May 10, 2008 1630 UTC Day 1 Convective Outlook
Updated: Sat May 10 16:48:17 UTC 2008
Probabilistic to Categorical Outlook Conversion Table (Effective Feb 14, 2006).
Public Severe Weather Outlook

The SPC is forecasting ...significant severe thunderstorms are expected from the arklatex and mid south region eastward across the gulf coast states today and tonight....   Please read the latest public statement about this event.

Categorical Graphic
20080510 1630 UTC Day 1 Outlook Graphic
Probabilistic Tornado Graphic
20080510 1630 UTC Day 1 Tornado Probabilities Graphic
Torndao Legend Image
Probabilistic Damaging Wind Graphic
20080510 1630 UTC Day 1 Damaging Wind Probabilities Graphic
Wind Legend Image
Probabilistic Large Hail Graphic
20080510 1630 UTC Day 1 Large Hail Probabilities Graphic
Hail Legend Image
   SPC AC 101635
   
   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   1135 AM CDT SAT MAY 10 2008
   
   VALID 101630Z - 111200Z
   
   ...THERE IS A MDT RISK OF SVR TSTMS THIS AFTERNOON AND TONIGHT OVER
   PORTIONS OF ERN OK...NERN TX...NRN LA...AR...SRN MO...SRN IL...WRN
   KY...WRN AND MIDDLE TN...NRN/CNTRL MS...NRN/CNTRL AL AND NRN/CNTRL
   GA...
   
   ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE CNTRL/SRN LOW PLAINS
   EWD INTO THE OH VALLEY AND THE GULF COAST STATES...
   
   --SEVERE WEATHER OUTBREAK EXPECTED TODAY AND TONIGHT FROM PARTS OF
   THE OZARK PLATEAU AND SRN LOW PLAINS EWD THROUGH THE LOWER OH/LOWER
   MS VALLEYS INTO CNTRL GULF STATES--
   
   ...SYNOPSIS...
   
   LARGE-SCALE PATTERN WILL UNDERGO AMPLIFICATION THIS PERIOD AS SHORT
   WAVE TROUGH OVER THE CNTRL ROCKIES INTENSIFIES CONSIDERABLY WHILE
   TRANSLATING EWD THROUGH THE MID MS VALLEY.  MORNING WATER VAPOR
   IMAGERY INDICATES A LEAD SHORT WAVE TROUGH OVER THE SRN HIGH PLAINS
   WHICH WILL SHIFT EWD INTO THE LOWER MS VALLEY BY THIS EVENING.  
   
   IN THE LOW LEVELS...SURFACE LOW OVER WRN KS WILL DEVELOP ENEWD
   ACROSS KS TODAY PRIOR TO THE ONSET OF RAPID CYCLOGENESIS ACROSS NRN
   MO INTO CNTRL IL OVERNIGHT.  ATTENDANT WARM FRONT CURRENTLY FROM THE
   RED RIVER VALLEY EWD THROUGH THE ARKLAMS WILL QUICKLY DEVELOP NWD
   THROUGH ERN PORTIONS OF KS/OK AND THE OZARK PLATEAU REGION AND
   EVENTUALLY LOWER OH VALLEY TONIGHT.  ERN EXTENSION OF THIS BOUNDARY
   WILL REMAIN MORE QUASI-STATIONARY ACROSS NRN GA/SC. 
   MEANWHILE...PRIMARY COLD FRONT WILL PUSH EWD FROM THE HIGH PLAINS
   THIS MORNING...LIKELY EXTENDING FROM LOW PRESSURE OVER ERN KS SWD
   INTO CNTRL OK AND THEN MORE SWWD INTO THE SRN TX PNHDL BY MID
   AFTERNOON.  A DRYLINE WILL EXTEND FROM THE INTERSECTION WITH FRONT
   OVER S-CNTRL OK SWD INTO CNTRL TX.  EXPECT THIS COLD FRONT TO SURGE
   EWD THROUGH THE MID MS AND MUCH OF THE LOWER MS VALLEYS BY SUNDAY
   MORNING.  
   
   ...CNTRL/SRN LOW PLAINS EWD THROUGH THE MID/LOWER MS VALLEY INTO THE
   OH VALLEY AND CNTRL GULF STATES...
   
   CURRENT SURFACE OBSERVATIONS AND 12Z OBSERVED SOUNDINGS INDICATE
   THAT A VERY MOIST BOUNDARY LAYER IS PRESENT S OF RETREATING WARM
   FRONT WITH DEWPOINTS IN THE MID 60S TO LOWER 70S AND LOWEST MEAN
   MIXING RATIOS OF 13-15 G/KG.  THIS MOISTURE COUPLED WITH STEEP
   MIDLEVEL LAPSE RATES OF 7.5-8.5 C/KM SPREADING EWD ACROSS THE REGION
   WILL SUPPORT RAPID AIR MASS DESTABILIZATION TODAY WITH MLCAPES
   INCREASING TO 1000-1500 J/KG TO THE S OF RETREATING WARM FRONT
   ACROSS ERN KS INTO MO...TO AS HIGH AS 2500-3500 J/KG AHEAD OF
   DRYLINE OVER SERN OK...ERN TX INTO PORTIONS OF SRN AR AND LA.
   
   AS MENTIONED ABOVE...A LEAD SHORT WAVE TROUGH OVER WRN OK/NWRN TX AS
   OF 15Z WILL TRANSLATE EWD TODAY INTO THE LOWER MS VALLEY.  FORCING
   FOR ASCENT ASSOCIATED WITH THIS FEATURE IS CONTRIBUTING TO INITIALLY
   ELEVATED TSTMS OVER PORTIONS OF OK AND AR AS OF MID MORNING.  THIS
   ACTIVITY IS EXPECTED TO BECOME PROGRESSIVELY MORE SURFACE-BASED WITH
   TIME TODAY AS WARM FRONT LIFTS NWD AND BOUNDARY LAYER AIR MASS
   RAPIDLY DESTABILIZES.  THE COMBINATION OF THE MODERATE
   INSTABILITY...40-60 KT OF EFFECTIVE BULK SHEAR AND RELATIVELY STRONG
   LOW-LEVEL SHEAR INDICATES THE POTENTIAL FOR INTENSE SUPERCELLS
   CAPABLE OF TORNADOES /SOME SIGNIFICANT/...VERY LARGE HAIL AND
   DAMAGING WINDS FOCUSED PRIMARILY ALONG WARM FRONT AND EVENTUALLY
   ALONG/AHEAD OF DRYLINE.
   
   STORMS MAY TEND TO GROW UPSCALE INTO ONE OR MORE MCS/S OVERNIGHT
   WITH ACTIVITY RAPIDLY MOVING EWD/SEWD ACROSS THE CNTRL GULF STATES. 
   ENVIRONMENT WILL REMAIN QUITE SUPPORTIVE OF EMBEDDED SUPERCELLS AND
   BOW ECHOES CAPABLE OF TORNADOES...IN ADDITION TO CORRIDORS OF
   DAMAGING WINDS AND LARGE HAIL.
   
   ADDITIONAL TSTMS ARE EXPECTED TO INTENSIFY THIS AFTERNOON ALONG COLD
   FRONT FROM ERN KS INTO N-CNTRL OR NERN OK IN CONJUNCTION WITH HEIGHT
   FALL CENTER/DYNAMIC FORCING FOR ASCENT ATTENDANT TO PRIMARY UPPER
   TROUGH.  KINEMATIC ENVIRONMENT WILL BE QUITE FAVORABLE FOR
   ORGANIZED/ROTATING UPDRAFTS GIVEN STRONG LOW-LEVEL SHEAR ALONG/N OF
   RETREATING WARM FRONT AND STRENGTHENING DEEP LAYER SHEAR WITH TIME. 
   THE PRIMARY UNCERTAINTY REMAINS THE DEGREE OF AIR MASS
   DESTABILIZATION THAT WILL OCCUR GIVEN THE INCREASING CLOUDS AND THE
   DISPLACEMENT OF RICHER BOUNDARY LAYER MOISTURE WELL TO THE S. 
   HOWEVER...LATEST MODEL GUIDANCE DOES INDICATE THAT AIR MASS WILL
   BECOME MODERATELY UNSTABLE LATER TODAY WITH THE POTENTIAL FOR
   SUPERCELLS AND BOWING STRUCTURES CAPABLE OF TORNADOES...DAMAGING
   WINDS AND LARGE HAIL.
   
   CONSIDERABLE MOISTURE FLUX/DESTABILIZATION AND STRENGTHENING
   LOW-LEVEL SHEAR IS FORECAST TO OCCUR AFTER 11/00Z AHEAD OF COLD
   FRONT OVER THE OZARK PLATEAU REGION INTO LOWER OH VALLEY IN RESPONSE
   TO THE RAPID CYCLOGENESIS.  THIS SHOULD ALLOW FOR THE MAINTENANCE OF
   A STRONGLY FORCED BAND OF TSTMS ALONG/AHEAD OF COLD FRONT.  EMBEDDED
   SUPERCELLS AND/OR BOWS WILL REMAIN POSSIBLE WITH A THREAT OF
   TORNADOES...DAMAGING WINDS AND HAIL.
   
   ...CNTRL/ERN GULF STATES...
   
   A MODERATELY UNSTABLE AIR MASS WILL DEVELOP ALONG AND S OF LOW-LEVEL
   BAROCLINIC ZONE WITH MORNING OBSERVED SOUNDINGS INDICATING A
   RELATIVELY WEAK CAP.  AS SUCH...DIURNAL TSTMS WILL BE POSSIBLE ALONG
   BOUNDARY THIS AFTERNOON WITHIN KINEMATIC ENVIRONMENT CHARACTERIZED
   BY 40-50 KT OF EFFECTIVE BULK SHEAR.  A FEW SUPERCELLS ARE POSSIBLE
   WITH A THREAT OF TORNADOES...DAMAGING WINDS AND LARGE HAIL.  AS
   MENTIONED ABOVE...ADDITIONAL TSTMS /PERHAPS AN MCS/ MAY MOVE INTO
   THE REGION FROM THE W WITH A CONTINUED THREAT OF DAMAGING
   WINDS...HAIL AND A FEW TORNADOES.
   
   ..MEAD/CROSBIE.. 05/10/2008
   
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