SPC AC 230557
DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1257 AM CDT WED AUG 23 2006
VALID 241200Z - 251200Z
...THERE IS A SLGT RISK OF SVR TSTMS FROM THE NRN/CNTRL PLAINS TO
THE UPPER GREAT LAKES...
DEEP CONVECTION SHOULD READILY DEVELOP ACROSS MUCH OF THE NRN PLAINS
INTO THE UPPER MS VALLEY REGION THURSDAY AHEAD OF SHORTWAVE TROUGH
AND UPPER HEIGHT FALLS. WHILE MODELS REMAIN CONSISTENT IN EJECTING
SHORTWAVE ACROSS THE DAKOTAS BY EARLY EVENING...LOW LEVEL WARM
ADVECTION MAY PROVE AS MUCH RESPONSIBLE FOR EXPECTED THUNDERSTORM
DEVELOPMENT FROM ND INTO CNTRL MN...TO THE NORTH OF THE WELL DEFINED
WARM FRONTAL ZONE.
LATEST THINKING IS THUNDERSTORM CLUSTERS MAY EVOLVE EARLY IN THE
PERIOD ACROSS WRN ND...POSSIBLY AN EXTENSION OF OVERNIGHT ACTIVITY
THAT SPREADS ACROSS MT AHEAD OF UPPER SHORTWAVE. AN MCS MAY EVOLVE
WITHIN STRONG ZONE OF FORCING AND PROPAGATE EWD...WELL TO THE NORTH
OF E-W WIND SHIFT. HAIL IS THE MOST LIKELY SEVERE THREAT WITH THIS
ELEVATED CONVECTION.
WITH TIME BOUNDARY LAYER INSTABILITY SHOULD INCREASE NEAR THE WARM
FRONT ACROSS SERN SD INTO SRN MN/NRN IA...IMMEDIATELY AHEAD OF SFC
LOW. THIS ZONE IS THE MOST LIKELY REGION FOR BOUNDARY LAYER
SUPERCELL DEVELOPMENT DURING THE LATE AFTERNOON HOURS. FORECAST
SOUNDINGS SUGGEST CAP WILL HOLD MUCH OF THE DAY ACROSS THE WARM
SECTOR...WITH SUSTAINED ASCENT NEAR THE FRONT EXPECTED TO WEAKEN THE
INHIBITION SUFFICIENTLY FOR NEAR SFC-BASED UPDRAFTS AFTER 21Z. IF
STORMS CAN INDEED DEVELOP ALONG THE WARM FRONT IT APPEARS EWD STORM
MOTIONS WOULD PROVE FAVORABLE FOR SUSTAINED HIGHER HELICITY
INFLOW...WITH THE POSSIBILITY FOR A FEW TORNADOES. OTHERWISE...AN
EXPANDING ZONE OF WARM ADVECTION...ELEVATED THUNDERSTORMS SHOULD
EVOLVE ACROSS CNTRL MN INTO WI DURING THE OVERNIGHT HOURS.
TRAILING COLD FRONT WILL LIKELY AID IN THE INITIATION OF HIGH BASED
MULTI-CELL...POSSIBLY SUPERCELLULAR...THUNDERSTORMS FROM CNTRL NEB
INTO NWRN KS BY 00Z. THIS ACTIVITY SHOULD PROPAGATE SWD THROUGH THE
CENTRAL PLAINS ENHANCED BY INCREASING LLJ ACROSS KS DURING THE
OVERNIGHT HOURS. WIND AND SOME HAIL SHOULD BE THE PRIMARY THREATS
WITH THIS ACTIVITY.
..DARROW.. 08/23/2006
CLICK TO GET WUUS02 PTSDY2 PRODUCT
NOTE: THE NEXT DAY 2 OUTLOOK IS SCHEDULED BY 1730Z
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