[SWODY1] SWODY1

[Severe Weather Outlook Day 1]

ACUS01 KWNS 291958
SWODY1
SPC AC 291956

DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
0156 PM CST WED NOV 29 2006

VALID 292000Z - 301200Z

...THERE IS A SLGT RISK OF SVR TSTMS FROM TX NEWD TO MO/IL...

...NRN TX/SERN OK/NWRN AR...
POWERFUL COLD FRONT CONTINUES TO SPREAD SEWD ACROSS NWRN TX AND SERN
OK LATE THIS AFTERNOON. MOIST AND INCREASING UNSTABLE AIR MASS WAS
DEVELOPING AHEAD OF AND ACROSS THE VERY SHARP FRONT AND CONTRIBUTING
TO AN EXPANDING AREA OF DEEP CONVECTION FROM THE RED RIVER VALLEY
NEWD ACROSS ECNTRL OK...AND INTO PARTS OF SERN KS AND WRN MO. SO
FAR...THE BULK OF THIS CONVECTION HAS OCCURRED ON THE IMMEDIATE COLD
SIDE OF THE SURFACE FRONT. HOWEVER...THAT HAS BEGUN TO CHANGE ACROSS
NORTH TX WHERE NEAR SURFACE-BASED STORMS APPEAR TO HAVE FORMED OVER
THE PAST 1-2 HOURS.

EXPECT TREND OF PRE-FRONTAL SURFACE-BASED CONVECTIVE DEVELOPMENT TO
CONTINUE ACROSS PARTS OF NRN TX...SERN OK...AND WRN AR THROUGH THIS
EVENING. LATEST OBJECTIVE ANALYSIS DATA SUGGESTS THAT MLCAPE OF
1000-1500 J/KG AND STRONG SHEAR ACROSS THESE AREAS WILL INITIALLY
SUPPORT SUPERCELLULAR STORMS WITH SOME POTENTIAL FOR A TORNADO OR
TWO...IN ADDITION TO DAMAGING WINDS AND LARGE HAIL. EXPECT THIS
ACTIVITY TO BECOME INCREASINGLY LINEAR AND UNDERCUT BY DEEPENING
SYNOPTIC COLD POOL AS THE FRONT MAKES GRADUAL SEWD PROGRESS THROUGH
THE NIGHT. LARGE SCALE ASCENT ASSOCIATED WITH AN INTENSE SHORT WAVE
TROUGH APPROACHING FROM NM THROUGH LATE TONIGHT WILL AID IN
STEEPENING MID LEVEL LAPSE RATES ATOP THE SURFACE-BASED COLD DOME.
IN COMBINATION WITH PERSISTENT MOIST ISENTROPIC LIFT ACROSS THE
FRONTAL ZONE...DEEP CONVECTION WITH THE CHANCE FOR HAIL WILL LIKELY
REMAIN A THREAT ACROSS PARTS OF TX/OK THROUGH LATE TONIGHT.

...MO/IL...
AFTERNOON SOUNDINGS FROM SGF AND ILX INDICATED WEAKER LAPSE RATES
AND MARGINAL INSTABILITY /MUCAPE AROUND 700 J PER KG/ IN THE
PRE-FRONTAL ENVIRONMENT ACROSS THESE AREAS. HOWEVER...LATEST
GUIDANCE REMAINS CONSISTENT IN SUGGESTING A CONTINUING POTENTIAL FOR
VIGOROUS CONVECTIVE DEVELOPMENT ALONG AND AHEAD OF THE COLD FRONT
THROUGH THIS EVENING. THIS DEVELOPMENT WILL OCCUR WITHIN A
SUFFICIENTLY STRONG FLOW REGIME WHERE UNIDIRECTIONAL SHEAR PROFILES
FAVOR FAST-MOVING LINE SEGMENTS CAPABLE OF PRODUCING WIND DAMAGE AND
PERHAPS MARGINALLY SEVERE HAIL.

..CARBIN.. 11/29/2006