SPC AC 241943
DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0243 PM CDT MON SEP 24 2007
VALID 242000Z - 251200Z
...THERE IS A SLGT RISK OF SVR TSTMS FROM PART OF THE CENTRAL PLAINS
NEWD TO SRN MN/WRN WI...
...SRN MN/WRN WI TO PARTS OF NRN/WRN KS...
A MID/UPPER LONG WAVE TROUGH EXTENDED FROM THE INTERMOUNTAIN WEST TO
THE CENTRAL/NRN HIGH PLAINS WITH STRONGER SHORT WAVE TROUGH/LOW OVER
NRN UT. THESE FEATURES WILL PROGRESS EWD AND SHOULD BE CENTERED
OVER THE CENTRAL/NRN PLAINS BY 12Z TUESDAY. A LEAD IMPULSE/JET
STREAK...CURRENTLY LOCATED OVER MID MO VALLEY...WILL PROVIDE ASCENT
FOR ADDITIONAL CONVECTIVE DEVELOPMENT FROM THE UPPER MS VALLEY
REGION SWWD INTO ERN NEB/WRN IA THIS FORECAST PERIOD. THIS ACTIVITY
WILL LIKELY REMAIN FOCUSED ALONG AND E OF A COLD FRONT WHICH
EXTENDED FROM NORTH CENTRAL TO SWRN MN INTO CENTRAL NEB AND EAST
CENTRAL CO EARLY THIS AFTERNOON. WARM SECTOR AIR MASS...ALTHOUGH
COMPRISED OF CLOUDINESS AND GENERALLY WEAK LAPSE RATES...SHOULD
REMAIN WEAKLY TO MODERATELY UNSTABLE GIVEN SOME SURFACE HEATING
WITHIN A MOIST BOUNDARY LAYER. THIS SOMEWHAT LIMITED INSTABILITY IS
EXPECTED TO REDUCE THE LIKELIHOOD FOR GREATER SEVERE WEATHER
COVERAGE...BUT INCREASING DEEP LAYER SHEAR SUGGESTS THE POTENTIAL
FOR SOME OF THE STORMS TO BECOME STRONG TO SEVERE.
FARTHER SW...OBJECTIVE ANALYSES INDICATED STRONGER INHIBITION
EXTENDING SWD FROM SRN NEB HAS LIMITED CONVECTIVE DEVELOPMENT ALONG
THE SRN EXTENT OF THE COLD FRONT. HOWEVER...ADDITIONAL SURFACE
HEATING AND INCREASED LOW LEVEL WAA ALONG NOSE OF STRENGTHENING SLY
LLJ INTO KS BY 25/00Z SHOULD WEAKEN THE CAP FOR TSTMS TO DEVELOP BY
LATE AFTERNOON WITH ADDITIONAL DEVELOPMENT THIS EVENING. MARGINAL
TO MODERATE INSTABILITY /MLCAPE 500-1000 J/KG/ AND INCREASING DEEP
LAYER SHEAR WITH APPROACH OF NRN UT LOW SHOULD SUPPORT A FEW STRONG
TO SEVERE TSTMS.
..PETERS.. 09/24/2007
CLICK TO GET WUUS01 PTSDY1 PRODUCT
NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 0100Z
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