Severe Thunderstorm Warning 137, NWS Raleigh, NC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
200 PM EDT SUN SEP 15 2002

THE FLOOD WATCH WILL BE EXTENDED THROUGH THE NIGHT. READ ON.

SATELLITE IMAGERY NOW INDICATING A WELL DEFINED LOW LEVEL CYCLONIC
CIRCULATION IN NW GEORGIA. THIS WILL MOVE ACROSS CENTRAL NORTH
CAROLINA IN THE OVERNIGHT HOURS. AS MENTION EARLIER TODAY THE
MID/UPPER LEVEL SUPPORT HAS BEEN SHEARED AWAY BUT PLENTY OF LOW
LEVEL MOISTURE REMAINS IN PLACE THROUGH DAYBREAK MONDAY. SINCE THE
SYSTEM WILL NOT HAVE A DEEP LAYER OF MOISTURE TO WORK WITH THE
RAINFALL TOTALS OF 2 INCHES IN A LOCATION PER SHIFT HAVE ALL BUT
GONE AWAY BUT THE POSSIBILITY OF 1/2 TO 3/4 OF INCH WITH ISOLATED
AREAS OF MORE POSSIBLE IS MORE LIKELY THE CASE. THE CHANCES OF RAIN
TONIGHT WILL AGAIN BE CATEGORICAL AS THE SYSTEM MOVES FROM SOUTHWEST
(EVENING) TO NORTHEAST (MORNING). THE ETA SEEMS A BIT FASTER MOTION
THAN THE AVN WITH THE SYSTEM BUT THINK THAT THE SLOWER MOTION IS
MORE LIKELY DUE TO THE TIMING OF THE LOW FORMING BEING SLOW. WINDS
FROM THE SOUTH INTO THE SYSTEM WILL MAKE FOR A SLOW MOTION AS WELL.

THE WIND PATTERN AT THE SURFACE IS DIVERGENT WITH MORE STABLE AIR IN
WESTERN NC ... THE MORE UNSTABLE AIR SHOULD PUSH INLAND TO ALONG A
LINE FROM RALEIGH TO FAYETTEVILLE. THUS RAIN MAY DECREASE A BIT AS
IT FORMS AND MOVES TOWARD THE FORECAST AREA FROM THE UPSTATE OF
SOUTH CAROLINA BEFORE BECOMING A BIT MORE ENERGIZED AS IT TRACKS
FURTHER EAST.

THEN A LARGE LULL WILL OCCUR IN THE PRECIPITATION FROM AROUND
DAYBREAK MONDAY UNTIL AFTERNOON/EVENING TIME FRAME WITH THE MOVEMENT
OF THE COLD FRONT FROM THE NORTHWEST TO SOUTHEAST THROUGH THE AREA.
WINDS SHIFT TO NORTHWEST FAIRLY EARLY AROUND THE TRIAD REGION AND
THEREFORE THE CHANCE OF RAIN MONDAY EVENING SHOULD BE SLIGHT AND
CONFINED TO THE EASTERN AND SOUTHERN SECTIONS OF THE FORECAST AREA.
TEMPERATURES SHOULD BE AROUND 80 TO LOWER 80S WITH A FEW BREAKS IN
THE CLOUDS DURING THE AFTERNOON IN THE TRIAD/WESTERN PIEDMONT AREAS
AND A GOOD SOUTHWESTERLY FLOW IN ADVANCE OF THE SYSTEM.

TUESDAY THROUGH SUNDAY...SURFACE HIGH AND AN UPPER RIDGE BUILD OVER
THE EAST COAST ON TUESDAY. DRIER AIR MOVES INTO THE AREA TUESDAY
BEHIND THE FRONT BUT TEMPS WILL WARM UNDER MOSTLY CLEAR
SKIES...HIGHS IN THE LOWER/MID 80S. THICKNESSES DROP A LITTLE FOR
WEDNESDAY...AND CLOUDS INCREASE AHEAD OF AN APPROACHING TROUGH. WILL
BEGIN PRECIP ON WEDNESDAY NIGHT AS A DEEP SOUTHERLY FLOW
DEVELOPS...THEN CONTINUE PRECIP INTO THURSDAY AS A BROAD TROUGH WILL
BE OVER THE EASTERN CONUS. THE TROUGH LIFTS OUT ON FRIDAY BUT A LOW
LEVEL SOUTHERLY FLOW CONTINUES AHEAD OF AN APPROACHING SURFACE
FRONT. WILL CONTINUE WITH PRECIP MENTION FRIDAY AND
SATURDAY...MAINLY DIURNALLY DRIVEN. WILL START SUNDAY WITH A CHANCE
OF SHOWERS AS THE FRONT APPROACHES. TEMPS FRIDAY THROUGH SUNDAY
LOWER-MID 60S/LOWER-MID 80S. -DGS

.RAH...FLOOD WATCH CENTRAL NORTH CAROLINA THROUGH TONIGHT.

CLINE