SPC AC 130720
DAY 3 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0220 AM CDT TUE MAY 13 2008
VALID 151200Z - 161200Z
...THERE IS A SLGT RISK OF SVR TSTMS OVER MUCH OF THE GULF STATES
AND SRN TN VALLEY...
...GULF STATES/TN VALLEY...
FAVORABLE TRAJECTORIES OFF THE WRN GULF OF MEXICO...IN CONJUNCTION
WITH INCREASING WSWLY FLOW WILL ENHANCE THE THERMODYNAMIC/SHEAR
PROFILES ACROSS THE GULF STATES FOR POTENTIALLY ROBUST THUNDERSTORM
ACTIVITY. ALL SHORT RANGE MODEL GUIDANCE IS CONSISTENT WITH
EJECTING SHORTWAVE ACROSS THE SRN PLAINS INTO THE TN VALLEY DURING
THE AFTERNOON HOURS. TRAILING PORTION OF THIS FEATURE WILL CLIP THE
NRN GULF STATES AS MAIN SPEED MAX TRANSLATES ACROSS AR/TN/KY. GIVEN
THE EXPECTED WIDESPREAD CONVECTION ACROSS THE SRN PLAINS/LOWER MS
VALLEY DURING THE DAY1-DAY2 TIME FRAME...ANY SIGNIFICANT EML WILL
NOT BE ADVECTED DOWNSTREAM BUT RATHER STABILIZED WELL WEST OF SLIGHT
RISK REGION. AS A RESULT...VERY MOIST BUT MARGINALLY STEEP LAPSE
RATES WILL EXIST ACROSS THE WARM SECTOR WHERE STRONG THUNDERSTORMS
ARE EXPECTED TO DEVELOP. IT'S NOT ENTIRELY CLEAR HOW THE CONVECTION
WILL EVOLVE...ESPECIALLY GIVEN THE PRIOR DAY'S CONVECTION.
HOWEVER...SIGNIFICANT LOW LEVEL WARM ADVECTION ACROSS THE TN VALLEY
SHOULD ENHANCE THUNDERSTORMS ALONG/NORTH OF WARM FRONT. OF MORE
CONCERN WILL BE THE RENEWED DEVELOPMENT ALONG/AHEAD OF ADVANCING
COLD FRONT. IT APPEARS DAYTIME HEATING WILL AID INITIATION BY MID
DAY ALONG THE COLD FRONT ACROSS MS/LA BEFORE SPREADING EAST INTO
AL/GA LATER IN THE AFTERNOON/EVENING. DEEP SWLY FLOW AND MODEST
SHEAR WOULD SUGGEST SEVERE MULTICELL CLUSTERS AND LINE
SEGMENTS...ALONG WITH A FEW DISCRETE SUPERCELLS.
..DARROW.. 05/13/2008
NOTE: THE NEXT DAY 3 OUTLOOK IS SCHEDULED BY 1100Z
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