SPC AC 231644
DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1144 AM CDT TUE JUN 23 2009
VALID 241200Z - 251200Z
...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE CENTRAL PLAINS AND
MID MS VALLEY...
...CENTRAL PLAINS/MID MS VALLEY...
MODELS CONTINUE EARLIER TRENDS OF FLATTENING UPPER RIDGE OVER THE
NRN PLAINS/UPPER MS VALLEY REGION...DUE PRIMARILY TO TRANSITORY
SHORTWAVE TROUGH MOVING EAST ALONG THE U.S./CANADIAN BORDER. ALONG
THE SRN FRINGE OF THIS FEATURE...SUFFICIENT WLY FLOW SHOULD EXIST
FOR THE MAINTENANCE OF ANY THUNDERSTORM CLUSTERS THAT MANAGE TO
EVOLVE ALONG SWD SAGGING FRONTAL ZONE.
ALTHOUGH LOW LEVEL WARM ADVECTION IS FORECAST TO BE SOMEWHAT
MARGINAL...BOTH THE GFS AND NAM SUGGEST CONVECTION WILL BE ONGOING
AT THE BEGINNING OF THE PERIOD ACROSS THE HIGH PLAINS FROM SERN MT
INTO NRN NEB. THIS ACTIVITY SHOULD PROPAGATE ESEWD ALONG/NORTH OF
SFC WIND SHIFT WHERE WEAK ISENTROPIC ASCENT SHOULD AID CONVECTIVE
LONGEVITY. WITH TIME...STRONG BOUNDARY LAYER HEATING AHEAD OF FRONT
WILL ALLOW MORE BUOYANT AIR TO BE ENTRAINED INTO MCS UPDRAFTS AND A
TRANSITION TOWARD WARM SECTOR/SFC-BASED ACTIVITY WILL TRANSPIRE.
THIS TRANSITION SHOULD OCCUR TOWARD MID-LATE AFTERNOON AS INHIBITION
WILL NEED TO BE REMOVED DUE TO STRONG HEATING.
ADDITIONALLY...UPSLOPE FLOW WITHIN POST-FRONTAL AIRMASS OVER THE NEB
PANHANDLE MAY ENHANCE POTENTIAL SUPERCELL THREAT ACROSS THIS REGION.
...CNTRL/ERN GULF STATES...
BELT OF HIGHER PWAT/INSTABILITY WILL CONTINUE TO SAG SWWD ACROSS
FL/NERN GULF OF MEXICO INTO THE CNTRL GULF COAST REGION WEDNESDAY.
WITH MODEST NNELY FLOW ALOFT IT APPEARS A FEW STORMS COULD PRODUCE
ISOLATED SEVERE WIND GUSTS...THOUGH MOST CONVECTION MAY ACTUALLY
DEVELOP OVER THE NRN/ERN GULF OF MEXICO.
..DARROW.. 06/23/2009
CLICK TO GET WUUS02 PTSDY2 PRODUCT
NOTE: THE NEXT DAY 2 OUTLOOK IS SCHEDULED BY 0600Z
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