May 12, 2010 0600 UTC Day 1 Convective Outlook
Updated: Wed May 12 06:02:23 UTC 2010
Probabilistic to Categorical Outlook Conversion Table
Categorical Graphic
20100512 1200 UTC Day 1 Outlook Graphic
Probabilistic Tornado Graphic
20100512 1200 UTC Day 1 Tornado Probabilities Graphic
Torndao Legend Image
Probabilistic Damaging Wind Graphic
20100512 1200 UTC Day 1 Damaging Wind Probabilities Graphic
Wind Legend Image
Probabilistic Large Hail Graphic
20100512 1200 UTC Day 1 Large Hail Probabilities Graphic
Hail Legend Image
   SPC AC 120600
   
   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   0100 AM CDT WED MAY 12 2010
   
   VALID 121200Z - 131200Z
   
   ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE SRN AND
   CNTRL PLAINS...MID-MS VALLEY AND OH VALLEY...
   
   ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE
   MID-ATLANTIC...
   
   ...SRN AND CNTRL PLAINS/MID-MO VALLEY
   AN UPPER-LEVEL LOW IN THE CNTRL ROCKIES TODAY WILL ACCELERATE NEWD
   AS A MID-LEVEL JET EJECTS NEWD ACROSS THE CNTRL AND SRN PLAINS. AT
   THE SFC...A COLD FRONT WILL MOVE SSEWD ACROSS THE CNTRL PLAINS WITH
   A MOIST AND VERY UNSTABLE AIRMASS IN PLACE ACROSS THE SLIGHT RISK
   AREA. FORECAST SOUNDINGS JUST AHEAD OF THE FRONT AT 21Z FROM THE
   MID-MO VALLEY TO THE SRN PLAINS SHOW MLCAPE VALUES IN THE 3000 TO
   4000 J/KG RANGE. FORECAST SOUNDINGS DURING THE DAY SUGGEST THE WARM
   SECTOR WILL REMAIN CAPPED UNTIL LATE AFTERNOON WHEN THE MODELS
   INTIATE NUMEROUS THUNDERSTORMS FROM NRN MO SSWWD ACROSS ERN KS INTO
   NRN OK. THIS ACTIVITY WILL BE LOCATED ON THE ERN EDGE OF A 60 TO 80
   KT MID-LEVEL JET CREATING STRONG VERTICAL SHEAR PROFILES FAVORABLE
   FOR SUPERCELLS. SUPERCELL DEVELOPMENT SHOULD BE RATHER QUICK DUE TO
   THE STRONG INSTABILITY IN PLACE WITH VERY LARGE HAIL POSSIBLE WITH
   THE MORE DOMINANT CELLS.
   
   THE CURRENT THINKING IS THAT A BROKEN LINE OF INTENSE STORMS WILL
   DEVELOP IN THE LATE AFTERNOON FROM NRN MO SSWWD ACROSS ERN KS INTO
   NRN OK ON THE WRN EDGE OF THE LOW-LEVEL JET. THE JET SHOULD CREATE
   STRONG LOW-LEVEL SHEAR PROFILES FAVORABLE FOR TORNADOES WITH THE
   MORE DOMINANT SUPERCELLS. MODEL FORECASTS ALSO SUGGEST STORM MODE
   MAY GRADUALLY TRANSITION TO A LINEAR STRUCTURE DURING THE EVENING AS
   A LARGE MCS ORGANIZES FROM THE OZARKS SWWD TO THE LOW-ROLLING PLAINS
   OF WEST TX. LARGE HAIL AND WIND DAMAGE WILL BE LIKELY WITH THE
   STRONGER CELLS ELEMENTS IN THE MCS.
   
   ...MID-MS AND OH VALLEYS...
   AN UPPER-LEVEL RIDGE IS FORECAST TO MOVE NEWD FROM THE MID-MS VALLEY
   INTO THE OH VALLEY TODAY. A LARGE WARM SECTOR SHOULD BE IN PLACE
   THIS AFTERNOON FROM MO EWD ACROSS MUCH OF SRN IL...SRN IND AND KY
   WHERE FORECAST SOUNDINGS SHOW MODERATE TO STRONG INSTABILITY.
   ALTHOUGH LARGE-SCALE ASCENT SHOULD REMAIN QUITE WEAK ACROSS THE
   REGION...THE NAM AND GFS SOLUTIONS DO INITIATE A CLUSTER OF
   THUNDERSTORMS FROM NEAR ST LOUIS ENEWD TO AROUND INDIANAPOLIS TODAY
   BUT DIFFER ON THE TIMING. THE CURRENT THINKING IS THAT ELEVATED
   THUNDERSTORMS WILL MOVE ACROSS THE REGION THIS MORNING WITH
   SFC-BASED STORM DEVELOPMENT HOLDING OFF UNTIL EARLY THIS AFTERNOON
   IN NRN MO MOVING EWD ACROSS THE OH VALLEY DURING THE LATE AFTERNOON.
   FORECAST SOUNDINGS ACROSS THE OH VALLEY AT 21Z SHOW 40 TO 50 KT OF
   0-6KM SHEAR SUGGESTING VERTICAL SHEAR WILL BE SUFFICIENT FOR
   ROTATING STORMS BUT SOME MULTICELL LINE-SEGMENTS MAY ALSO DEVELOP.
   STEEP LOW-LEVEL LAPSE RATES...UNIDIRECTIONAL WINDS AND INCREASING
   LOW-LEVEL FLOW MAY BE FAVORABLE FOR A WIND DAMAGE THREAT. HAIL WILL
   ALSO BE POSSIBLE WITH THE STRONGER UPDRAFTS.
   
   ...MID-ATLANTIC...
   NORTHWEST FLOW WILL BE IN PLACE ACROSS THE MID-ATLANTIC TODAY AS A
   COLD FRONT MOVES SLOWLY SWD ACROSS THE REGION. WARMING SFC TEMPS AND
   MODERATE DESTABILIZATION SHOULD RESULT IN SCATTERED THUNDERSTORM
   DEVELOPMENT AROUND MIDDAY ACROSS VA AND SRN MD. FORECAST SOUNDINGS
   IN NRN VA SHOW MODERATE DEEP LAYER SHEAR WITH UNIDIRECTIONAL WIND
   PROFILES SUGGESTING SEVERAL LINE-SEGMENTS WITH WIND DAMAGE POTENTIAL
   MAY DEVELOP AND MOVE EWD INTO THE IMMEDIATE COASTAL AREAS BY EARLY
   EVENING. HAIL WILL ALSO BE POSSIBLE WITH COVERAGE DEPENDENT UPON THE
   AMOUNT OF DESTABILIZATION.
   
   ..BROYLES/STOPPKOTTE.. 05/12/2010
   
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   NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 1300Z