[SWODY1] SWODY1

[Severe Weather Outlook Day 1]

ACUS01 KWNS 010058
SWODY1
SPC AC 010056

DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
0656 PM CST SUN DEC 31 2006

VALID 010100Z - 011200Z

...NO SVR TSTM AREAS FORECAST...

...SYNOPSIS...
CLOSED UPPER LOW...NOW CENTERED OVER MID MS VALLEY...IS EXPECTED TO
BECOME MORE NEGATIVELY TILTED AS IT LIFTS NEWD INTO THE GREAT LAKES
REGION OVERNIGHT.  MEANWHILE...PROGRESSIVE UPSTREAM SHORT WAVE
TROUGH WILL DIG SEWD INTO THE MS VALLEY...MAINTAINING ELONGATED
UPPER TROUGH ALONG THE MS VALLEY IN WAKE OF EJECTING UPPER LOW.

AT THE SURFACE...AREA OF LOW PRESSURE LOCATED OVER SWRN WI WILL
TRACK NEWD INTO THE UPPER GREAT LAKES TONIGHT...AS TRAILING COLD
FRONT SPREADS EWD AND SHOULD EXTEND FROM THE LOW ACROSS THE LOWER
GREAT LAKES AND CENTRAL APPALACHIANS SWWD TO THE NERN GULF.

...NERN IL/NRN IND TO SRN LOWER MI...
ASCENT ALONG LEADING EDGE OF UPPER LOW/VORTEX COMBINED WITH
STEEPENING LAPSE RATES PER MID LEVEL COOLING ATOP LOW LEVEL THERMAL
RIDGE ARE EXPECTED TO MAINTAIN ONGOING ERN IL TSTM CLUSTER AS THE
UPPER LOW TRACKS NE TOWARD THE GREAT LAKES REGION.  FOR ADDITIONAL
INFORMATION ABOUT THIS ACTIVITY AND ATTENDANT ISOLATED SEVERE
THREAT...PLEASE REFER TO SPC MESOSCALE DISCUSSION 0001.

...NRN FL/SERN GA NWD TO ERN TN/WRN NC/SWRN VA... 
UPPER LEVEL DIFFLUENT FLOW REGIME LOCATED E AND SE OF UPPER LOW IS
EXPECTED TO MAINTAIN TWO ONGOING AREAS OF CONVECTION...ONE OVER SERN
GA/NRN FL AND THE SECOND ALONG THE COLD FRONT FROM NRN GA NWD INTO
UPPER OH VALLEY.  AIR MASS IN ADVANCE OF SERN GA/NWRN FL CONVECTIVE
LINE IS MARGINALLY UNSTABLE...WITH EFFECTIVE BULK SHEAR VALUES OF
35-45 KT REMAINING FAVORABLE FOR SOME ORGANIZATION AND ATTENDANT LOW
PROBABILITY FOR PRIMARILY AN ISOLATED DAMAGING WIND GUST.

FARTHER N...FORCING SHOULD REMAIN SUFFICIENT ALONG THE COLD FRONT
FOR ADDITIONAL CONVECTION AND A FEW EMBEDDED TSTMS ACROSS PARTS OF
THE SRN AND CENTRAL APPALACHIANS.  HOWEVER...WEAK LAPSE RATES SHOULD
PRECLUDE A SEVERE WIND THREAT FROM NRN GA/ERN TN INTO SWRN VA/WRN NC
THIS EVENING.

..PETERS.. 01/01/2007