000
FXUS62 KGSP 051830
AFDGSP
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
230 PM EDT SAT JUL 5 2008
.SYNOPSIS...
A WEAK STATIONARY FRONT WILL REMAIN JUST NORTH AND WEST OF THE
FORECAST AREA FOR THE NEXT COUPLE OF DAYS. THIS FRONT WILL DISSIPATE
MONDAY AS AN UPPER LEVEL RIDGE BUILDS ACROSS THE REGION. HIGH
PRESSURE WILL STRENGTHEN OFF THE ATLANTIC COAST THROUGH THE MIDDLE
OF NEXT WEEK AND MOIST FLOW AROUND THE WESTERN EDGE OF THIS HIGH WILL
KEEP THE ATMOSPHERE UNSETTLED THROUGH THE MIDDLE OF NEXT WEEK.
&&
.NEAR TERM /THROUGH SUNDAY/...
BAND OF SHOWERS/TSTMS WILL MOVE THRU E CWA THIS AFTN. CLEARING
BEHIND THIS BAND HAS WARMED TEMPS QUICKLY TO DESTABILZE AREA FOR
CONVECTION THRU THIS EVE. FREEZING LEVEL AROUND 13KFT ON LAPS
SOUNDINGS YIELDS 50-55DBZ OF 31KFT FOR LARGE HAIL. WITH MOIST
PROFILE ALL THE WAY UP...DCAPE LOW TODAY...SO DAMAGING WINDS LESS
LIKELY AND WITH WBZ UP OVER 12KFT IT WILL TAKE A PRETTY BIG CORE FOR
HAIL TO REACH SFC...WHICH IS CERTAINLY PSBL. IN ANY CASE...HAVE
LIKELY POPS ACROSS CWA UNTIL 9PM...CHANCE OVERNIGHT. LOWS FROM NEAR
70 PIEDMONT...MID 50S TO LOW 60S MTNS. WITH SFC HIGH REMAINING OFF
THE SE COAST...MOIST S FLOW CONTINUES SUN WITH SOLID CHANCE POPS
ACROSS AREA...LOW END LIKELY ACROSS SE CWA. HIGHS SHOULD REACH THE
MID TO UPPER 80S WITH MID 70S TO AROUND 80 MTNS.
&&
.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY NIGHT/...
AS OF 1 PM SATURDAY...THE AXIS OF THE UPPER TROUGH INCHES CLOSE TO
THE SOUTHERN APPALACHIANS SUNDAY NIGHT...THEN DEAMPLIFICATION BEGINS
ON MONDAY...HOWEVER A WEAK SHEAR AXIS REMAINS JUST WEST OF THE
MOUNTAINS THROUGH TUESDAY NIGHT. THE WEAKENING STATIONARY FRONT IS
EXPECTED TO REMAIN TO OUR NORTHWEST FROM SUNDAY NIGHT THROUGH
TUESDAY NIGHT...WITH OUR AREA ON THE WARM AND MOIST SIDE OF THE
BOUNDARY. INSTABILITY WILL BE MAXIMIZED IN THE PIEDMONT ON MONDAY
AFTERNOON AND EVENING...AND IN THE SAVANNAH RIVER VALLEY AND
SOUTHERN MOUNTAINS TUESDAY AFTERNOON AND EVENING. CHANCE POPS WILL
BE TAILORED TO FIT THIS SCENARIO...AS LOW LEVEL WINDS BACK MONDAY TO
INTRODUCE A MODEST UPSLOPE COMPONENT ALONG THE SOUTHERN BLUE RIDGE
ESCARPMENT. WIND SHEAR WILL BE A LITTLE STRONGER ON SUNDAY THAN ON
MONDAY...BUT EITHER DAY WILL HAVE ENOUGH MOISTURE AND INSTABILITY TO
SUPPORT ISOLATED SEVERE THUNDERSTORMS...MAINLY OF THE PULSE VARIETY.
TEMPERATURES WILL RUN NEAR NORMAL...WITH A SLIGHTLY DECREASED
DIURNAL RANGE DUE TO CLOUD COVER.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
AS OF 210 PM SATURDAY...MODELS CONTINUE TO SHOW GOOD CONSENSUS WITH
BUILDING SUBTROPICAL RIDGE AND A STACKED BERMUDA SFC HIPRES OVER THE
SOUTHEAST REGION WED THROUGH THE EXTENDED PERIOD. A COLD FRONT WITH
LITTLE UPPER SUPPORT IS PROGGED TO REACH THE CWFA THU. THE 00Z ECMWF
AGREES WELL WITH THE 12Z GFS AND 12Z HPC GUIDANCE AS FAR AS TIMING
THE SFC BOUNDARY NORTH OF THE CWFA DURING THE AFTERNOON. WED SHOULD
HAVE A NORMAL SMALL CHANCE OF STRONG/SEVERE TS...AROUND 30
PERCENT...AS DEEP AND MOIST SOUTHERLY FLOW SETS OFF SCT AFTERNOON
CONVECTION. HOWEVER THU WILL BE A BIT MORE DYNAMIC AND CAPE VALUES
WILL INCREASE DUE TO DEWPOINT POOLING AHEAD OF THE FRONT. WILL
EXPECT A BIT MORE WIDESPREAD COVERAGE THU AND POPS WERE RAISED INTO
THE MID 40S ACROSS MOST OF THE CWFA. NO AIRMASS CHANGE IS EXPECTED
IN THE LLVLS FRI AS FRONT BARLEY IMPINGES ON THE AREA...BUT THE UPPER
LEVELS DRY OUT FAIRLY SIGNIFICANTLY WITH A 594 DM H5 HIGH BUILDING
ACROSS THE DEEP SOUTH IN THE WAKE OF THE EXITING UPPER TROF AND A
STRONG SUBSIDENCE ZONES SETS UP ACROSS THE CWFA. THIS BROAD STABLE
LAYER ALOFT SHOULD INHIBIT ANY GOOD CHANCE OF CONVECTION FOR FRI AND
SAT. POPS FOR THESE TWO DAYS HAVE BEEN REDUCED TO SLIGHT EXCEPT
ACROSS THE NC MTNS FRI AS LINGERING LLVL MOISTURE AIDED BY
MECHANICAL LIFTING MIGHT BE ENOUGH TO OVERCOME THE BUILDING CAP. MAX
TEMPS THROUGH THE PERIOD SHOULD BE RIGHT AROUND NORMAL WED AND
THU...BUT A CAT OR TWO ABOVE NORMAL IS EXPECTED FRI AND SAT WITH
DEEP MID/UPPER LEVEL DRYING PERSISTING.
&&
.AVIATION /19Z SATURDAY THROUGH THURSDAY/...
BAND OF SHOWERS WITH MVFR CIG/VSBY WILL MOVE THRU KHKY AND KCLT BY
20Z WITH SOME CLEARING BEHIND. LOOK FOR S TO SW SFC WINDS GENERALLY
LESS THAN 10 KTS. AS SFC HEATS UP EXPECT RESURGENCE OF CONVECTION
LATER THIS AFTN-EVE ACROSS AREA. KEPT LIKELY POPS OVER MTNS...SOLID
CHANCE ELSEWHERE...BECOMING LIKELY ACROSS MOST OF CWA FOR LATE
AFTN-EARLY EVE SO HAVE VCSH AND CB CLOUDS ALL TAF SITES. VSBY WILL
BE THE MAIN CONCERN LATE NIGHT THRU EARLY SUN WITH MVFR ALL
SITES...IFR KAVL. WITH MOIST SW FLOW CONTINUING AT LEAST CHANCE POPS
CONTINUE THRU SUN.
OUTLOOK...LITTLE OVERALL CHANCGE THRU DAY FIVE. AS SFC RIDGE REMAINS
OFFSHORE BRINGING MOISTURE UP OVER REGION EXPECT MAINLY DIURNAL
CONVECTION WITH ASSOC HAZARDS.
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...SBK
NEAR TERM...RB
SHORT TERM...JAT
LONG TERM...SBK
AVIATION...RB
