[SWODY1] SWODY1

[Severe Weather Outlook Day 1]

ACUS01 KWNS 171942
SWODY1
SPC AC 171940

DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
0140 PM CST SUN DEC 17 2006

VALID 172000Z - 181200Z

...NO TSTM AREAS FORECAST...

...SYNOPSIS AND DISCUSSION...

EVOLVING UPPER LOW OVER THE GREAT BASIN WILL CONTINUE SEWD INTO THE
LOWER CO VALLEY TONIGHT...WHILE WAVE TRAIN REMAINS MORE PROGRESSIVE
ACROSS CANADA.  IN THE LOW-LEVELS...SURFACE HIGH WILL BUILD SEWD
FROM THE NRN HIGH PLAINS INTO CNTRL PLAINS WITH COLD FRONT SLOWLY
PUSHING SWD THROUGH THE MID MS VALLEY AND SRN PLAINS.

A MOIST LOW-LEVEL AIR MASS EXISTS TODAY TO THE S OF COLD FRONT FROM
CNTRL/ERN TX INTO THE OZARK PLATEAU.  HOWEVER...12Z RAOBS INDICATE
THE PRESENCE OF WARM MID-LEVEL TEMPERATURES AND RESULTANT WEAK LAPSE
RATES.  SOME SHOWER ACTIVITY WILL BE POSSIBLE OVERNIGHT AS SWLY LLJ
REINTENSIFIES AND ENHANCES ISENTROPIC ASCENT NEAR AND N OF SURFACE
FRONT FROM OK INTO MO/IL.  THIS CONVECTION IS EXPECTED TO REMAIN TOO
SHALLOW/WARM TO SUPPORT CHARGE SEPARATION.

ELSEWHERE...LOW-LEVEL AIR MASS REMAINS MOIST ACROSS S FL...HOWEVER
LARGE-SCALE SUBSIDENCE IN WAKE OF SHORT WAVE TROUGH PUSHING E OF THE
BAHAMAS SHOULD SUPPRESS ANY CONVECTIVE DEVELOPMENT.

FINALLY...SOME THREAT OF AN ISOLATED LIGHTNING STRIKE OR TWO WILL
EXIST NEAR AND N OF THE FOUR CORNERS REGION AS HEIGHT FALLS AHEAD OF
UPPER TROUGH CONTRIBUTE TO STEEPENING LAPSE RATES.  THIS THREAT IS
TOO MARGINAL TO WARRANT A GENERAL THUNDER AREA.

..MEAD.. 12/17/2006