SWODY1
SPC AC 281616
DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1116 AM CDT WED MAR 28 2012
VALID 281630Z - 291200Z
...THERE IS A SLGT RISK OF SVR TSTMS FROM CENTRAL/ERN KS INTO WRN
MO...
...THERE IS A SLGT RISK OF SVR TSTMS FROM THE MIDDLE ATLANTIC REGION
INTO CENTRAL KY...
...CENTRAL/ERN KS INTO WRN MO...
THIS AREA IS LOCATED ALONG THE SRN EDGE OF STRONGER WESTERLY FLOW
ALOFT....COINCIDENT WITH A PLUME OF STEEP MID LEVEL LAPSE RATES
EXTENDING ACROSS KS TOWARD WRN MO. AT THE SURFACE... LOW PRESSURE
IS EXPECTED TO REMAIN OVER THE CENTRAL HIGH PLAINS AS A WEAKENING
UPPER SHORT WAVE TROUGH PROGRESSES ACROSS THE WRN STATES. AN
EAST/WEST WARM FRONT ACROSS CENTRAL MO/SRN KS IS EXPECTED TO LIFT
SLOWLY NWD DURING THE PERIOD...AS MODEST SOUTHERLY LOW LEVEL WINDS
TRANSPORT INCREASING MOISTURE NWD INTO KS/WRN MO. VISIBLE IMAGERY
SHOWS LIMITED CLOUDS ACROSS THE ERN HALF OF KS INTO MO WHICH WILL
PERMIT STRONG DIURNAL HEATING TO OCCUR INTO THE AFTERNOON. THIS
WILL CONTRIBUTE TO FURTHER DESTABILIZATION WITH MLCAPE OF 1500-2000
J/KG EXPECTED THIS AFTERNOON AND EVENING.
DYNAMIC FORCING FOR LARGE SCALE ASCENT IS LIKELY TO BE WEAK AS
SATELLITE IMAGERY SUGGESTS A SUBTLE PERTURBATION MOVING OVER WRN KS
ATTM. HOWEVER...STRONG HEATING AND MODEST LOW LEVEL
CONVERGENCE/WARM ADVECTION ALONG AND NORTH OF THE WARM FRONT SHOULD
SUFFICIENTLY WEAKEN THE CAP THIS AFTERNOON FOR CONVECTION TO
INITIATE OVER PARTS OF CENTRAL/ERN KS DURING THE MID/LATE AFTERNOON.
FORECAST WIND PROFILES EXHIBIT STRONG VEERING WITH HEIGHT AND
SUFFICIENT DEEP LAYER SHEAR /35-45 KT IN THE LOWEST 6 KM/ TO SUPPORT
ORGANIZED STORMS INCLUDING SUPERCELLS. VERY LARGE HAIL...DAMAGING
WIND GUSTS...AND ISOLATED TORNADOES WILL BE POSSIBLE WITH THE
STRONGER CELLS. ACTIVITY MAY EVOLVE INTO A SMALL MCS THIS EVENING
AS CELLULAR COLD POOLS MERGE AND GROW UPSCALE...WITH ACTIVITY
SPREADING EWD/ESEWD INTO PARTS OF WRN MO TONIGHT. SEVERE THREAT IS
EXPECTED TO SLOWLY DIMINISH AFTER 03Z-06Z AS BOUNDARY LAYER COOLING
OCCURS.
...MIDDLE ATLANTIC REGION INTO CENTRAL KY...
A PRE-FRONTAL BAND OF ELEVATED CONVECTION IS LOCATED FROM SRN NEW
ENGLAND WSWWD ACROSS PA AND OH...ALONG THE NRN EDGE OF THE PLUME OF
STEEPER MID LEVEL LAPSE RATES EXTENDING EWD ACROSS THE AREA. A FEW
OF THESE STORMS HAVE PRODUCED MARGINAL HAIL AS UPDRAFT INTENSITY HAS
BEEN ENHANCED BY THE STEEPER LAPSE RATES ALOFT.
VISIBLE IMAGERY INDICATES LIMITED CLOUD COVER SOUTH OF THE
CONVECTIVE BAND WHERE STRONGER DIURNAL HEATING IS OCCURRING.
ALTHOUGH LOW LEVEL MOISTURE HAS BEEN MARGINAL WITH EWD EXTENT THIS
MORNING...MOISTURE FROM LOWER OH VALLEY/TN VALLEY REGION IS BEING
TRANSPORTED RAPIDLY NEWD WITHIN A BAND OF VERY STRONG WSWLY LOW
LEVEL WINDS. AS THE BOUNDARY LAYER HEATS AND MOISTENS...THE
ELEVATED CONVECTION /ESPECIALLY FROM SRN OH INTO SWRN PA/ IS
EXPECTED TO GRADUALLY BECOME SURFACE-BASED WITH A COINCIDENT
INCREASE IN SEVERE STORM POTENTIAL. THIS WILL ENHANCE POTENTIAL FOR
THE STRONGER WINDS IN THE LOWEST 1-2 KM AGL TO REACH THE SURFACE
WITHIN CONVECTIVE DOWNDRAFTS...PARTICULARLY FOR ANY SHORT BOWING
LINE SEGMENTS THAT MAY DEVELOP. IN ADDITION...THE STEEP LAPSE RATES
ALSO FAVOR DEVELOPMENT OF LARGE HAIL WITH THE STRONGER CORES. THE
SEVERE THREAT IS EXPECTED TO CONTINUE INTO THE EVENING HOURS BEFORE
WEAKENING AFTER SUNSET.
..WEISS/DARROW.. 03/28/2012
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