DAY2SVR: Nws Storm Prediction Center Norman Ok

ACUS02 KWNS 251728
SWODY2
SPC AC 251727

DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1227 PM CDT WED APR 25 2012

VALID 261200Z - 271200Z

...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE CNTRL/SRN HIGH
PLAINS...

...CNTRL/SRN HIGH PLAINS...

WELL DEFINED UPPER LOW OFF THE SRN CA/NRN BAJA COAST...CENTERED NEAR
29N/127W...WILL EJECT INLAND EARLY IN THE DAY2 PERIOD BEFORE LIFTING
NEWD INTO CO/NM BY 27/00Z. THIS FEATURE WILL THEN SHIFT INTO THE
HIGH PLAINS DURING THE OVERNIGHT PERIOD. AS THE TROUGH SHIFTS
ACROSS THE ROCKIES LOW LEVEL FLOW WILL UNDOUBTEDLY RESPOND AND
BECOME DECIDEDLY SELY ACROSS THE HIGH PLAINS. WHILE THE LATEST
SHORT RANGE MODELS HAVE STRUGGLED RECENTLY REGARDING THE AGGRESSIVE
BOUNDARY LAYER MOISTURE RETURN...IT APPEARS A LEGITIMATE MOISTURE
SURGE WILL SPREAD ACROSS THE SRN PLAINS WARM SECTOR OVER THE NEXT
24-48HR AND 60-65 SFC DEW POINTS MAY BE IN PLACE ACROSS THE ERN
TX/OK PANHANDLE REGION BY PEAK HEATING. TIMING OF THE UPPER TROUGH
WILL FAVOR OVERNIGHT CONVECTION THOUGH STRONG BOUNDARY LAYER HEATING
SHOULD CONTRIBUTE TO DESTABILIZATION WITHIN THE UPSLOPE REGION FROM
THE TX PANHANDLE INTO EXTREME SERN CO. FOR THIS REASON IT APPEARS
SCATTERED THUNDERSTORMS WILL BEGIN DEVELOPING AROUND 21-22Z.
FORECAST SOUNDINGS SUGGEST SBCAPE COULD EASILY EXCEED 2000 J/KG
WITHIN A SHEARED ENVIRONMENT THAT WILL STRONGLY SUPPORT SUPERCELLS.
FAVORABLY SHEARED AND BACKED LOW LEVEL FLOW ALSO LENDS CREDENCE TO
THE POSSIBILITY OF TORNADOES. HAVE INCREASED THE SEVERE PROBS
ACROSS THE HIGH PLAINS TO ACCOUNT FOR THE LIKELIHOOD OF POTENTIALLY
TORNADIC SUPERCELLS IN ADDITION TO VERY LARGE HAIL. LATE
AFTERNOON/EVENING SUPERCELLS WILL ALSO DEVELOP FARTHER NORTH ACROSS
ERN CO WITHIN STRONGER ZONE OF FORCED ASCENT. THIS ACTIVITY COULD
EASILY SPREAD INTO SWRN NEB/NWRN KS BY MIDNIGHT AS LLJ INCREASES
DURING THE OVERNIGHT PERIOD.

...TN VALLEY TO MIDDLE ATLANTIC...

DIGGING UPPER TROUGH OVER THE OH VALLEY/NEW ENGLAND STATES WILL
ENSURE SFC PRESSURES RISE WEST OF THE APPALACHIANS DURING THE DAY2
PERIOD. THIS IN TURN WILL FORCE A COLD FRONT ACROSS WV/KY INTO TN
DURING THE LATE AFTERNOON HOURS. EARLY IN THE PERIOD IT APPEARS
STRONG LOW LEVEL WARM ADVECTION WILL BE PARTLY RESPONSIBLE FOR
THUNDERSTORM CLUSTERS THAT WILL SPREAD ACROSS PORTIONS OF THE MIDDLE
ATLANTIC REGION AHEAD OF SFC LOW. THIS EARLY ACTIVITY IS NOT
EXPECTED TO BE PARTICULARLY SEVERE AS INSTABILITY WILL BE SOMEWHAT
LACKING. HOWEVER...THERE IS SOME CONCERN THAT STRONG BOUNDARY LAYER
HEATING WILL CONTRIBUTE TO SIGNIFICANT INSTABILITY ALONG THE
ADVANCING COLD FRONT. WITH WEAK HEIGHT RISES EXPECTED ALONG THE
TRAILING BOUNDARY IT/S NOT ENTIRELY CLEAR HOW MUCH CONVECTION WILL
EVOLVE IN THE WAKE OF THE AFOREMENTIONED UPPER TROUGH. ADEQUATE
SHEAR WILL BE IN PLACE FOR POTENTIAL STORM ORGANIZATION AND A SLIGHT
RISK MAY BE REQUIRED IN LATER OUTLOOKS TO ACCOUNT FOR ISOLATED
SUPERCELLS. AT THIS TIME WILL MAINTAIN 5% SEVERE PROBS ALONG THE
ADVANCING BOUNDARY...BUT IF IT BECOMES MORE CLEAR THAT STORMS WILL
FORM IN GREATER CONCENTRATION THEN THESE PROBS WILL BE INCREASED TO
ACCOUNT FOR DAMAGING WINDS/HAIL.

..DARROW.. 04/25/2012

+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
To unsubscribe from WX-STORM send e-mail to LISTSERV@LISTSERV.ILLINOIS.EDU with
"unsub wx-storm" in the body of your message. For more information write cnovy@cox.net.