Storm Prediction Center Products

1. Storm Prediction CenterProducts Daniel McCarthy SPC Warning Coordination Meteorologist 2005 National Severe Weather Workshop

2. Use same paradigm for one goal = SAVE LIVES AND PROTECT PROPERTY!!! 2005 National Severe Weather Workshop

3. SPC Products • Severe Weather Outlooks • Day One (today) • Day Two (tomorrow) • Day Three (day after tomorrow) • Severe Weather Watches • Tornado • Severe Thunderstorm 2005 National Severe Weather Workshop

4. SPC Products • Mesoscale Discussions • Watch Status Messages • Fire Weather Outlooks • Day One (today) • Day Two (tomorrow) 2005 National Severe Weather Workshop

5. Severe Weather Outlooks • Two Types of Outlooks • Probabilistic • Tornadoes • Hail • Convective Winds • Categorical • Slight • Moderate • High 2005 National Severe Weather Workshop

6. Probability Outlooks • Details the threat within 25 miles of any point in the area • Tornadoes • Large hail • Severe convective winds • Provide the threat of significant severe activity 2005 National Severe Weather Workshop

7. Probability Outlooks • Tornadoes • 2%,5%,15%,25%,35%, 45% • Hail • 5%,15%,25%,35%, 45% • Convective Wind • 5%,15%,25%,35%, 45% 2005 National Severe Weather Workshop

8. Significant Event Forecast • Hatched Area • 10% or greater probability • Tornadoes producing F2 damage or worse • Large Hail 2 inches in diameter or larger • Convective Winds 65 kt or stronger 2005 National Severe Weather Workshop

9. Annual Tornado Cycle (within 25 miles of OKC) http://www.nssl.noaa.gov/hazard/ 2005 National Severe Weather Workshop

10. Tornado Probability Map (within 25 miles of any point) Around the end of May http://www.nssl.noaa.gov/hazard/ 2005 National Severe Weather Workshop

11. Severe Hail Probability Map (within 25 miles of any point) Around the end of May http://www.nssl.noaa.gov/hazard/ 2005 National Severe Weather Workshop

12. Severe Wind Probability Map (within 25 miles of any point) Around the end of May http://www.nssl.noaa.gov/hazard/ 2005 National Severe Weather Workshop

13. Any Severe Weather Probability Map (within 25 miles of any point) Around the end of May http://www.nssl.noaa.gov/hazard/ 2005 National Severe Weather Workshop

14. Probabilities Breakdown Precipitation 0% - 100% Severe 0% - 50% Tornado 0% - 25% Extreme Event 0% - 10% 2005 National Severe Weather Workshop

15. Converting to Categorical Descriptions 2005 National Severe Weather Workshop

16. Probabilities Summary • It’s not the number of reports, it’s the distribution of reports. Xenia, OH 4/3/1974 2005 National Severe Weather Workshop

17. Severe Weather Watches 2005 National Severe Weather Workshop

18. Tornado Watch • Issued when Strong/Violent Tornadoes (F2 – F5) damage is possible • 2 or More Tornadoes are Expected Not all tornadoes will occur in a watch!!! 2005 National Severe Weather Workshop

19. Severe Thunderstorm Watch • Organized widespread severe • Supercells • Squall lines • Multicell complexes • Organized significant severe • Wind gusts > 64 kt (73 mph) • Damage to permanent structures • Hail > 2.0 inches diameter 2005 National Severe Weather Workshop

20. “Particularly Dangerous Situation” Watches • Placed in Tornado Watches • Multiple strong or violent (F2 – F5 damage) events • Placed in Severe Thunderstorm Watches • Long lived wind events (derechoes) 2005 National Severe Weather Workshop

21. 2005 National Severe Weather Workshop

22. Watch By County • SPC uses the popular parallelogram to define the area of concern 2005 National Severe Weather Workshop

23. Watch By County • The parallelogram defines the counties proposed for the actual watch. 2005 National Severe Weather Workshop

24. Watch By County • This is the real watch defined by the counties in the watch. This is a collaboration between SPC and the NWS WFO. 2005 National Severe Weather Workshop

25. Watch Outline Update (SPC) MKCWOU2 ALL WOUS52 KSPC 262320 TORNADO WATCH OUTLINE UPDATE FOR WW#1002 NATIONAL WEATHER SERVICE NORMAN OK 520 PM CDT MAY 26 1999 TORNADO WATCH #1002 REMAINS IN EFFECT UNTIL 7:00 PM CDT FOR THE FOLLOWING LOCATIONS: ARC011-013-019-025-027-039-051-053-057-059-061-069-073-081-085-091-097-099-103-105-109-113-119-125-127-133-139-149-270100- AR IN ARKANSAS...COUNTIES INCLUDED ARE BRADLEY CALHOUN CLARK CLEVELAND COLUMBIA DALLAS GARLAND GRANT HEMPSTEAD HOT SPRING HOWARD JEFFERSON LAFAYETTE LITTLE RIVER LONOKE MILLER MONTGOMERY NEVADA OUACHITA PERRY PIKE POLK PULASKI SALINE SCOTT SEVIER UNION YELL $$ LAC013-015-017-027-061-111-119-270100- LA IN LOUISIANA...PARISHES INCLUDED ARE BIENVILLE BOSSIER CADDO CLAIBORNE LINCOLN UNION WEBSTER $$ TXC037-063-067-203-315-343-459-270100- TX IN TEXAS...COUNTIES INCLUDED ARE BOWIE CAMP CASS HARRISON MARION MORRIS UPSHUR $$ ATTN...LZK...SHV...FTW 270100;323,0918 355,0953 355,0918 323,0953; NNNN 2005 National Severe Weather Workshop

26. Mesoscale Convective Discussions • ISSUED (IDEALLY) 1-3 HOURS PRIOR TO A SEVERE THUNDERSTORM OR TORNADO WATCH - DEFINE AREA(S) OF CONCERN - STATE TYPE OF WATCH EXPECTED - PROVIDE METEOROLOGICAL REASONING ALSO ISSUED TO ADDRESS: - OUTLOOK UPGRADE - HEAVY RAINFALL - WINTER WEATHER 2005 National Severe Weather Workshop

27. Mesoscale Discussions MESOSCALE DISCUSSION 0067 NWS STORM PREDICTION CENTER NORMAN OK 0240 PM CST WED JAN 12 2005 AREAS AFFECTED...PORTIONS OF CENTRAL-ERN OK SWD INTO NRN TX CONCERNING...SEVERE THUNDERSTORM POTENTIAL VALID 122040Z - 122145Z WW MAY BE NEEDED DURING THE NEXT HOUR FOR PORTIONS OF CENTRAL-ERN OK INTO NRN TX. VIS/IR SATELLITE IMAGERY AT 20Z SHOWED ENHANCED CU FIELD DEVELOPING ACROSS NWRN NORTH TX INTO WRN OK INDICATIVE OF LEADING EDGE OF INCREASING UPWARD VERTICAL MOTION AHEAD OF STRONG UPPER TROUGH. 20Z SURFACE ANALYSIS SHOWED PRIMARY BAROCLINIC ZONE EXTENDING FROM A LOW OVER NWRN TX EWD INTO NORTH CENTRAL OK...AND THEN NEWD ACROSS SERN KS TO NRN MO. PRE-FRONTAL TROUGH/DRY LINE EXTENDED NNE-SSW FROM 15W END TO 15E ABI. 19Z OUN SOUNDING SHOWED THE STRONG CAP EVIDENT ON THE 12Z SOUNDING HAS WEAKENED SUBSTANTIALLY WITH MUCAPE OF 1100 J/KG. CAP FARTHER SOUTH ACROSS NRN TX IS ALSO WEAKENING PER 19Z FTW SOUNDING...BUT REMAINS STRONG ENOUGH TO LIMIT CONVECTIVE DEVELOPMENT UNTIL LATER THIS AFTERNOON/EARLY EVENING WHEN STRONGER FORCING SPREADS ACROSS THIS REGION. ONGOING STORMS OVER SRN OK/FAR NRN TX ARE EXPECTED TO INCREASE IN AREAL COVERAGE THROUGH THE LATE AFTERNOON AS UPPER FORCING WITH THE TROUGH SPREADS EWD ATOP THE MOISTURE/INSTABILITY AXIS ACROSS THE AREA OF CONCERN. STRONG DEEP AND LOW-LEVEL SHEAR WILL SUPPORT ORGANIZED STORMS EVOLVING INTO A SQUALL LINE...THOUGH ISOLATED OR EMBEDDED SUPERCELLS WILL BE POSSIBLE. ..PETERS.. 01/12/2005 ATTN...WFO...SHV...TSA...FWD...OUN...SJT... 33089981 35389822 36819721 36799517 35569466 33529524 32739604 32719854 2005 National Severe Weather Workshop

28. Winter Weather MD MESOSCALE DISCUSSION 0021 NWS STORM PREDICTION CENTER NORMAN OK 0705 AM CST TUE JAN 04 2005 AREAS AFFECTED...SWRN NE / MUCH OF WRN AND SRN KS / NWRN OK / EXTREME NERN TX PANHANDLE CONCERNING...FREEZINGRAIN VALID 041305Z - 041800Z WINTER PRECIPITATION WILL INCREASE IN COVERAGE THROUGH THE MORNING HOURS. FREEZING RAIN WITH SOME ACCUMULATION WILL FALL OVER NWRN OK AND SOUTHERN KS...WITH HOURLY RATES AROUND 0.05 IN. FARTHER N...FREEZING RAIN AND SLEET WILL BE LIKELY INTO NWRN KS...CHANGING TO A MIXTURE OF SLEET AND SNOW OVER SWRN NEBRASKA. ISENTROPIC LIFT NEAR 850 FRONT WILL PERSIST MUCH OF THE DAY...FROM THE TX PANHANDLE ENEWD ACROSS NRN OK AND INTO SERN KS / SWRN MO. 12Z DDC RAOB SHOWS VERY WARM TEMPERATURES BETWEEN 850-700 MB...WHICH WILL REMAIN ABOVE FREEZING EVEN WHEN SATURATED. FARTHER S...AMA AND OUN RAOBS EXHIBIT CONVECTIVE INSTABILITY. THEREFORE...ALTHOUGH HRLY PRECIPITATION RATES ARE EXPECTED TO AVERAGE AROUND 0.05 IN...OCCASIONAL HEAVY BURSTS OF 0.10-0.20 IN/HR ARE EXPECTED OVER NWRN OK AND FAR SRN KS. FARTHER N INTO NWRN KS AND SWRN NEBRASKA...SLEET AND SNOW WILL BE LIKELY...WITH SNOWFALL RATES OF 0.50-1.00 IN/HR . ..JEWELL.. 01/04/2005 ATTN...WFO...SGF...ICT...OUN...GID...LBF...DDC...GLD...AMA... 36530119 36220057 35910005 35799969 35799907 35919859 36399824 36789779 37259692 37419559 37689497 37849597 38099650 38529717 39119863 40439938 41299958 41630048 41380187 40980188 40050188 38330189 36730153 2005 National Severe Weather Workshop

29. Watch Status Messages • Issued at the top of every hour after watch • Delineates part of watch with continuing severe weather threat • Will refer to a Mesoscale Discussion every other hour after watch issuance 2005 National Severe Weather Workshop

30. Watch Status Messages ZCZC SPCWWASPC WOUS20 KWNS 291701 SPC WW-A 291700 ALZ000-LAZ000-MSZ000-TNZ000-291800- STATUS REPORT ON WW 839 SEVERE WEATHER THREAT CONTINUES EAST OF A LINE FROM 55 WNW JAN TO 20 NW GWO TO 20 W UOX TO 25 WSW MKL SEE MESOSCALE DISCUSSION #1701 FOR FURTHER DETAILS. ..MCCARTHY..11/24/01 ATTN...WFO...MEM...JAN 2005 National Severe Weather Workshop

31. Fire Weather Outlook • Delineates areas where there is a significant threat for the initiation of wildfires • Favorable fuel conditions • Favorable weather conditions • Used by field fire weather forecasters and others dealing with fire suppression 2005 National Severe Weather Workshop

32. Fire Weather Outlook • Two Types of Areas • Critical • Extremely Critical 2005 National Severe Weather Workshop

33. Meteorological Conditions • Below normal rainfall • Dry thunderstorms • Strong low level winds • Low RH • Steep lapse rates lower atmosphere • Critical fire weather patterns (Santa Ana) • Max temps/% sunshine 2005 National Severe Weather Workshop

34. Outlooks • The idea is to capture areas where fires can initiate due to favorable environmental conditions 2005 National Severe Weather Workshop

35. SPC Web Tools Composite Map Forecast Tools Mesoanalysis Graphics Upper Air New! 2005 National Severe Weather Workshop

36. Summary OUTLOOK Check plan of action Make sure shelter is ready WATCH Monitor weather conditions Stay tuned to TV/Radio WARNING Take Shelter! SAVE LIVES 2005 National Severe Weather Workshop

37. Storm Prediction Center Web Page • www.spc.noaa.gov • Products • Climatological data • Warnings • Images • Links to other severe storm sites 2005 National Severe Weather Workshop