...CAROLINAS/GA/NRN FL/MID-ATLANTIC...
A POTENT NEGATIVELY-TILTED UPPER-LEVEL LOW IS FORECAST TO MOVE NEWD
ACROSS THE OH AND TN VALLEYS ON WEDNESDAY. AT 12Z ON
WEDNESDAY...MODEL FORECASTS SHOW A SLAB OF STRONG LARGE-SCALE ASCENT
EXTENDING FROM THE SRN APPALACHIAN MTNS SWD ACROSS THE ERN GULF
COAST STATES ASSOCIATED WITH A WELL-DEVELOPED CONVECTIVE LINE. THIS
SQUALL-LINE IS FORECAST TO MOVE QUICKLY EWD ACROSS THE CAROLINAS
AROUND MIDDAY WHERE AN ENHANCED SEVERE THREAT SHOULD DEVELOP. A
POTENTIAL EXISTS FOR A SIGNIFICANT SEVERE WEATHER EVENT FROM LATE
MORNING ON WEDNESDAY INTO THE AFTERNOON.

FORECAST SOUNDINGS AT COLUMBIA SC WEDNESDAY GRADUALLY INCREASE SFC
DEWPOINTS INTO THE LOWER 60S F DURING THE MORNING ALLOWING MLCAPE
VALUES TO APPROACH 1000 J/KG BY 18Z. IN ADDITION...DEEP LAYER SHEAR
IS FORECAST TO INCREASE TO AROUND 65 KT AS THE EXIT REGION OF AN
IMPRESSIVE MID-LEVEL JET OVERSPREADS THE CAROLINAS. THIS COMBINED
WITH 0-3 KM STORM RELATIVE HELICITIES AROUND 400 M2/S2 SHOULD BE
FAVORABLE FOR SUPERCELLS AND TORNADOES WITH CELLS THAT REMAIN
DISCRETE AHEAD OF THE APPROACHING SQUALL-LINE. A STRONG TORNADO
COULD DEVELOP ESPECIALLY IF MOISTURE RETURN AND SFC HEATING ACROSS
THE CAROLINAS ENDS UP A BIT MORE THAN IS CURRENTLY FORECAST. THE
GREATEST TORNADO THREAT SHOULD EXIST WEDNESDAY AFTERNOON FROM JUST
EAST OF COLUMBIA SC EXTENDING NEWD TO JUST SOUTH OF RALEIGH NC WHERE
A 30 PERCENT SEVERE PROBABILITY AND SIGNIFICANT HATCHED AREA IS
MAINTAINED. A WIND DAMAGE THREAT SHOULD ALSO DEVELOP AS A LINEAR MCS
MOVES QUICKLY EWD ACROSS THE CAROLINAS AND GA AROUND MIDDAY.
FORECASTS SOUNDINGS AHEAD OF THE LINE SHOW 50 TO 60 KT OF FLOW JUST
ABOVE THE SFC SUGGESTING ANY FAST-MOVING SQUALL-LINE SHOULD BE VERY
EFFICIENT AT PRODUCING WIND DAMAGE.

AT THIS POINT...THE EXACT TIMING OF THE UPPER-LEVEL SYSTEM IS STILL
IN QUESTION. THE NAM IS THE SLOWEST SOLUTION AND IS PROBABLY THE
MOST FAVORABLE FOR SEVERE STORMS ACROSS THE CAROLINAS AND ERN GULF
COAST STATES. THIS WOULD ALLOW FOR MORE MOISTURE RETURN AND A
GREATER POTENTIAL FOR SFC HEATING.