[SWODY1] SWODY1

[Severe Weather Outlook Day 1]

ACUS01 KWNS 071927
SWODY1
SPC AC 071926

DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
ISSUED BY AFWA OFFUTT AIR FORCE BASE BELLEVUE NE
0126 PM CST THU DEC 07 2006

VALID 072000Z - 081200Z

...NO TSTM AREAS FORECAST...

...SYNOPSIS...

MERIDIONAL PATTERN EXISTS ACROSS THE COUNTRY WITH A DEEP TROUGH IN
THE EASTERN CONUS AND A RIDGE IN THE WEST.  THE EASTERN TROUGH IS
FORCING A STRONG SURFACE COLD FRONT THROUGH MOST OF THE COUNTRY EAST
OF THE ROCKIES...LEADING TO A COLD AND STABLE BOUNDARY LAYER IN MOST
AREAS. ADDITIONALLY...SHORTWAVE ENERGY IS UNDERCUTTING THE RIDGE IN
NORTHERN MEXICO WHERE A CLOSED UPPER LOW IS EXPECTED TO FORM LATER
TODAY.

...GREAT LAKES...

VERY COLD AIR AT ALL LEVELS IS OVERSPREADING THE GREAT LAKES WHERE
WATER TEMPERATURES ARE GENERALLY FROM 2 TO 8 DEGREES C...LEADING TO
INSTABILITY AND CONVECTIVE SNOW BANDS IN LOCATIONS WHERE THE SURFACE
FETCH IS DOWNSTREAM FROM THE LAKE.  THE CORE OF THE COLDEST AIR IS
ADVECTING OVER TOP LAKE ERIE...AND SOME ISOLATED LIGHTNING IS
POSSIBLE OVER THE LAKE AND ON THE SOUTHERN SHORES GIVEN EXPECTED
MIXED PHASE CLOUD CONTENT AND CAPES AROUND 250 J/KG.  HOWEVER...WITH
NORTHWESTERLY SURFACE FLOW THE FETCHES WILL BE LIMITED AND GIVEN
THAT NO LIGHTNING HAS BEEN OBSERVED THUS FAR...COVERAGE IS EXPECTED
TO BE LESS THAN 10 PERCENT.

...FLORIDA...

THE COLD FRONT IS PUSHING SLOWLY SOUTHWARD THROUGH FLORIDA
GENERATING SOME SHOWER ACTIVITY.  INSTABILITY IS LACKING EXCEPT IN
EXTREME SOUTHERN FLORIDA...WHERE FORCING AND MID LEVEL LAPSE RATES
ARE WEAK DESPITE AMPLE LOW LEVEL MOISTURE...AND EVEN THAT IS SLOWLY
DECREASING AS DRIER AIR FILTERS IN FROM THE NORTH.  ISOLATED
LIGHTNING IS POSSIBLE IF LOCAL BOUNDARY INTERACTIONS CAN GENERATE
ENOUGH FORCING FOR DEEP CONVECTION...BUT WIDESPREAD COVERAGE IS NOT
EXPECTED.

...SOUTHERN TEXAS...

SHOWER ACTIVITY IS ONGOING ALONG THE FRONT ENHANCED BY THE RIGHT
REAR QUADRANT OF A JET STREAK AT THE BASE OF THE TROUGH.  SOUNDINGS
INDICATE A MOIST ADIABATIC ATMOSPHERE AND LIMITED
INSTABILITY...PRECLUDING LIGHTNING.  A SHORTWAVE IN THE SUBTROPICAL
JET STREAM WILL BEGIN TO IMPACT THE REGION BUT NOT BEFORE THE COLD
FRONT HAS CLEARED THE AREA...LEADING TO STABLE CONDITIONS.

..AFWA.. 12/07/2006