[SWODY1] SWODY1

[Severe Weather Outlook Day 1]

ACUS01 KWNS 230451
SWODY1
SPC AC 230449

DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
1049 PM CST WED NOV 22 2006

VALID 231200Z - 241200Z

...NO SVR TSTM AREAS FORECAST...

A SIGNIFICANT PROGRESSIVE SHORT WAVE TROUGH...EMBEDDED WITHIN THE
STRONGER NORTHERN BRANCH OF THE POLAR WESTERLIES...IS FORECAST TO
LIFT RAPIDLY EAST NORTHEAST OF THE NORTHERN INTERMOUNTAIN REGION...
THROUGH THE CENTRAL CANADIAN/U.S. BORDER AREA BY 12Z FRIDAY.  THIS
IS EXPECTED TO OCCUR AS ANOTHER SHORT WAVE TROUGH MIGRATES INLAND
ACROSS SOUTHERN BRITISH COLUMBIA AND WASHINGTON.  MEANWHILE...A 
DOWNSTREAM RIDGE IS PROGGED TO SHIFT EAST OF THE MISSISSIPPI
VALLEY...AND MODELS SUGGEST THIS WILL CONTRIBUTE TO THE
NORTHEASTWARD ACCELERATION OF MID ATLANTIC COAST CLOSED LOW...OFF
NORTH ATLANTIC COASTAL AREAS.

IN THE WAKE OF THE EASTERN SYSTEM...LOW/MID-LEVEL RIDGING
...EXTENDING FROM THE UPPER OHIO VALLEY DEEP INTO THE WESTERN GULF
OF MEXICO...WILL INHIBIT THE NORTHWARD RETURN OF A SLOWLY
MODIFYING/MOISTENING WESTERN GULF BOUNDARY LAYER.  AND...A DRY
STABLY STRATIFIED ENVIRONMENT WILL PREVAIL ACROSS MOST AREAS EAST OF
THE ROCKIES...WITH NEGLIGIBLE POTENTIAL FOR THUNDERSTORM ACTIVITY. 
SIMILARLY DRY AND STABLE CONDITIONS ACROSS MUCH OF THE WEST WILL
ALSO MINIMIZE CONVECTIVE POTENTIAL.  AN EXCEPTION MAY EXIST ACROSS
PARTS OF THE PACIFIC NORTHWEST.

...PACIFIC NORTHWEST...
MODELS SUGGEST THAT ONSHORE LOW-LEVEL FLOW WILL BECOME MODERATE TO
STRONG BY LATE AFTERNOON...WITH 40-50 KT WESTERLY 850 MB FLOW
FOCUSED INTO SOUTHERN WASHINGTON/NORTHERN OREGON COASTAL AREAS. 
THIS WILL ENHANCE LIFT ALONG SOUTHERN PERIPHERY OF RETREATING
MID-LEVEL COLD POOL...WHERE EQUILIBRIUM LEVELS APPEAR LIKELY TO
REMAIN COLD ENOUGH TO SUPPORT A FEW THUNDERSTORMS.  POTENTIAL IS
EXPECTED TO DIMINISH BY LATE EVENING INTO THE OVERNIGHT HOURS...AS
UPPER IMPULSE PROGRESSES INLAND...ONSHORE FLOW WEAKENS...AND MID
LEVELS CONTINUE TO GRADUALLY WARM.

..KERR.. 11/23/2006