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Products at the Storm Prediction Center. Where Is the NOAA Storm Prediction Center ?. Norman , OK. Mission Statement.
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Products at the Storm Prediction Center
Where Is the NOAA Storm Prediction Center ? Norman, OK
Mission Statement SPC exists solely to protect life and property of the American people through the issuance of timely, accurate watch and forecast products dealing with tornadoes and other mesoscale hazardous weather.
NWS Concept Outlook * Watch/Advisory * Warning
SPC Products • Severe Weather Outlooks • Day One (today) • Day Two (tomorrow) • Day Three (day after tomorrow) • Severe Weather Watches • Tornado • Severe Thunderstorm
SPC Products • Mesoscale Convective Discussions • Watch Status Messages • Fire Weather Outlooks • Day One (today) • Day Two (tomorrow)
Severe Weather Outlooks • Two Types of Outlook • Categorical • Slight – Moderate – High Risk • Probabilistic • Tornadoes • Hail • Convective Winds
Categorical Outlooks • Slight (SLGT) • < 30 Hail Reports ¾” of larger • < 30 Wind events > 49 kt • 3-5 Tornadoes • Moderate (MDT) • > 30 Hail Reports • > 30 Wind Events • 6-19 Tornadoes • High • > 19 Tornadoes with 2+ potentially producing F3-F5 damage • Derecho producing significant wind damage (> 50 reports)
Probability Outlooks • Tornadoes • 2%,5%,15%,25%,35%, 45% • Hail • 5%,15%,25%,35%, 45% • Convective Wind • 5%,15%,25%,35%, 45% • Significant (> 10%) • Tornadoes F2+ damage • Hail 2.0 inches diam. + • Winds 65 kt +
Probability Outlooks • Will detail the threat with 25 nm miles of any point in the area • Tornadoes, • Large hail • Severe convective winds • Will detail the threat of significant severe activity
Tornado Watches • Issued when Strong/Violent Tornadoes (F2 – F5) damage is possible • 3 or More Tornadoes are Expected • Conditions favor Supercell Storms
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
“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)
Mesoscale Convective Discussions ZCZC MKCSWOMCD ALL;334,0996 373,0979 353,0979 314,0996; ACUS3 KMKC 032023 >MKC MCD 032023 TXZ000_OKZ000_032300_ SPC MESOSCALE DISCUSSION #0345 FOR...SW OK/NW TX... CONCERNING...SEVERE THUNDERSTORM POTENTIAL... WATER VAPOR IMAGERY SHOWS A LEAD MID LEVEL SHORT WAVE TROUGH MOVING ENEWD OVER E/NE NM THIS AFTERNOON...AND THIS IS CONFIRMED BY PROFILER TIME SERIES FROM AZC/GDA/TCC/JTN. MID/UPPER 60 DEWPOINTS AND TEMPERATURES NEAR 80 ARE CONTRIBUTING TO SURFACE_BASED CAPE VALUES OF 3500_5000 J/KG OVER WRN OK AND NW TX TO THE E OF THE DRYLINE. CONVERGENCE ON THE DRYLINE IS NOT STRONG AND A CIRRUS SHIELD OVER THE TX PANHANDLE/NW TX/WRN OK SHOULD LIMIT ADDITIONAL SURFACE HEATING...BUT VISIBLE/RADAR IMAGERY HAS SHOWN THE FIRST ATTEMPTS AT TCU OVER FAR NW TX AS OF 20Z WITHIN A BREAK IN THE CIRRUS. MID LEVEL FLOW AND VERTICAL SHEAR WILL INCREASE OVER NW TX AND WRN OK THROUGH LATE AFTERNOON... WITH AN INCREASING THREAT OF SUPERCELLS NEAR THE DRYLINE FROM 00_03Z. THIS AREA IS BEING MONITORED FOR A POSSIBLE TORNADO WATCH LATER THIS AFTERNOON. ..THOMPSON.. 05/03/99 ...PLEASE SEE WWW.SPC.NOAA.GOV/ FOR GRAPHIC PRODUCT... NNNN
Mesoscale Convective Discussions • ISSUED (IDEALLY) 1-3 HOURS PRIOR TO A SEVERE THUNDERSTORM OR TORNADO WATCH TO... - DEFINE AREA(S) OF CONCERN - STATE TYPE OF WATCH EXPECTED - PROVIDE METEOROLOGICAL REASONING ALSO ISSUED TO ADDRESS: - CONVECTIVE TRENDS - OUTLOOK UPGRADE - HEAVY RAINFALL - WINTER WEATHER
Fire Weather Outlook • Day 1 and Day 2 Forecasts • Issued at 0400 CTZ, 0200 PTZ) • Dry Thunderstorms • Critical Fire Weather Areas • Extremely Critical Fire Weather Areas (or No Large-Scale Areas of Significant Fire Weather
Day One Fire Weather Outlook ZCZC MKCFWDDY1 ALL FNUS21 KWNS 100859 STORM PREDICTION CENTER...NWS/NCEP...NORMAN OK 400 AM CDT THU AUG 10 2000 DAY 1 FIRE WEATHER OUTLOOK...REF AWIPS GRAPHIC PMWE98 KWNS VALID 101200_111200 ...CRITICAL FIRE WEATHER AREA 1 & 2 _ GREAT BASIN / NERN CA / ERN WA / ERN ORE / ID / EXTREME SWRN MT.. PRIMARY CONDITIONS: MODERATE SWLY WINDS / VERY LOW RH VALUES / VERY DRY FUELS / WIDELY SCATTERED DRY THUNDERSTORMS OVER AREA 2 APPROACHING UPPER TROUGH WILL BRING SWLY WINDS OF 15_25 MPH BY EARLY AFTERNOON TO THE DISCUSSION AREA. TEMPERATURES WILL BE JUST SLIGHTLY COOLER...AND HIGH TEMPERATURES AROUND 90 IN THE VALLEYS WILL CONTRIBUTE TO MINIMUM RH VALUES OF 10_20 PERCENT. WINDS WILL REMAIN STRONG DURING THE OVERNIGHT HOURS AT RIDGETOP LEVEL AND ALONG THE ERN SLOPES OF THE CASCADES...AND RESULT IN POOR RH RECOVERY IN THESE AREAS. A COLD FRONT WILL REACH WRN ID BY 11/12Z AND RESULT IN A SLIGHT SHIFT IN THE WINDS TO WLY OR NWLY IN ERN WA AND ORE INVERTED_V THERMODYNAMIC PROFILES WILL RESULT IN WIDELY SCATTERED DRY THUNDERSTORMS FROM CENTRAL ORE TO WRN MT. THESE STORMS WILL DEVELOP OVER MOUNTAINOUS AREAS AND MOVE GENERALLY NEWD AT 20_25 MPH BRINGING LOCALLY GUSTY WINDS AND DRY LIGHTNING STRIKES CAPABLE OF INITIATING NEW WILDFIRES ...EXTREMELY CRITICAL FIRE WEATHER AREA 3 _ N_CENTRAL NV / SERN ORE / SWRN ID.. PRIMARY CONDITIONS: STRONG WINDS AND EXTREMELY LOW RH VALUES / VERY DRY FUELS / HOT TEMPERATURES SOMEWHAT STRONGER SWLY WINDS OF 20_30 MPH AND EXTREMELY LOW RH VALUES IN THE 5_15 PERCENT RANGE WILL DEVELOP OVER A PORTION OF THE NRN GREAT BASIN AND THE HIGH PLATEAU OF SERN ORE AND SWRN ID. UNDER THE CORE OF STRONGEST UPPER FLOW...WINDS AT RIDGETOP LEVEL WILL REACH 40 MPH AT TIMES...AND COMBINED WITH THE DRY FUELS AND LOW AMBIENT MOISTURE RESULT IN AN EXTREMELY CRITICAL FIRE WEATHER THREAT LATE THIS AFTERNOON AND THROUGHOUT THE EVENING. MOSTLY SUNNY SKIES WILL LEAD TO DEEP DRY BOUNDARY LAYERS AND HIGH TEMPERATURES IN THE 90S. FAST MOVING WIND_DRIVEN WILDFIRES ACCOMPANIED BY LONG RANGE SPOTTING AND CROWN RUNS IN FORESTED SECTIONS ARE A DISTINCT THREAT WITH EXISTING ACTIVITY OVER THE EXTREMELY CRITICAL FIRE AREA ...SYNOPSIS.. IMPORTANT SYNOPTIC_SCALE CHANGES ARE EXPECTED DURING THE PERIOD IN REGARD TO WRN U.S. FIRE WEATHER SITUATION. THE NRN EXTENSION OF THE UPPER RIDGE INTO CENTRAL MT WILL BEGIN TO BREAKDOWN TODAY IN RESPONSE TO AN APPROACHING UPPER_LEVEL JET STREAK. THE JET IS EMBEDDED IN A BAND OF STRONG SWLY FLOW AHEAD OF THE CUTOFF LOW WHICH HAS BEEN DRIFTING SLOWLY EWD TOWARD THE NRN CA COAST DURING THE PAST SEVERAL DAYS. THIS SYSTEM WILL PHASE WITH A NRN STREAM SHORTWAVE OVER BRITISH COLUMBIA RESULTING IN A RELATIVELY STRONG AND ACCELERATING TROUGH / PACIFIC COLD FRONT MOVING INLAND ACROSS WA/ORE TODAY AND TONIGHT. UPWARD VERTICAL MOTION COMBINED WITH MID_ LEVEL MOISTURE AND INSTABILITY WILL BE SUFFICIENT FOR WIDELY SCATTERED DRY THUNDERSTORMS FROM CENTRAL ORE EWD TO WRN MT. AHEAD OF THE TROUGH AXIS...MODERATE SWLY WINDS AND VERY LOW RH VALUES WILL DEVELOP THIS AFTERNOON OVER MUCH OF THE GREAT BASIN AND THE NRN ROCKIES EAST OF THE CASCADES...WITH WINDS UP TO 40 MPH AT RIDGETOP LEVEL A PLUME OF MONSOONAL MOISTURE CONTINUES ALONG A N_S AXIS FROM ERN AZ NWD THROUGH UT AND WRN WY. A CONTINUATION OF VERY HOT AFTERNOON TEMPERATURES IS EXPECTED ALONG THE CONTINENTAL DIVIDE AND MOST OF MT WITH SCATTERED AND MOSTLY WET THUNDERSTORMS IN THE CENTRAL AND SRN ROCKIES BY LATE AFTERNOON. THUNDERSTORM ACTIVITY WILL DIMINISH AFTER 11/06Z ELSEWHERE ACROSS THE COUNTRY...LARGE_SCALE CRITICAL FIRE WEATHER CONDITIONS ARE NOT EXPECTED ..BANACOS.. 08/10/00 DAY1/DAY2 FIRE WEATHER TEXT/GRAPHICS OUTLOOKS ARE AVAILABLE AT WWW.SPC.NOAA.GOV/FIRE NNNN
Day Two Fire Weather Outlook FNUS22 KWNS 100901 STORM PREDICTION CENTER...NWS/NCEP...NORMAN OK 400 AM CDT THU AUG 10 2000 DAY2 FIRE WEATHER OUTLOOK...REF AWIPS GRAPHIC PMWI98 KWNS VALID 111200_121200 ...CRITICAL FIRE WEATHER AREA 1 & 2 _ SERN ID / MT / NRN AND WRN WY... PRIMARY CONDITIONS: WINDY WITH LOW RH VALUES / EXTREMELY DRY FUELS / WIDELY SCATTERED DRY THUNDERSTORMS SWRN AND S_CENTRAL MT WLY WINDS OF 15_30 MPH WILL DEVELOP OVER THE CRITICAL FIRE WEATHER AREA BY EARLY AFTERNOON AND LIKELY PERSIST INTO THE OVERNIGHT HOURS...PARTICULARLY IN HIGHER ELEVATIONS. THE WINDS WILL BE ASSOCIATED WITH A PACIFIC COLD FRONT MOVING ACROSS THE REGION...RESULTING IN TEMPERATURES ABOUT 10 DEGREES COOLER AND A RISE IN MINIMUM RH VALUES...GENERALLY BETWEEN 20_30 PERCENT. DESPITE THESE IMPROVEMENTS...THE EXTREMELY DRY FUELS OVER THE REGION AND LACK OF RAINFALL EXPECTED WITH THIS SYSTEM SUGGEST THE INCREASE IN WIND SPEED ALONE WARRANTS A CRITICAL FIRE WEATHER AREA. LONG_RANGE SPOTTING AND WIND DRIVEN WILDFIRE POTENTIAL WILL EXIST GIVEN EXPECTED CONDITIONS AND ANTECEDENT FUEL CONDITIONS. ALTHOUGH DRIER MID_LEVEL AIR IS EXPECTED TO MOVE INTO THE REGION FROM THE PACIFIC...CURRENT FORECAST MODELS SUGGEST SUFFICIENT INSTABILITY AND VERTICAL MOTION FOR WIDELY SCATTERED DRY THUNDERSTORMS IN SWRN AND S_CENTRAL PORTIONS OF MT. ...SYNOPSIS... UPPER TROUGH AND PACIFIC FRONT EXPECTED OVER WRN ID AT THE START OF THE DAY 2 PERIOD WILL MOVE RAPIDLY EWD ACROSS THE NRN ROCKIES AND INTO THE DAKOTAS BY 12/12Z. STRONG GRADIENT FLOW SUGGESTS GUSTY WLY SURFACE WINDS WILL DEVELOP IN ASSOCIATION WITH THIS SYSTEM ACROSS THE NRN ROCKIES WHERE MANY LARGE WILDFIRES ARE CURRENTLY BURNING. IN THE MID_LEVELS...DRIER PACIFIC AIR WILL MOVE INTO THE NWRN STATES BRINGING AN END TO THE RECENT DRY LIGHTNING THREAT OF THE PAST SEVERAL DAYS. SCATTERED WET THUNDERSTORMS ARE POSSIBLE IN THE FOUR CORNER REGION NEWD ACROSS THE CENTRAL HIGH PLAINS IN ASSOCIATION WITH A SUBTROPICAL MOISTURE PLUME EXTENDING FROM SRN AZ NEWD. ELSEWHERE IN THE SWRN STATES...THE STRONG UPPER RIDGE CENTERED OVER SWRN CO WILL KEEP THE REMAINDER OF THE REGION HOT AND RELATIVELY DRY...WITH LARGE_SCALE WINDS GENERALLY LESS THAN 15 MPH. THE POTENTIAL FOR PLUME DOMINATED FIRES EXISTS OVER MUCH OF THE GREAT BASIN. ELSEWHERE ACROSS THE COUNTRY...LARGE_SCALE CRITICAL FIRE WEATHER CONDITIONS ARE NOT EXPECTED.
Summary • OUTLOOKS • PLAN OF ACTION • WATCH/ADVISORY • ATMOSPHERE IS READY…ARE WE? • WARNING • ACT • TAKE COVER
Storm Prediction Center Web Page • www.spc.noaa.gov • Products • Climatological data • Warnings • Images • Links to other severe storm sites