...SYNOPSIS...
INTENSE CYCLONE LOCATED OVER WRN MO IS FORECAST TO BE EJECTED
INTO IL/IN AND WEAKEN...AS A COMPACT UPPER LOW ROTATES SEWD INTO
THE UPPER MIDWEST. ON THE WATER VAPOR IMAGERY...A SHORTWAVE TROUGH
WAS EVIDENT OVR SRN LA AND WILL MOVE INTO THE MID ATLANTIC STATES
BY EVENING. ANOTHER SHORTWAVE TROUGH WAS ALSO EVIDENT ACROSS NRN
MEXICO AND IS FORECAST TO BE LOCATED IN SRN MS BY DAYBREAK FRIDAY.
WARM FRONT CURRENTLY LOCATED ACROSS CENTRAL GA AND EXTREME SRN SC
IS EXPECTED TO LIFT NWD TONIGHT. SURFACE DRYLINE IS CURRENTLY
LOCATED OVER WRN AL...BUT DRY SWLY WIND JUST ABOVE THE SURFACE
SHOULD MIX THE DRYLINE INTO WRN GA BY EARLY AFTERNOON.
...SERN CONUS....
SLOW MOVING CONVECTION LOCATED FROM THE FL PANHANDLE NEWD INTO SC
IS LIFTING NEWD AS THE UPPER LEVEL DIFFLUENCE SLOWLY
DECREASES FROM THE SOUTHWEST. AREA OF CONSIDERABLE CONVECTION AND
CLOUDS WILL BE SLOW TO MOVE EAST AND THIS SHOULD RESULT IN POOR AIR
MASS RECOVERY. JAX MORNING SOUNDING SHOWS SHALLOW STABLE BOUNDARY
LAYER AIR MASS...WHICH APPEARS TO HAVE LIMITED THE WIND/TORNADO
POTENTIAL OVERNIGHT. ONCE THIS LAYER CAN BE WARMED...JAX SOUNDING
INDICATES THE AIR MASS WOULD BE MODERATELY UNSTABLE WITH DEEP LAYER
SHEAR OF 60 KT AND 1 KM SHEAR AROUND 30 KT. BEST POTENTIAL FOR
TORNADOES APPEARS TO BE LOCATED IN THE NARROW WEDGE OF STRONGER
INSTABILITY/SHEAR LOCATED AHEAD OF CONVECTION. MODERATE RISK HAS
BEEN MOVED SWD...SINCE AIR MASS IS NOT EXPECTED TO RECOVER
SUFFICIENTLY ACROSS SC AND SERN NC FOR AN ENHANCED TORNADO THREAT.
THUNDERSTORMS SHOULD REDEVELOP LATER TODAY OR TONIGHT ON DRYLINE AS
SHORTWAVE TROUGH MOVES INTO THE NWRN GULF AND STRENGTHENS THE UPPER
LEVEL DIFFLUENCE. BOTH ETAKF/ETA SUGGEST CONVECTION WILL DEVELOP
INTO A LINE ALONG THE DRYLINE WITH HAIL AND WIND DAMAGE THE MOST
LIKELY THREAT.
...OH/TN VALLEYS...
STRONG FORCING WILL BE LOCATED ACROSS THE AREA TODAY AS UPPER LOW
APPROACHES FROM THE WEST AND ADDITIONAL LIFT IS PROVIDED BY LEFT
EXIT REGION OF JET MAX MOVING NEWD THROUGH THE ERN PORTIONS OF THE
COUNTRY. DESPITE DEWPOINTS ONLY IN THE LOWER TO MID 50S...ELEVATED
MIXED LAYER AND -20 TO -22C TEMPERATURES AT 500 MB WILL RESULT IN
MLCAPE VALUES IN EXCESS OF 1500 J/KG. DEEP LAYER SHEAR WILL BE
SUFFICIENTLY STRONG FOR SUPERCELLS THIS AFTERNOON WITH LARGE HAIL
AND DAMAGING WINDS. TORNADOES ARE POSSIBLE GIVEN THE MODEST
INSTABILITY...STRONG KINEMATICS AND FORCING...BUT WEAK 1 KM SHEAR
AND RELATIVELY HIGH LCL/S INDICATE THE TORNADOES WOULD BE VERY
ISOLATED.
..IMY.. 03/20/03
NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED FOR 1630Z