# Presentation: 682112

## COOPERATIVE HUNTSVILLE-AREA RAINFALL MEASUREMENT (CHARM) NETWORK

**Local precipitation network ( est. 1/2001)**
- 157 sites in Huntsville & Madison County, AL
- NASA, Army, USGS, and NWS sites and weather enthusiasts
- Daily rainfall totals (1200UTC reports)
- 3600 km2 coverage (1 gauge per 6x6 km)
- Primarily 4” manual gauges (65%) with  remaining (35%) manual or automated tipping bucket (6” and 8”)
- 1-5 minute data from 30 automated sites

**Supports local weather and climate research**
-    validate weather radar and lightning data from satellites
-    monitor spatial distributions of precipitation for modeling activities
-    various satellite remote sensing studies of soil moisture and energy fluxes

## ACCESS TO CHARM

**ACCESS TO CHARM**
**(http://weather.msfc.nasa.gov/charm)**

**Data entry and display**
**Access historical data**
**How to take measurements**
**FAQs**
**What’s new**

## TYPES OF RAIN GAUGES IN CHARM

- 6”, 8” tipping bucket – recorded electronically

**TYPES OF RAIN GAUGES IN CHARM**

-  6”, 8” recording
-    weekly paper
-        charts

-  4” non-recording
-      “all-weather”
-          plastic

-  6”, 8” non-
-   recording
-      (metal)

## CHARM OBSERVERS

**CHARM OBSERVERS**

_**2001  **_
- Total – 96 – 76 manual, 3 recording (manual),  and 17	automated

## USE AND APPLICATIONS

**CHARM86** – supported NASA meteorological experiment over Huntsville
**Existing measurements systems**
- 	Aldridge Creek flood of 1999
- 	Flooding of the AXAF clean room out at MSFC (1997)
- 	Environmental studies for MSFC Redstone Arsenal
- CHARM observations are part of the **NWS (SHEF) data stream**
- LMRFC (Slidell) and SERFC (Atlanta) for hydrological studies
- Local WFOs (HUN)
- Satellite and ground based (radar) **intercomparison studies**
**Short-term precipitation climatology** studies

**CHARM data has been used to validate forecast model estimates of precipitation**

## PRECIPITATION  INTERCOMPARISON

-      _Forecast_:  24h accumulated rainfall for April 12-13, 2001, 0700 LDT.
-      Regional MM5 model (left) and early Eta (right)

- _Validation_: 24h accumulated rainfall derived from NWS radars, April 12-13, 2001, ending 7:00a LST.

- _[next](slide13.xml)_

## PRECIPITATION ESTIMATE FROM RADAR CHARM data indicates smaller scale variability

**CHARM data has been used to validate radar estimates of precipitation**

## DIGITAL PRECIPITATION PRODUCT

**DIGITAL PRECIPITATION PRODUCT**

- NWS offices produce their own precipitation estimates*** ***from their local WSR-88D radar.  The Nashville and Hytop (northeast of Huntsville) radars captured this storm event.
- Figures present storm totals (sum of hourly product over storm lifetime ~ 4-6 hours).  *** ***
* **Same general structure*
* **Nashville radar - more intense / widespread rainfall *
* **Radar calibration, elevation, scan patterns, distance from storm may all contribute to the difference.*

**4-5”**

**~3”**

## CHARM DATA ANALYSIS

- Rainfall totals reported at 1200UTC for the preceding 24h .  For June 4-5, the 24h totals capture only this storm event.

_***June 4-5, 2001 Case Study***_
*** ******Isolated heavy thunderstorm moves***
***      ******through the CHARM network***
*** ******Slow west-to-east movement over ***
***       ******Huntsville***

- _Details_:
-  Strong north-south gradient on
-     either side of the storm track
-  Width of heavy rainfall area - 10 km
- Maximum of 2.96” on east of
-     region, secondary max (2.73”) in
-     the western half of network

## CHARM data has been used to verify and enhance special rainfall products used for climate studies

## NWS HDP PRODUCTS

**Rainfall (cm)**

*Note the dual rainfall maximum in the stage III radar product corresponds nicely both in position and magnitude to the CHARM data. *

**NWS HDP PRODUCTS**

- _Stage I_  - integrated precipitation from local radar using standard or tropical Z-R relationships on
- 4 km grid – dependent on Z-R relationship used
- _Stage II_  - adjusted stage I product for bias using local (hourly) rain gauges
- _Stage III_  - combination of stage II HDP from individual radars to produce a regional precipitation estimate
-  minimal bias due to mis-calibration and different Z-R, local and seasonal adjustments
-  regional continuity and consistency

***Example of stage III radar product for***
***June 4, 2001 over Northern Alabama***
*Hourly stage III product summed *
*from 2100 – 0300 UTC.*

- CHARM

*Stellman et al. 2001 (Wea. Fore.)*

## STAGE III vs.  CHARM

**STAGE III vs.  CHARM**

- _Resolution issues will affect comparison_
- Radar:
-  radar volume – varies with distance
-  4km grid cells – arbitrary selection
- Rain gauge:
-  point measurement – microscale variability greatest in convective storms
-  multiple rain gauges for each grid cell (a single best comparison used in analysis below)

- Comparison shows little or no bias (0.19”) between CHARM measurements and radar estimates.  Scatter is considerable especially for amounts > 1.00”.

## CHARM data is regularly used to evaluate short-term variations in precipitation climatology.

##       HUNTSVILLE DROUGHT OF 2005 OR WAS IT?Huntsville had one significant rain event from 9/1 through 11/15 (2.5 months)  hottest time of year  in a year with minimum Springtime rainfall?  despite numerous tropical storms impinging on the ValleyYet there is significant variability between reported rainfall over the region!

**      ****HUNTSVILLE DROUGHT OF 2005 OR WAS IT?**Huntsville had one significant rain event from 9/1 through 11/15 (2.5 months)  hottest time of year  in a year with minimum Springtime rainfall?  despite numerous tropical storms impinging on the ValleyYet there is significant variability between reported rainfall over the region!

**Note absence **
**of any **
**rain events**

**Only 4 real rain events in 3 months**

## VARIABILITY IN MONTHLY RAINFALL - Fall 2005		Normal		Actual		RangeSeptember 	   4.3		  2.9	        (2.0 - 5.5in)October		   3.5		  0.1                (0.0 -  0.5in)November	   5.3		  3.0                (3.0 -  6.5in)Note difference in spatial variability!  Does it even out over the long term?

**VARIABILITY IN MONTHLY RAINFALL - Fall 2005**		Normal		Actual		RangeSeptember 	   4.3		  2.9	        (2.0 - 5.5in)October		   3.5		  0.1                (0.0 -  0.5in)November	   5.3		  3.0                (3.0 -  6.5in)Note difference in spatial variability!  Does it even out over the long term?

**+**

**+**

## CHARM 2005 selected station monthly rainfall and anomalies (departure from normal).

## 2005 RAINFALL

**2005 RAINFALL**

** ****SE HSV (blue) and airport (red) show below average rainfall most months**

## 2005 RAINFALL

**2005 RAINFALL**

** ****SE HSV (blue) and airport (red) show below average rainfall most months**
** ****NSSTC location (orange) similar to airport trends, Big Cove area (cyan) had a surplus during the summer**

## 2005 RAINFALL

**2005 RAINFALL**

** ****SE HSV (blue) and airport (red) show below average rainfall most months**
** ****NSSTC location (orange) similar to airport trends, Big Cove area (cyan) had a surplus during the summer**
** ****Madison area (green) shows large summer surplus, Cullman (grey) was dry**

## CHARM 2005 selected station monthly rainfall anomalies and yearly deficit (sum of departure from normal).

## 2005 ANOMALY AND DEFICIT

**2005 ANOMALY AND DEFICIT**

** ****At the airport (red), 2005 starts out dry and stays dry (-17+ in).**

## 2005 ANOMALY AND DEFICIT

**2005 ANOMALY AND DEFICIT**

** ****At the airport (red), 2005 starts out dry and stays dry (-17+ in).**
** ****SE HSV (blue) tracks airport but Big Cove area (cyan) only down -9 in for year.**

## 2005 ANOMALY AND DEFICIT

**2005 ANOMALY AND DEFICIT**

** ****At the airport (red), 2005 starts out dry and stays dry (-17+ in).**
** ****SE HSV (blue) tracks airport but Big Cove area (cyan) only down -9 in for year.**
** ****Summer rains keep Madison (green) with little (-3 in) deficit for the year.**

## -

- 2005 Deficit

**-13.5**

**-14.6**

**-2.7**

**-7.2**

**-17.2**

**-8.9**

**-16.3**

**-15.3**

**-7.8**

**-**

**CHARM 2005 rainfall deficit pattern shows large deficit throughout most of the region, however Madison and surrounding regions were not as hard hit with the drought.**

**Are the 2005 patterns a continuation of past trends?**

## CHARM can be used to look at short-term climate trends in rainfall.  The following analysis highlights the 2001-2005 period.

## 2001-2005 ANOMALY/DEFICIT

**2001-2005 ANOMALY/DEFICIT**

** ****2001 was wet.  2002-2005 experience growing deficits at airport (red).**

## 2001-2005 ANOMALY/DEFICIT

**2001-2005 ANOMALY/DEFICIT**

** ****2001 was wet.  2002-2005 experience growing deficits at airport (red).**
** ****NSSTC (orange) tracks airport deficit, but trend not as sharp in SE HSV (blue).  Rainfall surplus grows throughout the period in Big Cove region (cyan, 13+ in).**

## 2001-2005 ANOMALY/DEFICIT

**2001-2005 ANOMALY/DEFICIT**

** ****2001 was wet.  2002-2005 experience growing deficits at airport (red).**
** ****NSSTC (orange) tracks airport deficit, but trend not as sharp in SE HSV (blue).  Rainfall surplus grows throughout the period in Big Cove region (cyan, 13+ in).**
** ****While Madison stays most, Cullman shows extreme drought over last 4 years.**

## Process 5-8 more sites with continuous records

**Trends in quality controlled CHARM observations show distinctive patterns in 2001-2005 cumulative anomaly fields.**

**Process 5-8 more sites with continuous records**
**Need more long term precipitation observations**

## FUTURE OF CHARM

**Long-term activity to support NASA research projects**
- permanent (?) to support Tennessee Valley weather resources
- possible field program or GPM validation site
**Encourage long-term precipitation observations from existing participants**
- annual CHARM meeting of all participants
- workshop on equipment and observation methods, scientific analysis
- picnic or other gathering to share experiences
- more recording gauges
**Expand network**
- outlying areas – fill in gaps (NE Madison Co, south of River, east of HSV)
- weather enthusiasts