SWODY1
SPC AC 231224
DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0724 AM CDT MON APR 23 2007
VALID 231300Z - 241200Z
..THERE IS A MDT RISK OF SVR TSTMS PARTS OF WESTERN KANSAS...ERN
COLORADO AND PARTS OF NWRN OK AND TX PANHANDLE...
..THERE IS A SLGT RISK OF SVR TSTMS PARTS OF CENTRAL AND SRN
PLAINS...
..SYNOPSIS...
CONDITIONS WILL BECOME FAVORABLE FOR SEVERE THUNDERSTORMS BEGINNING
THIS AFTERNOON FROM THE COLORADO FRONT RANGE EWD ACROSS MUCH OF
CENTRAL AND NRN PORTION OF SRN PLAINS AS A MAJOR TROUGH NOW
INTERMOUNTAIN REGION APPROACHES.
SURFACE LOW MOVING EWD ACROSS GREAT LAKES WITH TRAILING FRONTAL ZONE
SWWD ACROSS LWR MO VALLEY. FRONT THEN EXTENDS WWD ACROSS NRN OK TO
DEVELOPING SURFACE LOW SERN CO. FRONT TO RETURN NWD AS A WARM FRONT
ACROSS KS AS CO LOW DEEPENS. GULF MOISTURE WITH DEWPOINTS INTO THE
LOW/MID 60S SPREADING NWD ON SLY LLJ THRU SRN INTO CENTRAL PLAINS
TODAY ...WHILE DRY LINE SETS UP THIS AFTERNOON FROM TX/OK PANHANDLE
SWD TO TX BIG BEND.
BAND OF STRONG MID/UPR WINDS WILL SWING OUT INTO CENTRAL AND SRN
HIGH PLAINS THIS AFTERNOON AND TONIGHT AS TROUGH MAKES STEADY EWD
PROGRESS ACROSS ROCKIES. SFC-6KM SHEAR WILL INCREASE OVER A LARGE
PORTION OF HIGH PLAINS TO 50-60KT WHICH COUPLED WITH BACKED BOUNDARY
LAYER WINDS PROVIDES KINEMATIC ENVIRONMENT VERY FAVORABLE FOR
SUPERCELL DEVELOPMENT.
..CO FRONT RANGE AND ADJACENT HIGH PLAINS...
MODELS ALL SUPPORT DEVELOPMENT OF DEN CYCLONE N OF PALMER DIVIDE
THIS AFTERNOON. WITH STEEP LAPSE RATES AND STRONG VEERING SHEAR
PROFILES...THE ADVECTION OF MID 40S DEWPOINTS WWD TO NEAR FRONT
RANGE WILL SUPPORT MLCAPES TO 1000 J/KG AND DEVELOPMENT OF SEVERE
THUNDERSTORMS BY MID AFTERNOON. ALONG WITH LARGE HAIL...TORNADOES
WILL BE POSSIBLE WITH THE ENHANCED SHEAR CREATED BY DEN CYCLONE.
..ERN CO PLAINS/WRN KS SWD THRU TX PANHANDLE AND WRN OK...
SEVERE THUNDERSTORMS WILL DEVELOP BY MID/LATE AFTERNOON ALONG THE
DEVELOPING DRY LINE TO SE OF CO SURFACE LOW. THE CURRENT CANOPY OF
SUBTROPICAL MID/UPR CLOUDINESS SHOULD SHIFT AWAY TO THE E BY THIS
AFTERNOON PERMITTING STRONG SURFACE HEATING ALONG DRY LINE. WITH
MLCAPES CLIMBING TO 1000-1500 J/KG SEVERE THUNDERSTORMS SHOULD
DEVELOP ALONG AND JUST E OF DRY LINE BY LATE AFTERNOON. VEERING
SHEAR PROFILES BOTH ALONG DRY LINE AND RETREATING WARM FRONT SUPPORT
SUPERCELLS. IN ADDITION TO VERY LARGE HAIL A FEW TORNADOES ARE
EXPECTED. STRONG TORNADOES WILL BE POSSIBLE BY EVENING AS BOTH
KINEMATIC AND THERMODYNAMIC SUPPORT CONTINUES TO INCREASE.
OVERNIGHT NAM FORECAST SOUNDINGS INDICATE THAT IMPRESSIVE ELEVATED
INSTABILITY DEVELOPS ACROSS MUCH OF WRN HALF OF KS AS THE MOIST GULF
AIRMASS IS LIFTED BY THE WARM FRONT. MUCAPES IN EXCESS OF 2000 J/KG
ALONG WITH STRONG/VEERING SHEAR PROFILES WILL MAINTAIN SUPERCELL
DEVELOPMENT ALONG WITH A VERY LARGE HAIL THREAT THRU THE NIGHT
POSSIBLY AS FAR N AS SRN NEB.
..OH VALLEY...
GREAT LAKES SURFACE LOW MOVES RAPIDLY EWD AND DEEPENS ACROSS SERN
ONTARIO TODAY. AHEAD OF THE TRAILING COLD FRONT 40-50 KT SHEAR
WOULD SUPPORT SEVERE THUNDERSTORMS PROVIDED ADEQUATE INSTABILITY WAS
AVAILABLE. HOWEVER WITH DEWPOINTS NOT EXPECTED TO RISE HIGHER THAN
LOW/MID 50S...MEAGER INSTABILITY WITH MLCAPES LESS THAN 500 J/KG
EXPECTED. THUNDERSTORMS SHOULD DEVELOP ALONG/AHEAD OF COLD FRONT BY
MID AFTERNOON. PRIMARY THREAT WILL BE GUSTY WINDS...GENERALLY BELOW
SVR LEVELS.
.HALES/JEWELL.. 04/23/2007
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