FXUS62 KGSP 040202 AAA
AFDGSP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
1000 PM EDT THU JUN 3 2004

.UPDATE...
THE MAIN CONCERN FOR THE OVERNIGHT HOURS IS THE POSSIBILITY OF 
FLOODING RAINS ACROSS MAINLY THE MOUNTAINS AND FOOTHILLS. IN SPITE 
OF A WEAKENING TREND OVER THE PAST HOUR...AS SEEN ON KGSP RADAR... 
CURRENT THINKING IS THAT EVENING WARM TOPPED CONVECTION HAS MERELY 
SET THE STAGE FOR POSSIBLE FLOODING LATER TONIGHT. IT APPEARS THAT 
WE WILL HAVE ENOUGH INGREDIENTS FOR FLOODING LATE TONIGHT AS SHORT 
WAVE APPROACHES FROM THE WEST. MOISTURE CONTINUES TO INCREASE THIS 
EVENING AND UPPER AIR ANALYSIS/WATER VAPOR IMAGERY SHOW DEEPER 
MOISTURE INVADING FROM THE WEST. PW EXPECTED TO CLIMB ABOVE 1.5 
INCHES WHICH WOULD BE ABOUT 150 PCT OF NORMAL. AS 850 MB LOW MOVES 
PAST TONIGHT...LOW LEVEL FLOW WILL CONTINUE TO BACK WITH EASTERLY 
UPSLOPE COMPONENT...ALREADY EVIDENT ON GSO SOUNDING...STRENGTHENING 
AND PULLING MORE LOW LEVEL MOISTURE INTO FORECAST AREA. ISENTROPIC 
UPGLIDE ALSO STRENGTHENS QUICKLY. UPPER DIFFLUENCE AHEAD OF 
APPROACHING WAVE AND UPPER DIVERGENCE IN RIGHT ENTRANCE REGION OF 
WEAK JET WILL ALSO ENHANCE UPWARD VERTICAL MOTION. MOST TROUBLING IS 
THE EXPECTED SLOW MOVEMENT OF CONVECTION THAT SHOULD DEVELOP IN 
FAVORED UPSLOPE AREA NEAR BLUE RIDGE ESCARPMENT. LOW LEVEL EASTERLY 
FLOW OPPOSING MID LEVEL WESTERLY FLOW SHOULD KEEP CELLS ANCHORED 
ONCE THEY DEVELOP. 

EXPECT RADAR TO LIGHT UP AS ALL THE INGREDIENTS COME INTO PLACE 
DURING THE EARLY MORNING HOURS. IN LIGHT OF QPFERD...THINK BEST 
COURSE OF ACTION IS TO ISSUE FLOOD WATCH FOR NC MOUNTAINS (WITH 
EXCEPTION OF GRAHAM AND MACON) AND THE ADJACENT NC FOOTHILLS... 
UNTIL NOON.

PRECIP CHANCES WILL BE BUMPED UP TO CATEGORICAL RANGE ACROSS 
MTNS/FOOTHILLS TONIGHT...AND OUT INTO PARTS OF NC PIEDMONT LATE 
TONIGHT AND FRIDAY MORNING. TEMPS WILL BE ADJUSTED UP A DEGREE OR 
TWO OWING TO INCREASE IN SKY COVER.

&&

.PREV DISCUSSION...
ISSUED AT 235 PM.
SHORT TERM...
UPPER RIDGE OVER ROCKIES WITH BROAD UPPER LOW OVER FAR NE 
COAST...WITH A SHORTWAVE TROF OVER UPPER MIDWEST DIGGING SOUTH 
TOWARD JUNCTION OF OH AND MS VALLEYS. CONVECTION FIRING OVER GULF 
STATES ONCE AGAIN TODAY WHICH IS EXPECTED TO STAY S AND CONTINUE 
TRACKING E AS IN PREV DAYS. HOWEVER...H5 SHORTWAVE MOVES SE OF OH 
VALLEY AND IS EXPECTED TO DESTABILIZE ATMOS LATE TONIGHT INTO FRI. 
AN H85 CLOSED LOW IS FORECAST TO DEVELOP WEST OF CWA THIS EVE WHICH 
WOULD CAUSE LOW LEVELS TO MOISTEN SIGNIFICANTLY OVERNIGHT WITH 
INCREASING SOUTHERLY FLOW AS LOW DEEPENS. THIS IS ALSO REFLECTED AT 
THE SURFACE WITH A STRONG LOW DEVELOPING WEST AND MOVING OVER AREA 
TONIGHT INTO FRI. WILL GO WITH LIKELY POPS OVERNIGHT THROUGH MIDDAY 
FRI. A WEAK RIDGE BUILDS IN SAT AND SUN.

LONG TERM...
THE AFFECTS OF THE DEVELOPING SYSTEM TONIGHT WILL RIPPLE TIMING 
CONCERNS INTO THE EXTENDED PERIOD. THE LATEST RUNS OF THE GFS KEEPS 
THE FRONTAL BOUNDARY SOUTH OF THE FA UNTIL IT LIFTS OVER THE REGION 
ON MON AS A WARM FRONT. IT CONTINUES TO APPEAR ON THE GFS THAT THE 
EAST TO WEST FRONT WILL BECOME STATIONARY OVER THE MID ATLANTIC 
THROUGH THE REST OF THE EXTENDED PERIOD. THE CWA SHOULD SEE A 
DIURNAL UNSTABLE PATTERN ON THE RIM OF THE BERMUDA HIGH. AS BEEN THE 
CASE...WILL ADVERTISE CHC POPS WITH FAVOR GIVEN TO THE MTNS...THIS 
LOOKS GOOD CONSIDERING BLYR LI/S OF -4 TO -6C. WITH DEEP RIDGING 
ALOFT WILL CONTINUE TO ADVERTISE TEMPS AT TO SLIGHTLY ABOVE CLIMO.
RB/NED
&&

.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...FLOOD WATCH UNTIL NOON FRIDAY NCZ033-034-048>055-059-063>067.
SC...NONE.
&&

$$

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