SPC AC 191246
DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0646 AM CST SAT FEB 19 2011
VALID 191300Z - 201200Z
...NO SVR TSTM AREAS FORECAST...
...SYNOPSIS...
AN AMPLIFIED BUT PROGRESSIVE PATTERN WILL PREVAIL OVER THE LWR 48
THIS PERIOD...WITH W CST TROUGH MOVING E TO THE GRT BASIN BY 12 SUN
AS RIDGE NOW OVER THE HI PLNS MOVES E TO THE MID MS/OH VLYS. LEAD
IMPULSE IN WRN TROUGH...NOW MOVING ONTO THE SRN CA CST...SHOULD
CONTINUE ENE INTO AZ/UT LATER TODAY...BEFORE SHEARING NE TO THE
CNTRL HI PLNS EARLY SUN. AS THIS OCCURS...EXPECT MAIN UPR
CIRCULATION CENTER NOW OFF THE NRN CA CST TO TURN SE TOWARD KMRY BY
EVE.
AT LWR LVLS...WAA REGIME ALREADY ESTABLISHED OVER THE SRN/CNTRL PLNS
SHOULD STRENGTHEN AND EXPAND NWD/EWD LATER TODAY AND TONIGHT IN
RESPONSE TO APPROACHING UPR IMPULSE. BY 12Z SUN...EXPECT MAIN
ASSOCIATED WARM FRONT TO EXTEND FROM A DEEPENING LOW IN FAR NW KS
E/ESE INTO NRN MO/WRN IL.
...CNTRL PLNS/LWR MO VLY...
SFC WARM FRONT SHOULD MOVE N INTO NRN OK/SRN KS BY LATE THIS AFTN.
LOW LVL TURNING INVOF FRONT WILL YIELD SIZABLE HODOGRAPHS...WITH
SUFFICIENT DEEP SHEAR FOR SUPERCELLS. BUT ABSENCE OF ANY UPR LVL
FORCING MECHANISM FOR ASCENT...AND MID LVL WARMING/STRENGTHENING EML
CAP...SUGGEST THAT TSTM POTENTIAL WILL REMAIN TOO LOW TO JUSTIFY
ADDITION OF CONDITIONAL SVR PROBABILITIES OVER REGION. IN THE
MEANTIME...ISOLD ELEVATED TSTMS MAY FORM THROUGH THE DAY IN AREA OF
STRONGEST ELEVATED MOISTURE INFLUX/WAA ASCENT OVER PARTS OF ERN KS
AND MO.
MORE WIDESPREAD TSTM COVERAGE SHOULD DEVELOP TONIGHT THROUGH EARLY
SUN FARTHER N AND NE...FROM NRN KS INTO MUCH OF NEB/THE LWR MO VLY
AND THE WRN CORN BELT...IN ZONE OF SUBSTANTIALLY STRONGER ELEVATED
WAA THAT SHOULD EVOLVE N OF WARM FRONT. WITH PW INCREASING TO
AROUND 1 INCH AND 500 MB TEMPS AOB MINUS 18C...SETUP COULD YIELD A
FEW POCKETS OF MUCAPE IN EXCESS OF 1250 J/KG...SUFFICIENT FOR SVR
HAIL GIVEN MODERATE LARGELY UNIDIRECTIONAL WSWLY CLOUD-LAYER FLOW.
THIS THREAT LIKELY WOULD BE GREATEST DURING THE EARLIER STAGES OF
STORM DEVELOPMENT...ESPECIALLY OVER NRN KS AND SRN/ERN NEB.
...CNTRL CA...
SCTD TSTMS EXPECTED ALONG THE CNTRL CA CST AND OVER THE CNTRL VLY
LATER TODAY AS DESTABILIZATION IS MAXIMIZED BY BOTH DIURNAL HEATING
AND THE ARRIVAL OF COOLER AIR ALOFT WITH MAIN UPR TROUGH. WHILE
SMALL HAIL MAY ACCOMPANY SOME CELLS...NEITHER STRENGTH OF SHEAR NOR
DEGREE OF INSTABILITY APPEAR LIKELY TO SUPPORT SUSTAINED SVR
ACTIVITY.
..CORFIDI/GARNER.. 02/19/2011
CLICK TO GET WUUS01 PTSDY1 PRODUCT
NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 1630Z
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