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AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
1022 PM EDT TUE SEP 1 2015

.SYNOPSIS...
GENERAL HIGH PRESSURE WILL LINGER ACROSS THE REGION THIS WEEK WITH 
WEAK UPPER LEVEL DISTURBANCES CROSSING OVERHEAD BEGINNING WEDNESDAY. 
A COOL AND MOIST AREA OF HIGH PRESSURE IS EXPECTED TO SETTLE ACROSS 
THE WESTERN CAROLINAS AND NORTHEAST GEORGIA THIS WEEKEND INTO EARLY 
NEXT WEEK.

&&

.NEAR TERM /THROUGH WEDNESDAY/...
AS OF 1020 PM...SHRA HAVE DISSIPATED...STRATOCU IS DIMINISHING AND 
WINDS ARE BECOMING CALM. GOING FCST IS ON TRACK WITH UPDATES MAINLY 
FOR CURRENT CONDITIONS.

AS OF 730 PM...SHRA LINGERING ACROSS THE NC MTNS WILL DISSIPATE 
EARLY THIS EVENING. OTHERWISE...EXPECT DIMINISHING STRATOCU 
OVERNIGHT WITH ANOTHER ROUND OF PATCHY DENSE MTN VALLEY FOG. LOW 
TEMPS ON TRACK...SO CHANGES MAINLY FOR CURRENT CONDITIONS.

AS OF 425 PM...SHRA BEGINNING TO DEVELOP OVER THE RIDGES OF THE NRN 
MTNS. EXPECT COVERAGE TO SLOWLY INCREASE THRU THE REST OF THE 
AFTERNOON THEN TAPER OFF EARLY IN THE EVENING. CURRENT FCST HAS THIS 
COVERED. UPDATED MAINLY FOR CURRENT CONDITIONS.

PREVIOUS DISCUSSION...ALTHOUGH THE LATEST VISIBLE SATELLITE IMAGERY 
INDICATES THE CU FIELD CONTINUES TO APPEAR QUITE HEALTHY ACROSS THE 
MTNS...HAVE YET TO SEE ANY DEEP CONVECTION INITIATE THIS AFTERNOON. 
THE ATM IS WEAKLY UNSTABLE...AND IT/S APPEARING THAT COVERAGE WILL 
BE QUITE MINIMAL THIS AFTERNOON. NEVERTHELESS...HAVEN/T GIVEN UP ON 
CONVECTION YET...ESP IN LIGHT OF THE WELL-DEVELOPED CU FIELD...THUS  
POPS WILL BE RETAINED IN THE 20-30 PERCENT RANGE ACROSS MOST OF THE 
MTNS AND FOOTHILLS. ANY CONVECTION THAT DOES DEVELOP WILL DISSIPATE 
QUICKLY THIS EVENING. MIN TEMPS SHOULD BE ABOUT A DEGREE WARMER THAN 
THIS MORNING/S READINGS...AS HEIGHTS CONTINUE TO INCREASE ALOFT. 

CONTINUED GRADUAL AIR MASS RECOVERY/INCREASING DEWPOINTS AND EVEN 
MORE WARMTH...WITH PROGGED LOW LEVEL THICKNESS VALUES SUPPORTING MAX 
TEMPS ABOUT TWO CATEGORIES ABOVE CLIMO...WILL RESULT IN INCREASING 
INSTABILITY FOR WED AFTERNOON...ALTHOUGH SBCAPE SHOULD REMAIN RATHER 
MODEST AT LESS THAN 2000 J/KG. MEANWHILE...SHORT TERM GUIDANCE IS IN 
GOOD AGREEMENT IN ALLOWING HEIGHT FALLS OVERSPREADING THE NORTH 
CENTRAL CONUS TO KICK THE AREA OF VORTICITY...CURRENTLY SITTING OVER 
INDIANA...TO KICK TOWARD THE CENTRAL APPALACHIANS AND MID-ATLANTIC 
TONIGHT THROUGH TOMORROW. CHANCE POPS WILL ONCE AGAIN BE FEATURED 
NEAR THE BLUE RIDGE...BUT ALSO ACROSS THE NC MTNS AND FHILLS...WHICH 
WILL BE CLOSER TO THE AREA OF UPPER FORCING. SLIGHT CHANCE POPS WILL 
BE FEATURED ACROSS MOST OF THE REMAINDER OF THE FORECAST AREA.

&&

.SHORT TERM /WEDNESDAY NIGHT THROUGH THURSDAY NIGHT/...
AS OF 145 PM TUESDAY...THE SHORT TERM WILL FEATURE OVERALL HEIGHT 
FALLS AT 500 MB ALONG THE APPALACHIAN CHAIN...AS A LARGE UPPER RIDGE 
BUILDS OVER THE MS VALLEY TO THE GREAT LAKES. THE MID AND UPR FLOW 
WILL REMAIN RATHER WEAK. HOWEVER...THE MODELS AGREE ON SOME Q-VECTOR 
CONVERGENCE ATOP THE CWFA...ESP ON FRIDAY. AT THE SFC...WEAK HIGH 
PRES WILL REMAIN CENTERED OVER THE AREA ON THURSDAY...BUT THEN GIVE 
WAY TO A WEAK BACK DOOR COLD FRONT THAT WILL PUSH INTO THE AREA ON 
FRIDAY. SO THURSDAY LOOKS LIKE ANOTHER VERY WARM DAY WITH ONLY 
ISOLATED TO WIDELY SCATTERED AFTN CONVECTION...MAINLY IN THE MTNS. 
WHILE FRIDAY LOOKS MORE ACTIVE...AS GUIDANCE IN GOOD AGREEMENT ON 
BETTER INSTBY...WITH PLENTY OF LLVL MOISTURE POOLING ALONG THE 
BNDRY. POPS RAMP UP TO SOLID CHC TO NEAR LIKELY IN THE MTNS AND 
LOW-END CHC ACRS THE PIEDMONT BY FRIDAY AFTN. TEMPS WILL BE IN THE 
LOW 90S ON THURSDAY ACRS THE PIEDMONT...AND A CATEGORY OR TWO COOLER 
ON FRIDAY. LOW TEMPS WILL BE ABOVE NORMAL WITH INCREASING HUMIDITY.

&&

.LONG TERM /FRIDAY THROUGH TUESDAY/...
AS OF 200 PM TUESDAY...AN ULVL PATTERN CHANGE IS IN STORE OVER THE 
WEEKEND. THERE IS GOOD GENERAL AGREEMENT WITH WITH THE DEVELOPMENT 
OF A CLOSED LOW DROPPING SOUTH ACROSS THE NORTH ATL ENABLING A NA 
OMEGA BLOCK AND A WEAKNESS OR BROAD CLOSED LOW DEVELOPING OVER THE 
SE CONUS. THE PERSISTENT UPPER RIDGE WILL ANCHOR A SFC HIGH ACROSS 
NEW ENG WITH SFC RIDGING INTO THE SE REGION TO SOME DEGREE. THERE IS 
SOME UNCERTAINTY AS TO THE STRENGTH OF THE LLVL RIDGE AND THUS THE 
QPF RESPONSE IN ISENT LIFTED ATL MOISTURE FLUX. 

SAT LOOKS TO HAVE THE BEST CHANCE FOR SCT TO PERHAPS NUMEROUS 
-SHRA...BUT WITH VARYING IDEAS TO THE PATTERN AND MOISTURE 
TRANSPORT...WILL SIDE ON THE LOWER END AND KEEP POPS IN THE LOW TO 
MID CHANCE RANGE. THE AMOUNT OF INSTABILITY WILL BE ANOTHER FACTOR 
THAT SHOULD BE LOW-END PER MODEL SOUNDINGS AND WEAK MLVL 
FORCING...THUS WILL LOWER GENERAL THUNDER MENTION TO ISOL COVERAGE. 
DECENT CONFIDENCE IS HAD IN THE LAYERED E/LY FLOW HOWEVER...AND THIS 
SHOULD LEAD TO A MODEST QPF RESPONSE MAINLY ACROSS THE BLUE RIDGE. 
THE CAD LIKE RIDGE WILL REMAIN IN PLACE AND WEAKEN A LITTLE SUN. 
WITH LESS ISENT LIFT AS THE SFC RIDGE WEAKENS...WILL FAVOR THE MTNS 
WITH CHANCE POPS AND ISOL ELSEWHERE. INSTABILITY ON SUNDAY WILL BE 
LESS THAN SAT AS WARMER AIR ALOFT DEVELOPS UNDER THE RIDGE 
AXIS...THUS THUNDER WILL NOT BE MENTIONED. MAX TEMPS WILL BE HELD A 
COUPLE CATS BELOW NORMAL BOTH SAT/SUN...WITH MINS RIGHT ARND OR A 
BIT ABOVE NORMAL IN GOOD NOCTURNAL CLOUD COVER. 

THE UPPER PATTERN SHIFTS SIGFNTLY AGAIN ON MON AS THE SE UPPER LOW 
BECOMES DOMINANT AND THE NRN RIDGE AXIS PUSHES EAST. THIS WILL 
WEAKEN THE SFC RIDGE FROM THE SOUTH THROUGH THE PERIOD AND DECREASE 
THE AMOUNT OF MOISTURE FLUX AS A BROAD COASTAL TROF FORMS. THERE 
WILL STILL BE A ENUF GENERAL LIFT AND INCREASING INSOL FOR AFTERNOON 
SHRA/TSTMS. THUS...POPS WERE MAINTAINED IN THE SEASONAL RANGE. MAX 
TEMPS AND TD/S WILL REMAIN RELATIVELY LOW AND RECOVER SLOWLY AS THE 
SFC FLOW IS HELD IN A NE/LY TO E/LY CONFIG DUE TO THE COASTAL 
TROF...SO ANY THUNDER MENTION WILL BE LIMITED TO THE SRN BLUE RIDGE 
WITHIN MTN TOP CONVERG. MAX TEMPS SHOULD REBOUND TO NORMAL LEVELS BY 
TUES.

&&

.AVIATION /02Z WEDNESDAY THROUGH SUNDAY/...
AT KCLT AND ELSEWHERE...VFR CONDITIONS ARE EXPECTED THROUGH THE 
PERIOD...WITH THE EXCEPTION OF ANOTHER ROUND OF MTN VALLEY LOW 
STRATUS AND FOG TOMORROW MORNING. THAT SAID...COULD BE ANOTHER 
MORNING WHERE VALLEYS ARE SOCKED IN...BUT CONDITIONS NOT AS BAD AT 
THE AIRPORT. CANNOT RULE OUT A BRIEF RESTRICTION AT KHKY/KAND AS FOG 
FLOATS OFF THE NEARBY LAKES. LINGERING STRATOCU WILL GRADUALLY 
DISSIPATE OVERNIGHT. CU RETURNS WITH HEATING WED. EXPECT A BETTER 
CHC OF CONVECTION WED AS AN UPPER LEVEL DISTURBANCE DRIFTS TOWARD 
THE AREA. HOWEVER...CHC LOW ENUF FOR PROB30 TO BE LIMITED TO KHKY 
AND KAVL. LIGHT WINDS BECOME CALM OVERNIGHT THEN BECOME SW WED... 
EXCEPT NLY AT KAVL AND NW AT KHKY.

OUTLOOK...A PATTERN OF DIURNAL ISOLATED/WIDELY SCT SHOWERS AND 
THUNDERSTORMS IS EXPECTED TO CONTINUE THROUGH THE WORK WEEK. BY THE 
WEEKEND...A MOIST EASTERLY FLOW IS EXPECTED TO DEVELOP...BRINGING 
BETTER CHANCES FOR SHOWERS AND RESTRICTIONS. LOW CLOUDS AND FOG  
WILL BE POSSIBLE EACH NIGHT IN THE MOUNTAIN VALLEYS.

CONFIDENCE TABLE...

            02-08Z        08-14Z        14-20Z        20-00Z 
KCLT       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%     
KGSP       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%     
KAVL       HIGH 100%     LOW   51%     HIGH 100%     HIGH 100%     
KHKY       HIGH 100%     HIGH  91%     HIGH 100%     HIGH 100%     
KGMU       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%     
KAND       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%     

THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY
EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS
ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)

WWW.WEATHER.GOV/GSP/AVIATION

&&

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

&&

$$
SYNOPSIS...SBK
NEAR TERM...JDL/RWH
SHORT TERM...ARK
LONG TERM...SBK
AVIATION...RWH

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