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NWS FACETs will enable ... • Robust quantification of the weather hazard risk Initial realizations of the FACETs Vision: Real- • Better individual and group decision making • Based on individual needs …through both NWS & the private sector time tools and information for • Consistent communication and DSS, commensurate to decision making risk • Rigorous quantification of potential impacts Dr. Russell S. Schneider

Director, NOAA-NWS Storm Prediction Center

3 March 2019

National Summit – Public Sheltering Workshop

NOAA NWS Storm Prediction Center www.spc.noaa.gov

• Forecast tornadoes, , and nationwide • Forecast information from 8 days to a few minutes in advance • World class team engaged with the research community • Partner with over 120 local offices

Current: Forecast & Warning Continuum SPC 24x7 Operations

Information Void(s)

Outlooks Watches Warnings Event

Time Days Hours Minutes

Space Regional State Local

Uncertainty

FACETs: Toward a true continuum optimal for the pace of emergency decision making

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Tornado Watch SPC Severe Weather Outlooks Alerting messages issued to the public through media partners

SPC Forecaster collaborating on watch characteristics with local NWS offices to communicate the forecast tornado threat to the Public

Issued since the early 1950’s

SPC Lead Forecaster SPC Lead Forecaster

National Experience

Average National Experience: 10 years as Lead; almost 20 overall

NWS Local Forecast Office Partners – 120+ Nationwide What makes this problem difficult?

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The Atmosphere is Inherently Chaotic Will there be a tornado where I live and thus Probabilistic today? “Chaos: When the present determines the future, but the approximate The Future is Not Deterministic: Not Black and White or Yes / No present does not approximately determine the future.” - Edward Lorenz

No Yes

Slingo and Bauer, Thorpe, and Palmer, 2011 Brunet 2015

13 14

Will there be a tornado where I live Will there be a tornado today? … within 25 miles of … The key is to embrace grayness (probabilities), and rigorously estimate how gray (how likely)! where I live today?

0% 50% 100% 0% 50% 100%

15 16

What is Normal? What is Normal? Near OKC 1.40% each day … within 25 miles of City OK … near peak in early May: 1.40% each day

0% 50% 100%

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Will there be a tornado Will there be a tornado … within 25 miles of … … within 25 miles of … where I live today? where I live today?

Marginal Slight Enhanced Moderate High Risk

0 2 5 10 15 30 45 60 0 2 5 10 15 30 45 60

Tornado Forecasts – more than 6 hours in advance 0% 60% 0% 60%

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Probabilistic Outlook Verification Probabilistic Severe Weather Outlooks SPC Severe Weather Outlook SPC Probabilistic Tornado Outlook SPC Experts: Estimating how likely a rare tornado is … every day for Historic 27 April 2011 for Historic 27 April 2011 Tornado Outbreak

Day 1 Probabilistic Outlooks Day 2 & 3 Probabilistic Outlooks “Reliable” “Reliable”

Under Under

Over Over Probability of Probability of Severe Convective Winds Large

Five year sample: 2010 - 2014 SPC Probabilistic Severe Weather Outlooks are statistically reliable

Tuscaloosa Alabama - 27 April 2011 Current SPC Focus Forecast & Warning Continuum Information Void(s)

Outlooks Watches Warnings Event

Time Days Hours Minutes

Space Regional State Local High Resolution Short Term Uncertainty Probabilistic Outlooks Toward a true continuum optimal for the pace of emergency decision making

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Ensembles: Scenarios & Impacts for IDSS Forecaster Tools: Storm Scale Ensembles

ARW – CN ARW – C0 NMM – CN NMM – C0 ARPS – CN ARPS – C0

18 hr Forecast - 1 km “Radar”

Observed Radar Reflectivity

HWT 2009 Spring Experiment Led by: Israel Jirak

23 Feb 2019: MS AL Tornado Clusters

12 tornadoes; 1 EF3 (Columbus MS); 1 EF 2; 4 EF1 with 1 fatalities & 19 injuries John Steuart Curry – Tornado over Kansas (1929)

What is Normal? … in Columbus MS 0.4% Probabilistic Severe Weather Outlook SPC Severe Weather Outlook – 23 February 2019 Probabilistic Tornado Outlook

Severe Convective Winds Large Hail

SPC Probabilistic Severe Weather Outlooks are statistically reliable

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High Resolution Severe Weather Outlooks High Resolution Severe Weather Outlooks

High Resolution Severe Weather Outlooks High Resolution Severe Weather Outlooks

High Resolution Severe Weather Outlooks High Resolution Severe Weather Outlooks

Future Capacity: WoF 4hr forecast supercell threat

A tornadic supercell is very likely to pass near your community in around 4 hours

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3 March 2019: AL GA Tornado Clusters www.spc.noaa.gov

24 preliminary tornado reports; with 14 fatalities (12 near Beauregard, AL) & many injuries

Many Challenges and Questions Remain www.spc.noaa.gov • How can weather professionals best communicate this emerging, http://facebook.com/NWSSPC highly detailed, science-based information to emergency managers http://twitter.com/NWSSPC and other emergency decision makers? [email protected] • How should current weather information forms best evolve to take advantage of this new information, while retaining key successful elements of our current approach familiar throughout the public?

• How can we best exploit this new, potentially rapidly evolving threat information for emergency decision making, but retain simple effective messages for the public?

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