Flash Flood Warning 49, NWS Raleigh, NC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
218 AM EDT MON OCT 11 1999

LATEST WATER VAPOR SHOW WEAK WAVE MOVING NORTHEAST THROUGH WESTERN
SECTIONS OF STATE BRINGING LAST ROUND OF HEAVIER RAIN. THEN EXPECT
LIGHTER RAIN FOR REST OF THE EARLY MORNING HOURS.

MODELS IN GENERAL AGREEMENT (NGM/ETA...AVN JUST COMING IN) IN MOVING
SHEARED S/W AXIS EAST THEN SOUTHEAST ACROSS AREA TODAY....WEAKENING
AS IT MOVES THROUGH. ALSO MOISTURE FEED DECREASES. BASED ON CURRENT
RADAR TRENDS PRECIP WILL CUT OFF OVER WESTERN CWA BY DAYBREAK AS
THIS AREA IN NVA BY THEN. ALSO ALREADY SEEING BACK EDGE OF PRECIP
IN FOOTHILLS.
ONCE S/W MOVES THROUGH NEARLY ZONAL FLOW DEVELOPS TONIGHT INTO
TUESDAY.

LATEST SURFACE ANALYSIS SHOW COLD FRONT APPROACHING MOUNTAINS. JUST
A FEW LIGHT SHOWERS ALONG FRONT. AGAIN MODELS SIMILAR ON
MOVING FRONT THRU WESTERN CWA BY DAYBREAK...CENTRAL MIDDAY TO EARLY
AFTERNOON AND EASTERN MID TO LATE AFTERNOON. WITH FRONT MOVING THROUGH
EASTERN SECTIONS DURING THE AFTERNOON ALONG WITH HEATING...LIFT...PRECIP
WATERS IN THE 1.5 RANGE AND FAVORED POSITION OF JET...SCATTERED
THUNDERSTORMS POSSIBLE. SOME CONCERN THAT FRONT MAY HANG UP IN THE
MOUNTAINS AS NOT SEEING BIG PUSH BEHIND...THUS DELAY FRONTAL PASSAGE
INTO AFTERNOON. IF THATS THE CASE...ISOLATED THUNDERSTORM POSSIBLE
CENTRAL CWA AS WELL. SPC DAY ONE KEEPS GENERAL THUNDER ALL OF CWA.
THINK DYNAMICS EAST OF WESTERN CWA TO NOT MENTION THUNDER.
HIGH PRESSURE BUILDING OVER THE REGION TONIGHT AND TUESDAY WITH FLOW
GOING NORTHEAST. NOT MUCH CHANGE IN AIR MASS AFTER FRONTAL PASSAGE.

FOR TODAY...AS AFOREMENTIONED ALREADY SEEING BACK EDGE OF RAIN IN
FOOTHILLS. PLAN TO TRIM POPS BACK TO CHANCES IN THE WEST...HIGH CHANCE
TO LIKELY CENTRAL AND EAST. FINAL ADJUSTMENT TO POPS JUST BEFORE
RELEASE DEPENING ON RADAR COVERAGE. PLENTY OF LOW LEVEL MOISTURE
REMAINING...SO CLOUDS WILL BE SLOW TO DISSIAPATE.

TONIGHT...PLENTY OF LOW LEVEL MOISTURE CONTINUING TONIGHT WITH DRYING
MID/UPPER LEVELS. THINK MOSTLY CLOUDY BEST BET.

TUESDAY...HIGH PRESSURE OVER AREA BUT MOVING OFFSHORE DURING THE
AFTERNOON WITH EASTERLY FLOW DEVELOPING...SOUTHEAST OVERNIGHT
TUESDAY. NOT SURE ABOUT MUCH BREAK IN THE CLOUDS AS PLENTY OF
LOW LEVEL MOISTURE REMAINS. BUT MID UPPER LEVELS CONTINUE TO DRY
OUT. NGM MOS KEEPS IN LOW POPS. WITH NORTHEAST FLOW...VARIABLY CLOUDY
MAY BE BEST.

TEMPERATURES...CURRENT FORECAST LOOKS REASONABLE. WILL ADJUST WHERE
NEEDED.

EXTENDED....EAST/SOUTHEAST FLOW SHOULD INCREASE MOISTURE TUESDAY
NIGHT. AGAIN MOS GIVES LOW POPS. FOR NOW WILL GO MOSTLY CLOUDY.
COLD FRONT TO CROSS STATE ON WEDNESDAY BRINGING ANOTHER ROUND OF
SHOWERS. EXTENDED GUIDANCE GIVES HIGH POPS...LIKELY. FOR NOW
WILL KEEP IN THE CHANCE. ABOVE NORMAL POPS INDICATED FOR THURSDAY
AS WELL BUT WILL KEEP DRY THURSDAY AND FRIDAY. WILL TAKE A LOOK AT
LONG RANGE MODELS AND ADJUST IF NEEDED.

HAVE A GOOD MORNING.

.RDU...NONE.

RA