SWODY1
SPC AC 061631
DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1131 AM CDT MON OCT 06 2008
VALID 061630Z - 071200Z
...THERE IS A SLGT RISK OF SVR TSTMS THIS AFTERNOON INTO EARLY
TONIGHT FROM NE TX INTO ERN OK/SE KS...
...SYNOPSIS...
A WELL-DEFINED MID LEVEL TROUGH IS MOVING EWD/ENEWD OVER S CENTRAL
KS/WRN AND CENTRAL OK/NW TX AS OF MID MORNING. AN ASSOCIATED WEAK
SURFACE LOW IS LOCATED IN W CENTRAL KS...WITH A COLD FRONT TRAILING
SWD INTO THE TX PANHANDLE...AND A RESIDUAL LEE TROUGH INTO NW TX.
THE SURFACE BOUNDARIES ACROSS TX/OK TRAIL BEHIND THE PRIMARY
EMBEDDED SPEED MAX ROTATING NNEWD OVER CENTRAL OK...AND THIS
STRUCTURE IS SUGGESTIVE OF A SLOWLY DECAYING BAROCLINIC WAVE.
...ERN OK/NE TX THIS AFTERNOON...
THE PRIMARY BAND OF PRE-FRONTAL CONVECTION HAS MOVED SLOWLY EWD INTO
SE OK AND NE TX. BOUNDARY LAYER DEWPOINTS ARE INCREASING INTO THE
68-70 F RANGE INTO E/NE TX AND WRN LA IN ADVANCE OF THESE STORMS.
MID LEVEL LAPSE RATES ARE NOT PARTICULARLY STEEP...BUT THE WARMING
SURFACE TEMPERATURES AND INCREASING MOISTURE WILL CONTRIBUTE TO
MLCAPE VALUES NEAR 1000 J/KG THIS AFTERNOON. LOW-LEVEL AND DEEP
LAYER SHEAR ARE SUFFICIENT FOR EMBEDDED BOWING SEGMENTS AND
SUPERCELLS WITHIN THE PRE-FRONTAL CONVECTIVE BAND...AND THERE WILL
BE SOME POTENTIAL FOR AN ISOLATED TORNADO ALONG WITH MARGINALLY
SEVERE HAIL AND STRONG GUSTS. HOWEVER...THE LLJ CORE IS EXPECTED TO
DEVELOP NWD TOWARD WRN MO IN CONJUNCTION WITH THE PRIMARY SPEED MAX
LIFTING NNEWD FROM OK. THE RESULTANT WEAKENING OF LOW-LEVEL
FLOW/SHEAR AND POOR MID LEVEL LAPSE RATES SUGGEST THAT THE SEVERE
STORM THREAT WILL BE SOMEWHAT MARGINAL FOR A SLIGHT RISK.
...N TX INTO CENTRAL OK THIS AFTERNOON/EVENING...
LOW-LEVEL MOISTENING IS EXPECTED TO CONTINUE IN THE WAKE OF THE
MORNING CONVECTION...WHILE A FEW CLOUD BREAKS WILL ALLOW MODEST
SURFACE HEATING THIS AFTERNOON. REGIONAL 12Z SOUNDINGS SUGGEST THAT
INSTABILITY WILL BE RATHER MODEST THIS AFTERNOON...WITH THE ONLY
RELATIVELY STEEP UPSTREAM LAPSE RATES OBSERVED AT AMA. AN INITIAL
STRONG SHORTWAVE TROUGH HAS ALREADY PASSED THIS AREA...THOUGH THE
MAIN TROUGH AXIS REMAINS A LITTLE FARTHER TO THE W. A FEW
THUNDERSTORMS COULD DEVELOP THIS AFTERNOON ALONG AND E OF THE
RESIDUAL LEE TROUGH ACROSS NW TX AND WRN OK...AND THE STRONGEST
STORMS MAY PRODUCE MARGINALLY SEVERE HAIL.
...ERN KS/WRN MO THIS AFTERNOON INTO EARLY TONIGHT...
THE PRIMARY SHORTWAVE TROUGH AND ASSOCIATED LOW-MID LEVEL SPEED
MAXIMA WILL LIFT NNEWD FROM OK TO ERN KS/WRN MO THIS AFTERNOON.
THIS WILL RESULT IN SUFFICIENT VERTICAL SHEAR FOR SUPERCELLS...BUT
WIDESPREAD CLOUDS AND POOR LAPSE RATES WILL SUBSTANTIALLY LIMIT
INSTABILITY. AN ISOLATED ROTATING STORM CANNOT BE RULED
OUT...ESPECIALLY ON THE NE EDGE OF THE MID LEVEL DRY INTRUSION IN
KS...BUT THE OVERALL SEVERE STORM PROBABILITIES WILL REMAIN RATHER
LOW THROUGH THE PERIOD.
..THOMPSON/GRAMS.. 10/06/2008
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
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.
No comments:
Post a Comment