[SWODY1] SWODY1

[Severe Weather Outlook Day 1]

ACUS01 KWNS 071634
SWODY1
SPC AC 071632

DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
1032 AM CST SUN JAN 07 2007

VALID 071630Z - 081200Z

...THERE IS A SLGT RISK OF SVR TSTMS THIS AFTERNOON ACROSS THE SRN
GULF STATES...AND LATER THIS AFTERNOON AND TONIGHT ACROSS PARTS OF
THE CAROLINAS....

...SYNOPSIS...
LATEST WATER VAPOR SATELLITE IMAGERY SHOWS MID/UPPER LEVEL SHORTWAVE
TROUGH/ASSOCIATED VORTICITY MAX IS OVER SRN IL EXTENDING SSWWD INTO
SERN TX.  THIS FEATURE IS LOCATED JUST AHEAD OF MAIN TROUGH OVER THE
ERN NRN PLAINS EXTENDING SSWWD THROUGH W TX.  15Z SURFACE ANALYSIS
HAS LOW PRESSURE OVER NERN MS/SWRN TN WITH A COLD FRONT EXTENDING
THROUGH S CENTRAL LA...AND A QUASISTATIONARY FRONT THAT REACHES SEWD
INTO CENTRAL GA BEFORE CURVING ENEWD ACROSS SERN SC.  IT SEEMS THAT
THE FOCUS FOR SEVERE ACTIVITY TODAY AND TONIGHT WILL BE THE COLD
FRONT AS IT MOVES EWD/NEWD AS THE LOW TRAVELS THROUGH MIDDLE TN THIS
AFTERNOON INTO WRN UPSTATE NEW YORK TONIGHT.

...PARTS OF ERN MS INTO SWRN GA...

LATEST VISIBLE SATELLITE IMAGERY SHOWS CONSIDERABLE CLOUD COVER
ACROSS MUCH OF THE GULF STATES WITH A FEW BREAKS OVER SERN MS INTO
SWRN GA.  STRONG FORCING IS EXPECTED TO OCCUR AS THE COLD FRONT
MOVES EWD THIS AFTERNOON JUST AHEAD OF SECOND STRONGER TROUGH MOVING
OVER THE SRN HALF OF THE MS VALLEY REGION DURING THE LATTER HALF OF
THE PERIOD.  EXPECT THAT AN INCREASE IN INTENSITY WILL OCCUR WITH
CURRENT BAND OF SHOWERS/THUNDERSTORMS THAT EXTENDS FROM NWRN LA SWWD
INTO S CENTRAL LA AS THEY MOVE INTO AL EARLY THIS AFTERNOON.  DEEP
LAYER SHEAR WILL BECOME MORE ENHANCED IN ASSOCIATION WITH REAR
ENTRANCE REGION OF STRONG 300 MB JET /130-160 KT/ COUPLED WITH SSWLY
30-50 KT LOW LEVEL JET.  MAIN THREAT WILL BE DAMAGING WINDS WITH
THIS ACTIVITY.

...PARTS OF THE CAROLINAS INTO SERN VA...

MAIN CONCERN AT THIS TIME IS HOW THE QUASISTATIONARY BOUNDARY
/MAINLY DUE TO COLD AIR DAMMING ON THE LEE SIDE OF THE APPALACHIANS/
WILL PLAY A ROLE LATER THIS AFTERNOON AND TONIGHT.  ATTENTION NEEDS
TO BE GIVEN TO STRONG LOW LEVEL JET OF 50-60 KT AHEAD OF THE MAIN
TROUGH THAT WILL EXTEND FROM SWRN GA INTO CENTRAL NC BY 08/00Z. 
MODELS INDICATE STRONG LOW LEVEL WARM ADVECTION AND ENHANCED UVVS
ACROSS THE CAROLINAS...AND FEEL THAT IF THERE IS ANY SUPERCELL
THREAT IT WILL BE WITH THE BOUNDARY AS IT BECOMES A WARM FRONT AND
MOVES NWD INTO CENTRAL/NRN NC THIS EVENING.  ONCE AGAIN...
INSTABILITY WILL REMAIN VERY LIMITED WITH MUCAPE STRUGGLING TO BE
AROUND 500 J/KG...BUT VERTICAL SHEAR PROFILES/STORM RELATIVE
HELICITY VALUES ARE FORECAST TO BE 300-500 M2/S2 JUST SOUTH OF THE
BOUNDARY AND HIGHER JUST NORTH OF IT.

THUS...EXPECT COMPARATIVELY DISCRETE LOW-TOPPED SUPERCELLS TO
DEVELOP AHEAD OF THE MAIN FRONTAL BOUNDARY THIS EVENING AND TONIGHT
ACROSS PARTS OF THE CAROLINAS WITH THE MAIN THREAT BEING ISOLATED
TORNADOES THIS EVENING...WITH MORE WIDESPREAD DAMAGING WINDS
ASSOCIATED WITH THE COLD FRONT LATER TONIGHT AND TOWARDS THE END OF
THE PERIOD.

..MCCARTHY.. 01/07/2007