Damaging Winds in North Carolina, May 22, 2001

AREA FORECAST DISCUSSION...CORRECTED TO INCLUDE SVR TSTM WATCH
NATIONAL WEATHER SERVICE RALEIGH NC
210 PM EDT TUE MAY 22 2001

NEAR TERM...
ENVIRONS AHEAD OF THE COLD FRONT IN THE RAH CWA REMAIN UNSTABLE BUT
LACK A MESOSCALE FOCUS.  BEHIND A LEAD N-S ORIENTED WAVE IN CENTRAL
SECTIONS AT 17Z...SURFACE PARAMETERS SHOW A SLIGHTLY DIVERGENT FLOW
AND NEGATIVE ADVECTION OF THETA-E.  WIND PROFILE ALOFT REMAINS
UNIDIRECTIONAL AND WEAKLY SHEARED WITH WINDS FROM THE SOUTHWEST
AVERAGING 25-30 KNOTS.  LEAD WAVE MAY YET ENHANCE DEEP CONVECTION IN
THE EASTERN HALF OF THE CWA BEFORE EXITING NORTHEAST.  OTHERWISE IT
MAY TAKE 2-4 MORE HOURS BEFORE PROXIMITY OF THE SURFACE FRONT
IMPACTS THE RAH CWA FROM THE WEST.

TONIGHT...
THE COLD FRONT SHOULD MOVE THROUGH THE CWA THIS EVENING...EXITING
THE EASTERN CWA COUNTIES BY MIDNIGHT.  THE HIGH CHANCE OR LIKELY
THREAT OF SHOWERS AND THUNDERSTORMS SHOULD DIMINISH QUICKLY BEHIND
THE FRONT. SOUTHWEST FLOW ABOVE THE BOUNDARY LAYER CONTINUES
HOWEVER.  THIS MAY RESULT IN PROLONGED HIGHER CLOUDINESS EAST AND
LEAVE MOST OF THE ADVECTION OF COOL DRY AIR BANKED UP IN THE
MOUNTAINS.  WITH RESIDUAL SURFACE MOISTURE AND DIMINISHING WIND
BEHIND THE FRONT...SOME FOG IS APT TO DEVELOP TOWARD MORNING.
PREVIOUS MIN TEMPERATURE FORECASTS LOOK REASONABLE.

NEXT FEW DAYS...
WEATHER THE NEXT FEW DAYS WILL BE DOMINATED BY A LARGE-SCALE LOW
PRESSURE GYRE OVER THE NORTHERN MIDWEST. THIS WILL CAUSE A
PERSISTENT CYCLONIC SOUTHWEST FLOW AT MOST LEVELS OVER CENTRAL NORTH
CAROLINA.  THE AIRMASS WILL REMAIN SOMEWHAT UNSTABLE WITH HEATING
EACH DAY RESULTING IN ENHANCE STRATO CU.  MODELS VARY IN THEIR
PROJECTION OF SHORT WAVES AROUND THE GIANT LOW WITH ABILITY TO
RESOLVE THE WAVES DIMINISHING IN TIME THROUGH THE MEDIUM RANGE.
MODELS SUGGEST STRONGEST OF THESE WAVES MAY CAUSE SHOWERS FRIDAY
NIGHT OR SATURDAY. OTHERWISE PARTLY OR VARIABLY CLOUDY SKIES CAN BE
EXPECTED EACH DAY.  LACK OF ANY HIGH PRESSURE SURGE OF COLD DRY
AIR...TEMPERATURES WILL AVERAGE CLOSE TO NORMAL VALUES FOR THIS TIME
OF YEAR WITH MAXS NEAR 80 AND MINS 55 TO 60.

.RAH...SVR TSTM WATCH WESTERN HALF THROUGH 500 PM.

RFG