SPC AC 310601
DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0101 AM CDT MON MAR 31 2008
VALID 311200Z - 011200Z
...THERE IS A MDT RISK OF SVR TSTMS ACROSS MUCH OF EASTERN
OK/NORTHEAST TX INTO SOUTHWEST MO/WESTERN AR...
...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE SOUTHERN PLAINS INTO
THE MIDDLE MISSISSIPPI VALLEY/MIDWEST...
...SYNOPSIS...
POTENT UPPER TROUGH IS FORECAST TO TRANSITION EASTWARD ACROSS THE
PLAINS TODAY AND TONIGHT. THE PRIMARY SURFACE LOW SHOULD ADVANCE
NORTHEASTWARD/GRADUALLY DEEPEN FROM EASTERN KS TOWARD THE WESTERN
GREAT LAKES BY THE END OF THE PERIOD...WHILE A SECONDARY SURFACE LOW
IS EXPECTED TO DEVELOP ACROSS SOUTHERN OK/NORTH TX. WITH THE OK/TX
DRYLINE AND SOUTHEAST ADVANCING COLD FRONT ACROSS THE MISSOURI
VALLEY SERVING AS FOCI...IT APPEARS A FAIRLY WIDESPREAD SEVERE
WEATHER EVENT WILL UNFOLD THIS EVENING ACROSS PORTIONS OF THE
SOUTHERN PLAINS/ARKLATEX VICINITY INTO THE MISSOURI VALLEY/MIDDLE
MISSISSIPPI VALLEY REGIONS.
...MUCH OF CENTRAL/EASTERN OK AND TX INTO MO/SOUTHEAST KS AND THE
ARKLATEX VICINITY...
AS THE UPPER TROUGH SHIFTS EASTWARD ACROSS THE CENTRAL
STATES...SEVERE THUNDERSTORMS ARE EXPECTED TO DEVELOP BY AFTERNOON
ACROSS EASTERN OK/NORTHEAST TX INTO FAR SOUTHEAST KS/SOUTHWEST MO.
QUASI-DISCRETE SUPERCELLS ARE LIKELY AMIDST 50 KT WEST-SOUTHWESTERLY
MID LEVEL FLOW...ORIENTED LARGELY NORMAL TO THE EXPECTED DRYLINE
POSITION FROM EAST CENTRAL OK INTO NORTH TX. WITH WIDESPREAD MIDDLE
TO UPPER 60S F DEWPOINTS...STEEP MID LEVEL LAPSE RATES AND MODERATE
TO STRONG INSTABILITY WITH 1500-3000 J/KG MLCAPE SHOULD SUPPORT A
FAIRLY WIDESPREAD COVERAGE OF LARGE HAIL /SOME SIGNIFICANT/. A FEW
TORNADOES APPEAR LIKELY AS WELL ACROSS EASTERN OK/NORTHEAST TX AND
THE ADJACENT ARKLATEX VICINITY...OWING TO A RELATIVELY MOIST
BOUNDARY LAYER AND CURVED LOW LEVEL HODOGRAPHS...LIKELY TO BE AIDED
BY BACKING LOW LEVEL FLOW AHEAD OF A SECONDARY SURFACE LOW PROGGED
TO DEVELOP NEAR THE RED RIVER DURING THE AFTERNOON/EARLY EVENING.
...EASTERN IA/MUCH OF IL INTO SOUTHERN WI/WESTERN INDIANA...
THE MAGNITUDE OF THE SEVERE THREAT WITH NORTH/NORTHEAST EXTENT
ACROSS THE MIDDLE TO UPPER MISSISSIPPI VALLEY/WESTERN GREAT LAKES
REGION IS MUCH MORE CONDITIONAL/UNCERTAIN AT THIS TIME.
OVERALL...THE MODEST NATURE OF THE EXPECTED BOUNDARY LAYER
MOISTURE/INSTABILITY SHOULD RESULT IN A MORE ISOLATED/LOWER
PROBABILITY SEVERE THREAT. BUT IN SPITE OF 00Z MODELS/21Z SREF
GUIDANCE SUGGESTING RATHER MEAGER INSTABILITY /LESS THAN 500 J/KG
MLCAPE/ INTO EASTERN IA/MUCH OF IL AND SOUTHERN WI/WESTERN
INDIANA...SOME POTENTIAL WILL EXIST FOR SURFACE BASED STORMS THIS
AFTERNOON/EVENING AHEAD OF SURFACE LOW TRACK AND/OR IN VICINITY OF
NORTHWARD ADVANCING WARM FRONT. PROVIDED SUFFICIENT HEATING AND AT
LEAST MARGINAL SURFACE BASED INSTABILITY...STRONG FLOW FIELDS WOULD
SUPPORT AN ORGANIZED SEVERE RISK...POTENTIALLY AS FAR NORTH AS
NORTHERN IL/SOUTHERN WI.
..GUYER/SMITH.. 03/31/2008
CLICK TO GET WUUS01 PTSDY1 PRODUCT
NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 1300Z
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