Apr 1, 2009 1730 UTC Day 2 Convective Outlook
Updated: Wed Apr 1 17:33:41 UTC 2009
Probabilistic to Categorical Outlook Conversion Table (Effective Feb 14, 2006).
Categorical Graphic
20090401 1730 UTC Day 2 Outlook Graphic
Probabilistic Graphic
20090401 1730 UTC Day Probabilitic Graphic
Probability Legend Image
   SPC AC 011730
   
   DAY 2 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   1230 PM CDT WED APR 01 2009
   
   VALID 021200Z - 031200Z
   
   ...THERE IS A MDT RISK OF SVR TSTMS FROM PARTS OF SWRN TN...MS AL
   AND WRN GA...
   
   ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE LOWER MS VALLEY...SRN
   PARTS OF THE OH VALLEY AND MUCH OF THE SERN STATES...
   
   ...SYNOPSIS...
   
   SHORTWAVE TROUGH NOW OVER THE CNTRL ROCKIES WILL MOVE SE INTO THE
   SRN PLAINS TONIGHT BEFORE EJECTING ENEWD THROUGH THE SERN STATES
   THURSDAY. ATTENDANT LEE CYCLONE OVER OK EARLY THURSDAY WILL LIFT
   ENEWD THROUGH THE LOWER MS AND TN VALLEYS...REACHING THE OH VALLEY
   OVERNIGHT. TRAILING PACIFIC FRONT WILL ADVANCE EAST AND EXTEND FROM 
   THE WRN CAROLINAS SWWD THROUGH THE WRN FL PANHANDLE BY THE END OF
   THE PERIOD. WARM FRONT OVER THE NRN GULF WILL LIKELY LIFT NWD INTO
   THE GULF COASTAL STATES...BUT NWD PROGRESSION OF THIS BOUNDARY MAY
   BE LIMITED TO SOME DEGREE BY THE POTENTIAL FOR ONGOING CONVECTION.
   
   
   ...LOWER MS VALLEY THROUGH SERN STATES AND TN VALLEY...
   
   THREAT STILL EXISTS FOR A SIGNIFICANT SEVERE EVENT OVER A PORTION OF
   THE SERN STATES. HOWEVER POTENTIAL LIMITING FACTORS DO EXIST. THE
   RICH LOW LEVEL MOISTURE WITH DEWPOINTS IN THE UPPER 60S TO AROUND 70
   HAS BEEN SHUNTED SWD INTO THE NRN GULF SOUTH OF A CONVECTIVELY
   ENHANCED FRONTAL BOUNDARY. POTENTIAL COMPLICATING FACTORS INVOLVE
   IMPULSES EMBEDDED WITHIN THE SUBTROPICAL JET STREAM. ONE SUCH
   IMPULSE IS FORECAST TO EJECT NEWD THROUGH THE NRN GULF REGION EARLY
   THURSDAY WITH A CORRESPONDING INCREASE IN THE LOW LEVEL JET. THIS
   WILL LIKELY ENHANCE LIFT IN VICINITY OF THE BOUNDARY OVER THE NRN
   GULF...RESULTING IN THE DEVELOPMENT OF STORMS. CONCERN IS THAT THIS
   ACTIVITY MAY LIMIT THE NWD RETURN OF THE RICH GULF MOISTURE TO SOME
   EXTENT WITH LOW TO MID 60S MORE LIKELY OVER THE SERN STATES THAN
   UPPER 60S INLAND FROM COASTAL AREAS. REMNANT EML WILL LIKELY ADVECT
   EWD ABOVE THE RETURNING MOIST AXIS...AND IN ADDITION TO POTENTIAL
   FOR EARLY STRATUS COULD RESULT IN A CAP IN MUCH OF THE WARM SECTOR.
   THE ATMOSPHERE WILL LIKELY UNDERGO SOME DESTABILIZATION DURING THE
   DAY AS MOISTURE RETURNS NWD AND LOW CLOUDS BEGIN TO MIX OUT...WITH
   MLCAPE FROM 1000-1500 J/KG.
   
   STORMS WILL LIKELY BE ONGOING WITHIN ZONE OF FORCING/DPVA ALONG AND
   JUST AHEAD OF THE FRONT AND ATTENDANT SHORTWAVE TROUGH FROM ERN TX
   INTO AR. THIS ACTIVITY WILL LIKELY CONTINUE EAST DURING THE DAY AND
   GROW UPSCALE INTO AN MCS. ACTIVITY WILL BE EMBEDDED WITHIN STRONG
   VERTICAL SHEAR WITH HODOGRAPHS SUFFICIENT FOR EMBEDDED SUPERCELLS
   AND LEWP STRUCTURES. THE STORMS WILL LIKELY INTENSIFY AS THE
   ATMOSPHERE DESTABILIZES DOWNSTREAM. DAMAGING WIND...LARGE HAIL AND
   TORNADOES WILL BE POSSIBLE WITH THIS ACTIVITY.
   
   FARTHER EAST IN THE WARM SECTOR ACROSS AL...LOW LEVEL HODOGRAPHS
   WILL INITIALLY NOT BE PARTICULARLY LARGE DUE TO THE SPLIT LOW LEVEL
   JET STRUCTURE WITH ONE BRANCH FARTHER WEST IN ASSOCIATION WITH THE 
   PROGRESSIVE SHORTWAVE TROUGH...AND ANOTHER BRANCH FARTHER SWD ALONG
   THE GULF COAST. DISCRETE INITIATION AWAY FROM THE FRONTAL BOUNDARY
   IS POSSIBLE BUT IS MORE UNCERTAIN DUE TO POTENTIAL FOR AT LEAST A
   MODEST CAP AND PRESENCE OF LOW CLOUDS. HOWEVER...IF SUFFICIENT
   BREAKS OCCUR A FEW DISCRETE STORMS MAY DEVELOP DURING THE AFTERNOON.
   THE LOW LEVEL JET WILL LIKELY STRENGTHEN WITH TIME IN THIS REGION AS
   THE UPPER TROUGH CONTINUES EAST. IF DISCRETE MODES CAN DEVELOP AND
   BE MAINTAINED AS THE LOW LEVEL JET STRENGTHENS...THE THE TORNADO
   THREAT WOULD CORRESPONDINGLY BE HIGHER.
   
   OTHER SEVERE STORMS WILL BE LIKELY WITH CONVECTION DEVELOPING IN
   VICINITY OF THE BOUNDARY ALONG THE GULF COASTAL REGION.
   
   ...SE GA INTO CAROLINAS...
   
   THE UPPER TROUGH AND STRONGER LOW-MID LEVEL FLOW WILL SHIFT ENEWD
   THROUGH SRN GA AND THE CAROLINAS OVERNIGHT. SOME INLAND RECOVERY IS
   POSSIBLE...ESPECIALLY FROM SRN GA INTO THE ERN CAROLINAS AS THE
   BOUNDARY LAYER FLOW STRENGTHENS. THREAT WILL EXIST FOR ORGANIZED
   STORMS INCLUDING SUPERCELLS WITH DAMAGING WIND...ISOLATED TORNADOES
   AND LARGE HAIL POSSIBLE.
   
   ..DIAL.. 04/01/2009
   
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