DAY1SVR: Day 1 Convective Outlook

ACUS01 KWNS 061300
SWODY1
SPC AC 061257

DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0657 AM CST THU NOV 06 2008

VALID 061300Z - 071200Z

...THERE IS A SLGT RISK OF SVR TSTMS OVER THE WRN GULF CST/LWR MS
VLY...

...SYNOPSIS...
DEEP CLOSED LOW NOW ALONG THE NE/SD BORDER WILL EDGE SLOWLY E TO
NEAR FSD/SUX THIS EVE AND CONTINUE E ALONG THE IA/MN BORDER EARLY
FRIDAY. TRAILING COLD FRONT WILL SWEEP STEADILY E ACROSS THE WRN
GRT LKS AND THE LWR OH AND TN VLYS THROUGH THE PERIOD...WHILE
SRN-MOST PORTION PROGRESSES MORE SLOWLY SE ACROSS E TX/LA AND MS.

...WRN GULF CST INTO LWR MS VLY...
AFOREMENTIONED COLD FRONT WILL SERVE TO FOCUS TSTM DEVELOPMENT OVER
THE LWR MS VLY/WRN GULF CST REGION LATER TODAY THROUGH TONIGHT.
LARGE SCALE ASCENT/HEIGHTS FALLS ACROSS REGION WILL BE WEAK
TODAY...ALTHOUGH A MODEST INCREASE MAY OCCUR TONIGHT AS UPSTREAM JET
MAX NOW OVER ID CONTINUES SEWD.

MID LVL LAPSE RATES WILL BE WEAK ON S SIDE OF POLAR JET. BUT
BOUNDARY LAYER MOISTURE WILL INCREASE /DEWPOINTS IN THE MID 60S F/
...AND SCTD TSTMS SHOULD FORM/STRENGTHEN ALONG AND AHEAD OF COLD
FRONT IN RESPONSE TO AFTN HEATING FROM SE TX AND LA INTO ERN AR/W
TN. EXCEPT WITHIN A SHALLOW NEAR-SFC LAYER...MODERATE TO
STRONG...LARGELY UNIDIRECTIONAL DEEP WSW FLOW WILL PREVAIL...WITH
SPEEDS INCREASING FROM S TO N ACROSS OUTLOOKED REGION. A NON-ZERO
THREAT WILL EXIST FOR A FEW SUSTAINED STORMS AND POSSIBLY A
SUPERCELL OR TWO. BUT OVERALL SETUP...WITH 500-1000 J/KG SBCAPE AND
30-40 KT DEEP SHEAR ORIENTED PARALLEL TO BOUNDARY...SUGGESTS THAT
DOMINANT CONVECTIVE MODE WILL BE BROKEN LINE SEGMENTS. EMBEDDED
SMALL SCALE BOWS COULD YIELD OCCASIONAL WIND DMG...AND PERHAPS AN
ISOLD TORNADO. THE SVR THREAT SHOULD DIMINISH WITH NEWD EXTENT DUE
TO MORE LIMITED BUOYANCY AND ABSENCE OF ANY APPRECIABLE INCREASE IN
FORCING.

ALTHOUGH MOST OF THE CONVECTION SHOULD WEAKEN AFTER MID EVE...TSTMS
MAY INCREASE LATER IN THE PERIOD ALONG THE TX GULF CSTL PLN AS
STRENGTHENING LARGE SCALE ASCENT ASSOCIATED WITH APPROACHING JET MAX
ENCOUNTERS INCREASINGLY RICH GULF MOISTURE.

..CORFIDI/HURLBUT.. 11/06/2008

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