[SWODY1] SWODY1

[Severe Weather Outlook Day 1]

ACUS01 KWNS 190555
SWODY1
SPC AC 190553

DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
1153 PM CST MON DEC 18 2006

VALID 191200Z - 201200Z

...NO SVR TSTM AREAS FORECAST...

...SYNOPSIS...
MAIN UPPER FEATURE OF INTEREST ACROSS THE CONUS THIS PERIOD WILL BE
THE SWRN U.S. CLOSED LOW -- INITIALLY FORECAST TO BE CENTERED OVER
SRN CA/WRN AZ/NWRN MEXICO.  THE LOW IS FORECAST TO PROGRESS EWD 
THROUGH THE PERIOD...REACHING ERN NM BY 20/12Z.  IN RESPONSE TO THIS
FEATURE...AN INVERTED SURFACE TROUGH IS EXPECTED TO EVOLVE ACROSS W
TX AND WRN OK THROUGH THE END OF THE PERIOD.

...ERN AZ/THE FOUR CORNERS EWD INTO SRN KS/OK/TX...
WIDESPREAD SHOWERS AND SCATTERED TO ISOLATED THUNDERSTORMS SHOULD BE
ONGOING AT THE START OF THE PERIOD -- INVOF UPPER COLD POOL OVER THE
SWRN U.S. AS WELL AS WITHIN WARM ADVECTION REGIME FURTHER E INTO THE
SRN HIGH PLAINS.  THIS GENERAL SCENARIO WILL CONTINUE/SHIFT SLOWLY
EWD WITH TIME...WITH SHOWERS AND SPORADIC LIGHTNING STRIKES ACROSS
THE SRN ROCKIES/SWRN U.S. AND MORE WIDESPREAD THUNDERSTORMS SHIFTING
ACROSS TX AND OK THROUGH THE END OF THE PERIOD.

DEEP-LAYER WIND FIELD WILL INCREASE ACROSS THE SRN PLAINS DURING THE
SECOND HALF OF THE PERIOD...AS 80 KT MID-LEVEL JET SPREADS EWD ATOP
STRENGTHENING NOCTURNAL LOW-LEVEL JET.  HOWEVER...VERY WEAK LAPSE
RATES ARE FORECAST ACROSS THE ENTIRE REGION...WHICH WILL GREATLY
LIMIT AVAILABLE INSTABILITY.  THEREFORE...ANY SEVERE THREAT APPEARS
TO BE MINIMAL ATTM.

..GOSS.. 12/19/2006