SPC AC 290100
DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0800 PM CDT WED OCT 28 2009
VALID 290100Z - 291200Z
...THERE IS A SLGT RISK OF SVR TSTMS N CNTRL TX INTO NWRN TX...WRN
OK...AND S CNTRL KS...
...SRN PLAINS AREA...
A WARM FRONT EXTENDS FROM THE NRN GULF COAST NWWD THROUGH NWRN TX
WHERE IT INTERSECTS A DRYLINE THAT STRETCHES FROM THE ERN TX
PANHANDLE SWD THROUGH ERN PORTIONS OF WRN TX. A COLD FRONT EXTENDS
FROM A SURFACE LOW IN WRN KS SWD THROUGH THE TX PANHANDLE AND INTO
THE TRANSPECOS OF SWRN TX. RICHER GULF MOISTURE CURRENTLY RESIDING
ACROSS CNTRL AND S TX WILL ADVECT NWD OVERNIGHT ALONG A 50+ KT SLY
LOW LEVEL JET. HOWEVER...SELY NEAR SURFACE TRAJECTORIES SUGGEST THE
GREATEST INCREASE IN SURFACE DEWPOINTS WILL OCCUR ACROSS NWRN TX AND
SWRN OK LATER TONIGHT. THE ADVECTION OF LOW-LEVEL MOISTURE WILL
CONTRIBUTE TO NWD DESTABILIZATION WITH TIME WITH AN AXIS OF
1000-1500 J/KG MUCAPE DEVELOPING THROUGH NWRN TX AND WRN OK
OVERNIGHT.
A ZONE OF DEEP ASCENT ALONG BAROCLINIC ZONE HAS DEVELOPED FROM WRN
TX THROUGH THE ERN TX PANHANDLE IN ASSOCIATION FORCING WITHIN UPPER
JET EXIT REGION. THIS ZONE OF ASCENT WILL SHIFT E AND NE
OVERNIGHT...EVENTUALLY SPREADING INTO KS.
STORMS CURRENTLY DEVELOPING OVER THE ERN TX PANHANDLE ARE BASED
AROUND 700 MB. HOWEVER...AS MOISTURE CONTINUES TO ADVECT
NWWD...POTENTIAL WILL EXIST FOR NEAR SURFACE BASED STORMS TO DEVELOP
FROM NWRN TX THROUGH WRN OK AND S CNTRL KS OVERNIGHT. PRIMARY
CONVECTIVE MODE WILL LIKELY REMAIN LINEAR...GIVEN THAT STORM
INITIATION WILL LIKELY STAY CONFINED TO THE ZONE OF STRONG FORCING
ALONG THE FRONT. HOWEVER...EFFECTIVE SHEAR IN EXCESS OF 50 KT
SUGGESTS SOME EMBEDDED SUPERCELLS AND BOWING SEGMENTS ARE LIKELY.
PRIMARY THREATS WILL LIKELY BE ISOLATED DAMAGING WIND AND
HAIL...THOUGH AN ISOLATED TORNADO OR TWO CANNOT BE RULED OUT.
...CNTRL THROUGH SERN TX INTO WRN LA...
THE ATMOSPHERE WILL CONTINUE TO DESTABILIZE NWD ACROSS CNTRL AND
SERN TX INTO LA OVERNIGHT. HOWEVER...THE 00Z RAOB DATA SHOW A CAP IN
PLACE ACROSS N-CNTRL THROUGH S TX AND SWLY FLOW ALOFT WILL LIKELY
CONTRIBUTE TO THIS WARMER LAYER ADVECTING NEWD TOWARD THE LOWER MS
VALLEY WITH TIME. RADAR DATA CONTINUE TO SHOW SHALLOW CONVECTION
DEVELOPING WITHIN THE BROAD WARM ADVECTION REGIME FROM SERN TX INTO
SWRN LA. GIVEN THAT THE DEEPER FORCING WILL LIKELY REMAIN NW OF THIS
REGION OVERNIGHT...IT WILL PROBABLY BE DIFFICULT FOR THE
THERMODYNAMIC ENVIRONMENT TO MODIFY SUFFICIENTLY FOR DEEP CONVECTION
TO DEVELOP. VERY STRONG LOW LEVEL AND DEEP LAYER SHEAR WILL PERSIST
IN THESE AREAS OVERNIGHT AND WOULD SUPPORT A CONDITIONAL THREAT FOR
SUPERCELLS AND ISOLATED TORNADOES. HOWEVER...GIVEN THAT THE THREAT
IS HIGHLY CONDITIONAL...WILL MAINTAIN LOW PROBABILITIES FOR THE
OVERNIGHT.
..DIAL.. 10/29/2009
CLICK TO GET WUUS01 PTSDY1 PRODUCT
NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 0600Z
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