- 2 ). The thunderstorm outflow and associated dust continued north

northwestward and arrived in the Pho enix area during the 2200 LST hour on August 14,

accompanied by significant reductions in visibility at KPHX ( Figure 3

- 3 ). PM 10 

## concentrations at

the two exceedance monitors in Maricopa County increased sharply over this time period, with

1

- hr PM 10 

## concen trations exceeding 3,500 μ g/m 3 

## at West 43 rd 

## Avenue ( Figure 3

- 4 ) and

2,500 μ g/m 3 

## at Durango Complex ( Figure 3

- 5 ) . Collocated wind observations at these monitors

showed wind gusts in excess of 45 mph coincident with the high PM 10 

## concentrations. Several

other wind monitors in the Phoenix area reported strong winds at the same time as the high

PM 10 

## concentrations ( Appendix A ), but wind gusts were highest in the vicinity of the two

exceedance monitors. Visibility cameras in the Ph oenix area also clearly showed blowing dust

and reduced visibility after 2200 LST as the outflow arrived ( Figure 3

- 6 ). Links to these videos

and other media coverage and images pertaining to this windblown dust event are shown in

Appendix B . It is also i mportant to note that the abrupt increase in PM 10 

## corresponded with the

arrival of high winds in the Phoenix area, whereas in the hours immediately before and after the

event, winds were lighter and PM 10 

## concentrations were lower. In response to the appro aching

thunderstorm outflow and associated dust and low visibilities, the NWS office in Phoenix issued

a Blowing Dust Advisory ( Appendix D ).

Figure 3

- 2

. Hourly PM 10 

## concentrations at Pinal County monitors on August 14 and 15,

2012. PM 10 

## concentrations sharply increased between 2000 and 2300 LST on August

14, 2012, coinciding with the arrival of windblown dust.

### Exceptional Event, Phoenix, August 14, 2012 Causal Relationship



## 3 Figure 3

- 3

. Hourly PM 10 

## concentrations at Maricopa County monitors and visibility at

KPHX. Visibility was greatly reduced at 2200 and 2300 L ST on August 1 4, 2012,

coinciding with the sharp increase in PM 10 

## concentrations at Phoenix area monitors,

indicating the arrival of windb lown dust.

Figure 3

- 4

. Hourly PM 10 

## concentrations and wind speeds at the West 43 rd 

## Avenue

monitor on August 14 and 15, 2012. PM 10 

## concentrations and wind speeds sharply

increased at 2200 LST on August 14, 2012, indicating the arrival of windblown dust.

### Exceptional Event, Phoenix, August 14, 2012 Causal Relationship



## 4 Figure 3

- 5 . Hourly PM 10 

## concentrations and wind speeds at the Durango Complex

monitor on August 14 and 15, 2012. PM 10 

## concentrations and wind speeds sharp ly

increased at 2200 LST on August 14, 2012, indicating the arrival of windblown dust.

Sustained winds of nearly 20 mph, with gusts over 45 mph, were measured.

Figure 3

- 6

. Image from an ADEQ visibility camera near downtown Phoenix facing

northeast toward Camelback Mountain. Windblown dust associated with thunderstorm

outflow caused reduced visibilities throughout the Phoenix area.

### Exceptional Event, Phoenix, August 14, 2012 Causal Relationship



## 5 

## The progression of the thunderstorm outfl ow and windblown dust through the Phoenix

area is summarized by the radar velocity and wind vector spatial plots shown in Figures 3

- 7

through 3

- 10

.

2030

- 2100 LST (Figure 3

- 7)

Doppler radar indicated an outflow boundary over Pinal County moving northwest to ward

the Phoenix area. Hourly PM 10 

## concentrations at monitors in Pinal County near the outflow

boundary had increased to over 500  g/m 3 

## . Conditions across Maricopa County and far

northwestern Pinal County prior to the arrival of the dust

- laden outflow we re generally

characterized by low PM 10 

## concentrations, low wind speeds, and high visibilities.

2130

- 2200 LST (Figure 3

- 8)

Between 2130 and 2200 LST, the outflow boundary continued northwestward and

passed through western Pinal County into the southernmost part of Maricopa County, where 5

-

minute PM 10 

## concentrations exceeded 1000 μ g/m 3 

## at some monitors, south to southeasterly

winds gusted to over 30 mph, and visibilities dropped to below 1 mile at some monitors.

Monitors not yet affected by the outflow acros s most of Maricopa County continued to report low

PM 10 

## concentrations, low wind speeds, and high visibilities.

2230

- 2300 LST ( Figure 3

- 9)

Doppler radar indicated that the outflow boundary became better defined as it

progressed into Maricopa County, with a large area of strong south

- to

- southeasterly winds

(bright orange/red areas) over much of the central and eastern portions of the county. 5

- minute

PM 10 

## concentrations increased to over 2500 μ g/m 3 

## at several monitors in Maricopa County and

over 5000  g/m 3 

## a t the Durango Complex and West 43 rd 

## Avenue monitors, with widespread

gusty winds and reduced visibilities. Although only two monitors in Maricopa County (Durango

Complex and West 43 rd 

## Avenue) recorded PM 10 

## concentrations in exceedance of the NAAQS, it

is apparent that nearly all monitors showed elevated PM 10 

## concentrations as the outflow

boundary moved through, illustrating that the outflow affected most of the metropolitan area.

The Durango Complex and West 43 rd 

## Avenue monitors showed the highest PM 10



## c oncentrations, most likely because of locally stronger winds of over 40 mph in the vicinity of the

monitors. Winds were also gusty across much of central and eastern Maricopa County, but they

were not quite as strong as the winds observed near the Durango Complex and West 43 rd



## Avenue monitors. Doppler radar also indicated a corridor of enhanced south

- southeasterly flow

aimed directly at the Durango Complex and West 43 rd 

## Avenue monitors. The locally strong

winds in the vicinity of the two exceedance monitors likely overwhelmed all dust control

measures in place near those monitors. Wind directions near the two exceedance monitors

were from the southeast, consistent with the movement of the outflow boundary. The two

exceedance monitors were on the southern side of the Phoenix urban area, closer to the source

region of the thunderstorm outflow and windblown dust, and thus they were subject to greater

quantities of transpo rted PM 10 

## than were other monitors in the nonattainment area.

### Exceptional Event, Phoenix, August 14, 2012 Causal Relationship



## 6 

## 2330

- 0000 LST (Figure 3

- 10)

As the outflow boundary continued northwestward, gusty winds continued across much

of Maricopa County, but PM 10 

## concentrations started to decrease at most monitors, including

the two exceedance monitors. PM 10 

## concentrations increased again to over 2500  g/m 3 

## at two

Pinal County monitors because of another thunderstorm outflow affecting that area, as indicated

by the strong outbound radar velocities over western Pinal County and strong surface winds.7



## Figure 3

- 7

. Maximum 5

- minute PM 10 

## concentrations (colored circles), 5

- minute wind speed and direction, maximum wind gusts,

and minimum visibility observations at Maricopa and Pinal County monitors between 2030 and 2100 LST on Augus t 14, 2012.

Where 5

- minute data are not available (e.g., PM 10 

## concentrations in Pinal County), 1

- hour data are used. Underlying are Doppler

radar velocity data at 2032 LST, where greens indicate motion toward the radar and oranges/reds indicate motion aw ay from the

radar.89 

## Figure 3

- 8

. Similar to Figure 3

- 7 , but representing observations from 2130 to 2200 LST. Doppler radar data are from 2133 LST.10



## Figure 3

- 9

. Similar to Figure 3

- 7 , but representing observations from 2230 to 2300 LST. Doppler radar data are from 2234 LST.11



## Figure 3

- 10

. Similar to Figure 3

- 7 , but representing observations from 2330 to 0000 LS T. Doppler radar data are from 2330 LST.

### Exceptional Event, Phoenix, August 14, 2012 Causal Relationship



## 12 

# 3.2 Summary

The information presented in this section demonstrates a clear causal relationship

between the windblown dust and the PM 10 

## exceedances measured in the Phoenix PM 10 

## nonattainment area on August 14, 2012. The wind, visibility, PM 10 

## , and radar data shown in this

section illustrate the spatial and temporal extent of the dust storm as it moved through Maricopa

County. In additio n, meteorological data tables found in Appendix A show that the sharp

increase in PM 10 

## concentrations coincided with the gusty winds, low visibilities, and airport

reports of blowing dust. The fact that PM 10 

## concentrations in Pinal County spiked before PM 10 

## concentrations increased in Maricopa County shows that a vast majority of the dust that

impacted the nonattainment area monitors originated outside of Maricopa County and was

transported into the Phoenix PM 10 

## nonattainment area. The proximity of the ex ceed ance

monitor s to the open and desert areas of far southern Maricopa County and western Pinal

County, combined with strong wind gusts over 40 mph that likely overwhelmed all available

control measures, provide s solid evidence showing why these two monit ors within the Maricopa

County nonattainment area recorded an exceedance

.

### Exceptional Event, Phoenix

, August 14, 2012 Historical Norm



## 1 

# 4. Historical Norm

4.1 Analysis

PM 10 

## concentrations measured at Phoenix

- area monitors on August 14, 2012 , were

unusual and in excess of normal historical fluctuations. To establish the severity of this event,

PM 10 

## concentrations measured on August 14, 2012 , were compared to a historical 2007

- 201 2

six

- year annual data set at each monitor ( Figure 4

- 1 , 4

- 2, and Appendix C ). The PM 10



## concentrations measured at the West 43rd monitor ( Figure 4

- 1 ) on August 14, 2012

, resulted in

one of the highest 24

- hr averages me asured over the five

- year period, as well as one of the

highest daily maximum hourly averages measured over the same period

. Similar time

- series

plots for the other monitors with exceedances of the 24

- hr PM 1 0 

## standard are shown in

Appendix C.

Figure 4

- 1

. 24

- hr average PM 10 

## concentrations at the West 43 rd 

## monitor (200 7

– 201 2 ).

The 24

- hr average PM 10 

## concentration on August 14, 2012 , is highlighted in red

.

### Exceptional Event, Phoenix

, August 14, 2012 Historical Norm



## 2 F igure 4

- 2

. Daily maximum hourly average PM 10 

## concentrations at the West 43 rd



## monitor (200 7

- 201 2 ). The daily maximum hourly average PM 10 

## concentration on

August 14, 2012

, is highlighted in red

.



# 4.2 Summary

Given the recorded values and using a methodology similar to the one accepted by the

EPA, it is clear that the PM 10 

## levels on August 14, 2012, were outsi de normal historical

fluctuations. This analysis provides evidence that the event affected air quality on a historic

scale.

### Exceptional Event, Phoenix

, August 14, 2012 Not Reasonably Controllable or Preventable



## 1 

# 5. Not Reasonably Controllable or Preventable

5.1 Background

ADEQ and MCAQD are responsible for implementing regulatory measures to control

emissions from agricultural sources, stationary sources, fugitive dust sources, and open burning

within Maricopa County. Three major programs provide or contribute to air pollution control

measures for th e Greater Phoenix area. These programs include

1. ADEQ’s Agricultural Best Management Program (Ag BMP)

2. Maricopa County’s Inspection and Compliance Program

3. ADEQ’s Air Quality Forecasting Program

Specifically, ADEQ is responsible for compliance assistance and enforcement of

Agricultural Best Management Practices developed by the Governor’s Agricultural Best

Management Practices Committee, while MCAQD is responsible for compliance assurance for

all other significant sources of PM 10 

## emissions. In addition to routine inspections and

inspections driven by complaints, inspec tions are often increased when (1) ADEQ forecasters

issue a Maricopa County Dust Control Forecast of “High Risk”, (2) ADEQ forecasters issue a

High Pollution Advisory, or (3) near

- real

- time monitoring data indicate unique activity via high

PM concentrations

. The forecasting program and inspection/compliance programs work

together so that resources can be best utilized during days of greatest risk for elevated PM

emissions.

On Ju ly 25, 2002, EPA took initial action to finalize approval of the Best Available

Control Measure (BACM) and the Most Stringent Measure (MSM) demonstrations in the Serious

Area PM 10 

## plan for the Maricopa County portion of the metropolitan Phoenix PM 10



## nonatt ainment area (67 FR 48718). These BACM and MSM demonstrations were again

approved by EPA on July 14, 2006 (71 FR 43979). The Agricultural Best Management

Practices General Permit rule and related definitions have been adopted into the Arizona

Administrat ive Code as R18

- 2

- 610 and R18

- 2

- 611, pursuant to Arizona Revised Statutes

§49

- 457 2



## .



# 5.1.1 Control Measures

Maricopa County regulations of PM 10 

## emissions are listed in Table 5

- 1

.

2 

### Updates to the AgBMP program in December, 2011, clarified BMPs for crop s and added BMPs for animal

operations. Effective 12/29/2011, R18

- 2

- 611 was renumbered to R18

- 2

- 610.01 Agri cultural PM10 General Permit

for Crop Operations and R18

- 2

- 611.01 Animal Operations PM10 General Permit was added. Definitions for Crop

Operations were revised at R18

- 2

- 610 and new definitions for Animal Operations were added at R18

- 2

- 611.

### Exceptional Event, Phoenix

, August 14, 2012 Not Reasonably Controllable or Preventable



## 2 Table 5

- 1

. Rules and ordinances re gulating PM emissions in Maricopa County.



## Rule/Ordinance Number & Title Description

Rule 300: Visible e missions Establishes standards for visible emissions and opacity.

Rule 310: Fugitive dust from dust

generating o perations Establishes limits for the emissions of particulate matter into the

ambient air from any property, operations, or activity that may serve as

a fugitive dust source.

Rule 310.01: Fugitive d ust from non

traditional sources of fugitive d ust Establishes limits for the emissions of particulate matter into the

ambient air from open areas, vacant lots, unpaved parking lots, and

unpaved roadways which are not regulated by Rule 310 and which are

not required to have either a permit or a dust control plan.

Rule 311: Particulate matter f rom

process i ndustries Establishes emission rates based on process weight applicable to any

affected oper ations not subject to Rule 316.

Rule 312: Abrasive b lasting Establishes limits for particulate emissions from abrasive blasting

operations.

Rule 314: Open outdoor fires and

indoor fireplaces at c o mmercial and

institutional e stablishments Establishes limits for the emissions of air contaminants produced from

open burning.

Rule 316: Nonmetallic mineral

p rocessing Establishes limits for the emissions of particulate matter into the

ambient air from any nonmetallic mining operation or rock product

processing plant.

Rule 317: Hospital/medical/infectious

waste i ncinerators Establishes limits for the emissions of air pollutants from medical

waste incinerators.

Rule 322: Power plant o perations Establishes limits for the emissions of nitrogen oxides, sulfur oxides,

carbon monoxide

, and particulate matter from existing power plants

and cogeneration plants.

Rule 323: Fuel burning equipment

from industrial/commercial/

institutional (ICI) s ources Establishes limits for the emissions of nitrogen oxides, sulfur oxides,

carbon monoxide and particulate matter from ICI sources.

Rule 324: Stationary internal

combustion (IC ) e ngines Establishes limits for the emissions of carbon monoxide, nitrogen

oxides, sulfur oxides, volatile organic compounds, and particulate

matter from stationary internal combustion engines, including

stationary IC engines used in cogeneration.

Rule 325: Brick and structural clay

products (BSCP) m anufacturing Establishes limits for particulate matter emissions from the use of

tunnel kilns for curing in the BSCP manufacturing processes.

Ordinance P

- 25: Leaf blower

r estriction Establishes restrictions for leaf blowers in incorporated and

unincorporated sections of Area A in Maricopa County.

Ordinance P

- 26: Residential wood

burning r estriction Establishes restrictions for residential wood burning.

Ordinance P

- 27: Vehicle parking

and use on unstabilized vacant l ots Establishes restrictions for vehicle parking and use on unstabilized

vacant lots in unincorporated sections of Area A in Maricopa County.

Ordinance P

- 28: Off

- road vehicle

use in unincorporated a reas of

Maricopa County Establishes restrictions for operating vehicles on unpaved property in

unincorporated areas of Maricopa County.

### Exceptional Event, Phoenix

, August 14, 2012 Not Reasonably Controllable or Preventable



## 3 

## Rule/Ordinance Number & Title Description

Arizona Administrative Code R18

-

2

- 611 & 610: Agricultural PM 10



## g eneral permit Establishes a requirement for commercia l farmers to implement best

management practices and maintain a record demonstrating

compliance

.



# 5.1.2 Additional Measures

In addition to the rules and regulations listed in Table 5

- 1 , other PM 10 

## - reducing control

measures (e.g., paving unpaved roads, PM 10 

## - certified street sweepers, controlling unpaved

parking lots, etc.) have been committed to and implemented by local jurisdictions throughout the

PM 10 

## nonattainment area and incorporated into the Arizona state implementation plan (SIP)

through PM 10 

## plans su ch as the Revised Maricopa Association of Governments’ (MAG) 1999

Serious Area Particulate Plan for PM 10 

## for the Maricopa County Nonattainment Area. The Pinal

County Air Quality Control District (PCAQCD) also implements regulatory control measures on

emissions from existing and new non

- point sources within Pinal County (see Table 5

- 2 ).

Additionally, the PCAQCD implements specific nonattainment rules for that part of the Phoenix

PM 10 

## nonattainment area that resides in Pinal County (see Table 5

- 3 )

.

T able 5

- 2

. Pinal County rules regulating existing and new non

- point sources in Pinal County.



## Article Number & Title Description

Article 2: Fugitive d ust Provides a mechanism to reasonably regulate operations which

periodically may cause fugitive dust emissions into the atmosphere

.

Article 3: Construction sites

– f ugitive d ust Improves the control of excessive fugitive dust emissions that have

been traditionally associated with construction, earthwork, and land

development, and thereby minimize nuisance impacts

.

Table 5

- 3

. Pinal County rules regulating fugitive dust in Pinal County portion of the

Phoenix PM 10 

## Nonattainment Area.



## Article Number & Title Descript ion

Article 4: Nonattainment area r ule s;

dustproofing for commercial parking,

drives, and y ards Establishes rules to avoid violations of the prevailing PM 10 

## standard

and additionally minimize nuisance impacts by improving control of

excessive fugitive dust emissions from unpaved parking lots

.

Article 5: Nonattainment area r ules;

stabilization for residential parking

and d rives Establishes rules for stabilizing residential properties

.

Article 6: Restrictions on v eh icle

parking and use on vacant l ots Establishes r ules for unpaved or unstable vacant lots

.

Article 7: Construction sites in

nonattainment areas

– fugitive d ust Establishes rules to avoid violations of the prevailing PM 10 

## standard

and additionally minimize nuisance impacts by improving control of

excessive fugitive dust emissions from activities associated with

construction, earthwork, or land development.

### Exceptional Event, Phoenix

, August 14, 2012 Not Reasonably Controllable or Preventable



## 4 

## Article Number & Title Descript ion

Article 8: Nonattainment area rules,

requirement for stabil ization of

disturbed a reas at v a cant l ots Establishes rules for stabilizing disturbed areas at vacant lots

.



# 5.1.3 PM 10 

# Rule Effectiveness

MCAQD analyzed the effectiveness of its fugitive dust rules (Rules 310, 310.01 and 316)

in terms of permit compliance rates. This rule effectiveness (RE) study was designed to assess

how many sources regulated by MCAQD during the subject time period recei ved no PM 10



## emissions

- related violations. As a basis for comparison, the percentage of permitted sources in

compliance during calendar year 2007 was 76% for sources subject to Rule 310, 85% for Rule

310.01 sources, and 40% for Rule 316 sources. In early 2008, Rules 310, 310.01, and 316

were strengthened, and new ordinances (covering additional source categories such as leaf

blowers, vacant lots, and off

- road vehicles) were adopted. These enhancements resulted from

MCAQD’s obligations under such agreements as the 20 05 Revised PM 10 

## State Implementation

Plan for the Salt River Area and the Maricopa A ssociation of Governments 2007 Five Percent

Plan for PM 10 

## for the Maricopa County Nonattainment Area to reduce PM 10 

## emissions

throughout the county. Three major areas that contributed to increased compliance were an

increase in departmental staffing (especially inspectors), a robust training program, and

regulatory changes that broadened and strengthened control measures under Rules 310,

310.01, and 316.

Source compliance r ates were re

- assessed for FY 2009 (July 2008

– June 2009), a

period that allowed time for the new and revised regulations to take effect. The results showed

significant increases in compliance compared with the earlier period: to 90% (from 76%) for

Rule 31 0 sources, 95% compliance (from 85%) for Rule 310.01 sources, and 65% (from 40%)

for Rule 316 sources. These improvements continued into calendar year 2010 with compliance

rates of 94% for Rule 310 sources, 96% for Rule 310.01 sources , and 73% for Rule 31 6

sources. The timeline below ( Figure 5

- 1 ) il lustrates the improvements in RE over the last

several years ; it also points out significant revisions to previous rules, as well as newly adopted

rules and ordinances.

### Exceptional Event, Phoenix

, August 14, 2012 Not Reasonably Controllable or Preventable



## 5 Figure 5

- 1

. Timeline of Maricopa County fugitive dust rules and ordinances.



# 5.1.4 Compliance and Enforcement Activities

MCAQD is prepared to proactively respond to high wind events and protect human

health and well

- being. MCAQD ‘s approach consists o f two primary components: proactive

inspections conducted routinely, as well as surveillance inspections conducted during and after

significant air quality events. MCAQD routinely inspects dust control

- permitted sites and

increases the frequency of inspe ctions for permits covering areas of 10 acres or more. Rule

316 sources are also regularly inspected multiple times every year. Maricopa County responds

to the majority of complaints within 24 hours.

Maricopa County monitors the ADEQ Five

- Day Dust Contro l Forecast to identify the

potential for elevated PM 10 

## pollution levels due to high winds or stagnant conditions. When a

High Pollution Advisory (HPA) is issued for Maricopa County, MCAQD conducts increased

surveillance before, during, and after the forec ast event(s). MCAQD also conducts event

surveillance and post

- event activities during exceedance days that had not been forecast (i.e.,

those instances in which an HPA had not been issued).

Pre

- event surveillance consists of surveying high

- risk areas for any dust

- generating

activities, educating sources of the impending HPA event, and issuing violations for failure to

comply with local, state, or federal regulations. During the event, MCAQD inspectors survey

high

- risk areas to confirm that control measure s are in place, document any violations, and

contact other regulatory agencies if necessary. Post

- event activities include continued surveys

of high

- risk areas, re

- inspecting sources that had incurred violations within two business days,

and an internal M CAQD debriefing of event activities.

During 2011 and 2012, a total of 17 MCAQD air monitoring sites were upgraded with

new equipment that allows the monitoring sites to automatically report measured readings at

5

- minute intervals. Previously, only hourly readings were available. The real

- time data

reporting system includes a mechanism to alert MCAQD field staff when PM concentrations are

### Exceptional Event, Phoenix

, August 14, 2012 Not Reasonably Controllable or Preventable



## 6 

## elevated. The system allows MCAQD responders to review concentrations at the monitors and

to consult the National Weat her Service website to check for weather event activity. This

capability allows the MCAQD responder to identify regional events and monitor specific issues.

If necessary, the MCAQD responders can inform nearby stakeholders and local governments of

the el evated PM 10 

## concentrat i ons.



# 5.1.5 Review of Source

- Permitted Inspections and Public Complaints

ADEQ’s Arizona Unified Repository for Information Tracking of the Environment

(AZURITE) database and Maricopa County’s Environmental Management System were queried

to compile a list of inspections for the permitted sources in the Maricopa area around the time of

the August 14, 2012 , PM 10 

## exceedances. An evaluation of all inspection reports, air quality

complaints, compliance reports, and other documentation did not indicate any evidence of

unusual anthropogenic

- based PM 10 

## emissions. During the period of August 11

- 17, 2012,

MCAQD inspectors conducted a total of 230 inspections of permitted facilities, of which 148

were at fugitive dust sources. Additionally , MCAQD conducted 41 inspections on vacant lots

and unpaved parking lots. During this seven

- day period, a total of 30 violations were issued

countywide for PM 10 

## and non

- PM 10 

## related violations. No violations were issued for PM 10



## emissions within a four

- m ile radius of an exceedance monitor.

MCAQD was prepared for any complaints received due to the high wind event. During

the seven

- day period from August 11

- 17, 2012 , MCAQD received 25 complaints, of which 14

were related to windblown dust. Each complaint was assigned to

, and investigated by

, a

MCAQD inspector. A review of all pertinent records from this period indicates that MCAQD

inspectors did not observe any PM 10 

## emission violations of local, state, or federal regulations

within a four

- mile radius of a n exceedance monitor

.

In addition to MCAQD’s efforts in pre

- event surveillance and proactive inspections,

ADEQ’s Ag BMP inspector also monitors the ADEQ Five

- Day Dust Control Forecast and the

MCAQD air monitoring sites that include real

- time data. The ADE Q Ag BMP inspector uses

specific knowledge of seasonal activities and associations with the local growers and dairymen

to communicate the importance of limiting dust

- generating activities, especially during high wind

events. Additional outreach is conduct ed with facility representatives prior to forecast high wind

alert days. Should the PM 10 

## readings at a MCAQD air monitoring site show a notable increase,

the ADEQ Ag BMP inspector is dispatched to contact the owners and operators of agricultural

fields in the area to discern whether their activities are causing negative impacts. The Ag BMP

inspector is prepared to respond to most agriculture complaints within 24 hours.

Based on a review of the inspection reports and site visit documentation, there is no

e vidence to suggest that agricultural a ctivities produced unusual PM 10 

## emissions on August 14,

2012. T he ADEQ Ag BMP inspector did not receive any complaints in the two days pr ior to the

event.



# 5.2 Forecasts and Warnings

Dust forecasts and statements were rele ased prior to the event by both ADEQ and the

NWS office in Phoenix (Appendix D). On August 13, 2012, ADEQ issued a Maricopa County

### Exceptional Event, Phoenix

, August 14, 2012 Not Reasonably Controllable or Preventable



## 7 

## Dust Control Forecast for August 14, 2012, indicating a moderate risk level for unhealthy PM 10



## . The Dust Control Forecast a lso indicated a potential for westerly winds of 10

- 20 mph with higher

gusts and strong winds possible during the afternoon due to outflow from thunderstorms.

At 2141 LST on August 14, 2012, the NWS office in Phoenix issued Blowing Dust

Advisories for porti ons of Pinal and Maricopa counties during the period of gusty outflow winds

and high PM 10 

## concentrations in the Phoenix area. These advisories warned residents of the

potential for gusty winds to 40 mph and visibilities reduced below one mile due to blowi ng dust.



# 5.3 Wind Observations

Wind data during the event ( Figure 3

- 2, Figure 3

- 3, and Appendix A ) showed sustained

wind speeds of over 20 mph and wind gusts of over 40 mph coincident with the high PM 10 

## concentrations. While gusty winds were reported througho ut the region, they were particularly

strong in the vicinity of the Durango Complex and West 43 rd 

## Avenue monitors; these strong

winds likely overwhelmed all available control measures.



# 5.4 Summary

The thunderstorm outflow event of August 1 4 , 2012

, produced strong winds that

transported dust and PM 10 

## into the Phoenix PM 10 

## n onattainment a rea. The source region of the

outflows that caused the exceedances was largely located in areas outside the Phoenix PM 10 

## nonattainment area, primarily the deserts s outh of Maricopa County

. The Phoenix area is

designated as a serious nonattainment area for PM 10 

## and is required to have BACM for all

significant sources of PM 10



## . BACM on significant anthropogenic sources were in place and

enforced during the events, and proactive tracking and response to the events by regulatory

agencies and local governments confirmed the uncontrollable nature of the dust emissions;

therefore, these pre

- existing prior

- approved required controls are adequate for meeting the

requirements of an exceptional event and should be considered “reasonable” for these

purposes.

Despite the deployment of comprehensive control measures and sophisticated response

programs, high wind conditions associated with the thunderstorm outflow transported high

concentrations of PM 10 

## into, and also overwhelmed controls within, the Phoenix PM 10



## nonattainment area. Widespread sustained winds in excess of 20 mph with gusts over 40 mph

were strong enough to overwhelm available efforts to limit PM 10 

## concentrations d uring the event.

The fact that these were natural events involving strong winds that transported PM 10 

## emissions

into and across Maricopa County, with a majority of the PM 10 

## e missions recorded by Maricopa

County area monitors coming from sources outside of the Phoenix PM 10 

## nonattainment area,

provides strong evidence that the exceedances of August 14, 2012, recorded within the Phoenix

PM 10 

## n onattainment area were not reasonably controllable or preventable.

### Exceptio nal Event, Phoenix

, August 14, 2012 B ut

- For Analysis



## 1 

# 6. B ut

- For Analysis

6.1 Discussion

Section 50.14(c)(3)(iv)(D) in 40 CFR Part 50 requires that an exceptional event

demonstration satisfy the condition that “[t]here would have been no exceedance or violation but

for the event.” The prior sections of this submittal have provided detailed information that, in

regard to the PM 10 

## exceedances at Phoenix area monitors on August 14, 2012,

 the exc eedance was not reasonably controllable or preventable, and

 there was a clear causal relationship between PM 10 

## transported strong winds originating

in desert areas outside the Phoenix PM 10 

## nonattainment area and the measured PM 10



## exceedances in the Phoenix PM 10 

## nonattainment area.

The weight of evidence in these sections demonstrates that, but for the existence of dust

emissions generated by strong winds and the associated transport of PM 10 

## , there would have

been no exceedance of the NAAQS for 24

- hr average PM 10



## .

As shown in Section 3, maps and time

- series plots of PM 10 

## and wind speeds establish a

clear causal relationship between windblown dust due to thunderstorm outflow and elevated

PM 10 

## concentrations at Phoenix

- area monitors. Multiple independent measu rements of wind

speed, wind direction, and visibility point to the presence of gusty winds generated by

thunderstorm outflow as the mechanism for transport of PM 10 

## into the Phoenix nonattainment

area. In addition, PM 10 

## concentrations were well below the N AAQS on days immediately before

and after the windblown dust event. The source region for the PM 10 

## is clearly identified as

desert areas south of the Phoenix PM 10 

## nonattainment area. The weight of evidence presented

in this submittal provides no alternat ive that could tie the exceedance of August 14, 2012, to any

causal source except PM 10 

## transported by strong winds, confirming that there would have been

no exceedance but for the presence of this uncontrollable natural event.

As detailed in Section 5, all reasonable control measures were in place and/or

implemented on a continual basis. Air quality

- related inspection and compliance data revealed

no violations or complaints in the vicinity of an exceedance monitor within three days before and

after the tim e of the event. Local regulatory agencies, industry, and the general public were

alerted to the possibility of dust storms due to strong winds via daily forecasts and media

reports. Winds were particularly strong in the vicinity of the two exceedance mon itors, which

likely overwhelmed all available control measures.



# 6.2 Summary

The weight of evidence presented in this submittal provides no alternative that could tie

the exceedance of August 14, 2012, to any causal source other than PM 10 

## transported by gusty

w inds due to thunderstorm outflow, confirming that there would have been no exceedance but

for the presence of this uncontrollable natural event.

### Exceptional Event, Phoenix

, August 14, 2012 Conclusions



## 1 

# 7. Conclusions

The PM 10 

## exceedance s that occurred on August 14, 2012, satisfy the criteria of the EER,

which states that in order to justify the exclusion of air quality monitoring data, evidence must be

provided for the following elements:

 The event satisfies the criteria set forth in 40 CFR 50.1 (j) that

a. the event affected air quality,

b. the event was not reasonably controllable or preventable, and

c. the event wa s caused by human activity unlikely to recur in a particular location or

was a natural event;

 There is a clear causal relationship between the measurement(s) under consideration

and the event;

 The event is associated with a measured concentration(s) in exc ess of normal historical

fluctuations; and

 There would have been no exceedance or violation but for the event.



# 7.1 Affects Air Quality

As stated in the preamble to the EER , the event in question is considered to have

affected air quality if it can be shown tha t there is a clear causal relationship between the

monitored exceedance s and the event, and that the event is associated with a measured

concentration in excess of normal historical fluctuations. Given the information presented in

Sections 2, 3, 4

, and 5, we can reasonably conclude that the event in question affected air

quality.



# 7.2 Not Reasonably Controllable or Preventable

Section 50.1(j) of 40 CFR Part 50 requires that an event must be “not reasonably

controllable or preventable” in order to be defined as an exceptional event. This requirement is

met by demonstrating that despite reason able control measures in place within Maricopa

County, high winds overwhelmed all reasonably available controls (Section 5). The PM 10 

## exceedances discussed in this report w ere caused by naturally occurring gusty winds

associated with thunderstorm outflow that transported dust into the Phoenix area from areas

largely outside the Phoenix PM 10 

## nonattainment area. These facts provide strong evidence that

the PM 10 

## exceedances on August 14, 2012, were not reasonably controllable or preventable.



# 7.3 Natural Event

As discussed above, the PM 10 

## exceedances in the Phoenix area on August 14, 2012,

were shown to be caused by transport of PM 10 

## into the Phoenix area from gusty winds

associated with thunderstorm outflow. The event therefore qualifies as a natural event.

### Exceptional Event, Phoenix

, August 14, 2012 Conclusions



## 2 

# 7.4 Clear Causal Relationship

The following points demonstrate that the high PM 10 

## concentrations were caused by

windblown dust:

 Time

- series graphs of PM 10 

## concentrations show that t he timing of high PM 10 

## at Phoenix

area monitors was consistent with gusty winds and low visibilities at Phoenix

- area

meteorological stations (Section 3).

 High PM 10 

## concentrations and gusty winds were reported at several monitors throughout

the Phoenix metr opolitan area (Sections 3 and 5).

 PM 10 

## concentrations were well below the NAAQS on days immediately before and after

the windblown dust event (Section 3).

 Dry conditions preceding the event resulted in soils that were particularly susceptible to

particulat e suspension by high winds (Section 3).

 Wind directions, thunderstorm generated outflow boundary propagation, and

concentration patterns showing elevat ed levels of PM 10 

## in Pinal County prior to levels

increasing in Maricopa County illustrate that a vast ma jority of the dust that impacted the

nonattainment area monitors originated outside of Maricopa County and was transported

to the nonattainment area. While winds were gusty throughout the region, winds were

particularly strong (in excess of 40 mph) near t he two exceedance monitors. Thus, the

wind magnitudes and wind direction, combined with the proximity of the exceed ance

monitor s to open and desert areas of northwestern Pinal County

, provide solid evidence

as to why only two monitors within the Maricopa County nonattainment area recorded an

exceedance (Section 3)

.

 Visibility cameras clearly illustrate the arrival of dust and significant reductions in visibility

in the Phoenix area coinciding with the sharp increases in PM 10 

## concentrations.



# 7.5 Historical Norm

The 24

- hr average PM 10 

## values measured at Phoenix area monitors were historically

unusual compared to a multi

- year data set (Section 4).



# 7.6 But For

On the basis of the weight of evidence described above and in Section 6, the

exceedances of the federal 24

- hr PM 10 

## standard on August 14, 2012, in the Phoenix PM 10 

## nonattainment area would not have occurred but for the high winds and transport of dust from

areas largely outside the Phoenix PM 10 

## nonattainment area.

### Exceptional Event, Phoenix

, August 14, 2012 Appendix A



## 1 

# Appendix A:

Air Quality and Meteorological Data for Maricopa County

This section contains tables of meteorological data from NWS sites in the Phoenix area

for August 14, 2012. Reduced visibilities, gusty winds, and blowing dust or dust storms were

reported coincident with the arrival of thunderstorm outflow and high PM 10 

## concentrations.2 U.S. Department of Commerce

National Oceanic & Atmospheric Administration 

## QUALITY CONTROLLED LOCAL

CLIMATOLOGICAL DATA (final)

HOURLY OBSERVATIONS TABLE

PHOENIX SKY HARBOR INTL AIRPORT (23183)

PHOENIX, AZ (08/2012) National Climatic Data Center

Federal Building

151 Patton Avenue

Asheville, North Carolina 28801



## Elevation: 1107 ft. above sea level

Latitude: 33.427

Longitude:

- 112.003

Date Time

(LST) Station

Type Sky

Conditions Visibilit

y (SM) Weather

Type Dry

Bulb

Temp Wet

Bulb

Temp Dew

Point

Temp Rel

Humd

% Wind

Speed

(MPH) Wind

Dir Wind

Gusts

(MPH) Station

Pressur

e (in. hg) Press

Tend Net

3

- hr

Chg

(mb) Sea

Level

Pressur

e (in. hg) Report

Type Precip.

Total

(in) Alti

meter

(in. hg) (F) (C) (F) (C) (F) (C)

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23

14

14

14

14

14

14

14

14

14

14

14

14

14

14

14

14

14

14

14

14

14

14

14

14

14

14

14

14

14 0051

0151

0204

0244

0251

0351

0451

0551

0651

0751

0851

0951

1051

1151

1251

1351

1451

1551

1651

1751

1851

1951

2051

2151

2226

2242

2251

2332

2351 11

11

11

11

11

11

11

11

11

11

11

11

11

11

11

11

11

11

11

11

11

11

11

11

11

11

11

11

11 FEW110 SCT160 BKN210

FEW110 SCT160 BKN210

FEW110CB SCT160

BKN210

FEW110 SCT160 BKN210

FEW110 SCT160 BKN210

SCT160 BKN210

SCT160 BKN210

FEW160 BKN210

FEW160 SCT210 SCT250

SCT170 BKN210

FEW170 SCT210

FEW170 SCT210

FEW170 SCT210

FEW120 SCT170 SCT210

FEW120 SCT170 SCT250

FEW120 SCT170 SCT250

FEW120 SCT170 SCT250

FEW120 SCT170 SCT250

FEW120 SCT170 SCT250

FEW120 SCT170 SCT250

FEW120 SCT170 SCT250

FEW120 SCT170 SCT250

FEW120 SCT170 SCT250

BKN130

BKN 130CB

BKN130CB

BKN130CB

BKN130CB

BKN130CB 10.00

10.00

10.00

10.00

10.00

10.00

10.00

10.00

10.00

10.00

10.00

10.00

10.00

10.00

10.00

10.00

10.00

10.00

10.00

10.00

10.00

10.00

10.00

10.00

2.50

5.00

10.00

10.00

10.00 TS

TS BLDU

TS BLDU

TS

- TSRA

TS 99

98

99

97

96

95

94

92

94

96

98

101

103

107

108

109

112

110

111

110

109

107

105

104

95

88

88

84

84 37.2

36.7

37.0

36.0

35.6

35.0

34.4

33.3

34.4

35.6

36.7

38.3

39.4

41.7

42.2

42.8

44.4

43.3

43.9

43.3

42.8

41.7

40.6

40.0

35.0

31.0

31.1

29.0

28.9 70

69

70

70

70

70

70

69

69

69

70

71

71

71

71

71

72

72

71

70

71

70

70

70

72

72

72

74

73 21.1

20.5

21.1

20.8

21.2

21.3

20.8

20.5

20.3

20.7

21.2

21.7

21.8

21.7

21.8

21.8

22.4

22.1

21.6

21.3

21.3

21.0

21.1

21.2

22.3

22.1

22.1

23.5

22.8 54

52

54

54

56

57

56

56

54

54

55

55

54

51

51

50

51

51

48

47

48

48

50

51

61

64

64

70

68 12.2

11.1

12.0

12.0

13.3

13.9

13.3

13.3

12.2

12.2

12.8

12.8

12.2

10.6

10.6

10.0

10.6

10.6

8.9

8.3

8.9

8.9

10.0

10.6

16.0

18.0

17.8

21.0

20.0 22

21

22

24

26

28

28

30

26

24

24

22

20

15

15

14

13

14

12

12

13

14

16

17

32

45

45

63

59 6

7

5

13

11

6

5

0

0

0

3

5

3

3

0

7

9

8

11

9

10

8

5

3

23

21

10

15

16 340

330

350

080

060

100

120

000

000

000

090

060

080

VR

000

340

210

290

290

290

230

240

220

VR

150

170

160

170

210 18

18

22

33

36

3 1

23

31 28.60

28.61

28.61

28.60

28.60

28.58

28.59

28.60

28.61

28.63

28.64

28.64

28.63

28.61

28.58

28.56

28.53

28.50

28.48

28.45

28.47

28.47

28.49

28.53

28.57

28.57

28.59

28.59

28.61 1

5

3

8

8

6

5

3 009

006

015

001

024

025

004

042 29.70

29.70

M

M

29.69

29.68

29.68

29.70

29.71

29.73

29.74

29.74

29.73

29.70

29.67

29.65

29.62

29.59

29.57

29.55

29.56

29.57

29.59

29.62

M

M

29.70

M

29.72 AA

AA

SP

SP

AA

AA

AA

AA

AA

AA

AA

AA

AA

AA

AA

AA

AA

AA

AA

AA

AA

AA

AA

AA

SP

SP

AA

SP

AA T

0.05 29.77

29.78

29.78

29.77

29.77

29.75

29.76

29.77

29.78

29.80

29.81

29.81

29.80

29.78

29.75

29.73

29.70

29.67

29.65

29.62

29.64

29.64

29.66

29.70

29.74

29.74

29.76

29.76

29.78



### Figure A

- 1. Quality controlled local climato logical data hourly observations table for Phoenix Sky Harbor International Airport, Phoenix, Arizona

(08/14/2012). Note in the Weather Type column that BLDU (blowing dust) was reported around the time of the high PM 10 

### concentrations. For a

more detailed explanation of the weather codes shown in the table above, please see

http://www.nws.noaa.gov/oso/oso1/oso12/document/guide.shtml . Data dynamically generated via http://cdo.ncdc.noaa.gov/qclcd/QCLCD

.3 U.S. Department of Commerce

National Oceanic & Atmospheric Administration 

## QUALITY CONTROLLED LOCAL

CLIMATOLOGICAL DATA (final)

HOURLY OBSERVATIONS TABLE

PHOENIX DEER VALLEY ARPT (03184)

PHOENIX, AZ (08/2012) National Climatic Data Center

Federal Building

151 Patton Avenue

Asheville, North Carolina 28801



## Elevation: 1455 ft. above sea level

Latitude: 33.688

Longitude:

- 112.081

Data Version: VER2

Date Time

(LST) Station

Type Sky

Conditions Visibility

(SM) Weather

Type Dry

Bulb

Temp Wet

Bulb

Temp Dew

Point

Temp Rel

Humd

% Wind

Speed

(MPH) Wind

Dir Wind

Gusts

(MPH) Station

Pressure

(in. hg) Press

Tend Net

3

- hr

Chg

(mb) Sea

Level

Pressure

(in. hg) Report

Type Precip.

Total

(in) Alti

meter

(in. hg) (F) (C) (F) (C) (F) (C)

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23

14

14

14

14

14

14

14

14

14

14

14

14

14

14

14

14

14

14

14

14

14

14

14

14

14

14

14

14 0053

0153

0253

0353

0453

0553

0653

0753

0853

0953

1053

1153

1253

1353

1453

1553

1653

1753

1853

1953

2028

2053

2153

2238

2253

2306

2308

2353 12

12

12

12

12

12

12

12

12

12

12

12

12

12

12

12

12

12

12

12

12

12

12

12

12

12

12

12 CLR

CLR

CLR

CLR

CLR

CLR

CLR

CLR

CLR

CLR

CLR

CLR

CLR

CLR

CLR

C LR

CLR

CLR

CLR

CLR

CLR

CLR

CLR

CLR

CLR

SCT043

SCT045

CLR 10.00

10.00

10.00

10.00

10.00

10.00

10.00

10.00

10.00

10.00

10.00

10.00

10.00

10.00

10.00

10.00

10.00

10.00

10.00

10.00

10.00

10.00

10.00

10.00

10.00

3.00

3.00

10.00 TS

TS

VCTS

- RA

- RA 95

94

95

95

95

92

91

93

96

99

102

105

106

107

108

109

108

108

107

105

102

103

102

99

98

93

93

86 35.0

34.4

35.0

35.0

35.0

33.3

32.8

33.9

35.6

37.2

38.9

40.6

41.1

41.7

42.2

42.8

42.2

42.2

41.7

40.6

39.0

39.4

38.9

37.0

36.7

34.0

34.0

30.0 69

68

68

6 8

68

67

67

68

69

69

70

70

70

71

71

71

71

70

69

70

70

70

69

69

69

71

72

72 20.4

20.0

19.7

19.9

19.7

19.2

19.3

19.9

20.4

20.6

21.1

21.3

21.2

21.6

21.5

21.7

21.5

21.3

20.8

21.3

21.1

21.0

20.6

20.6

20.4

21.4

22.0

22.1 54

53

51

52

51

51

52

53

53

52

52

51

50

51

50

50

50

49

47

51

52

51

50

52

52

59

61

65 12.2

11.7

10.6

11.1

10.6

10.6

11.1

11.7

11.7

11.1

11.1

10.6

10.0

10.6

10.0

10.0

10.0

9.4

8.3

10.6

11.0

10.6

10.0

11.0

11.1

15.0

16.0

18.3 25

25

22

23

22

25

26

26

23

21

19

16

15

15

14

14

14

14

13

16

19

18

17

21

21

3 2

34

50 9

5

10

9

0

0

3

0

0

5

3

7

6

6

8

11

9

7

9

10

7

0

6

18

20

26

26

14 010

030

040

090

000

000

010

000

000

160

200

250

230

VR

250

220

280

240

250

220

230

000

070

030

060

130

130

160 20

25

28

33

33

24 28.25

28.26

28.23

28.21

28.23

28 .24

28.25

28.27

28.28

28.27

28.27

28.24

28.22

28.20

28.17

28.15

28.12

28.10

28.11

28.12

28.13

28.14

28.17

28.18

28.18

28.20

28.20

28.25 1

5

3

8

8

8

5

1 010

011

013

000

023

027

002

024 29.72

29.72

29.70

29.68

29.69

29.7 0

29.71

29.73

29.74

29.74

29.73

29.71

29.68

29.66

29.63

29.60

29.57

29.56

29.56

29.57

M

29.60

29.63

M

29.65

M

M

29.72 AA

AA

AA

AA

AA

AA

AA

AA

AA

AA

AA

AA

AA

AA

AA

AA

AA

AA

AA

AA

SP

AA

AA

SP

AA

SP

SP

AA T 29.81

29.82

29.79

29.77

2 9.79

29.80

29.81

29.83

29.84

29.83

29.83

29.80

29.78

29.76

29.73

29.70

29.67

29.65

29.66

29.67

29.68

29.69

29.73

29.74

29.74

29.76

29.76

29.81



### Figure A

- 2. Quality controlled local climatological data hourly observations table for Phoenix Deer Valley Airport, Phoenix, Arizona

(08/14/2012). Note that visibilities were reduced with gusty winds after 2200 LST, coincident with high PM 10 

### concentrations in the Pho enix area.

Dynamically generated via http://cdo.ncdc.noaa.gov/qclcd/QCLCD

.4

U.S. Department of Commerce

National Oceanic & Atmospheric Administration 

## QUALITY CONTROLLED LOCAL CLIMATOLOGICAL DATA (final)

WILLIAMS GATEWAY AIRPORT (23104), PHOENIX, AZ (08/2012) National Climatic Data Center

Federal Building

151 Patton Avenue

Asheville, North Carolina 28801



## Elevation: 1382 ft. above sea level

Latitude: 33.3, Longitude:

- 111.666

Date Time

(LST) Station

Type Sky

Conditions Visibility

(SM) Weather

Type Dry

Bulb

Temp Wet

Bulb

Temp Dew

Point

Temp Rel

Humd

% Wind

Speed

(MPH) Wind

Dir Wind

Gusts

(MPH) Station

Pressure

(in. hg) Press

Tend Net

3

- hr

Chg

(mb) Sea

Level

Pressure

(in. hg) Report

Type Precip.

Total

(in) Alti

meter

(in. hg) (F) (C) (F) (C) (F) (C)

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23

14

14

14

14

14

14

14

14

14

14

14

14

14

14

14

14

14

14

14

14

14

14

14

14

14

14

14

14

14

14

14

14

14

14

14

14

14

14 0015

0035

0055

0115

0135

0155

0215

0335

0355

0415

0435

0515

0547

0647

0747

0847

0947

1047

1147

1247

1347

1447

1547

1647

1747

1847

1947

1955

2015

2035

2047

2055

2115

2132

2135

2155

2215

2335 0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0 CLR

CLR

CLR

CLR

CLR

CLR

CLR

CLR

CLR

CLR

CLR

CLR

SCT120 BKN250

SCT120 BKN200

SCT120 BKN200

SCT120 BKN200

SCT150 BKN200

SCT150 BKN200

FEW150 SCT200

FEW120

FEW120

FEW120 FEW250

FEW120 FEW250

SCT120 SCT250

FEW120 SCT200

FEW120 BKN250

BKN

CLR

CL R

CLR

BKN

CLR

CLR

FEW002 BKN100

CLR

SCT001 SCT070 SCT110

CLR

CLR 10.00

10.00

10.00

10.00

10.00

10.00

10.00

7.00

10.00

10.00

10.00

10.00

20.00

30.00

30.00

30.00

30.00

30.00

30.00

30.00

30.00

30.00

30.00

30.00

30.00

20.00

20.00

10.00

10.00

10.00

20.00

10.00

10.00

0.75

4.00

3.00

3.00

10.00 DS

HZ

HZ

VCTSHZ 100

100

97

97

97

93

93

93

93

91

88

91

97

90

97

100

104

108

108

109

109

109

111

111

111

109

108

106

106

104

106

100

100

102

100

97

97

86 38.0

38.0

36.0

36.0

36.0

34.0

34.0

34.0

34.0

33.0

31.0

33.0

36.0

32.0

36.0

38.0

40.0

42.0

42.0

43.0

43.0

43.0

44.0

44.0

44.0

43.0

42.0

41.0

41.0

40.0

41.0

38.0

38.0

39.0

38.0

36.0

36.0

30.0 70

70

69

69

69

68

68

68

68

67

67

67

69

67

69

70

71

72

71

72

70

70

71

70

70

69

M

69

69

68

M

69

69

71

72

72

71

71 21.3

21.3

20.3

20.8

20.8

20.1

20.1

20.1

20.1

19.3

19.3

19.3

20.8

19.1

20.8

21.3

21.9

22.0

21.6

22.1

21.3

21.3

21.6

21.2

21.2

20.7

M

20.2

20.4

20.1

M

20.3

20.3

21.5

22.0

22.1

21.5

21.8 54

54

52

54

54

54

54

54

54

52

54

52

54

52

54

54

54

52

50

52

48

48

48

46

46

45

46

45

46

46

48

50

50

54

57

59

57

64 12.0

12.0

11.0

12.0

12.0

12.0

12.0

12.0

12.0

11.0

12.0

11.0

12.0

11.0

12.0

12.0

12.0

11.0

10.0

11.0

9.0

9.0

9.0

8.0

8.0

7.0

8.0

7.0

8.0

8.0

9.0

10.0

10.0

12.0

14.0

15.0

14.0

18.0 21

21

22

24

24

27

27

27

27

2 6

31

26

24

27

24

21

19

16

14

15

13

13

12

11

11

12

M

13

13

14

M

19

19

20

24

28

26

48 0

0

3

3

0

3

5

5

6

6

5

9

3

5

3

6

6

7

9

11

6

7

5

11

9

6

6

6

3

0

3

0

0

23

24

24

24

0s 000

000

240

240

000

100

090

060

060

110

110

120

110

100

170

100

100

250

200

270

220

230

2 60

330

290

280

260

270

260

000

280

000

000

150

150

170

180

000 33

33

32 28.37

28.37

28.37

28.36

28.36

28.36

28.36

28.36

28.35

28.34

28.34

28.34

28.35

28.36

28.38

28.39

28.40

28.38

28.36

28.34

28.32

28.29

28.26

28.23

28.22

28.23

M

28.25

28.25

28.25

M

28.26

28.27

28.31

28.31

28.34

28.34

28.40 M

M

M

M

M

M

M

M

M

M

M

M

M

M

M

M

M

M

M

M

M

M

M

M

M

M

M

M

M

M

M

M

M

M

M

M

M

M AA

AA

AA

AA

AA

AA

AA

AA

AA

AA

AA

AA

AA

AA

AA

AA

AA

AA

AA

AA

AA

AA

AA

AA

AA

AA

AA

AA

AA

AA

AA

AA

AA

AA

AA

AA

AA

AA 29.83

29.83

29.83

29.82

29.82

29.82

29.82

29.82

29.81

29.80

29.80

29.80

29.81

29.82

29.84

29.85

29.86

29.84

29.82

29.80

29.78

29.75

29.72

29. 69

29.68

29.69

29.69

29.70

29.70

29.71

29.71

29.72

29.73

29.77

29.77

29.80

29.80

29.86



### Figure A

- 3. Quality controlled local climatological data hourly observations table for Williams Gateway Airport, Phoenix, Arizona (08/14/ 2012).

Note in the Weather Type column that DS (dust) and HZ (haze) with reduced visibilities and gusty winds were reported between 2132 and 2215

LST, coincident with high PM 10 

### concentrations in the Phoenix area. Dynamically generated via http://cdo.ncdc.noaa.gov/qclcd/QCLCD

.5 U.S. Department of Commerce

National Oceanic & Atmospheric Administration 

## QUALITY CONTROLLED LOCAL

CLIMATOLOGICAL DATA (final)

HOURLY OBSERVATIONS TABLE

LUKE AFB AIRPO RT (23111), GLENDALE, AZ (08/2012) National Climatic Data Center

Federal Building

151 Patton Avenue

Asheville, North Carolina 28801



## Elevation: 1085 ft. above sea level

Latitude: 33.55, Longitude:

- 112.366

Date Time

(LST) Station

Type Sky

Conditions Visibility

(SM) Weather

Type Dry

Bulb

Temp Wet

Bulb

Temp Dew

Point

Temp Rel

Humd

% Wind

Speed

(MPH) Wind

Dir Wind

Gusts

(MPH) Station

Pressure

(in. hg) Press

Tend Net

3

- hr

Chg

(mb) Sea

Level

Pressure

(in. hg) Report

Type Precip.

Total

(in) Alti

meter

(in. hg) (F) (C) (F) (C) (F) (C)

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23

14

14

14

14

14

14

14

14

14

14

14

14

14

14

14

14

14

14

14

14

14

14

14

14

14

14

14

14

14

14

14

14

14

14

14

14 0034

0055

0103

0119

0137

0155

0255

0355

0455

0555

0655

0755

0855

0955

1055

1155

1255

1355

1455

1555

1655

1755

1855

1955

2055

2155

2255

2306

2323

2331

2337

2338

2347

2350

2355

2357 0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0 SCT150

BKN140

FEW09 0CB BKN140

FEW090CB BKN140

FEW007 SCT140 SCT180

CLR

CLR

BKN220

FEW150

FEW160

CLR

CLR

CLR

CLR

CLR

CLR

CLR

CLR

CLR

CLR

CLR

CLR

CLR

CLR

CLR

SCT170

FEW140

FEW006 BKN130

BKN130

BKN005 BKN130

BKN005

BKN005

BKN005

SCT005

SCT005

SCT005 10.00

10.00

10.00

10.00

10.0 0

10.00

10.00

10.00

10.00

10.00

10.00

10.00

10.00

10.00

10.00

10.00

10.00

10.00

10.00

10.00

10.00

10.00

10.00

10.00

10.00

10.00

10.00

0.50s

5.00

4.00

2.50

3.00

2.50

2.00

2.50

3.00 TS

- TSRA

BLDUs

HZ

HZ

HZ

HZ

HZ

HZ

VCTS HZ

VCTS HZ 97

98

99

99

97

97

96

95

92

92

90

97

100

103

105

106

108

109

110

112

111

111

109

105

101

101

101

100

95

95

93

93

91

91

91

90 36.0

36.8

37.0

37.0

36.0

36.3

35.7

35.0

33.5

33.1

32.2

35.9

37.5

39.5

40.4

41.3

42.3

42.9

43.5

44.2

44.1

43.8

42.7

40.7

38.6

38.3

38.5

38.0

35.0

35.0

34.0

34.0

33.0

33.0

32.5

32.0 71

70

70

71

70

70

70

69

69

69

69

71

72

72

72

72

73

73

73

73

72

71

72

72

71

71

70

72

73

73

73

73

73

73

73

73 21.6

21.2

21.1

21.4

20.8

20.8

20.9

20.7

20.8

20.8

20.7

21.8

22.3

22.0

22.1

22.0

22.5

22.6

22.8

22.8

22 .3

21.6

22.2

22.0

21.7

21.7

21.2

22.0

22.9

22.9

22.9

22.9

22.6

22.6

22.9

22.5 57

55

54

55

54

54

55

55

57

57

58

58

58

55

54

53

54

54

54

53

51

48

52

54

55

55

53

57

63

63

64

64

64

64

65

64 14.0

12.8

12.0

13.0

12.0

12.3

12.6

12.6

13.8

14.1

14.7

14.4

14.2

13.0

12.2

11.5

12.0

12.3

12.0

11.5

10.4

8.7

11.3

12.4

13.0

12.7

11.6

14.0

17.0

17.0

18.0

18.0

18.0

18.0

18.2

18.0 26

24

22

23

24

24

25

26

31

31

34

27

25

20

18

17

17

16

16

14

14

12

15

18

22

22

20

24

35

35

38

38

41

41

42

42 14

16

13

15

20

14

10

7

6

0

7

0

5

3

0

8

10

11

0

11

9

9

10

8

8

8

8

29

24

31

25

28

34

33

32

30 030

010

360

010

350

030

040

040

310

000

350

000

050

150

000

160

220

190

000

210

250

230

230

210

230

260

010

120

120

130

130

130

140

140

140

140 24

28

39

30

43

43

43

41

41

41

41 2 8.62

28.62

28.61

28.62

28.61

28.61

28.61

28.61

28.61

28.63

28.64

28.66

28.66

28.66

28.65

28.63

28.60

28.58

28.55

28.52

28.50

28.47

28.48

28.49

28.51

28.54

28.57

28.57

28.59

28.60

28.60

28.60

28.62

28.62

28.63

28.63 8

3

3

8

8

6

5

3 001

002

015

003

023

027

003

025 29.67

29.67

M

29.67

29.66

29.66

29.66

29.66

29.67

29.68

29.69

29.71

29.72

29.72

29.71

29.69

29.66

29.63

29.60

29.57

29.55

29.53

29.54

29.55

29.57

29.59

29.62

29.62

29.65

29.66

29.66

29.66

29.67

2 9.68

29.69

29.69 AA

AA

AA

AA

AA

AA

AA

AA

AA

AA

AA

AA

AA

AA

AA

AA

AA

AA

AA

AA

AA

AA

AA

AA

AA

AA

AA

AA

AA

AA

AA

AA

AA

AA

AA

AA T

T

T

T 29.77

29.77

29.76

29.77

29.76

29.76

29.76

29.76

29.76

29.78

29.79

29.81

29.81

29.81

29.80

29 .78

29.75

29.73

29.70

29.67

29.65

29.62

29.63

29.64

29.66

29.69

29.72

29.72

29.74

29.75

29.75

29.75

29.77

29.77

29.78

29.78



### Figure A

- 4. Quality controlled local climatological data hourly observations table for Luke Air Force Base, Glendale, Arizona (08/14/2012). Note

in the Weather Type column that HZ (haze) and BLDU (blowing dust) with reduced visibilities and gusty winds were reported coi ncident with high

PM 10 

### concentrations in the Phoenix area. Dynamically generated via http://cdo.ncdc.noaa.gov/qclcd/QCLCD

.U.S. Department of Commerce

National Oceanic & Atmospheric Administration 

## QUALITY CONTROLLED LOCAL

CLIMATOLOGICAL DATA

(final)

HOURLY OBSERVATIONS TABLE

SCOTTSDALE AIRPORT (03192)

SCOTTSDALE, AZ

(08/2012) National Climatic Data Center

Federal Building

151 Patton Avenue

Asheville, North Carolina 28801



## Elevation: 1473 ft. above sea level

Latitude: 33.622

Longitude:

- 111.910

Data Version: VER2

Date Time

(LS T) Station

Type Sky

Conditions Visibility

(SM) Weather

Type Dry

Bulb

Temp Wet

Bulb

Temp Dew

Point

Temp Rel

Humd

% Wind

Speed

(MPH) Wind

Dir Wind

Gusts

(MPH) Station

Pressure

(in. hg) Press

Tend Net

3

- hr

Chg

(mb) Sea

Level

Pressure

(in. hg) Report

Type Precip.

Total

(in) Alti

meter

(in. hg) (F) (C) (F) (C) (F) (C)

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23

14

14

14

14

14

14

14

14

14

14

14

14

14

14

14

14

14

14

14

14

14

14

14

14

14

14

14 0053

0153

0253

0353

0453

0553

0653

0753

0853

0953

1053

1153

1253

1353

1453

1553

1653

1753

1853

1953

2053

2153

2237

2243

2253

2315

2353 12

12

12

12

12

12

12

12

12

12

12

12

12

12

12

12

12

12

12

12

12

12

12

12

12

12

12 CLR

CLR

FEW065 SCT080 SCT100

CLR

CLR

CLR

CLR

CLR

CLR

CLR

CLR

CLR

CLR

CLR

CLR

CLR

CLR

CLR

CLR

CLR

CLR

CLR

SCT029

BKN027

BKN027

SCT027

FEW075 BKN100 10.00

10.00

10.00

10.00

10.00

10.00

10.00

10.00

10.00

10.00

10.00

10.00

10.00

10.00

10.00

10.00

10.00

10.00

10.00

10.00

10.00

10.00

2.50

3.00

4.00

8.00

10 .00 - RA

VCTS HZ

VCTS HZ

VCTS HZ 96

96

90

94

92

91

92

94

97

100

103

105

106

108

111

109

109

109

107

105

103

102

95

93

94

91

88 35.6

35.6

32.2

34.4

33.3

32.8

33.3

34.4

36.1

37.8

39.4

40.6

41.1

42.2

43.9

42.8

42.8

42.8

41.7

40.6

39.4

38.9

35.0

34.0

34.4

33.0

31.1 70

69

74

70

70

70

69

70

69

70

70

70

70

71

72

71

70

71

71

70

69

69

71

71

71

72

71 20.9

20.6

23.4

21.3

21.3

20.8

20.5

20.8

20.5

21.0

21.0

21.3

21.2

21.5

22.0

21.7

21.3

21.7

21.4

21.1

20.5

20.4

21.7

21.4

21.9

22.3

21.5 55

54

67

58

59

58

56

56

53

53

51

51

50

50

50

50

48

50

50

50

49

49

59

59

60

63

62 12.8

12.2

19.4

14.4

15.0

14.4

13.3

13.3

11.7

11.7

10.6

10.6

10.0

10.0

10.0

10.0

8.9

10.0

10.0

10.0

9.4

9.4

15.0

15.0

15.6

17.0

16.7 25

24

47

30

33

33

30

28

23

21

18

16

15

14

13

14

13

1 4

15

16

16

17

30

32

32

39

42 7

6

13

3

0

0

0

0

0

3

3

6

6

5

3

7

7

7

7

7

6

11

14

5

15

9

11 010

030

050

070

000

000

000

000

000

VR

180

200

VR

250

VR

230

260

250

220

240

080

060

170

VR

190

130

130 17

29

29

22

20

22 28.24

28.23

28.25

28. 20

28.21

28.22

28.23

28.26

28.27

28.26

28.25

28.23

28.20

28.18

28.16

28.12

28.10

28.08

28.08

28.10

28.13

28.15

28.21

28.22

28.23

28.24

28.24 0

8

3

8

8

6

5

3 000

009

017

002

023

026

001

044 29.73

29.72

29.74

29.69

29.70

2 9.71

29.72

29.75

29.76

29.75

29.74

29.72

29.70

29.67

29.65

29.62

29.59

29.57

29.57

29.59

29.62

29.64

M

M

29.73

M

29.73 AA

AA

AA

AA

AA

AA

AA

AA

AA

AA

AA

AA

AA

AA

AA

AA

AA

AA

AA

AA

AA

AA

SP

SP

AA

SP

AA T

T

T 29.83

29.82

29.84

29.79

29 .80

29.81

29.82

29.85

29.86

29.85

29.84

29.82

29.79

29.77

29.75

29.71

29.69

29.67

29.67

29.69

29.72

29.74

29.80

29.81

29.82

29.83

29.83



### Figure A

- 5. Quality controlled local climatological data hourly observations table for Scottsdale Airport, Scottsdale, Arizona (08/14/2012). Note

in the Weather Type column that HZ (haze) with reduced visibilities and gusty winds were reported coincident with high PM 10 

### concentrations in

the Phoenix area. Dynamically generated via http://cdo.ncdc.noaa.gov/qclcd/QCLCD

.U.S. Department of Commerce

National Oceanic & Atmospheric Administration 

## QUALITY CONTROLLED LOCAL

CLIMATOLOGICAL DATA

(final)

HOURLY OBSERVATIONS TABLE

CASA GRANDE MUNICIPAL ARPT (03914)

CASA GRANDE, AZ

(08/2012) National Climatic Data Center

Federal Building

151 Patton Avenue

Asheville, North Carolina 28801



## Elevation: 1462 ft. above sea level

Latitude: 32.95

Longitude:

- 111.766

Data Version: VER2

Date Time

(LST) Station

Type Sky

Conditions V isibility

(SM) Weather

Type Dry

Bulb

Temp Wet

Bulb

Temp Dew

Point

Temp Rel

Humd

% Wind

Speed

(MPH) Wind

Dir Wind

Gusts

(MPH) Station

Pressure

(in. hg) Press

Tend Net

3

- hr

Chg

(mb) Sea

Level

Pressure

(in. hg) Report

Type Precip.

Total

(in) Alti

meter

(in. hg) (F) (C) (F) (C) (F) (C)

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23

14

14

14

14

14

14

14

14

14

14

14

14

14

14

14

14

14

14

14

14

14

14

14

14

14

14

14

14

14

14

14

14

14

14 0015

0035

0055

0115

0135

0155

0215

0235

0255

0315

0335

0355

0415

0435

0455

0515

0535

0555

0615

0635

0655

0715

0735

0755

0815

0835

0855

0915

0935

0955

1015

1035

1055

1115 0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0 CLR

CLR

CLR

CLR

CLR

CLR

CLR

CLR

CLR

CLR

CLR

CLR

CLR

CLR

CLR

CLR

CLR

CLR

CLR

CLR

CLR

CLR

CLR

CLR

CLR

CLR

CLR

CLR

CLR

CLR

CLR

CLR

CLR

CLR 10.00

10.00

10.00

10.00

10.00

10.00

10.00

10.00

10.00

10 .00

10.00

10.00

10.00

10.00

10.00

10.00

10.00

10.00

10.00

10.00

10.00

10.00

10.00

10.00

10.00

10.00

10.00

10.00

10.00

10.00

10.00

10.00

10.00

10.00 93

93

93

91

91

91

91

91

90

91

91

91

91

90

90

88

88

86

84

84

84

86

88

90

91

93

93

97

99

100

100

100

102

102 34.0

34.0

34.0

33.0

33.0

33.0

33.0

33.0

32.0

33.0

33.0

33.0

33.0

32.0

32.0

31.0

31.0

30.0

29.0

29.0

29.0

30.0

31.0

32.0

33.0

34.0

34.0

36.0

37.0

38.0

38.0

38.0

39.0

39.0 68

68

68

68

68

68

68

68

67

67

67

67

67

66

66

66

66

65

65

65

65

66

67

67

68

68

68

69

70

71

71

71

71

71 20.1

20.1

20.1

19.8

19.8

19.8

19.8

19.8

19.6

19.3

19.3

19.3

19.3

19.1

19.1

18.8

18.8

18.4

18.0

18.0

18.6

18.9

19.5

19.6

19.8

20.1

20.1

20.8

21.1

21.5

21.5

21.5

21.5

21.8 54

54

54

54

54

54

54

54

54

52

52

52

52

52

52

52

52

52

52

52

54

54

55

54

54

54

54

54

54

55

55

55

54

55 12.0

12.0

12.0

12.0

12.0

12.0

12.0

12.0

12.0

11.0

11.0

11.0

11.0

11.0

11.0

11.0

11.0

11.0

11.0

11.0

12.0

12.0

13.0

12.0

12.0

12.0

12.0

12.0

12.0

13.0

13.0

13.0

12.0

13.0 27

27

27

29

29

29

29

29

29

26

26

26

26

27

27

29

29

31

33

33

36

33

33

29

29

27

27

24

22

22

22

22

20

21 8

6

7

7

5

7

9

8

7

8

10

8

9

8

8

7

3

7

5

6

0

3

3

0

7

9

5

9

7

8

8

13

9

3 040

040

350

010

350

360

360

010

360

040

040

020

040

040

060

070

060

260

250

230

000

170

160

000

080

110

140

120

140

140

150

210

180

220 28.28

28.28

28.28

28.27

28.27

28.27

28.27

28.27

28.27

28.27

28.25

28.27

28. 27

28.25

28.25

28.25

28.27

28.27

28.27

28.28

28.28

28.29

28.30

28.30

28.30

28.30

28.30

28.30

28.30

28.30

28.30

28.30

28.29

28.29 2

7

2

7 007

007

017

003 M

M

M

M

M

M

M

M

M

M

M

M

M

M

M

M

M

M

M

M

M

M

M

M

M

M

M

M

M

M

M

M

M

M AA

AA

AA

AA

AA

AA

AA

AA

AA

AA

AA

AA

AA

AA

AA

AA

AA

AA

AA

AA

AA

AA

AA

AA

AA

AA

AA

AA

AA

AA

AA

AA

AA

AA 29.83

29.83

29.83

29.82

29.82

29.82

2 9.82

29.81

29.81

29.81

29.80

29.81

29.81

29.80

29.80

29.80

29.81

29.82

29.82

29.83

29.83

29.84

29.85

29.85

29.85

29.85

29.85

29.85

29.85

29.85

29.85

29.85

29.84

29.8414

14

14

14

14

14

14

14

14

14

14

14

14

14

14

14

14

14

14

14

14

14

14

14

14

14

14

14

14

14

14

14

14

14

14

14

14

14 1135

1155

1215

1235

1255

1315

1335

1355

1415

1435

1455

1515

1535

1555

1615

1635

1655

1715

1735

1755

1815

1835

1855

1915

1935

1955

2015

2035

2055

2115

2135

2155

2215

2235

2255

2315

2335

2355 0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0 CLR

CLR

CLR

CLR

CLR

CLR

CLR

CLR

CLR

C LR

CLR

CLR

CLR

CLR

CLR

CLR

CLR

CLR

CLR

CLR

CLR

CLR

CLR

CLR

CLR

CLR

CLR

CLR

CLR

CLR

CLR

CLR

CLR

SCT050 BKN070 BKN120

FEW030 BKN047 OVC120

SCT029 BKN048 OVC065

SCT021 BKN031 OVC110

FEW021 SCT040 BKN060 10.00

10.00

10.00

10.00

10.00

10.00

10.00

10.00

10.00

10.00

10.00

10.00

10.00

10.00

10.00

10.00

10.00

10.00

10.00

10.00

10.00

10.00

10.00

10.00

10.00

10.00

10.00

10.00

10.00

1.75

7.00

10.00

10.00

10.00

9.00

10.00

8.00

10.00 VCTS

TS

TS

TS

TS

TS 104

104

106

106

108

108

108

108

108

108

108

108

109

109

109

109

109

109

108

108

108

106

106

106

104

102

102

102

100

93

91

91

91

91

86

77

73

75 40.0

40.0

41.0

41.0

42.0

42.0

42.0

42.0

42.0

42.0

42.0

42.0

43.0

43.0

43.0

43.0

43.0

43.0

42.0

42.0

42.0

41.0

41.0

41.0

40.0

39.0

39.0

39.0

38.0

3 4.0

33.0

33.0

33.0

33.0

30.0

25.0

23.0

24.0 71

71

72

72

72

72

72

72

72

72

72

72

72

72

73

73

73

73

72

72

72

72

72

72

71

71

71

71

70

70

69

69

69

69

71

70

68

68 21.8

21.8

22.1

22.1

22.4

22.4

22.4

22.4

22.4

22.0

22.0

22.0

22.1

22.1

22.6

22.6

22 .5

22.5

22.4

22.4

22.4

22.1

22.1

22.1

21.8

21.5

21.8

21.5

21.2

20.9

20.6

20.6

20.6

20.6

21.5

20.9

20.2

19.9 54

54

54

54

54

54

54

54

54

52

52

52

52

52

54

5 4

54

54

54

54

54

54

54

54

54

54

55

54

54

57

57

57

57

57

63

66

66

64 12.0

12.0

12.0

12. 0

12.0

12.0

12.0

12.0

12.0

11.0

11.0

11.0

11.0

11.0

12.0

12.0

12.0

12.0

12.0

12.0

12.0

12.0

12.0

12.0

12.0

12.0

13.0

12.0

12.0

14.0

14.0

14.0

14.0

14.0

17.0

19.0

19.0

18.0 19

19

18

18

17

17

17

17

17

16

16

16

15

15

16

16

16

16

17

17

17

18

18

18

19

20

21

20

21

30

32

32

32

32

46

69

79

69 8

0

0

6

10

11

10

13

3

9

9

9

7

6

11

10

16

14

15

14

14

1 0

11

9

6

6

6

6

5

31s

29

23

18

24

28

21

17

18 230

000

000

260

270

260

300

220

330

320

300

290

320

240

270

260

260

260

250

250

250

260

260

260

250

280

250

250

210

150

160

160

140

130

130

140

240

220 16

20

20

21

20

22

20

18

40

36

29

30

32

28

24

24 28.28

28.27

28.27

28.25

28.25

28.25

28.25

28.24

28.23

28.22

28.21

28.20

28.19

28.18

28.18

28.17

28.15

28.15

28.14

28.14

28.15

2 8.15

28.16

28.16

28.16

28.16

28.17

28.18

28.20

28.23

28.24

28.25

28.28

28.27

28.28

28.32

28.30

28.31 7

7

2

2 020

030

003

044 M

M

M

M

M

M

M

M

M

M

M

M

M

M

M

M

M

M

M

M

M

M

M

M

M

M

M

M

M

M

M

M

M

M

M

M

M

M AA

AA

AA

AA

AA

AA

AA

AA

AA

AA

AA

AA

AA

AA

AA

AA

AA

AA

AA

AA

AA

AA

AA

AA

AA

AA

AA

AA

AA

AA

AA

AA

AA

AA

AA

AA

AA

AA 0.03

0.03

0.03

0.25

0.25

0.25 29.83

29.82

29.81

29.80

29.80

29.79

29.79

29.78

29.77

29.76

29.75

29.74

29.73

29.72

29.72

29.71

29.69

29.69

29.68

29.68

29.69

29.69

29.70

29.70

29.70

29.70

29.71

29.72

29.74

29.77

29.78

29.80

29.83

29.82

29.83

29.87

29.85

29.86



### Figure A

- 6. Quality controlled local climatological data hourly observations table for Casa Grande Municipal Airport, Casa Grande, Arizona

(08/14/2012). Note that reduced visibilities and gusty winds were reported coincident with high PM 10 

### concentrations after 2100 LST in the Casa

Grande area. Dynamically generated via http://cdo.ncdc.noaa.gov/qclcd/QCLCD

.

### Exceptional Event, Phoenix

, August 14, 2012 Appendix B



## 1 

# Appendix B: Media Coverage, Videos, and Images

Video Links

ADEQ visibility cameras in the Phoenix area:

South Mountain: www.phoenixvis.net/videos/mpeg4/SOMT_08142012.mp4

Estrella Mountains: www.phoenixvis.net/videos/mpeg4/ESMO_08142012.mp4

Camelback Mountains: www.phoenixvis.net/videos/mpeg4/CAME_08142012.mp4

Superstition Mountains: www.phoenixvis.net/videos/mpeg4/SUPM_ 08142012.mp4

Local citizens often create videos during storms, documenting their observations. Here are

some links to these videos.

Arizona Monsoon

- August 14th, 2012

http://www.youtube.com/wa tch?v=Za4IL9iW65k

Arizona Thunder Storm 8/14/2012

http://www.youtube.com/watch?v=FFUe2A

- rAtk

### Exceptional Event, Phoenix

, August 14, 2012 Appendix B



## 2 

# Articles and Image Links

http://www.azfamily.com/news/Photos

- Overnight

- storm

- brings

- rain

- morning

- haze

- and

- airport

delays

- 166277196.html (see video at link)

Photos: Overnight storm brings rain, morning haze and airport delays

By Mike Gertzman

Posted on August 15, 2012 at 10:00 AM

Azfamily.com

PHOENIX

-- Monsoon storms rolled through the Valley overnight. The storms brought rain,

thunder and plenty of lightning.

Parts of the Valley, from central Phoenix to Ahwatukee, got heav y rain. Enough rain fell in some

areas to cause street flooding. More than 1.5 inches of rain fell in Maricopa, Ariz. The north side

of the Valley, including Scottsdale and all the way to the northwest side of town, barely got any

rain.

A power outage aro und 7th and Glendale Avenues was likely caused by the storm. That

neighborhood was dark and the traffic lights were not working. More than 1,000 SRP customers

were left without electricity. Utility crews went to work on the problem right away and the power

was quickly restored.

The most severe weather was seen in the town of Maricopa, Ariz. where lightning hit a house at

about 3:00 a.m. and caused a fire.

Lightning sparks house fire in Maricopa

The streets were dry by morning, but the sunrise revealed a very hazy sky. Tower cameras and

ADOT traffic cameras that normally show miles of visibility were only offering very limited views

on Wednesday morning.

Visibility was so poor that there were flight delays at Sky Harbor Airport. Airport officials reported

delays of 10 to 20 minutes.

The air was so thick that it appeared to be filled with smoke, fog or smog. But 3TV meteorologist

April Warnecke explained that it was actually dust suspended in the air because it was hanging

on to all the moisture particles that came with the overnight rain.

Also, the Valley cooled off overnight creating an inversion that trapped all of that particulate

pollution near the ground.

Temperatures around the Valley dropped into the 80's for the first time in several days. The

Na tional Weather Service has canceled the Excessive Heat Warning a day before it was set to

expire.

### Exceptional Event, Phoenix

, August 14, 2012 Appendix B



## 3 

## With more moisture coming into the Valley this week, we could some much more monsoon

storm activity over the next few days.

The forecast high for Wednesday i s 106 degrees

-- the first day in the past 10 days that the high

will be below 110 degrees.

http://www.azfamily.com/news/Photos

- Overnight

- storm

- brings

- rain

- morning

- haze

- and

- airport

delays

- 166277196.html?gallery=y&img=0&c=y#/news/Photos

- Overnight

- storm

- brings

- rain

morning

- haze

- and

- airport

- delays

- 166277196.html?gallery=y&img=0&c=y

Selected pictur es (more at link above):

### Exceptional Event, Phoenix

, August 14, 2012 Appendix C



## 1 

# Appendix C: Historical Fluctuation Time

- Series Graphs

Figure C

- 1

. 24

- hr average PM 10 

## concentrations at the Durango monitor (2007

- 2012 ).

The 24

- hr average PM 10 

## concentration on August 14, 2012 , is shown in red

.

### Exceptional Event, Phoenix

, August 14, 2012 Appendix C



## 2 Figure C

- 2

. Daily maximum hourly average PM 10 

## concentrations at the Durango monitor

(200 7

- 201 2). The maximum hourly average PM 10 

## concentration on August 14, 2012 , is

shown in red

.

### Exceptional Event, Phoenix

, August 14, 2012 Appendix D



## D

- 1 

# Appendix D:

ADEQ and NWS Forecast Products

### Exceptional Event, Phoenix

, August 14, 2012 Appendix D



## D

- 2 JRP 04/28/2 0 11

### Exceptional Event, Phoenix

, August 14, 2012 Appendix D



## D

- 3 VERY UNH E A LTHY (201

- 3 0 0)

UNH E A L THY ( 151

- 200)

UNH E A L THY FOR SENSITIVE GROUPS (101

- 150)

MODE R A

TE ( 51

- 1 00)

GOOD (0

- 50)

For more info r mation vi s it:

http:/ / w w w

. a ir n o w

. gov/ i n de x .cfm?action= a q i b asics.a q i

*LINK TO 2 0 12 A I R POLLUT I ON EXCEE D A NCE G R A P H*



# AIR QUALITY FORECAST FOR Tuesda y

, August 14, 2012, 2012

This report is u p dated b y 1:00 p

. m. Sund a y t hru F rid a y and is valid

for areas w i thin a nd bord e ring Ma ri copa Coun t y in Arizona



## FOR E CAST

DATE

NOT I CES

(*SEE BELOW

FOR DE T AILS)

A I R POLLU T A NT 

## YESTERD A Y

Sun 08/ 1 2 /2 01 2

High e st AQI R e ad ing/S i te



### (* Prelimina r y da t a on l y *) 

## TODAY

Mon 08/ 1 3 /2 01 2

O z one Heal t h

Watch

Dust 

## TOMORROW

T ue 08/14/20 1 2

Dust 

## E X T E N DED

W ed 08/15 / 20 1 2

Dust



# O3* 101

North P ho e nix 

## 97

Mod e r a te 

## 71

Mod e r a te 

## 64

Mod e r a te



# CO* 7

West Ph o enix 

## 6

Good 

## 6

Good 

## 6

Good



# PM

- 10* 59

D y s art 

## 65

Mod e r a te 

## 65

Mod e r a te 

## 75

Mod e r a te



# PM

- 2.5* 44

West Ph o enix 

## 42

Good 

## 44

Good 

## 47

Good

* O 3

= O z one C O

= Car b on Mono x ide PM

- 10

= P articl e s 10 m i cro n s & smaller PM

- 2.5

= Pa r t icl e s smal l er than 2

. 5 m i cr o ns

*“ O z one Health W a tc h ” mea n s th a t the high e st co n c entrat i on o f OZONE may approach the fed er al hea l th standa r d.

“ PM

- 10 or PM

- 2 .5 Health W a tch ” m ea ns th a t the high e st co n c entrati o n o f PM

- 10 or PM

- 2 .5 m a y approach the f ed eral hea l th stan d a r d.

“ High Poll u tion Ad v isor y ” means t h at t h e high e st co n c e n tr a t ion of OZON E

, P M

- 10, or PM

- 2.5 may e x ceed the fede r al hea l th standar d

.

“ DUS T ” means t h at sh o rt peri o ds of h i gh PM

- 10 conc e nt r atio n s ca u s ed by outflow from thunde r st o rms are possib le

.

### Exceptional Event, Phoenix

, August 14, 2012 Appendix D



## D

- 4 M ode r ate

M ode r ate

M ode r ate

M ode r ate

M ode r ate

M ode r ate

M ode r ate

M ode r ate

M ode r ate

M ode r ate

M ode r ate

M ode r ate

M ode r ate

USG

M ode r ate 

## Health St a t em ents

Mon d a y

, 08/13 /2 012 

### Unu s u a lly se n s it i v e p e ople s hould c on s i de r r e du c ing prolo n g e d or h e a v y

ex e rtion o ut d oor s

.

Tue s d a y

, 08

/ 14 / 2012 

### Unu s u a lly se n s it i v e p e ople s hould c on s i de r r e du c ing prolo n g e d or h e a v y

ex e rtion o ut d oor s

.



## SYNOPSIS AND DISCU S SION

AN OZONE HEALTH W A TCH REMAINS IN EFFECT UNTIL L A TE THIS EVENING

OZ O NE: Although a noth e r excee d a n ce occurr e d on Sunday, the local o z o ne concentrati o n

trend h a s st ar ted downward and this s h ould contin u e for the next few da y s at least. The big g est

factor causing this dec r ease will be the daytime surface w i nds wh i c h

– due to the comb i nation of

grad i ent and ups l ope fl o w

– sh o uld b e come w e st e rly for the foreseeab l e future with g u sts o v er 20

mph p o ss i ble by Tuesday. This sit u ation hel p s to disperse the l o cal oz o ne pl u me and l e ss e ns the

potential for h igh c o ncentr a tions over a l arge a r e a. Still have to get t hru today, howev e r, and an

O z one Health Wat c h remains in effe c t.

PARTICLES: Although a l o w

- g r a de su m mer mo n s o on period i s for e c a st for the n ext few

days, moist u re will re m ain suffici e nt for a ch a nce for sh o w e rs a nd thund e rst o r m s in proximity to

the Phoenix metro a rea u ntil a more s i gnific a nt return of moisture by Wed n esd a y. As a result, the

possibility for peri o ds of d e nse b l ow i ng a nd t r a n sp o rt e d dust g e ner a ted by strong thund e rst o rm

outflow b o u n dary wi n ds h ave resulted i n a for e cast f or elevated P M

- 10 (c o arse particl e )

co n c e ntratio n s

– with pot e ntial for local l y much hig he r re a din g s d e pend i ng on winds a nd vol u me

of dust. Otherw i se, particle pollution levels will be low.

Ch ec k b a ck t omorr o w for the latest. Unt i l then, have a good day!

- C.Reith

MONITORING SITE MAPS

S T A T IC M A P ht t p:/ / w w w

. a z deq.g o v

/ e n v i r on/a i r/mon i tor i ng/ im ages/ m ap. j pg

INTE R A CTIVE M A PS http:// a q w w w

. m aricopa

. g o v / A ir Monitori n g/Sit e Pollut i onM a p.a s px

ht t p://1 5 6.42.96

. 39/alert / G o ogle / air.h t ml

ht t p:/ / w w w

. airn o w .g o v

/



## POLLUT I ON MONI TO R RE A DI N GS FOR S u nd a y

, Aug u st 12, 2012



# O3 (OZONE)

Info on cur r ent 8

- hour ozone sta n dard: h t t p:/ / w ww.epa. g o v

/air/o z o nep o llut i on / p df s/2008_03

_ aqi

_ cha n ges. p df

For a rchived AQI maps go to: h tt p :/ / w w w

. airn o w .g o v

/i n dex.c f m ?a ction= a irn o w .maps

SITE N A M E M A X 8

- HR V A L UE (PPB) M A X A Q I A Q I CO L O R CO DE

A l amo Lake 

### 60 51

A p a c he Junct i on 

### 61 54

B l u e P o i n t 

### 63 61

Buck e y e 

### 62 58

Casa G r ande 

### 62 58

Ca v e Creek 

### 62 58

Cent r al Phoen i x 

### 68 77

D y sart 

### 69 80

Fa l c o n F i e l d 

### 61 54

Founta i n H i l l s 

### 60 51

G l enda l e 

### 62 58

Humbo l dt M ount a i n 

### 63 61

Phoen i x Supe r s i te 

### 69 80

No r th Phoen i x 

### 76 101

Pinal A i r Park 

### 62 58

### Exceptional Event, Phoenix

, August 14, 2012 Appendix D



## D

- 5 M ode r ate

M ode r ate

Good

M ode r ate

M ode r ate

M ode r ate

M ode r ate

M ode r ate

M ode r ate

M ode r ate

Good

Good

Good

Good

M ode r ate

Good

Good

Good

M ode r ate

M ode r ate

Good

Good

Good

Good

Good

Good

Good

Good

Good

Good

M ode r ate

Good

Good

Good

Good

Good

Good

Good

Good

Good

Good Pinnacle Peak 

### 70 84

Queen Vall e y 

### 62 58

R i o Ve r d e 

### 59 50

South Phoen i x 

### 70 84

South Scottsda l e 

### 73 93

Tempe 

### 64 64

Tonto Nat ’ l M on. 

### 61 54

West Chandler 

### 62 58

West Phoen i x 

### 71 87

Yuma 

### 63 61



# CO (CARBON MO NOXIDE)

SITE N A M E M A X 8

- HR V A L UE (PPM) M A X A Q I A Q I CO L O R CO DE

Cent r al Phoen i x 

### 0.3 3

G r ee n w ood 

### 0.4 5

West Phoen i x 

### 0.6 7



# PM

- 10 (PARTICLES)

SITE N A M E M A X 24

- HR V A LUE (μg/m 3 ) 

### M A X A Q I A Q I CO L O R CO DE

A p a c he Junct i on 

### 41.9 39

Buck e y e 

### 61.9 54

Cent r al Phoen i x 

### 48.7 44

Combs School (Pinal Coun t y ) 

### 49.3 46

Du r a ngo 

### 40.7 37

D y sart 

### 71.7 59

G l enda l e 

### 65.7 56

G r ee n w ood 

### 44.5 41

H i g le y 

### 45.5 41

M a ri copa (P i na l C oun t y ) 

### 44.7 41

No r th Phoen i x 

### 53.3 49

Phoen i x Supe r s i te 

### 50.3 46

South Phoen i x 

### 48.6 44

Tempe 

### 45.1 41

West Chandler 

### 45.4 41

West Fo rt y T h ir d 

### 37.7 34

West Phoen i x 

### 48.3 44

Zuni H i l l s 

### 71.2 59



# PM

- 2.5 (PARTICLES)

(Some data de r i v e d f r om lig h t

- s catter i ng equipme n t)



### For maps go t o : ht t p:/

/ w w w

. airn o w .g o v

/

SITE N A M E M A X 24

- HR V A LUE (μg/m 3 ) 

### M A X A Q I A Q I CO L O R CO DE

Du r a ngo 

### 10.2 33

D y sart 

### 10.0 32

Est r e ll a M ounta i n Pa r k 

### 6.7 22

G l enda l e 

### 11.3 37

Phoen i x Supe r s i te 

### 7.8 25

No r th Phoen i x 

### 11.5 37

South Phoen i x 

### 7.2 23

Tempe 

### 9.0 29

Veh i c l e Em i s s i ons Lab 

### 6.0 19

West Phoen i x 

### 13.5 44

### Exceptional Event, Phoenix

, August 14, 2012 Appendix D



## 6 

## Statements, Advisories, and Warnings issued by the National Weather Service office in

Phoenix, AZ pertaining to this dust storm event:

SHORT TERM FORECAST

NATIONAL WEATHER SERVICE PHOENIX AZ

823 PM MST TUE AUG 14 2012

AZZ028

- 150500

-

NORTHWEST AND NORTH CENTRAL PINAL COUNTY

INCLUDING THE CITIES OF...APACHE JUNCTION...CASA GRANDE...COOLIDGE...

AND FLORENCE

823 PM MST TUE AUG 14 2012

.NOW...

GUSTY SOUTHEAST WINDS 20 TO 30 MPH WILL OVERSPREAD MUCH OF NORTHWEST

PINAL COUNTY THROUGH 10 PM. SOME BLOWING DUST WILL BE POSSIBLE.

LOCATIONS LIKELY TO EXPERIENCE GUSTY WINDS AND SOME BLOWING DUST

INCLUDE COOLIDGE...FLORENCE...AND CASA GRANDE. THERE WILL BE A SLIGHT

CHANCE FOR A THUNDERSTORM THIS EVENING.

SHORT TERM FORECAST

NATIONAL WEATHER SERVICE PHOENIX AZ

918 PM MST TUE AUG 14 2012

AZZ023

- 150700

-

GREATER PHOENIX AR EA

INCLUDING THE CITIES OF...BUCKEYE...CAREFREE...CAVE CREEK...

CHANDLER...FOUNTAIN HILLS...GILBERT...GLENDALE...MESA...PEORIA...

PHOENIX...SCOTTSDALE...SUN CITY...AND TEMPE

918 PM MST TUE AUG 14 2012

.NOW...

SOUTHEAST WINDS 20 TO 30 MPH...WITH GUSTS TO 35 MPH...WILL OVERSPREAD

THE GREATER PHOENIX METROPOLITAN AREA THROUGH 11 PM. SOME BLOWING

DUST WILL LIKELY ACCOMPANY THE ONSET OF THE GUSTY WINDS...ESPECIALLY

OVER THE SOUTHEAST VALLEY BETWEEN 915 PM AND 945 PM...WHERE VISIBILITY

COULD BRIEFLY DROP BELOW 2 MILES. AN ISOLATED THUNDERSTORM WILL BE

POSSIBLE THROUGH MIDNIGHT.

$$

AZZ027

- 150700

-

SOUTHWEST MARICOPA COUNTY

INCLUDING THE CITY OF...GILA BEND

918 PM MST TUE AUG 14 2012

.NOW...

SOUTHEAST WINDS 15 TO 30 MPH...WITH GUSTS TO 35 MPH...WILL

OVERSPREAD MUCH OF SOUTHWEST MARICOPA COUNTY THROUGH 11 PM. SOME

BLOWING DUST WILL LIKELY ACCOMPANY THE ONSET OF THE GUSTY

WINDS...WITH VISIBILITY BRIEFLY DROPPING BELOW 2 MILES. AN ISOLATED

THUNDERSTORM WILL BE POSSIBLE THROUGH MIDNIGHT.

### Exceptional Event, Phoenix

, August 14, 2012 Appendix D



## 7 AZZ022

- 150700

-

NORTHWEST MARICOPA COUNTY

INCLUDING THE CITIES OF...BUCKEYE...LAKE PLEASANT...MORRISTOWN...

NEW RIVER...TONOPAH...AND WICKENBURG

918 PM MST TUE AUG 14 2012

.NOW...

SOUTHEAST WIND 15 TO 25 MPH...WITH GUSTS TO 30 MPH...WILL OVERSPREAD

NORTHWEST MARICOPA COUNTY BETWE EN 10 PM AND MIDNIGHT. SOME BLOWING

DUST WILL LIKELY ACCOMPANY THE ONSET OF GUSTY WINDS...WITH VISIBILITY

BRIEFLY DROPPING BELOW 2 MILES. AN ISOLATED THUNDERSTORM WILL BE

POSSIBLE THROUGH MIDNIGHT.

URGENT

- WEATHER MESSAGE

NATIONAL WEATHER SERVICE PHOENIX AZ

941 PM MST TUE AUG 14 2012

AZZ023

- 150600

-

/O.NEW.KPSR.DU.Y.0034.120815T0441Z

- 120815T0600Z/

/O.CON.KPSR.EH.W.0011.000000T0000Z

- 120816T0300Z/

GREATER PHOENIX AREA

INCLUDING THE CITIES OF...BUCKEYE...MESA...PHOENIX

941 PM MST TUE AUG 14 2012

...BLOWING DUST ADVISORY IN EFFECT UNTIL 11 PM MST THIS

EVENING...

...EXCESSIVE HEAT WARNING REMAINS IN EFFECT UNTIL 8 PM MST

WEDNESDAY...

THE NATIONAL WEATHER SERVICE IN PHOENIX HAS ISSUED A BLOWING DUST

ADVISORY...WHICH IS IN EFFECT UNTIL 11 PM MST THIS EVENING. AN

EXCESSIVE HEAT WARNING REMAINS IN EFFECT UNTIL 8 PM MST

WEDNESDAY.

* AFFECTED AREA...PHOENIX METROPOLITAN AREA...ESPECIALLY THE

SOUTHEAST VALLEY.

* TIMING...UNTIL 11 PM.

* WINDS...SOUTHEAST 20 TO 30 MPH...WITH GUSTS TO NEAR 40 MPH.

* VISIBILITY ...BELOW 1 MILE AT TIMES MAINLY SOUTHEAST VALLEY

* IMPACTS...SUDDENLY REDUCED VISIBILITIES ON ROADWAYS WILL CREATE

DANGEROUS DRIVING CONDITIONS. MULTI

- CAR PILEUPS ARE MORE LIKELY

DURING BLOWING DUST EVENTS.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

BE READY FOR A SUDDEN DROP IN VISIBILITY. IF YOU ENCOUNTER BLOWING

DUST ON THE ROADWAY OR SEE IT APPROACHING...PULL OFF THE ROAD AS FAR

AS POSSIBLE AND PUT YOUR VEHICLE IN PARK. TURN THE LIGHTS ALL THE WAY

OFF AND KEEP YOUR FOOT OFF THE BRAKE PEDAL.

### Exceptional Event, Phoenix

, August 14, 2012 Appendix E



## 1 

# Appendix E:

Affidavit of Public Notice