New Products and Services at the Storm Prediction Center

Dr. Russell S. Schneider

Dr. Joseph T. Schaefer

Dr. David R. Bright

Steven J. Weiss

Andy R. Dean

DOC/NOAA/NWS/NCEP Storm Prediction Center

BASC - June 2008

“Where America’s Weather and Climate Services Begin”

Outline• Forecast Service Advances

• Severe weather outlooks through Day 8• Probabilistic hazard forecasts

• Individual hazard probabilities (Day 1 & Watches)– forecast for (extreme) tornado, hail, wind

• Science Infusion & Collaboration• Specialized mission specific software and data• Hazardous Weather Testbed

• Early integration of ensemble forecast systems

• Storm-resolving WRF NWP

• Storm-scale Ensemble Forecast System

“The Storm Prediction Center exists solely to protect the life and property of the American

people through the issuance of timely, accurate watch and forecast products dealing with tornadoes and other hazardous mesoscale

weather phenomena.”

Severe Weather Outlooks

Day 4-8 OutlookOperational since March 2007

Severe Weather OutlooksExploit ensembles to produce probabilistic information

through Day 8

Day 6

Day 7

Day 6

Day 8

Day 4-8 OutlookOperational since March 2007

First Outlook

“Super Tuesday” Outbreak5 February 2008

56 Fatalities - 15th Largest Death Toll

since 1950

Day 4-8 Convective OutlookOperational since March

200730% Probability of an Event within 25 mi of a point

(“high end” Slight Risk)“Potential too Low”

<30 % Probability

“Predictability too

Low” Widespread severe weather possible, but too much

uncertainty to forecast

an area

Graphic & Short Discussion

Issued at 2:30 am Central

Day 3 & Day 2 Convective Outlook

Operational since: 2001 & 1986 (categorical); 2001 &

2000 (probabilistic)Probability of Severe Weather within 25 miles of a point

Hatched Area --- 10% or greater chance of an extreme event

(EF2 or greater tornado, 2” or larger hail, 65 kt or faster gust)

Graphic & DiscussionValid for 24 hour period 1200 UTC – 1200 UTC

Issued at 2:30 am Central Issued at 1:00 am Central& updated at 1730 UTC

DAY AFTER TOMORROW TOMORROW

Day 1 Convective Outlook

Operational since 1955 (catagorical) & 2000 (probabilistic)Probability of individual hazards within 25 miles of a pointHatched Areas --- 10% or greater chance of an extreme event

(F2 or greater tornado, 2” or larger hail, 65 kt or faster gust)

Issued at 0600 UTC; updated at 1300, 1630, 2000, 0100 UTCValid for period ending at 1200 UTC

Categorical Risk

Hail Probability

Tornado Probability

Wind Probability

Tornado Reliability (2006 Final)

0

10

20

30

40

50

60

70

80

90

100

0 10 20 30 40 50 60 70 80 90 100

Forecast (% )

Ob

se

rve

d (

%)

Verification of Probabilistic OutlooksTornado (2006: Initial Day 1)

Significant tornado forecast (hatched area)

Hail Reliability (2006 Final)

0

10

20

30

40

50

60

70

80

90

100

0 10 20 30 40 50 60 70 80 90 100

Forecast (% )

Ob

se

rve

d (

%)

Verification of Probabilistic OutlooksHail (2006 - Initial Day 1)

Significant hail forecast (hatched area)

All Convective Watches do not have the same risk

Watch Hazard Probabilities

All watches are not created equal

Use the probabilities to refine the specific threat within the watch and

gauge forecaster confidence in the specific convective hazards

Operational since 2006

SigTor Watch (2006 Final)

0

10

20

30

40

50

60

70

80

90

100

0 10 20 30 40 50 60 70 80 90 100

Forecast (%)

Ob

se

rve

d (

%)

Verification of Watch ProbabilitiesOne or More Significant Tornadoes (EF2-EF5)

> EF2

First Guess for Forecast is Based on Hazard Climatology

SPC Watch Verification for Significant Tornadoes (EF2-EF5)

0102030405060708090

100

1970-1979

1975-1984

1980-1989

1985-1994

1990-1999

1995-2004

Per Cent of Sig Tor inAny Watch

Per Cent of Sig.Tornadoes in TorWatchPer Cent of tornadoesthat are Sig

Percent of Extreme Tornado Events in a WatchPercent of Extreme Tornadoes in a Tornado Watch

Percent of Extreme Tornadoes

2006: POD > 94%

Science Infusion

& Collaboration

National Weather Center• Co-location !!!

• SPC

• WFO Norman

• NSSL

• WDTB

• CIMMS

• OU School of Meteorology

• CAPS, OCS

• Private Sector (nearby)

SPC Personnel Distribution (33 Government, 4 Contract, 2 Students)

• Operations Branch• 1 Branch Chief1 Branch Chief• 5 Lead Forecasters5 Lead Forecasters• 10 Mesoscale/Outlook10 Mesoscale/Outlook• 5 Assistant Mesoscale5 Assistant Mesoscale

Administration 1 Director1 Director 1 WCM (outreach)1 WCM (outreach) 1 Administrative Officer1 Administrative Officer 1 Contract Admin. Coord.1 Contract Admin. Coord.

Science Support Branch 1 Branch Chief1 Branch Chief 1 Science & Operations (SOO)1 Science & Operations (SOO) 3 Science & Tech. Infusion 3 Science & Tech. Infusion 1 1 Contract Met. ProgrammerContract Met. Programmer 1 ESA1 ESA 1 Software Analyst1 Software Analyst 1 System Administrator1 System Administrator 2 Contract Computer Support2 Contract Computer Support 2 SCEP2 SCEP

Organic Science Infusion

Capability

Examples of Organic (day-to-day)

Science Infusion Activities

Severe Storm Environment Relational Database• All “final” severe weather reports since 1950

• Environmental estimates from SPC - RUC analysis (2003 - present)

• All historic SPC forecast products

• Lightning & radar derived data

139,715 reports & 7396 tornadoes

Context Based VerificationS

hear

Instability

Where we must improve …S

hear

Instability

Overall POD: 0.69

NOAA Hazardous Weather Testbed

Two Main Program Areas…

Experimental

Warning

Program

Experimental

Forecast

Program EFP

EWP

Prediction of hazardous weather events from a few hours to a week

in advance

Detection and prediction of hazardous weather events up to several hours in

advance

NOAA Hazardous Weather Test Bed• HWT – Experimental Forecast Program Objectives

• Advance the science of weather forecasting and prediction of severe convective weather consistent with NOAA strategic goals

• Enhance collaboration between researchers and forecasters on topics of mutual interest through real-time forecasting and evaluation activities during active severe weather

• Provide for thorough examination and efficient delivery of scientific advances for SPC and NWS operations

Disciplined collaboration to advance forecast

operations

HWT Contributions to Advances in SPC Operations

• Short Range Ensemble Forecast System (SREF)• SREF Workshop (NCEP 1994)• Collaboration on SREF with EMC & NSSL (1999-2002)• SPC focused SREF guidance in Operations (2003)• Developing additional calibrated high impact wx. guidance

• Global Ensemble Forecast System (GEFS)• SPC Focused GEFS Guidance in Operations (2005)• Working toward NAEFS tools (2009)

• Convection Allowing High Resolution NWP• Experimental WRF data in Operations (2004)• Operational WRF data in Operations (2008)

Severe Event of April 7, 2006• SREF environmental guidance increased forecaster

confidence leading to a “High Risk” Day 2 outlook• This was the first Day 2 High Risk ever issued by SPC • Impact: More than 800 total severe reports

– 3 killer tornadoes and 10 deaths

SREF Combined or Joint Probability

Pr [MUCAPE > 2000 J/kg] XPr [ESHR > 40 kts] X

Pr [C03I > 0.01”]

Probability of convection in high CAPE, high shear environment

(favorable for supercells)

Calibrated Products at SPC

– Use large-scale environmental forecasts to calibrate (i.e., statistically post-process) the ensemble and downscale to the phenomena of interest

• Probability of Thunderstorms (CG Lightning)• Probability of Severe Thunderstorms (Reports)• Probability of Dry Thunderstorms (Lightning & RH)• Probability of Snowfall accumulation (MADIS)

Calibrated Probability of a Thunderstorm Calibrated Probability of a Thunderstorm

15h Forecast Ending: 00 UTC 01 Sept 2004Calibrated probability: Solid/Filled

3 hr valid period: 21 UTC 31 Aug to 00 UTC 01 Sept 2004

15h Forecast Ending: 00 UTC 01 Sept 2004Calibrated probability: Solid/Filled; NLDN CG Strikes (Yellow +)

3 hr valid period: 21 UTC 31 Aug to 00 UTC 01 Sept 2004

Calibrated Probability of a Thunderstorm Calibrated Probability of a Thunderstorm

Perfect Forecast

No Skill

Perfect Forecast

No Skill

Calibrated ReliabilityCalibrated Reliability (5 Aug to 5 Nov 2004)(5 Aug to 5 Nov 2004)

Calibrated Thunder Probability

Climatology

Frequency[0%, 5%, …, 100%]

SREF 6h Calibrated Probability of Snow/Ice Accum

Accumulation calibration based on MADIS road surface observations

Wide range of high impact SREF guidance are available at the

SPC websitehttp://www.spc.noaa.gov/exper/sref/

WRF 24 hr Reflectivity Forecasts Valid 00z 26 May 2005

ARW4

ARW2

NMM4

RADAR

4 km WRF-ARW

2 km WRF-ARW

4.5 km WRF-NMM

RADAR VERIFICA

TION

Simulated Reflectivity 24-h Fcsts Valid 00 UTC 26 May

2005

WRF 24 hr Reflectivity Forecasts Valid 00z 26 May 2005

ARW4

ARW2

NMM4

RADAR

4 km WRF-ARW

2 km WRF-ARW

4.5 km WRF-NMM

RADAR VERIFICA

TION

Simulated Reflectivity 24-h Fcsts Valid 00 UTC 26 May

2005

Experimental Storm Scale Ensemble Forecast (SSEF)

• NOAA Hazardous Weather Testbed (HWT)• HWT Spring Experiment

Focused on experimental high-res WRF forecasts since 2004 (dx ~2-4 km)• Convection allowing ensemble forecasts (2007-2009) to address uncertainty

10 WRF members 4 km grid length over 3/4 CONUS Major contributions from: SPC, NSSL, OU/CAPS, EMC, NCAR

• Evaluate the ability of convection allowing ensembles to predict: Convective mode (i.e., type of severe wx) Magnitude of severe type (e.g., peak wind) Aviation impacts (e.g., convective lines/tops) QPF/Excessive precipitation Year 1 Objective (2007): Assess the role of physics vs. initial condition uncertainty at high resolution

2 km AGL

5 km AGL

Convective Mode: Supercell Detection

Besides simulated reflectivity, need a quantitative tool for supercell detection and strength in deterministic and ensemble forecasts

Probability Updraft Helicity > 50 m2/s2

Supercell Forecast (26 hour)

Radar BREF 0142 UTC 22

Apr 2008

F026: Valid 02 UTC 22 Apr

2008

Updaft Helicity > 50 m2s-2 within

25 miles

Supercell Observed

Convective Mode Prediction: Linear

• Determine contiguous areas exceeding 35 dbZ

• Estimate mean length-to-width ratio of the contiguous area; search for ratios > 5:1

• Flag grid point if the length exceeds:• 50 miles• 100 miles• 200 miles

Probability Linear Mode Exceeding 200 miles

Squall Line PredictionF026: Valid 02 UTC 18 Apr 2008Linear mode + 25 miles

Linear Convective Mode: Impacts

Aviation impacts ~ 01 UTC18 April 2008

Challenges for Severe Weather• Enhance Operations – Research Collaboration

• Support Testbed Infrastructure (R2O & O2R)– Staff

• Increase Participation through AO Process– Travel Support– Research Support

• Reward Effective Collaborators– Operational Meteorologists– Researchers (Government & Academic)

• Experimental Data Flows & Workstations– GOES-R Proving Ground

• Invest in NOAA Computer Capacity• Harvest Potential of Storm Resolving NWP

– Deterministic & Ensemble

NOAA Storm Prediction Centerwww.spc.noaa.gov