Summary of Progress on 

Implementation of 

Recommendations from 

the Joplin Tornado 

Investigation

June 30, 2020

NCST Advisory 

Committee Meeting

Long Phan

Leader, Structures Group

1

NOTE – A summary of the 

recommendations are 

included in the following 

slides for context. The 

complete recommendations 

are available in the final 

report of the NIST Technical 

Investigation of the Joplin 

Tornado, at 

https://dx.doi.org/10.6028/

NIST.NCSTAR.3
NIST Joplin Tornado Investigation

• 16 recommendations for 

improving:

• Tornado hazard characterization

• Design and construction of 

buildings and shelters in tornado–

prone regions

• Emergency communications that 

warn of threats from tornadoes

http://dx.doi.org/10.6028/NIST.NCSTAR.3

The first tornado study to include storm 

characteristics, building performance, 

emergency communication and human 

behavior together - with assessment of 

the impact of each on fatalities

2
List of Joplin Recommendations Hazard Characteristics Buildings, Shelters, Designated Safe Areas, and Lifelines Emergency Communicatio

n

3

R # RECOMMENDATION SUMMARY

1 Development and deployment of technology to measure tornado wind fields

2 Archival of tornado event data

3 Development of tornado hazard maps

4 Improvement of EF Scale; means for continued improvement; adoption by NWS

5 Development of performance-based standards for tornado-resistant design

6 Development of performance-based tornado design methodologies

7 a) Development of tornado shelter standard for existing buildings; 

b) Installation of tornado shelters in more buildings in tornado-prone regions

8 Development of guidelines for public tornado sheltering strategies

9 Development of guidelines for selection of best available refuge areas 

10 Prohibition of aggregate roof coverings and ballast in tornado-prone regions

11 Development of requirements for enclosures of egress systems in critical facilities

12 a) Development of tornado vulnerability assessment guidelines for critical facilities;

b) Performance of vulnerability assessments by critical facilities in tornado-prone

13 Development of codes, standards, and guidance for emergency communications; 

Development of joint plan by emergency managers/media/NWS for consistent alerts

14 Deployment of “push” technologies for transmission of emergency information

15 Research to identify factors to enhance public perception of personal risk

16 Develop technology for real-time, spatially-resolved tornado threat information
R # RECOMMENDATION SUMMARY PROGRESS UPDATES IN THIS BRIEFING

1 Development and deployment of technology to measure tornado wind fields

2 Archival of tornado event data

3 Development of tornado hazard maps

4 Improvement of EF Scale; means for continued improvement; adoption by NWS

5 Development of performance-based standards for tornado-resistant design

6 Development of performance-based tornado design methodologies

7 a) Development of tornado shelter standard for existing buildings; 

b) Installation of tornado shelters in more buildings in tornado-prone regions

8 Development of guidelines for public tornado sheltering strategies

9 Development of guidelines for selection of best available refuge areas 

10 Prohibition of aggregate roof coverings and ballast in tornado-prone regions

11 Development of requirements for enclosures of egress systems in critical facilities

12 a) Development of tornado vulnerability assessment guidelines for critical facilities;

b) Performance of vulnerability assessments by critical facilities in tornado-prone

13 Development of codes, standards, and guidance for emergency communications; 

Development of joint plan by emergency managers/media/NWS for consistent alerts

14 Deployment of “push” technologies for transmission of emergency information

15 Research to identify factors to enhance public perception of personal risk

16 Develop technology for real-time, spatially-resolved tornado threat information

List of Joplin Recommendations

Hazard Characteristics

Buildings, Shelters, Designated Safe Areas, and Lifelines

Emergency Communicatio

n

4
Highlights of Implementation Activities 

and Successes since 9/19 Meeting (1/3)

R3: Tornado Hazard Maps

5

Example tornado map, speeds in mph

• Tornado maps completed!

• Submitted to ASCE 7 Wind Load Subcmte (WLSC)

• Technical Report and Tornado Database to be 

published in Q4/FY20

R5/6: Performance-based 

standards/design methodologies 

for tornado resistant design

• Tornado load design methodology completed!

• Proposed provisions for ASCE 7-22 completed!

o Provisions being balloted through ASCE 7 WLSC

o Technical reports to be published in Q1/FY21:

— Tornado load coefficients

— Tornado load reliability / tornado map return period 

analysis

MRI = 3,000 years

Effective Plan Area 

Ae = 250,000 ft2

Building model in tornado simulator.

Tornado load coefficients were developed 

using data from a combination of 

experimental and computational models.

© 2018 WindEEE Research Institute. Used with Permission.
Highlights of Implementation Activities 

and Successes since 9/19 Meeting (2/3)

NIST awarded grants1 to 4 universities totaling $2.24M in August 2019 

under the Disaster Resilience Grant Research Program, supporting sensor 

development and field deployments to collect, analyze and disseminate 

spatiotemporal data on windstorm phenomena, including surface-level winds and 

near ground velocity profiles in tornadoes and other high wind events. 

Year 1 Progress Briefings for these projects will be presented at the July 28-29

VIRTUAL-2020 NIST Disaster Resilience Symposium

For registration, see https://www.nist.gov/news-events/events/2020/07/virtual-2020-nist-disaster-resilience-symposium

6 1 https://www.nist.gov/news-events/news/2019/08/nist-awards-66-million-research-help-structures-better-withstand

R1: Development and deployment of technology to 

measure tornado wind fields

R2: Archival of tornado event data
Grant Projects Supporting R1 & R2 (1/4)

7

© 2020, Frank Lombardo. Used with Permission.
8

© 2020, John Schroeder. Used with Permission.

Grant Projects Supporting R1 & R2 (2/4)
9

© 2020, Mike Biggerstaff. Used with Permission.

Grant Projects Supporting R1 & R2 (3/4)
10

© 2020, Chelakara Subramanian. Used with Permission.

Grant Projects Supporting R1 & R2 (4/4)
Highlights of Implementation Activities 

and Successes since 9/19 Meeting (3/3)

Field research to application: a study of human 

response to the 2011, Joplin tornado and its 

impact on alerts and warnings in the USA

By Erica Kuligowski, Natural Hazards (2020)

https://doi.org/10.1007/s11069-020-03945-6

11

R13: Development of codes, standards, and guidance for 

emergency communications; and development of joint plan 

by emergency managers/media/NWS for consistent alerts

New Publication:
Body of Work Supporting R13

12

NFPA 1600 — Standard on Continuity, Emergency, and Crisis Management

• Annex K: Emergency Communications: Public Alerts and Warnings in 

Disaster Response

NFPA 1616 —Standard on Mass Evacuation, Sheltering, and Re-entry Programs

• Annex K: Emergency Communication: Public Alerts and Warnings

• Annex L: Social Media Planning

Developed guidance for communities on the creation and provision of public 

alerts via outdoor siren (warning) systems and social media (incl. mobile alerts)

• Stakeholder workshops on 1) siren policies and procedures and 2) short message alerting

• Publications, including:

Impacts on Standards

J. Sutton, E. Kuligowski, Alerts and warnings on short messaging channels: 

guidance from an expert panel process, Nat. Hazards Rev. 20 (2019). 

https://doi.org/10.1061/(ASCE)NH.1527-6996.0000324. 

© 2016 NFPA, reproduced with permission. This 

presentation and/or publication is not affiliated 

with or approved by the NFPA.
Tornado Hazard Characteristics

Performance of Buildings, Shelters, 

Designated Safe Areas, and Lifelines

Marc Levitan, Research Wind Engineer

Structures Group
Progress – Improvement of the EF Scale

R4: Standardize the Enhanced Fujita (EF) scale and improve through 

addition of scientific/quantifiable damage indicators, particularly those 

that better distinguish between the most intense tornado events

ASCE/SEI/AMS Standard on Wind Speed Estimation in Tornadoes 

and Other Windstorms (NIST and NOAA co-chair this standards committee)

14

• Complete drafts of chapters for all methods 

in the standard

• 1st Main Committee (MC) ballots on the 

following method chapters have been 

completed to date in FY20

o Radar

o EF Scale

o Forensic Eng.

o Treefall Pattern

• Chapters for remaining 2 methods are in 

Subcommittee review prior to MC ballot

o In Situ

o Remote Sensing Condition Assessment

Summary of input requirements 

for each treefall-based wind 

speed estimation method
Progress – Tornado Hazard Maps (1/2) 

R3: Development of tornado hazard maps for use in the engineering 

design of buildings and infrastructure, considering spatially based 

estimates of the tornado hazard instead of point–based estimates.

15

Production of all 56 tornado hazard maps has been completed,

incorporating the significant effects of target size

A. Target Sizes, ft2 (Square targets)

1. Geometrical Point (no area) 

2. 2,000 (45’ x 45’)

3. 10,000 (100’ x 100’)

4. 40,000 (200’ x 200’)

5. 100,000 (316’ x 316’)

6. 250,000 (500’ x 500’)

7. 1,000,000 (1,000’ x 1,000’)

8. 4,000,000 (2,000’ x 2,000’)

Maps Produced

1. 300

2. 700 

3. 1,700 

4. 3,000 

5. 10,000

6. 100,000

7. 1,000,000

8. 10,000,000

B. Return Periods (Years)

.

Point 

Target

Offset Tornado Path 

Misses Point Target

Tornado 

Path

Area 

Target

Offset Tornado 

Strikes Area Target

Target Size Effects

Tornado 

Path
Progress – Tornado Hazard Maps (2/2) 

16

<<< ARA

NIST >>> 

Final Map

PRELIMINARY Map presented at 9/19 NCSTAC meeting 

Do Not Use or Cite

Completed Mapping Methodology

• Preliminary Maps

− Maps as of 9/19 NCSTAC meeting

(see slides 11-19 from that meeting1)

• Final Maps

− Added interior ‘plateau’ isotach

The automated procedures used to create the 

preliminary maps resulted in isotachs at 10 mph 

increments, thus truncating the peaks in the 

center of the country.

The truncation interfered with interpolation 

between different target sizes at same return 

period.

− Added smoothing of all isotachs using 

Polynomial Approximation with 

Exponential Kernel (PAEK) method

− Updated formatting

− Hand-cleanups 1 https://www.nist.gov/system/files/documents/2019/09/19/02_phan_levitan_ncstac_sept2019_joplin_recommendations_update_final.pdf
• Tornado speeds are 3-s peak gusts at 33 ft height 

• Linear interpolation between maps using the logarithm of the effective plan area sizes is permitted

• Tornado speeds less than those shown in ASCE 7-16 Chapter 26 may still produce loads that control the 

wind load design, due to differences in other load coefficients for tornadoes (e.g., KzT, KdT, GCpiT and others)

Tornado Hazard Map Examples

17

Risk Category III Risk Category IV
Progress – Tornado Load Design (1/2)

R6: Develop risk–balanced, performance–based tornado design 

methodologies 

ASCE 7-22 Tornado Task Committee 

(NIST chairs this committee)

• Developed New Tornado Load Methodology

• Completed drafts for all tornado provisions and 

chapters of the standard (completely new)

1: General

2: Load Combinations

26: Wind Loads

26: Appendix: Long MRI Wind Hazard Maps

32: Tornado Loads

32: Appendix: Long MRI Tornado Hazard Maps

• All 23 ballot items passed the Wind Load 

Subcommittee on 1st round (Jan. 2020)

• Worked closely with mobile radar community to 

analyze radar-measured tornado wind speeds 

and develop tornado velocity profile for ASCE 7-22, 

consistent with assumptions used in development of 

tornado hazard maps
• Developed New and Modified Wind Load Coefficients 

for Tornadoes

o Tornado Velocity Pressure Exposure Coefficient KzT

(see previous slide)

o Tornado Directionality Factor KdT, for MWFRS, C&C

o Internal Pressure Coefficient GCpiT, including effects of 

atmospheric pressure change

o Tornado Pressure Coefficient Adjustment Factor for 

Vertical Winds KvT, for MWFRS and C&C

• Incorporated multiple requirements to differentiate 

tornado load provisions for ‘Risk Category IV and 

other facilities intended to remain operational’, in 

support of performance-based design

• Created and led Tornado Load Reliability Working 

Group, to identify tornado map return periods that 

provide reasonable consistency with the reliability 

delivered by ASCE 7-16 MWFRS wind load 

provisions

o Collaboration between ASCE 7 Load Combinations 

Subcommittee and ASCE 7 Wind Load Subcommittee

• Developed tornado load combinations for Chapter 2

Progress– Tornado Load Design (2/2)

Dimensions and plan areas for the three 

buildings used for KdT and KvT modeling.

KdT as a function of roof zone and building plan 

area for tornado-induced C&C loads

© 2018 WindEEE Research Institute. Used with Permission.
Progress – Tornado Shelter Standard

R7a: Development of tornado shelter standard for existing buildings

20

• 1st Public Comment Ballot - Oct 2019

• NIST-led proposals include

o Expansion of scope to include shelters in 

existing buildings

o Treatment of design and construction 

issues specific to installation of shelters in 

existing buildings

o New 10,000-year MRI hurricane shelter 

design wind speed map

o New provisions for impact loads due to 

laydown hazards and falling debris hazards

o New load combinations provisions

ICC 500-2020: ICC/NSSA Standard on Design and Construction 

of Storm Shelters (NIST chairs this standards committee)
Progress – Tornado Vulnerability Assessment

R12a: Development of tornado vulnerability assessment guidelines for 

critical facilities

21

• Methods to assess vulnerability of critical facilities to 

• wind pressure

• wind-borne debris

• wind-driven rain

• Guidelines apply to critical facilities “both within and 

outside hurricane-prone regions and to critical 

facilities in tornado-prone regions”

• NIST contributed to the development of these 

guidelines

FEMA P-2062: Guidelines for Wind Vulnerability Assessments 

of Existing Critical Facilities

Source: FEMA

New Publication
Implementation Progress to Date

R # RECOMMENDATION SUMMARY

1 Development and deployment of technology to measure

tornado wind fields

2 Archival of tornado event data

3 Development of tornado hazard maps

4 Improvement of EF Scale; means for continued improvement; adoption by NWS

5 Development of performance-based standards for tornado-resistant design

6 Development of performance-based tornado design methodologies

7 a) Development of tornado shelter standard for existing buildings;

b) Installation of tornado shelters in more buildings in tornado-prone regions

8 Development of guidelines for public tornado sheltering strategies

9 Development of guidelines for selection of best available refuge areas

10 Prohibition of aggregate roof coverings and ballast in tornado-prone regions

11 Development of requirements for enclosures of egress systems in critical facilities

12 a) Development of tornado vulnerability assessment guidelines for critical facilities;

b) Performance of vulnerability assessments by critical facilities in tornado-prone areas

13 Development of codes, standards, and guidance for emergency communications;

Development of joint plan by emergency managers/media/NWS for consistent alerts

14 Deployment of “push” technologies for transmission of emergency information

15 Research to identify factors to enhance public perception of personal risk

16 Develop technology for real-time, spatially-resolved tornado threat information

Hazard Characteristics

Buildings, Shelters, Designated Safe Areas, and Lifelines

Emergency Communicatio

n

22

Legend

Published code/std/guidance

Significant activities/progress

In planning/modest progress

On schedule for 

completion in Q1FY21

Completed 

in FY20

Maps recently completed 

Technical Report to be published later this year 

Tornado load design method 

completed in FY20
Progress on Implementation 

of Joplin Tornado 

Recommendations

QUESTIONS?

June 30, 2020

NCST Advisory 

Committee Meeting

Long Phan

Leader, Structures Group

Marc Levitan

Research Wind Engineer, Structures Group

23

Please ‘raise your hand’ using the 

Blue Jeans Participant window and 

unmute your audio and video