[SWODY1] SWODY1

[Severe Weather Outlook Day 1]

ACUS01 KWNS 131303
SWODY1
SPC AC 131301

DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
0701 AM CST WED DEC 13 2006

VALID 131300Z - 141200Z

...NO SVR TSTM AREAS FORECAST...

...SYNOPSIS...
A LARGELY ZONAL FLOW REGIME IS EXPECTED OVER THE CONUS THROUGH
TOMORROW...WITH THE PRIMARY JET FROM THE PAC NW TO THE GREAT LAKES. 
AN INITIAL MID LEVEL SHORTWAVE TROUGH OVER THE APPALACHIANS THIS
MORNING WILL WEAKEN AND MOVE NEWD OVER THE MID ATLANTIC/NEW ENGLAND
BY EARLY TONIGHT.  THIS MID LEVEL WAVE WILL BE ACCOMPANIED BY A
DIFFUSE SURFACE TROUGH/WEAK FRONT WHICH WILL BECOME EVEN LESS
DEFINED WITH TIME.  MEANWHILE...THE LOW LEVELS HAVE WARMED/MOISTENED
ALONG AND SE OF A COASTAL TROUGH OFF GA AND THE CAROLINAS. 
INITIALLY SHALLOW CONVECTION ALONG THIS TROUGH SHOULD DEEPEN DURING
THE DAY...WITH THE THREAT FOR THUNDERSTORMS EXPECTED TO INCREASE
JUST OFFSHORE.  MORE ISOLATED CONVECTION...AND PERHAPS A FEW
LIGHTNING STRIKES...WILL BE POSSIBLE JUST INLAND OF THE SE ATLANTIC
COAST THROUGH THIS EVENING.  THUNDERSTORM COVERAGE SHOULD REMAIN
RATHER SPARSE GIVEN MARGINAL INSTABILITY AND RATHER WEAK FORCING FOR
ASCENT.

A STRONG TROUGH IS MOVING INLAND OVER WA AND BRITISH COLUMBIA...AND
THIS SYSTEM WILL PROGRESS QUICKLY EWD TOWARD THE NRN HIGH PLAINS BY
EARLY THURSDAY.  RELATIVELY STEEP LAPSE RATES AND COLD MID LEVEL
TEMPERATURES COULD SUPPORT ISOLATED THUNDERSTORMS THE FIRST HALF OF
THE DAY...BEFORE THE THUNDERSTORM THREAT ENDS IN ASSOCIATION WITH
SHORTWAVE RIDGING BY THIS EVENING.  OTHERWISE...A WEAK MID LEVEL
TROUGH FROM NW MEXICO INTO NM WILL MOVE SEWD TOWARD THE LOWER RIO
GRANDE VALLEY LATE IN THE PERIOD.  GRADUAL MOISTENING/
DESTABILIZATION NEAR THE LOWER TX COAST COULD SUPPORT AN ISOLATED
THUNDERSTORM THREAT BY EARLY THURSDAY JUST OFFSHORE.

..THOMPSON.. 12/13/2006