SWODY1
SPC AC 171939
DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0239 PM CDT FRI JUN 17 2011
VALID 172000Z - 181200Z
...THERE IS A SLGT RISK OF SVR TSTMS OVER ERN CO AND WRN KS...
...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PORTIONS OF THE CNTRL
PLAINS EWD INTO THE LOWER OH VALLEY...
...THERE IS A SLGT RISK OF SVR TSTMS OVER E CNTRL MS INTO CNTRL AND
SRN AL...
EXPANDED SLIGHT RISK SEWD ACROSS THE LOWER OH VALLEY FOR ONGOING
ADVANCING MCS...AND ALSO INTO NRN AR WHERE EXTREME DESTABILIZATION
IS OCCURRING. GPS PW SENSORS INDICATE 1.50 TO 1.80 INCHES. IF
ORGANIZED SEVERE CONVECTION DEVELOPS ALONG THE OLD OUTFLOW BOUNDARY
FROM ERN KS INTO CNTRL MO...STORMS MAY PROPAGATE IN A SWD
DIRECTION...EVENTUALLY AFFECTING NRN AR. MODELS SUGGEST 22-00Z THE
MOST LIKELY TIME FOR INITIATION.
MUCH OF THE AREA FROM OK INTO KS AND MO REMAINS CAPPED. THE 18Z LMN
SOUNDING INDICATED SURFACE TEMPERATURES APPROACHING 105 F WOULD BE
NEEDED TO REMOVE ALL CONVECTIVE INHIBITION. TEMPERATURES WILL
CONTINUE TO WARM IN THIS AREA AS WELL AS SWD ALONG THE DRYLINE IN OK
AND ISOLATED DEVELOPMENT IS STILL ANTICIPATED.
..JEWELL.. 06/17/2011
.PREV DISCUSSION... /ISSUED 1059 AM CDT FRI JUN 17 2011/
...SYNOPSIS...
WHILE VIGOROUS S/WV NRN HI PLAINS ROTATES NWD INTO SASKATCHEWAN THE
PRIMARY TROUGH REMAINS OVER WRN U.S. WITH SWLY FLOW ACROSS MUCH OF
PLAINS. DEEPENING SURFACE LOW MOVES NWD INTO SRN SASKATCHEWAN AS
COLD FRONT PUSHES EWD ACROSS NRN PLAINS...TRAILING SWWD CENTRAL
PLAINS INTO SERN CO. SEPARATE SURFACE LOW VICINITY SWRN KS/OK
BORDER PERSISTS AND MAINTAINS A STRONG LOW LEVEL SWLY FLOW OF A VERY
WARM...DEEPLY MIXED AIR MASS EWD ACROSS SRN /CENTRAL PLAINS AHEAD OF
THE COLD FRONT.
..CENTRAL PLAINS AND MID MS VALLEY...
CLUSTERS OF THUNDERSTORMS FUELED BY STRONG WARM ADVECTION ASSOCIATED
WITH THE LOW LEVEL JET CONTINUES EWD ACROSS NRN MO. THESE CLUSTERS
WILL PROVIDE LOW LEVEL OUTFLOW BOUNDARIES TO FOCUS
RE-DEVELOPMENT OF STORMS LATER THIS AFTERNOON. WIDESPREAD MOIST AND
VERY UNSTABLE CONDITIONS WILL DEVELOP ACROSS THIS REGION BY
AFTERNOON IN THOSE AREAS WHERE HEATING CAN OCCUR. DESPITE WEAK
SHORTWAVE RIDGING ACROSS THE MID MS VALLEY THROUGH THE
DAY...THE CAP IN THE WARM SECTOR IS EXPECTED TO WEAKEN SUFFICIENTLY
BY LATE AFTERNOON TO INITIATE SEVERE THUNDERSTORMS VICINITY
BOUNDARIES ACROSS PORTION OF MO/IA/IL. DEEP LAYER SHEAR IS NOT
PARTICULARLY STRONG THUS STORM MODE SHOULD RANGE FROM MULTICELL
CLUSTERS TO ISOLATED SUPERCELLS. WHILE ISOLATED TORNADOS ARE
POSSIBLE THE PRIMARY THREAT GIVEN THE MDT/STG INSTABILITY SHOULD BE
LARGE HAIL AND DAMAGING WINDS. THERE IS THE LIKELIHOOD FOR LARGER
SCALE COLD POOLS TO DEVELOP WITH MCS/S THIS EVENING AS LOW LEVEL JET
ONCE AGAIN INCREASES FOR A GREATER WIND DAMAGE RISK.
...ERN CO...
HAVE EXPANDED THE SEVERE RISK VICINITY PALMER DIVIDE SWD AS
PARAMETERS NOW LOOK FAVORABLE FOR SUPERCELL DEVELOPMENT BY LATE
AFTERNOON. UPSLOPE FLOW ON N SIDE OF COLD FRONT AND SURFACE LOW
PROVIDING DEWPOINTS INTO THE LOW 50S WHICH COUPLED WITH STEEP LAPSE
RATES LEAD TO MLCAPES AOA 1000 J/KG. VEERING SHEAR PROFILES WITH
40-50KT OF BRN SHEAR SUPPORT SUPERCELLS INCLUDING BOTH LARGE
HAIL/DAMAGING WINDS AND A COUPLE TORNADOES.
...ECENTRAL MS/AL...
WELL DEVELOPED COLD POOL DROPPING SSEWD NRN AL/MS WILL BE
INTERSECTING AN INCREASINGLY UNSTABLE AIR MASS BY EARLY AFTERNOON AS
MLCAPES CLIMB TO AOA 2500 J/KG. DEVELOPMENT OF STORMS ALONG COLD
POOL BOUNDARY SHOULD LEAD TO AT LEAST A WIND DAMAGE THREAT AS THE
ACTIVITY MOVES SWD AND EVENTUALLY INTERSECTS THE ACTIVE SEA BREEZE
FRONT NOW MOVING INLAND WRN FL PANHANDLE TO SERN MS.
...CENTRAL OK...
OBSERVED AND MODEL SOUNDINGS INDICATE A VERY HOT...DEEPLY MIXED
BOUNDARY LAYER WILL DEVELOP EWD ACROSS WRN OK THIS AFTERNOON. EVEN
WITH VERY WARM MID LEVEL TEMPS...SURFACE TEMPS ABOVE 100F WILL LEAD
TO AN UNCAPPED DEEPLY MIXED BOUNDARY LAYER TO NEAR 500MB. GIVEN THE
COMBINATION OF SUFFICIENT CAPE TO SUPPORT SOME VERY HIGH BASED
STORMS AND EXTREME DCAPES IN EXCESS OF 2000 J/KG...HAVE INCREASED
THE THREAT OF DAMAGING WINDS WHICH WOULD LIKELY OCCUR WITH ANY
THUNDERSTORM THAT IS ABLE TO DEVELOP LATER THIS AFTERNOON ACROSS
CENTRAL OK VICINITY DRY LINE. THE THREAT IS HIGHLY CONDITIONAL
DEPENDENT ON STORM DEVELOPMENT.
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