FXUS62 KGSP 111826
AFDGSP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
226 PM EDT TUE MAR 11 2008

.SYNOPSIS...
HIGH PRESSURE WILL CONTINUE OVER GEORGIA AND THE CAROLINAS INTO 
THURSDAY...WITH STEADILY WARMING TEMPERATURES.  A SERIES OF UPPER 
LEVEL DISTURBANCES WILL CROSS THE REGION FRIDAY THROUGH 
SATURDAY...BEFORE A RETURN TO COOLER TEMPERATURES UNDER HIGH 
PRESSURE ON SUNDAY.
&&

.NEAR TERM /THROUGH WEDNESDAY/...
WEAKENING SHORTWAVE PRODUCING SCT LIGHT RAIN SHOWERS OVER CNTRL GA 
WILL CONTINUE MOVG E THIS AFTN. SOME LIGHT RETURNS CONTINUE JUST SW 
OF CWA BUT SFC OBS SHOW MAINLY SCT LOW CLOUDS AND BROKEN MID CLOUDS. 
MODELS CONTINUE TO SHOW ALL BUT MID/HIGH LEVEL MOISTURE DISSIPATING 
THIS FAR TO THE NE BUT SPRINKLES AND ISOLD SHOWERS ARE PSBL OVER THE 
S CWA THROUGH EARLY EVE SO CARRIED SLIGHT CHANCE POPS THERE. 
SHORTWAVE PASSES E AND SKIES CLEAR LATE THIS EVE. WITH LIGHT WINDS 
OVERNIGHT SLIGHTLY BELOW AVG MORNING LOWS ARE EXPECTED. FOR WED 
AFTN...HIGH PRESSURE... PLENTY OF SUNSHINE...LIGHT WINDS...LOW RH 
AND RELATIVELY HIGH THICKNESS VALUES...SHOULD ALLOW HI TEMPS TO WARM 
SEVERAL CATEGORIES ABOVE AVG.
&&

.SHORT TERM /WEDNESDAY NIGHT THROUGH THURSDAY NIGHT/...
AS OF 145 PM TUESDAY...A LOW AMPLITUDE UPPER AIR PATTERN WILL EXIST 
ACROSS MUCH OF THE EASTERN HALF OF THE COUNTRY THROUGH THE SHORT 
TERM. WEAK SHORT EMBEDDED SHORT WAVE TROUGHS WILL MOVE THROUGH THE 
PATTERN ON OCCASION...BUT MOISTURE SHOULD REMAIN INCONSEQUENTIAL... 
SO POPS WILL BE HELD OUT OF THE FORECAST. THE MAIN STORY THROUGH THE 
SHORT TERM WILL BE WARM TEMPERATURES...WITH MAXES EXPECTED TO REACH 
THE LOWER 70S ACROSS MUCH OF THE NON-MOUNTAINOUS AREAS ON THURSDAY. 
&&


.LONG TERM /FRIDAY THROUGH TUESDAY/...
AS OF 2 PM TUESDAY...A FRONTAL BOUNDARY WILL SAG INTO THE TENNESSEE 
AND OHIO VALLEYS BY FRIDAY...WITH DEEP SOUTHERLY/SOUTHWESTERLY FLOW 
DEVELOPING AHEAD OF THIS FEATURE. BY THEN...THE GULF WILL BEGIN TO 
OPEN UP...SO MOISTURE WILL BE ON THE INCREASE DURING THIS TIME. 
MEANWHILE...A LOW-AMPLITUDE SW TROUGH WILL EJECT OUT OF THE SOUTHERN 
PLAINS FRIDAY NIGHT/EARLY SATURDAY. IN RESPONSE TO THIS...LOW 
PRESSURE DEVELOPING ALONG THE FRONT WILL GIVE IT A PUSH TOWARD THE 
CAROLINAS SATURDAY/ SATURDAY AFTERNOON. THE FLOW ASSOCIATED WITH 
THIS FEATURE WILL BE QUITE STRONG...WITH SHEAR VALUES MORE THAN 
ADEQUATE FOR ORGANIZED CONVECTION. THE VERY INTERESTING ASPECT OF 
THIS SYSTEM (AT LEAST FROM THE PERSPECTIVE OF THE GFS) IS THE 
ELEVATED MIXED LAYER AIR THAT ADVECTS FROM THE MEXICAN PLATEAU... 
ACROSS THE SOUTHEAST AND INTO THE CAROLINAS IN ADVANCE OF THIS 
SYSTEM. THIS RESULTS IN VERY STEEP MID-LEVEL LAPSE RATES. THE 
CONSEQUENCE OF THIS IS THAT CAPE VALUES WOULD BE UNUSUALLY HIGH FOR 
THIS TIME OF YEAR. THIS IS A HIGHLY UNUSUAL SITUATION FOR OUR AREA. 
IN FACT...GFS FORECAST SOUNDINGS BEAR A STRONG RESEMBLANCE TO THE 
TEXTBOOK /LOADED GUN/ SOUNDINGS FROM THE PLAINS. I CERTAINLY HAVE MY 
DOUBTS ABOUT THIS  VERIFYING. HOWEVER...THIS WILL BE SOMETHING TO 
KEEP AN EYE ON...AS A PERFECT PROG OF THE GFS WOULD LIKELY SPELL 
ANOTHER SIGNIFICANT SEVERE WEATHER OUTBREAK FOR OUR AREA ON 
SATURDAY.    

NORTHWEST FLOW RAIN/SNOW SHOWERS ARE EXPECTED BEHIND THE FRONT...AND 
THERE COULD BE SOME ACCUMULATING SNOW...AT LEAST IN THE HIGHER 
ELEVATIONS. THE LATEST GFS HAS BACKED OFF A BIT ON WINDS IN THE COLD 
ADVECTION FLOW...BUT SUNDAY SHOULD STILL BE QUITE BREEZY. 

FOR SUNDAY NIGHT AND MONDAY WE ARE UNDER AN UPPER RIDGE WITH SURFACE 
HIGH PRESSURE CENTERED NEAR THE GREAT LAKES.  A DEVELOPING LOW 
PRESSURE AND FRONT OVER THE ROCKIES THEN OVER THE PLAINS WILL BE 
PROGRESSING TOWARD THE EAST.  WITH THE HIGH CENTERED BETWEEN THE 
GREAT LAKES AND NEW ENGLAND MID DAY MONDAY...NORTHEAST FLOW WILL 
PROVIDE A COOLING INFLUENCE TO OUR NORTHEAST ZONES.  THE COLD FRONT 
WILL BE CROSSING TENNESSEE AND ALABAMA LATE TUESDAY WITH SHOWERS 
INCREASING FROM THE WEST.  THE LATEST GFS RUN HAS THE FRONT MOVING 
IN FASTER.  THE END PERIOD OF THE NEW DAY 7 HAS THE FRONT MOVING 
ACROSS THEN EAST OF OUR FORECAST AREA.  THE ECMWF HAS A DIFFERENT 
SOLUTION WITH ANOTHER STRONG SHORTWAVE MOVING IN FROM THE WEST AT 
THE END OF THE NEW DAY 7...TUESDAY NIGHT. THIS EC WAY HOLDS THE MAIN 
SLUG OF PRECIP FROM GETTING TO US FOR AT LEAST ANOTHER DAY AND 
POSSIBLY MORE PRECIP AS THE GFS FRONTAL PRECIP WAS GETTING THINNER.
&&

.AVIATION /19Z TUESDAY THROUGH SUNDAY/...
SHORTWAVE ALOFT AND ASSOC SFC BOUNDARY APPROACHING FROM THE W WILL 
SPREAD MID CLOUD CIGS ACROSS AREA. EXPECT SCT VFR LOW CLOUDS MID AFTN 
THROUGH MID EVE. THERE IS A SLIGHT CHANCE OF LIGHT RAIN SHOWERS OVER 
S CWA BUT TOO LOW TO MENTION IN TAFS. SKIES WILL BEGIN TO SCT OUT 
AROUND MID EVENING FROM THE W. LIGHT SW WINDS EXPECTED THIS 
AFT-EVE...NW AT KAVL...THEN W TO NW WED MORNING.

OUTLOOK...HIGH PRESSURE REBUILDS OVER THE AREA THROUGH THU. A COLD 
FRONT WILL MOVE IN FROM THE W WITH SHOWERS LATE FRI AND A CHANCE OF 
TSTMS SAT. 
&&

.FIRE WEATHER...
ABOVE AVG TEMPS ALONG WITH LOW DEWPOINTS WILL LEAD TO MIN RH VALUES 
AROUND 25 PERCENT ACROSS THE FOOTHILLS AND PIEDMONT WED AFTN. 10 
HOUR FUEL MOISTURE VALUES ACROSS NE GA APPEAR TO BE VERY CLOSE TO 10 
PERCENT...WITH RH AT OR BELOW 25 PERCENT FOR 2-3 HOURS. THIS DOES 
NOT QUITE REACH RED FLAG CRITERIA BUT WILL BE CLOSELY MONITORED FOR 
POSSIBLE RED FLAG WARNING FOR WED AFTN.
&&

.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.

&&

$$

SYNOPSIS...DEO
NEAR TERM...RB
SHORT TERM...JDL
LONG TERM...JDL/DEO 
AVIATION...RB 
FIRE WEATHER...RB