000
ACUS03 KWNS 040733
SWODY3
SPC AC 040730

DAY 3 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
0230 AM CDT SAT OCT 04 2008

VALID 061200Z - 071200Z

...NO SVR TSTM AREAS FORECAST...

...SYNOPSIS...

BROAD UPPER TROUGH WILL MOVE EAST THROUGH THE CNTRL AND SRN PLAINS
WHILE GRADUALLY WEAKENING AND EVENTUALLY BECOMING CUT OFF FROM THE
MAIN BRANCH OF POLAR WLYS FARTHER NORTH. A SERIES OF IMPULSES WILL
ROTATE THROUGH THE UPPER TROUGH. AT THE SURFACE A COLD FRONT WILL
ADVANCE EAST AND SE THROUGH THE CNTRL AND SRN PLAINS LIKELY
EXTENDING FROM ERN OK SWWD THROUGH N CNTRL AND SW TX BY THE END OF
THE PERIOD.


...SRN PLAINS THROUGH MID MS VALLEY REGION...

AXIS OF SOMEWHAT RICHER BOUNDARY LAYER MOISTURE RESIDING OVER THE
WRN GULF WITH LOW TO MID 60S DEWPOINTS WILL ADVECT NWD THROUGH THE
SRN PLAINS WARM SECTOR BY MONDAY. MODELS CONTINUE TO INDICATE THAT
AN IMPULSE WILL EJECT NEWD ALONG ERN PORTIONS OF UPPER TROUGH INTO
THE MID MS VALLEY EARLY MONDAY. THIS WILL CONTRIBUTE TO THE LOW
LEVEL JET GRADUALLY LIFTING NWD THROUGH ERN KS...MO AND IA DURING
THE DAY. STORMS ARE EXPECTED TO BE ONGOING ALONG THE WARM CONVEYOR
BELT FROM PARTS OF NRN TX THROUGH OK AND KS MONDAY MORNING...BUT
WILL GRADUALLY DEVELOP EAST INTO THE MS VALLEY REGION BY EVENING.
THIS ACTIVITY WILL BE EMBEDDED WITHIN VERTICAL SHEAR PROFILES
SUFFICIENT FOR ORGANIZED SEVERE STORMS...BUT IT APPEARS THAT THE
THERMODYNAMIC ENVIRONMENT WILL REMAIN SOMEWHAT MARGINAL.

OPPORTUNITY WILL EXIST FOR THE ATMOSPHERE TO DESTABILIZE IN WAKE OF
INITIAL STORMS FROM N CNTRL TX THROUGH OK AND KS WHERE LOW LEVEL
WINDS WILL HAVE WEAKENED...BUT BULK SHEAR WILL REMAIN SUFFICIENT FOR
ROTATING UPDRAFTS. PARTIAL CLEARING IN DRY SLOT REGION IN WAKE OF
LEAD IMPULSE AND POSSIBILITY OF MIXING OUT OF LOW CLOUDS FROM THE
WEST MAY RESULT IN AT LEAST MARGINAL MLCAPE IN THESE REGIONS.
ADDITIONAL STORMS MAY DEVELOP IN NARROW INSTABILITY AXIS ALONG AND
JUST AHEAD OF THE COLD FRONT AS UPSTREAM IMPULSE DROPS SEWD THROUGH
BASE OF UPPER TROUGH.

THREAT IS SOMEWHAT CONDITIONAL GIVEN LINGERING UNCERTAINTIES
REGARDING EVOLUTION OF EARLY CONVECTION AND DESTABILIZATION
POTENTIAL. WILL INTRODUCE LOW SEVERE PROBABILITIES THIS OUTLOOK.
HOWEVER...AN UPGRADE TO CATEGORICAL RISK MAY BE NEEDED IN LATER
UPDATES.

..DIAL.. 10/04/2008