Home > Products > Valid Products > AFD

000
FXUS62 KGSP 240601
AFDGSP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
201 AM EDT THU APR 24 2014

.SYNOPSIS...
DRY HIGH PRESSURE...CENTERED NEAR THE GREAT LAKES...WILL CONTROL OUR
WEATHER THROUGH THURSDAY. A WEAK COLD FRONT WILL CROSS THE FORECAST
AREA ON FRIDAY...WITH A REINFORCING FRONT STALLING IN THE VICINITY
OF THE REGION OVER THE WEEKEND. A WET AND POSSIBLY STORMY PATTERN
WILL SET UP FOR EARLY NEXT WEEK...FOLLOWED BY COOLER WEATHER.

&&

.NEAR TERM /THROUGH TODAY/...
AS OF 1245 AM...TEMPS/DEWPTS/WINDS ARE PRETTY MUCH ON TRACK. SO NO
CHANGES NEEDED EXCEPT TO UPDATE THE AVIATION GRIDS FOR THE 06Z TAFS.

AT 1030 PM EDT... VIRTUALLY NO CHANGES NEEDED IN LATE EVENING
UPDATE.  HIGH PRESSURE SYSTEM EXTENDING FROM CANADA SOUTHWARD INTO
THE SOUTHEASTERN STATES WILL BE THE PRIMARY FEATURE AFFECTING THE
WEATHER OVERNIGHT AND THURSDAY. WINDS CONTINUE... GENERALLY LESS
THAN 10 MPH... BUT WEAKENING TREND WILL PERSIST AS SURFACE-BASED
INVERSION DEVELOPS. AT 10 PM... NOAA/ESRL PROFILER AT MARION STILL
HAD FAIRLY DEEP LAYER... TO ABOUT 8000 FT... OF NORTHWEST WIND
AROUND 10 KT WHILE OLD FORT PROFILER AT THE FOOT OF THE BLUE RIDGE
ESCARPMENT DISPLAYED A VARIABLE WIND AT LESS THAN 10 MPH FROM THE
SURFACE TO ABOUT 4500 FEET. NEW NAM INDICATES SURFACE PRESSURE
GRADIENT RELAXES A BIT OVER WESTERN NORTH CAROLINA BY 2 AM... SO
EXPECT SPEEDS WILL DECREASE PER THE FORECAST.

PREVIOUS DISCUSSIONS...
AT 730 PM EDT... SATELLITE IMAGERY SHOWS CLOUD-FREE SKY CONTINUES
INTO THE EVENING ACROSS MUCH OF THE EASTERN U.S. CENTER OF HIGH
PRESSURE IS NEAR HUDSON BAY BUT THE SURFACE RIDGE EXTENDS SOUTHWARD
ALL THE WAY TO THE GULF COAST STATES. HIGH HAS SUPPRESSED MOISTURE
FAR TO OUR SOUTH AND UPPER LEVEL RIDGE IS OVER THE MISSISSIPPI
VALLEY SO CLEAR WEATHER WILL CONTINUE OVERNIGHT. AIR IS SO DRY THAT
FOG... EVEN IN MOUNTAIN VALLEYS... SHOULD NOT BE AN ISSUE. THURSDAY
MORNING LOW TEMPERATURES IN THE MID AND UPPER 30S IN THE MOUNTAIN
VALLEYS ARE SUFFICIENTLY COLD FOR FROST... BUT THE DRY AIR SHOULD
RESULT IN ONLY PATCHY FROST AS SUNRISE APPROACHES.

AT 445 PM EDT... HIGH PRESSURE CENTERED TO OUR NORTH AND UPPER LEVEL
RIDGE TO THE WEST CONTINUE THE FAIR WEATHER ACROSS THE REGION.
REMAINING GUSTINESS IN THE SURFACE WINDS WILL DIMINISH QUICKLY
AROUND SUNSET. ONLY CHANGES TO FORECAST AT THIS TIME TAKE INTO
ACCOUNT CURRENT TEMPERATURES AND DEWPOINTS.

AS OF 150 PM...WEAKENING PRESSURE GRADIENT HAS RESULTED IN MID TO
UPPER TEEN WIND GUSTS ACROSS THE MTNS AND NC FOOTHILLS/PIEDMONT THIS
AFTERNOON. LATEST OBSERVATIONS INDICATED A NOTICEABLE DROP IN RH
VALUES ACROSS THE REGION...ESPECIALLY ACROSS PIEDMONT AREAS. THE
FIRE DANGER STATEMENT CONTINUES TO LOOK WELL PLACED AND TIMED ACROSS
THE NC ZONES.

OVERNIGHT...DRY HIGH PRESSURE WILL RIDGE ACROSS THE WESTERN
CAROLINAS AS A COLD FRONT SLIDES ACROSS OK/TX. WINDS ARE FORECAST TO
REMAIN LIGHT FROM THE NE OR BECOME CALM DURING THE PRE DAWN HOURS.
THE LIMITED MIXING AND CLEAR/MOSTLY CLEAR SKY COVER WILL FAVOR
RADIATIONAL COOLING. HOWEVER...SOUTH H85 WINDS AROUND 15KTS AND LOW
AMPLITUDE RIDGING MAY PROVIDE WEAK LLVL WAA ACROSS THE SOUTHERN
APPALACHIANS. GIVEN THE WEAK WAA...I WILL INDICATE A SLIGHT INVERSE
LAPSE RATE IN THE MIN TEMPERATURE ACROSS THE MTNS. BLENDING OF THE
PREFERRED GUIDANCE SUPPORTS MIN TEMPERATURES BETWEEN 3 TO 6 DEGREES
BELOW NORMAL. I WILL INDICATE UPPER 30S ACROSS THE MTNS AND NC
FOOTHILLS...WITH LOW 40S ACROSS THE I-40 CORRIDOR...WITH MID TO
UPPER 40S ACROSS THE UPPER SAVANNAH RIVER VALLEY AND UPSTATE. PATCHY
FROST IS POSSIBLE WITHIN THE MTNS VALLEYS...BUT BELOW FROST ADVISORY
CRITERIA.

THURSDAY...THE COLD FRONT WILL SWEEP EAST ACROSS THE
ARKLATX...GRADUALLY INCREASING THE RETURN FLOW ACROSS THE FORECAST
AREA. DEWPOINTS ARE FORECAST TO RECOVER 5 TO 10 DEGREES FROM THIS
AFTERNOON. HIGH TEMPERATURES ARE FORECAST TO RANGE WITHIN 1 TO 2
DEGREES OF NORMAL...RESULTING IN RH VALUES IN THE 30S.
OVERALL...CONDITIONS SHOULD REMAIN DRY WITH MOSTLY SUNNY CONDITIONS.

&&

.SHORT TERM /TONIGHT THROUGH SATURDAY/...
AS OF 240 PM WED...A RELATIVELY STRONG SHORT WAVE APPROACHES THE
AREA THU NITE AND CROSSES THE AREA FRI. THIS WAVE WILL PUSH A COLD
FRONT ACROSS THE AREA FRIDAY AS WELL. MOISTURE AND ISENTROPIC LIFT
INCREASE THU NITE...BRINGING CHC POP TO THE MTNS AND FOOTHILLS AFTER
MIDNIGHT. GOOD FORCING MOVES IN FRI MORNING WITH THE FRONT AND SHORT
WAVE...BRINGING LIKELY POP TO THE MTNS AND GOOD CHC POP TO THE I-40
CORRIDOR. FORCING AND DEEP MOISTURE IS A LITTLE LOWER OVER NE GA AND
THE WESTERN UPSTATE. THEREFORE...HAVE LIMITED POP TO 40 PERCENT OVER
ALL BUT THE MOUNTAIN PORTIONS. BEST CHC POP SHIFTS TO THE I-77
CORRIDOR FOR THE AFTERNOON AS THE FRONT MOVES INTO THAT AREA. THE
GFS STILL HAS MORE INSTABILITY THAN THE NAM...BUT ITS VALUES HAVE
DECREASED. WHILE THERE WILL BE SOME SHEAR GIVEN THE STRENGTH OF THE
SHORT WAVE AND COLD FRONT...IT GENERALLY REMAINS IN THE LIGHT RANGE.
THEREFORE...ALTHOUGH SCT THUNDERSTORMS WILL DEVELOP...SEVERE STORM
POTENTIAL IS LOW. QPF AMOUNTS ARE NOT EXPECTED TO BE EXCESSIVE
EITHER. TEMPS WILL BE AROUND 5 DEGREES ABOVE NORMAL.

PRECIP WILL QUICKLY TAPER OFF EARLY FRI EVENING AS THE FRONT MOVES
EAST OF THE AREA. A LOW AMPLITUDE UPPER TROF WILL CROSS THE AREA SAT
AS AN UPPER LOW MOVES FROM THE GREAT LAKES INTO NEW ENGLAND. AT THE
SFC...HIGH PRESSURE BUILDS IN BRIEFLY BEFORE A WEAK BACK DOOR COLD
FRONT APPROACHES FROM THE NORTH BY THE END OF THE DAY. THE RESULT
WILL BE DRY WX AND MOSTLY SUNNY SKIES. LOWS WILL RANGE FROM NEAR
NORMAL TO 5 DEGREES ABOVE NORMAL. HIGHS WILL BE 5 TO 10 DEGREES
ABOVE NORMAL.

&&

.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
AS OF 240 PM EDT WED...THE EXTENDED PART OF THE FORECAST STARTS WITH
A DEEP-LAYER SHORTWAVE RIDGE TRANSLATING ACROSS THE REGION. THIS
SHOULD BRING FAIR AND MILD WEATHER. HOWEVER...THE MODELS HAVE BEEN
TRADING OFF RUN TO RUN AS TO WHETHER A BACK DOOR COLD FRONT CROSSES
THE REGION...BRINGING WITH IT COOLER AND POTENTIALLY CLOUDY WEATHER
IN THE FORM OF COLD AIR DAMMING. FOR NOW I STAYED WITH THE WARMER
AND DRIER EC SOLUTION.

BY MONDAY PW/S BEGIN TO INCREASE ON THE GFS AND LLVL ISENTROPIC
UPGLIDE AND UPSLOPE FLOW DEVELOPS. THE ECMWF IS A LITTLE
SLOWER...THOUGH IT HAS BASICALLY THE SAME SOLUTION. AGAIN...THERE
ISN/T MUCH TO DISAGREE WITH CONCERNING THE WPC GRIDS AND I HAVE
MOSTLY CLOUDY SKIES AND A CHANCE OF SHOWERS. INSTABILITY WILL BE
LIMITED AND ONLY A SMALL CHANCE OF TSTMS IS EXPECTED. BY MONDAY
NIGHT AND TUESDAY THE GFS PW/S INCREASE TO ALMOST 1.75 INCHES AND
THERE IS A CONSIDERABLE INCREASE IN THE LLVL FLOW. WE SHOULD ALSO BE
UNDER STRONG UPPER DIVERGENCE AS A UPPER TROPOSPHERIC JET MAX SHIFTS
EASTWARD UNDER A BROAD UPPER LOW THAT WILL BE CENTERED OVER
MISSOURI. THE POTENTIAL EXISTS FOR HEAVY RAIN LATER MONDAY INTO
TUESDAY. THERE MAY ALSO BE A SEVERE THREAT...THOUGH THE MOIST
WORKED-OVER AIRMASS AND GENERALLY VEERED LLVL FLOW DOESN/T SEEM
CONDUCIVE TO THE HIGH END SEVERE THREAT THAT WILL AFFECT THE PLAINS
WITH THE SYSTEM OVER THE WEEKEND. OF COURSE IT IS STILL QUITE EARLY
TO GET TOO CUTE WITH THE CHANCES OF SEVERE WEATHER FOR THE MON/TUE
PART OF THE FORECAST.

CONFIDENCE IN THE DAY 7 PART OF THE FORECAST IS LOW AS THERE WILL BE
SEVERAL CHUNKS OF SHORT WAVE ENERGY EMBEDDED WITHIN THE BROAD UPPER
LOW THAT WILL SLOWLY CROSS INTO THE EASTERN CONUS. ALL THE MODELS
AGREE THAT THERE WILL BE CONSIDERABLE DOWNSTREAM BLOCKING...SO THE
TROUGH SHOULD DEFINITELY PARK OVER THE REGION FOR A FEW DAYS.
HOWEVER...DEPENDING ON THE TIMING AND HOW ADVECTIVE INDIVIDUAL SHORT
WAVES ARE...THERE MIGHT BE A CHANCE FOR SOME ORGANIZED SEVERE
WEATHER WITH THE COOLING HEIGHTS.

&&

.AVIATION /06Z THURSDAY THROUGH MONDAY/...
KCLT AND ELSEWHERE...VFR CONDITIONS EXPECTED THRU THE PERIOD. A N-S
AXIS OF DRY HIGH PRES WILL SHIFT EAST OF THE AREA TODAY...CAUSING
THE WINDS TO VEER FROM NE OVERNIGHT TO SE BY MIDDAY. WINDS SHUD
REMAIN FAIRLY LIGHT...GENERALLY UNDER 10 KTS. OTHER THAN OCCASIONAL
FILAMENTS OF CIRRUS...IT SHUD BE SKC THRU THIS AFTN. A COLD FRONT
WILL ENTER THE OHIO/TENN VALLEY TONIGHT...WITH INCREASING MID AND
HIGH CLOUDS TOWARD THE END OF THE TAF PERIOD.

OUTLOOK...A COLD FRONT WITH POTENTIAL FOR SHOWERS/TSTMS IS EXPECTED
TO CROSS THE REGION FRIDAY. THEN DRY HIGH PRES RETURNS SATURDAY THRU
SUNDAY.

CONFIDENCE TABLE...

            06-12Z        12-18Z        18-24Z        00-06Z
KCLT       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KGSP       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KAVL       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KHKY       HIGH 100%     HIGH 100%     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_TABLES

&&

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

&&

$$
SYNOPSIS...DEO
NEAR TERM...ARK/LGL
SHORT TERM...RWH
LONG TERM...MCAVOY
AVIATION...ARK








000
FXUS62 KGSP 240231
AFDGSP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
1031 PM EDT WED APR 23 2014

.SYNOPSIS...
DRY HIGH PRESSURE...CENTERED NEAR THE GREAT LAKES...WILL CONTROL OUR
WEATHER THROUGH THURSDAY. A WEAK COLD FRONT WILL CROSS THE FORECAST
AREA ON FRIDAY...WITH A REINFORCING FRONT STALLING IN THE VICINITY
OF THE REGION OVER THE WEEKEND. A WET AND POSSIBLY STORMY PATTERN
WILL SET UP FOR EARLY NEXT WEEK...FOLLOWED BY COOLER WEATHER.

&&

.NEAR TERM /THROUGH THURSDAY/...
AT 1030 PM EDT... VIRTUALLY NO CHANGES NEEDED IN LATE EVENING
UPDATE.  HIGH PRESSURE SYSTEM EXTENDING FROM CANADA SOUTHWARD INTO
THE SOUTHEASTERN STATES WILL BE THE PRIMARY FEATURE AFFECTING THE
WEATHER OVERNIGHT AND THURSDAY. WINDS CONTINUE... GENERALLY LESS
THAN 10 MPH... BUT WEAKENING TREND WILL PERSIST AS SURFACE-BASED
INVERSION DEVELOPS. AT 10 PM... NOAA/ESRL PROFILER AT MARION STILL
HAD FAIRLY DEEP LAYER... TO ABOUT 8000 FT... OF NORTHWEST WIND
AROUND 10 KT WHILE OLD FORT PROFILER AT THE FOOT OF THE BLUE RIDGE
ESCARPMENT DISPLAYED A VARIABLE WIND AT LESS THAN 10 MPH FROM THE
SURFACE TO ABOUT 4500 FEET. NEW NAM INDICATES SURFACE PRESSURE
GRADIENT RELAXES A BIT OVER WESTERN NORTH CAROLINA BY 2 AM... SO
EXPECT SPEEDS WILL DECREASE PER THE FORECAST.

PREVIOUS DISCUSSIONS...
AT 730 PM EDT... SATELLITE IMAGERY SHOWS CLOUD-FREE SKY CONTINUES
INTO THE EVENING ACROSS MUCH OF THE EASTERN U.S. CENTER OF HIGH
PRESSURE IS NEAR HUDSON BAY BUT THE SURFACE RIDGE EXTENDS SOUTHWARD
ALL THE WAY TO THE GULF COAST STATES. HIGH HAS SUPPRESSED MOISTURE
FAR TO OUR SOUTH AND UPPER LEVEL RIDGE IS OVER THE MISSISSIPPI
VALLEY SO CLEAR WEATHER WILL CONTINUE OVERNIGHT. AIR IS SO DRY THAT
FOG... EVEN IN MOUNTAIN VALLEYS... SHOULD NOT BE AN ISSUE. THURSDAY
MORNING LOW TEMPERATURES IN THE MID AND UPPER 30S IN THE MOUNTAIN
VALLEYS ARE SUFFICIENTLY COLD FOR FROST... BUT THE DRY AIR SHOULD
RESULT IN ONLY PATCHY FROST AS SUNRISE APPROACHES.

AT 445 PM EDT... HIGH PRESSURE CENTERED TO OUR NORTH AND UPPER LEVEL
RIDGE TO THE WEST CONTINUE THE FAIR WEATHER ACROSS THE REGION.
REMAINING GUSTINESS IN THE SURFACE WINDS WILL DIMINISH QUICKLY
AROUND SUNSET. ONLY CHANGES TO FORECAST AT THIS TIME TAKE INTO
ACCOUNT CURRENT TEMPERATURES AND DEWPOINTS.

AS OF 150 PM...WEAKENING PRESSURE GRADIENT HAS RESULTED IN MID TO
UPPER TEEN WIND GUSTS ACROSS THE MTNS AND NC FOOTHILLS/PIEDMONT THIS
AFTERNOON. LATEST OBSERVATIONS INDICATED A NOTICEABLE DROP IN RH
VALUES ACROSS THE REGION...ESPECIALLY ACROSS PIEDMONT AREAS. THE
FIRE DANGER STATEMENT CONTINUES TO LOOK WELL PLACED AND TIMED ACROSS
THE NC ZONES.

OVERNIGHT...DRY HIGH PRESSURE WILL RIDGE ACROSS THE WESTERN
CAROLINAS AS A COLD FRONT SLIDES ACROSS OK/TX. WINDS ARE FORECAST TO
REMAIN LIGHT FROM THE NE OR BECOME CALM DURING THE PRE DAWN HOURS.
THE LIMITED MIXING AND CLEAR/MOSTLY CLEAR SKY COVER WILL FAVOR
RADIATIONAL COOLING. HOWEVER...SOUTH H85 WINDS AROUND 15KTS AND LOW
AMPLITUDE RIDGING MAY PROVIDE WEAK LLVL WAA ACROSS THE SOUTHERN
APPALACHIANS. GIVEN THE WEAK WAA...I WILL INDICATE A SLIGHT INVERSE
LAPSE RATE IN THE MIN TEMPERATURE ACROSS THE MTNS. BLENDING OF THE
PREFERRED GUIDANCE SUPPORTS MIN TEMPERATURES BETWEEN 3 TO 6 DEGREES
BELOW NORMAL. I WILL INDICATE UPPER 30S ACROSS THE MTNS AND NC
FOOTHILLS...WITH LOW 40S ACROSS THE I-40 CORRIDOR...WITH MID TO
UPPER 40S ACROSS THE UPPER SAVANNAH RIVER VALLEY AND UPSTATE. PATCHY
FROST IS POSSIBLE WITHIN THE MTNS VALLEYS...BUT BELOW FROST ADVISORY
CRITERIA.

THURSDAY...THE COLD FRONT WILL SWEEP EAST ACROSS THE
ARKLATX...GRADUALLY INCREASING THE RETURN FLOW ACROSS THE FORECAST
AREA. DEWPOINTS ARE FORECAST TO RECOVER 5 TO 10 DEGREES FROM THIS
AFTERNOON. HIGH TEMPERATURES ARE FORECAST TO RANGE WITHIN 1 TO 2
DEGREES OF NORMAL...RESULTING IN RH VALUES IN THE 30S.
OVERALL...CONDITIONS SHOULD REMAIN DRY WITH MOSTLY SUNNY CONDITIONS.

&&

.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/...
AS OF 240 PM WED...A RELATIVELY STRONG SHORT WAVE APPROACHES THE
AREA THU NITE AND CROSSES THE AREA FRI. THIS WAVE WILL PUSH A COLD
FRONT ACROSS THE AREA FRIDAY AS WELL. MOISTURE AND ISENTROPIC LIFT
INCREASE THU NITE...BRINGING CHC POP TO THE MTNS AND FOOTHILLS AFTER
MIDNIGHT. GOOD FORCING MOVES IN FRI MORNING WITH THE FRONT AND SHORT
WAVE...BRINGING LIKELY POP TO THE MTNS AND GOOD CHC POP TO THE I-40
CORRIDOR. FORCING AND DEEP MOISTURE IS A LITTLE LOWER OVER NE GA AND
THE WESTERN UPSTATE. THEREFORE...HAVE LIMITED POP TO 40 PERCENT OVER
ALL BUT THE MOUNTAIN PORTIONS. BEST CHC POP SHIFTS TO THE I-77
CORRIDOR FOR THE AFTERNOON AS THE FRONT MOVES INTO THAT AREA. THE
GFS STILL HAS MORE INSTABILITY THAN THE NAM...BUT ITS VALUES HAVE
DECREASED. WHILE THERE WILL BE SOME SHEAR GIVEN THE STRENGTH OF THE
SHORT WAVE AND COLD FRONT...IT GENERALLY REMAINS IN THE LIGHT RANGE.
THEREFORE...ALTHOUGH SCT THUNDERSTORMS WILL DEVELOP...SEVERE STORM
POTENTIAL IS LOW. QPF AMOUNTS ARE NOT EXPECTED TO BE EXCESSIVE
EITHER. TEMPS WILL BE AROUND 5 DEGREES ABOVE NORMAL.

PRECIP WILL QUICKLY TAPER OFF EARLY FRI EVENING AS THE FRONT MOVES
EAST OF THE AREA. A LOW AMPLITUDE UPPER TROF WILL CROSS THE AREA SAT
AS AN UPPER LOW MOVES FROM THE GREAT LAKES INTO NEW ENGLAND. AT THE
SFC...HIGH PRESSURE BUILDS IN BRIEFLY BEFORE A WEAK BACK DOOR COLD
FRONT APPROACHES FROM THE NORTH BY THE END OF THE DAY. THE RESULT
WILL BE DRY WX AND MOSTLY SUNNY SKIES. LOWS WILL RANGE FROM NEAR
NORMAL TO 5 DEGREES ABOVE NORMAL. HIGHS WILL BE 5 TO 10 DEGREES
ABOVE NORMAL.

&&

.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
AS OF 240 PM EDT WED...THE EXTENDED PART OF THE FORECAST STARTS WITH
A DEEP-LAYER SHORTWAVE RIDGE TRANSLATING ACROSS THE REGION. THIS
SHOULD BRING FAIR AND MILD WEATHER. HOWEVER...THE MODELS HAVE BEEN
TRADING OFF RUN TO RUN AS TO WHETHER A BACK DOOR COLD FRONT CROSSES
THE REGION...BRINGING WITH IT COOLER AND POTENTIALLY CLOUDY WEATHER
IN THE FORM OF COLD AIR DAMMING. FOR NOW I STAYED WITH THE WARMER
AND DRIER EC SOLUTION.

BY MONDAY PW/S BEGIN TO INCREASE ON THE GFS AND LLVL ISENTROPIC
UPGLIDE AND UPSLOPE FLOW DEVELOPS. THE ECMWF IS A LITTLE
SLOWER...THOUGH IT HAS BASICALLY THE SAME SOLUTION. AGAIN...THERE
ISN/T MUCH TO DISAGREE WITH CONCERNING THE WPC GRIDS AND I HAVE
MOSTLY CLOUDY SKIES AND A CHANCE OF SHOWERS. INSTABILITY WILL BE
LIMITED AND ONLY A SMALL CHANCE OF TSTMS IS EXPECTED. BY MONDAY
NIGHT AND TUESDAY THE GFS PW/S INCREASE TO ALMOST 1.75 INCHES AND
THERE IS A CONSIDERABLE INCREASE IN THE LLVL FLOW. WE SHOULD ALSO BE
UNDER STRONG UPPER DIVERGENCE AS A UPPER TROPOSPHERIC JET MAX SHIFTS
EASTWARD UNDER A BROAD UPPER LOW THAT WILL BE CENTERED OVER
MISSOURI. THE POTENTIAL EXISTS FOR HEAVY RAIN LATER MONDAY INTO
TUESDAY. THERE MAY ALSO BE A SEVERE THREAT...THOUGH THE MOIST
WORKED-OVER AIRMASS AND GENERALLY VEERED LLVL FLOW DOESN/T SEEM
CONDUCIVE TO THE HIGH END SEVERE THREAT THAT WILL AFFECT THE PLAINS
WITH THE SYSTEM OVER THE WEEKEND. OF COURSE IT IS STILL QUITE EARLY
TO GET TOO CUTE WITH THE CHANCES OF SEVERE WEATHER FOR THE MON/TUE
PART OF THE FORECAST.

CONFIDENCE IN THE DAY 7 PART OF THE FORECAST IS LOW AS THERE WILL BE
SEVERAL CHUNKS OF SHORT WAVE ENERGY EMBEDDED WITHIN THE BROAD UPPER
LOW THAT WILL SLOWLY CROSS INTO THE EASTERN CONUS. ALL THE MODELS
AGREE THAT THERE WILL BE CONSIDERABLE DOWNSTREAM BLOCKING...SO THE
TROUGH SHOULD DEFINITELY PARK OVER THE REGION FOR A FEW DAYS.
HOWEVER...DEPENDING ON THE TIMING AND HOW ADVECTIVE INDIVIDUAL SHORT
WAVES ARE...THERE MIGHT BE A CHANCE FOR SOME ORGANIZED SEVERE
WEATHER WITH THE COOLING HEIGHTS.

&&

.AVIATION /03Z THURSDAY THROUGH MONDAY/...
KCLT AND ELSEWHERE...CEILING UNLIMITED AND VISIBILITY UNRESTRICTED.
CENTER OF HIGH PRESSURE IS NEAR HUDSON BAY BUT THE SURFACE RIDGE
EXTENDS SOUTHWARD INTO THE SOUTHEASTERN U.S. SURFACE RIDGE WILL
DRIFT SLOWLY TO THE EAST ON THURSDAY. WINDS ARE IN THE PROCESS OF
BECOMING NORTHEAST... BUT SPEEDS WILL BECOME VERY LOW DURING THE
EARLY MORNING HOURS AS SURFACE INVERSION DEVELOPS. AFTER SUNRISE
THURSDAY... SURFACE INVERSION DISSIPATES AND VEERING WIND TREND WILL
CONTINUE AS HIGH DRIFTS EAST. CIRRUS CLOUD WILL INCREASE BY LATE
THURSDAY AS MOISTURE BEGINS TO INCREASE AHEAD OF FRONTAL SYSTEM
APPROACHING FROM THE WEST.

OUTLOOK...ANOTHER COLD FRONT WITH POTENTIAL FOR SHOWERS/TSTMS IS
THEN EXPECTED TO CROSS THE REGION FRIDAY...DRYING OUT BY SATURDAY.

CONFIDENCE TABLE...

            02-08Z        08-14Z        14-20Z        20-02Z
KCLT       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KGSP       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KAVL       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KHKY       HIGH 100%     HIGH 100%     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_TABLES

&&


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

&&

$$
SYNOPSIS...DEO
NEAR TERM...LGL
SHORT TERM...RWH
LONG TERM...MCAVOY
AVIATION...LGL








000
FXUS62 KGSP 232356
AFDGSP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
756 PM EDT WED APR 23 2014

.SYNOPSIS...
DRY HIGH PRESSURE...CENTERED NEAR THE GREAT LAKES...WILL CONTROL OUR
WEATHER THROUGH THURSDAY. A WEAK COLD FRONT WILL CROSS THE FORECAST
AREA ON FRIDAY...WITH A REINFORCING FRONT STALLING IN THE VICINITY
OF THE REGION OVER THE WEEKEND. A WET AND POSSIBLY STORMY PATTERN
WILL SET UP FOR EARLY NEXT WEEK...FOLLOWED BY COOLER WEATHER.

&&

.NEAR TERM /THROUGH THURSDAY/...
AT 730 PM EDT... SATELLITE IMAGERY SHOWS CLOUD-FREE SKY CONTINUES
INTO THE EVENING ACROSS MUCH OF THE EASTERN U.S. CENTER OF HIGH
PRESSURE IS NEAR HUDSON BAY BUT THE SURFACE RIDGE EXTENDS SOUTHWARD
ALL THE WAY TO THE GULF COAST STATES. HIGH HAS SUPPRESSED MOISTURE
FAR TO OUR SOUTH AND UPPER LEVEL RIDGE IS OVER THE MISSISSIPPI
VALLEY SO CLEAR WEATHER WILL CONTINUE OVERNIGHT. AIR IS SO DRY THAT
FOG... EVEN IN MOUNTAIN VALLEYS... SHOULD NOT BE AN ISSUE. THURSDAY
MORNING LOW TEMPERATURES IN THE MID AND UPPER 30S IN THE MOUNTAIN
VALLEYS ARE SUFFICIENTLY COLD FOR FROST... BUT THE DRY AIR SHOULD
RESULT IN ONLY PATCHY FROST AS SUNRISE APPROACHES.

PREVIOUS DISCUSSIONS...
AT 445 PM EDT... HIGH PRESSURE CENTERED TO OUR NORTH AND UPPER LEVEL
RIDGE TO THE WEST CONTINUE THE FAIR WEATHER ACROSS THE REGION.
REMAINING GUSTINESS IN THE SURFACE WINDS WILL DIMINISH QUICKLY
AROUND SUNSET. ONLY CHANGES TO FORECAST AT THIS TIME TAKE INTO
ACCOUNT CURRENT TEMPERATURES AND DEWPOINTS.

AS OF 150 PM...WEAKENING PRESSURE GRADIENT HAS RESULTED IN MID TO
UPPER TEEN WIND GUSTS ACROSS THE MTNS AND NC FOOTHILLS/PIEDMONT THIS
AFTERNOON. LATEST OBSERVATIONS INDICATED A NOTICEABLE DROP IN RH
VALUES ACROSS THE REGION...ESPECIALLY ACROSS PIEDMONT AREAS. THE
FIRE DANGER STATEMENT CONTINUES TO LOOK WELL PLACED AND TIMED ACROSS
THE NC ZONES.

OVERNIGHT...DRY HIGH PRESSURE WILL RIDGE ACROSS THE WESTERN
CAROLINAS AS A COLD FRONT SLIDES ACROSS OK/TX. WINDS ARE FORECAST TO
REMAIN LIGHT FROM THE NE OR BECOME CALM DURING THE PRE DAWN HOURS.
THE LIMITED MIXING AND CLEAR/MOSTLY CLEAR SKY COVER WILL FAVOR
RADIATIONAL COOLING. HOWEVER...SOUTH H85 WINDS AROUND 15KTS AND LOW
AMPLITUDE RIDGING MAY PROVIDE WEAK LLVL WAA ACROSS THE SOUTHERN
APPALACHIANS. GIVEN THE WEAK WAA...I WILL INDICATE A SLIGHT INVERSE
LAPSE RATE IN THE MIN TEMPERATURE ACROSS THE MTNS. BLENDING OF THE
PREFERRED GUIDANCE SUPPORTS MIN TEMPERATURES BETWEEN 3 TO 6 DEGREES
BELOW NORMAL. I WILL INDICATE UPPER 30S ACROSS THE MTNS AND NC
FOOTHILLS...WITH LOW 40S ACROSS THE I-40 CORRIDOR...WITH MID TO
UPPER 40S ACROSS THE UPPER SAVANNAH RIVER VALLEY AND UPSTATE. PATCHY
FROST IS POSSIBLE WITHIN THE MTNS VALLEYS...BUT BELOW FROST ADVISORY
CRITERIA.

THURSDAY...THE COLD FRONT WILL SWEEP EAST ACROSS THE
ARKLATX...GRADUALLY INCREASING THE RETURN FLOW ACROSS THE FORECAST
AREA. DEWPOINTS ARE FORECAST TO RECOVER 5 TO 10 DEGREES FROM THIS
AFTERNOON. HIGH TEMPERATURES ARE FORECAST TO RANGE WITHIN 1 TO 2
DEGREES OF NORMAL...RESULTING IN RH VALUES IN THE 30S.
OVERALL...CONDITIONS SHOULD REMAIN DRY WITH MOSTLY SUNNY CONDITIONS.

&&

.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/...
AS OF 240 PM WED...A RELATIVELY STRONG SHORT WAVE APPROACHES THE
AREA THU NITE AND CROSSES THE AREA FRI. THIS WAVE WILL PUSH A COLD
FRONT ACROSS THE AREA FRIDAY AS WELL. MOISTURE AND ISENTROPIC LIFT
INCREASE THU NITE...BRINGING CHC POP TO THE MTNS AND FOOTHILLS AFTER
MIDNIGHT. GOOD FORCING MOVES IN FRI MORNING WITH THE FRONT AND SHORT
WAVE...BRINGING LIKELY POP TO THE MTNS AND GOOD CHC POP TO THE I-40
CORRIDOR. FORCING AND DEEP MOISTURE IS A LITTLE LOWER OVER NE GA AND
THE WESTERN UPSTATE. THEREFORE...HAVE LIMITED POP TO 40 PERCENT OVER
ALL BUT THE MOUNTAIN PORTIONS. BEST CHC POP SHIFTS TO THE I-77
CORRIDOR FOR THE AFTERNOON AS THE FRONT MOVES INTO THAT AREA. THE
GFS STILL HAS MORE INSTABILITY THAN THE NAM...BUT ITS VALUES HAVE
DECREASED. WHILE THERE WILL BE SOME SHEAR GIVEN THE STRENGTH OF THE
SHORT WAVE AND COLD FRONT...IT GENERALLY REMAINS IN THE LIGHT RANGE.
THEREFORE...ALTHOUGH SCT THUNDERSTORMS WILL DEVELOP...SEVERE STORM
POTENTIAL IS LOW. QPF AMOUNTS ARE NOT EXPECTED TO BE EXCESSIVE
EITHER. TEMPS WILL BE AROUND 5 DEGREES ABOVE NORMAL.

PRECIP WILL QUICKLY TAPER OFF EARLY FRI EVENING AS THE FRONT MOVES
EAST OF THE AREA. A LOW AMPLITUDE UPPER TROF WILL CROSS THE AREA SAT
AS AN UPPER LOW MOVES FROM THE GREAT LAKES INTO NEW ENGLAND. AT THE
SFC...HIGH PRESSURE BUILDS IN BRIEFLY BEFORE A WEAK BACK DOOR COLD
FRONT APPROACHES FROM THE NORTH BY THE END OF THE DAY. THE RESULT
WILL BE DRY WX AND MOSTLY SUNNY SKIES. LOWS WILL RANGE FROM NEAR
NORMAL TO 5 DEGREES ABOVE NORMAL. HIGHS WILL BE 5 TO 10 DEGREES
ABOVE NORMAL.

&&

.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
AS OF 240 PM EDT WED...THE EXTENDED PART OF THE FORECAST STARTS WITH
A DEEP-LAYER SHORTWAVE RIDGE TRANSLATING ACROSS THE REGION. THIS
SHOULD BRING FAIR AND MILD WEATHER. HOWEVER...THE MODELS HAVE BEEN
TRADING OFF RUN TO RUN AS TO WHETHER A BACK DOOR COLD FRONT CROSSES
THE REGION...BRINGING WITH IT COOLER AND POTENTIALLY CLOUDY WEATHER
IN THE FORM OF COLD AIR DAMMING. FOR NOW I STAYED WITH THE WARMER
AND DRIER EC SOLUTION.

BY MONDAY PW/S BEGIN TO INCREASE ON THE GFS AND LLVL ISENTROPIC
UPGLIDE AND UPSLOPE FLOW DEVELOPS. THE ECMWF IS A LITTLE
SLOWER...THOUGH IT HAS BASICALLY THE SAME SOLUTION. AGAIN...THERE
ISN/T MUCH TO DISAGREE WITH CONCERNING THE WPC GRIDS AND I HAVE
MOSTLY CLOUDY SKIES AND A CHANCE OF SHOWERS. INSTABILITY WILL BE
LIMITED AND ONLY A SMALL CHANCE OF TSTMS IS EXPECTED. BY MONDAY
NIGHT AND TUESDAY THE GFS PW/S INCREASE TO ALMOST 1.75 INCHES AND
THERE IS A CONSIDERABLE INCREASE IN THE LLVL FLOW. WE SHOULD ALSO BE
UNDER STRONG UPPER DIVERGENCE AS A UPPER TROPOSPHERIC JET MAX SHIFTS
EASTWARD UNDER A BROAD UPPER LOW THAT WILL BE CENTERED OVER
MISSOURI. THE POTENTIAL EXISTS FOR HEAVY RAIN LATER MONDAY INTO
TUESDAY. THERE MAY ALSO BE A SEVERE THREAT...THOUGH THE MOIST
WORKED-OVER AIRMASS AND GENERALLY VEERED LLVL FLOW DOESN/T SEEM
CONDUCIVE TO THE HIGH END SEVERE THREAT THAT WILL AFFECT THE PLAINS
WITH THE SYSTEM OVER THE WEEKEND. OF COURSE IT IS STILL QUITE EARLY
TO GET TOO CUTE WITH THE CHANCES OF SEVERE WEATHER FOR THE MON/TUE
PART OF THE FORECAST.

CONFIDENCE IN THE DAY 7 PART OF THE FORECAST IS LOW AS THERE WILL BE
SEVERAL CHUNKS OF SHORT WAVE ENERGY EMBEDDED WITHIN THE BROAD UPPER
LOW THAT WILL SLOWLY CROSS INTO THE EASTERN CONUS. ALL THE MODELS
AGREE THAT THERE WILL BE CONSIDERABLE DOWNSTREAM BLOCKING...SO THE
TROUGH SHOULD DEFINITELY PARK OVER THE REGION FOR A FEW DAYS.
HOWEVER...DEPENDING ON THE TIMING AND HOW ADVECTIVE INDIVIDUAL SHORT
WAVES ARE...THERE MIGHT BE A CHANCE FOR SOME ORGANIZED SEVERE
WEATHER WITH THE COOLING HEIGHTS.

&&

.AVIATION /00Z THURSDAY THROUGH MONDAY/...
KCLT AND ELSEWHERE...CEILING UNLIMITED AND VISIBILITY UNRESTRICTED.
CENTER OF HIGH PRESSURE IS NEAR HUDSON BAY BUT THE SURFACE RIDGE
EXTENDS SOUTHWARD INTO THE SOUTHEASTERN U.S. SURFACE RIDGE WILL
DRIFT SLOWLY TO THE EAST ON THURSDAY. WINDS ARE IN THE PROCESS OF
BECOMING NORTHEAST... BUT SPEEDS WILL BECOME VERY LOW DURING THE
NIGHT AS SURFACE INVERSION DEVELOPS. AFTER SUNRISE THURSDAY...
SURFACE INVERSION DISSIPATES AND VEERING WIND TREND WILL CONTINUE AS
HIGH DRIFTS EAST. CIRRUS CLOUD WILL INCREASE BY LATE THURSDAY AS
MOISTURE BEGINS TO INCREASE AHEAD OF FRONTAL SYSTEM APPROACHING FROM
THE WEST.

OUTLOOK...ANOTHER COLD FRONT WITH POTENTIAL FOR SHOWERS/TSTMS IS
THEN EXPECTED TO CROSS THE REGION FRIDAY...DRYING OUT BY SATURDAY.

CONFIDENCE TABLE...

            00-06Z        06-12Z        12-18Z        18-24Z
KCLT       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KGSP       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KAVL       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KHKY       HIGH 100%     HIGH 100%     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_TABLES

&&


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

&&

$$
SYNOPSIS...DEO
NEAR TERM...LGL
SHORT TERM...RWH
LONG TERM...MCAVOY
AVIATION...LGL









000
FXUS62 KGSP 232054
AFDGSP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
454 PM EDT WED APR 23 2014

.SYNOPSIS...
DRY HIGH PRESSURE...CENTERED NEAR THE GREAT LAKES...WILL CONTROL OUR
WEATHER THROUGH THURSDAY. A WEAK COLD FRONT WILL CROSS THE FORECAST
AREA ON FRIDAY...WITH A REINFORCING FRONT STALLING IN THE VICINITY
OF THE REGION OVER THE WEEKEND. A WET AND POSSIBLY STORMY PATTERN
WILL SET UP FOR EARLY NEXT WEEK...FOLLOWED BY COOLER WEATHER.

&&

.NEAR TERM /THROUGH THURSDAY/...
AT 445 PM... HIGH PRESSURE CENTERED TO OUR NORTH AND UPPER LEVEL
RIDGE TO THE WEST CONTINUE THE FAIR WEATHER ACROSS THE REGION.
REMAINING GUSTINESS IN THE SURFACE WINDS WILL DIMINISH QUICKLY
AROUND SUNSET. ONLY CHANGES TO FORECAST AT THIS TIME TAKE INTO
ACCOUNT CURRENT TEMPERATURES AND DEWPOINTS.

PREVIOUS DISCUSSION...
AS OF 150 PM...WEAKENING PRESSURE GRADIENT HAS RESULTED IN MID TO
UPPER TEEN WIND GUSTS ACROSS THE MTNS AND NC FOOTHILLS/PIEDMONT THIS
AFTERNOON. LATEST OBSERVATIONS INDICATED A NOTICEABLE DROP IN RH
VALUES ACROSS THE REGION...ESPECIALLY ACROSS PIEDMONT AREAS. THE
FIRE DANGER STATEMENT CONTINUES TO LOOK WELL PLACED AND TIMED ACROSS
THE NC ZONES.

OVERNIGHT...DRY HIGH PRESSURE WILL RIDGE ACROSS THE WESTERN
CAROLINAS AS A COLD FRONT SLIDES ACROSS OK/TX. WINDS ARE FORECAST TO
REMAIN LIGHT FROM THE NE OR BECOME CALM DURING THE PRE DAWN HOURS.
THE LIMITED MIXING AND CLEAR/MOSTLY CLEAR SKY COVER WILL FAVOR
RADIATIONAL COOLING. HOWEVER...SOUTH H85 WINDS AROUND 15KTS AND LOW
AMPLITUDE RIDGING MAY PROVIDE WEAK LLVL WAA ACROSS THE SOUTHERN
APPALACHIANS. GIVEN THE WEAK WAA...I WILL INDICATE A SLIGHT INVERSE
LAPSE RATE IN THE MIN TEMPERATURE ACROSS THE MTNS. BLENDING OF THE
PREFERRED GUIDANCE SUPPORTS MIN TEMPERATURES BETWEEN 3 TO 6 DEGREES
BELOW NORMAL. I WILL INDICATE UPPER 30S ACROSS THE MTNS AND NC
FOOTHILLS...WITH LOW 40S ACROSS THE I-40 CORRIDOR...WITH MID TO
UPPER 40S ACROSS THE UPPER SAVANNAH RIVER VALLEY AND UPSTATE. PATCHY
FROST IS POSSIBLE WITHIN THE MTNS VALLEYS...BUT BELOW FROST ADVISORY
CRITERIA.

THURSDAY...THE COLD FRONT WILL SWEEP EAST ACROSS THE
ARKLATX...GRADUALLY INCREASING THE RETURN FLOW ACROSS THE FORECAST
AREA. DEWPOINTS ARE FORECAST TO RECOVER 5 TO 10 DEGREES FROM THIS
AFTERNOON. HIGH TEMPERATURES ARE FORECAST TO RANGE WITHIN 1 TO 2
DEGREES OF NORMAL...RESULTING IN RH VALUES IN THE 30S.
OVERALL...CONDITIONS SHOULD REMAIN DRY WITH MOSTLY SUNNY CONDITIONS.

&&

.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/...
AS OF 240 PM WED...A RELATIVELY STRONG SHORT WAVE APPROACHES THE
AREA THU NITE AND CROSSES THE AREA FRI. THIS WAVE WILL PUSH A COLD
FRONT ACROSS THE AREA FRIDAY AS WELL. MOISTURE AND ISENTROPIC LIFT
INCREASE THU NITE...BRINGING CHC POP TO THE MTNS AND FOOTHILLS AFTER
MIDNIGHT. GOOD FORCING MOVES IN FRI MORNING WITH THE FRONT AND SHORT
WAVE...BRINGING LIKELY POP TO THE MTNS AND GOOD CHC POP TO THE I-40
CORRIDOR. FORCING AND DEEP MOISTURE IS A LITTLE LOWER OVER NE GA AND
THE WESTERN UPSTATE. THEREFORE...HAVE LIMITED POP TO 40 PERCENT OVER
ALL BUT THE MOUNTAIN PORTIONS. BEST CHC POP SHIFTS TO THE I-77
CORRIDOR FOR THE AFTERNOON AS THE FRONT MOVES INTO THAT AREA. THE
GFS STILL HAS MORE INSTABILITY THAN THE NAM...BUT ITS VALUES HAVE
DECREASED. WHILE THERE WILL BE SOME SHEAR GIVEN THE STRENGTH OF THE
SHORT WAVE AND COLD FRONT...IT GENERALLY REMAINS IN THE LIGHT RANGE.
THEREFORE...ALTHOUGH SCT THUNDERSTORMS WILL DEVELOP...SEVERE STORM
POTENTIAL IS LOW. QPF AMOUNTS ARE NOT EXPECTED TO BE EXCESSIVE
EITHER. TEMPS WILL BE AROUND 5 DEGREES ABOVE NORMAL.

PRECIP WILL QUICKLY TAPER OFF EARLY FRI EVENING AS THE FRONT MOVES
EAST OF THE AREA. A LOW AMPLITUDE UPPER TROF WILL CROSS THE AREA SAT
AS AN UPPER LOW MOVES FROM THE GREAT LAKES INTO NEW ENGLAND. AT THE
SFC...HIGH PRESSURE BUILDS IN BRIEFLY BEFORE A WEAK BACK DOOR COLD
FRONT APPROACHES FROM THE NORTH BY THE END OF THE DAY. THE RESULT
WILL BE DRY WX AND MOSTLY SUNNY SKIES. LOWS WILL RANGE FROM NEAR
NORMAL TO 5 DEGREES ABOVE NORMAL. HIGHS WILL BE 5 TO 10 DEGREES
ABOVE NORMAL.

&&

.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
AS OF 240 PM EDT WED...THE EXTENDED PART OF THE FORECAST STARTS WITH
A DEEP-LAYER SHORTWAVE RIDGE TRANSLATING ACROSS THE REGION. THIS
SHOULD BRING FAIR AND MILD WEATHER. HOWEVER...THE MODELS HAVE BEEN
TRADING OFF RUN TO RUN AS TO WHETHER A BACK DOOR COLD FRONT CROSSES
THE REGION...BRINGING WITH IT COOLER AND POTENTIALLY CLOUDY WEATHER
IN THE FORM OF COLD AIR DAMMING. FOR NOW I STAYED WITH THE WARMER
AND DRIER EC SOLUTION.

BY MONDAY PW/S BEGIN TO INCREASE ON THE GFS AND LLVL ISENTROPIC
UPGLIDE AND UPSLOPE FLOW DEVELOPS. THE ECMWF IS A LITTLE
SLOWER...THOUGH IT HAS BASICALLY THE SAME SOLUTION. AGAIN...THERE
ISN/T MUCH TO DISAGREE WITH CONCERNING THE WPC GRIDS AND I HAVE
MOSTLY CLOUDY SKIES AND A CHANCE OF SHOWERS. INSTABILITY WILL BE
LIMITED AND ONLY A SMALL CHANCE OF TSTMS IS EXPECTED. BY MONDAY
NIGHT AND TUESDAY THE GFS PW/S INCREASE TO ALMOST 1.75 INCHES AND
THERE IS A CONSIDERABLE INCREASE IN THE LLVL FLOW. WE SHOULD ALSO BE
UNDER STRONG UPPER DIVERGENCE AS A UPPER TROPOSPHERIC JET MAX SHIFTS
EASTWARD UNDER A BROAD UPPER LOW THAT WILL BE CENTERED OVER
MISSOURI. THE POTENTIAL EXISTS FOR HEAVY RAIN LATER MONDAY INTO
TUESDAY. THERE MAY ALSO BE A SEVERE THREAT...THOUGH THE MOIST
WORKED-OVER AIRMASS AND GENERALLY VEERED LLVL FLOW DOESN/T SEEM
CONDUCIVE TO THE HIGH END SEVERE THREAT THAT WILL AFFECT THE PLAINS
WITH THE SYSTEM OVER THE WEEKEND. OF COURSE IT IS STILL QUITE EARLY
TO GET TOO CUTE WITH THE CHANCES OF SEVERE WEATHER FOR THE MON/TUE
PART OF THE FORECAST.

CONFIDENCE IN THE DAY 7 PART OF THE FORECAST IS LOW AS THERE WILL BE
SEVERAL CHUNKS OF SHORT WAVE ENERGY EMBEDDED WITHIN THE BROAD UPPER
LOW THAT WILL SLOWLY CROSS INTO THE EASTERN CONUS. ALL THE MODELS
AGREE THAT THERE WILL BE CONSIDERABLE DOWNSTREAM BLOCKING...SO THE
TROUGH SHOULD DEFINITELY PARK OVER THE REGION FOR A FEW DAYS.
HOWEVER...DEPENDING ON THE TIMING AND HOW ADVECTIVE INDIVIDUAL SHORT
WAVES ARE...THERE MIGHT BE A CHANCE FOR SOME ORGANIZED SEVERE
WEATHER WITH THE COOLING HEIGHTS.

&&

.AVIATION /21Z WEDNESDAY THROUGH MONDAY/...
KCLT AND ELSEWHERE...VFR. THE CENTER OF CANADIAN HIGH PRESSURE
LOCATED OVER THE GREAT LAKES REGION THIS EVENING WILL LIKELY SPLIT
TONIGHT...WITH THE SOUTHERN CENTER REACHING THE CAROLINA COAST BY
18Z THURSDAY. THIS PATTERN WILL YIELD VEERING WINDS THROUGH THE
PERIOD...RANGING FROM NW THIS AFTERNOON TO SE BY THURSDAY AFTERNOON.
WIND SPEEDS MAY REMAIN AROUND 10 KTS UNTIL SUNSET THIS
EVENING...BECOMING LIGHT NE TO CALM TONIGHT...THEN INCREASING 5 TO
10 KTS THURSDAY MORNING. FEW CIRRUS CLOUDS AND CONTRAILS EXPECTED ON
THURSDAY.

OUTLOOK...ANOTHER COLD FRONT WITH POTENTIAL FOR SHOWERS/TSTMS IS
THEN EXPECTED TO CROSS THE REGION FRIDAY...DRYING OUT BY SATURDAY.

CONFIDENCE TABLE...

            21-03Z        03-09Z        09-15Z        15-21Z
KCLT       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KGSP       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KAVL       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KHKY       HIGH 100%     HIGH 100%     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_TABLES

&&

.FIRE WEATHER...
THE FIRE DANGER STATEMENT WILL REMAIN IN PLACE UNTIL EXPIRATION AS
THE VERY LOW RH VALUES AND LOW END WIND GUSTS CONTINUE INTO THE
EARLY EVENING. RH VALUES SHOULD RECOVER THU WITH LOWER TEMPS AND
INCREASED DEW POINTS.

&&

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

&&

$$
SYNOPSIS...DEO
NEAR TERM...LGL/NED
SHORT TERM...RWH
LONG TERM...MCAVOY
AVIATION...LGL/NED
FIRE WEATHER...








000
FXUS62 KGSP 231853
AFDGSP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
253 PM EDT WED APR 23 2014

.SYNOPSIS...
DRY HIGH PRESSURE...CENTERED NEAR THE GREAT LAKES...WILL CONTROL OUR
WEATHER THROUGH THURSDAY. A WEAK COLD FRONT WILL CROSS THE FORECAST
AREA ON FRIDAY...WITH A REINFORCING FRONT STALLING IN THE VICINITY
OF THE REGION OVER THE WEEKEND. A WET AND POSSIBLY STORMY PATTERN
WILL SET UP FOR EARLY NEXT WEEK...FOLLOWED BY COOLER WEATHER.

&&

.NEAR TERM /THROUGH THURSDAY/...
AS OF 150 PM...WEAKENING PRESSURE GRADIENT HAS RESULTED IN MID TO
UPPER TEEN WIND GUSTS ACROSS THE MTNS AND NC FOOTHILLS/PIEDMONT THIS
AFTERNOON. LATEST OBSERVATIONS INDICATED A NOTICEABLE DROP IN RH
VALUES ACROSS THE REGION...ESPECIALLY ACROSS PIEDMONT AREAS. THE
FIRE DANGER STATEMENT CONTINUES TO LOOK WELL PLACED AND TIMED ACROSS
THE NC ZONES.

OVERNIGHT...DRY HIGH PRESSURE WILL RIDGE ACROSS THE WESTERN
CAROLINAS AS A COLD FRONT SLIDES ACROSS OK/TX. WINDS ARE FORECAST TO
REMAIN LIGHT FROM THE NE OR BECOME CALM DURING THE PRE DAWN HOURS.
THE LIMITED MIXING AND CLEAR/MOSTLY CLEAR SKY COVER WILL FAVOR
RADIATIONAL COOLING. HOWEVER...SOUTH H85 WINDS AROUND 15KTS AND LOW
AMPLITUDE RIDGING MAY PROVIDE WEAK LLVL WAA ACROSS THE SOUTHERN
APPALACHIANS. GIVEN THE WEAK WAA...I WILL INDICATE A SLIGHT INVERSE
LAPSE RATE IN THE MIN TEMPERATURE ACROSS THE MTNS. BLENDING OF THE
PREFERRED GUIDANCE SUPPORTS MIN TEMPERATURES BETWEEN 3 TO 6 DEGREES
BELOW NORMAL. I WILL INDICATE UPPER 30S ACROSS THE MTNS AND NC
FOOTHILLS...WITH LOW 40S ACROSS THE I-40 CORRIDOR...WITH MID TO
UPPER 40S ACROSS THE UPPER SAVANNAH RIVER VALLEY AND UPSTATE. PATCHY
FROST IS POSSIBLE WITHIN THE MTNS VALLEYS...BUT BELOW FROST ADVISORY
CRITERIA.

THURSDAY...THE COLD FRONT WILL SWEEP EAST ACROSS THE
ARKLATX...GRADUALLY INCREASING THE RETURN FLOW ACROSS THE FORECAST
AREA. DEWPOINTS ARE FORECAST TO RECOVER 5 TO 10 DEGREES FROM THIS
AFTERNOON. HIGH TEMPERATURES ARE FORECAST TO RANGE WITHIN 1 TO 2
DEGREES OF NORMAL...RESULTING IN RH VALUES IN THE 30S.
OVERALL...CONDITIONS SHOULD REMAIN DRY WITH MOSTLY SUNNY CONDITIONS.

&&

.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/...
AS OF 240 PM WED...A RELATIVELY STRONG SHORT WAVE APPROACHES THE
AREA THU NITE AND CROSSES THE AREA FRI. THIS WAVE WILL PUSH A COLD
FRONT ACROSS THE AREA FRIDAY AS WELL. MOISTURE AND ISENTROPIC LIFT
INCREASE THU NITE...BRINGING CHC POP TO THE MTNS AND FOOTHILLS AFTER
MIDNIGHT. GOOD FORCING MOVES IN FRI MORNING WITH THE FRONT AND SHORT
WAVE...BRINGING LIKELY POP TO THE MTNS AND GOOD CHC POP TO THE I-40
CORRIDOR. FORCING AND DEEP MOISTURE IS A LITTLE LOWER OVER NE GA AND
THE WESTERN UPSTATE. THEREFORE...HAVE LIMITED POP TO 40 PERCENT OVER
ALL BUT THE MOUNTAIN PORTIONS. BEST CHC POP SHIFTS TO THE I-77
CORRIDOR FOR THE AFTERNOON AS THE FRONT MOVES INTO THAT AREA. THE
GFS STILL HAS MORE INSTABILITY THAN THE NAM...BUT ITS VALUES HAVE
DECREASED. WHILE THERE WILL BE SOME SHEAR GIVEN THE STRENGTH OF THE
SHORT WAVE AND COLD FRONT...IT GENERALLY REMAINS IN THE LIGHT RANGE.
THEREFORE...ALTHOUGH SCT THUNDERSTORMS WILL DEVELOP...SEVERE STORM
POTENTIAL IS LOW. QPF AMOUNTS ARE NOT EXPECTED TO BE EXCESSIVE
EITHER. TEMPS WILL BE AROUND 5 DEGREES ABOVE NORMAL.

PRECIP WILL QUICKLY TAPER OFF EARLY FRI EVENING AS THE FRONT MOVES
EAST OF THE AREA. A LOW AMPLITUDE UPPER TROF WILL CROSS THE AREA SAT
AS AN UPPER LOW MOVES FROM THE GREAT LAKES INTO NEW ENGLAND. AT THE
SFC...HIGH PRESSURE BUILDS IN BRIEFLY BEFORE A WEAK BACK DOOR COLD
FRONT APPROACHES FROM THE NORTH BY THE END OF THE DAY. THE RESULT
WILL BE DRY WX AND MOSTLY SUNNY SKIES. LOWS WILL RANGE FROM NEAR
NORMAL TO 5 DEGREES ABOVE NORMAL. HIGHS WILL BE 5 TO 10 DEGREES
ABOVE NORMAL.

&&

.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
AS OF 240 PM EDT WED...THE EXTENDED PART OF THE FORECAST STARTS WITH
A DEEP-LAYER SHORTWAVE RIDGE TRANSLATING ACROSS THE REGION. THIS
SHOULD BRING FAIR AND MILD WEATHER. HOWEVER...THE MODELS HAVE BEEN
TRADING OFF RUN TO RUN AS TO WHETHER A BACK DOOR COLD FRONT CROSSES
THE REGION...BRINGING WITH IT COOLER AND POTENTIALLY CLOUDY WEATHER
IN THE FORM OF COLD AIR DAMMING. FOR NOW I STAYED WITH THE WARMER
AND DRIER EC SOLUTION.

BY MONDAY PW/S BEGIN TO INCREASE ON THE GFS AND LLVL ISENTROPIC
UPGLIDE AND UPSLOPE FLOW DEVELOPS. THE ECMWF IS A LITTLE
SLOWER...THOUGH IT HAS BASICALLY THE SAME SOLUTION. AGAIN...THERE
ISN/T MUCH TO DISAGREE WITH CONCERNING THE WPC GRIDS AND I HAVE
MOSTLY CLOUDY SKIES AND A CHANCE OF SHOWERS. INSTABILITY WILL BE
LIMITED AND ONLY A SMALL CHANCE OF TSTMS IS EXPECTED. BY MONDAY
NIGHT AND TUESDAY THE GFS PW/S INCREASE TO ALMOST 1.75 INCHES AND
THERE IS A CONSIDERABLE INCREASE IN THE LLVL FLOW. WE SHOULD ALSO BE
UNDER STRONG UPPER DIVERGENCE AS A UPPER TROPOSPHERIC JET MAX SHIFTS
EASTWARD UNDER A BROAD UPPER LOW THAT WILL BE CENTERED OVER
MISSOURI. THE POTENTIAL EXISTS FOR HEAVY RAIN LATER MONDAY INTO
TUESDAY. THERE MAY ALSO BE A SEVERE THREAT...THOUGH THE MOIST
WORKED-OVER AIRMASS AND GENERALLY VEERED LLVL FLOW DOESN/T SEEM
CONDUCIVE TO THE HIGH END SEVERE THREAT THAT WILL AFFECT THE PLAINS
WITH THE SYSTEM OVER THE WEEKEND. OF COURSE IT IS STILL QUITE EARLY
TO GET TOO CUTE WITH THE CHANCES OF SEVERE WEATHER FOR THE MON/TUE
PART OF THE FORECAST.

CONFIDENCE IN THE DAY 7 PART OF THE FORECAST IS LOW AS THERE WILL BE
SEVERAL CHUNKS OF SHORT WAVE ENERGY EMBEDDED WITHIN THE BROAD UPPER
LOW THAT WILL SLOWLY CROSS INTO THE EASTERN CONUS. ALL THE MODELS
AGREE THAT THERE WILL BE CONSIDERABLE DOWNSTREAM BLOCKING...SO THE
TROUGH SHOULD DEFINITELY PARK OVER THE REGION FOR A FEW DAYS.
HOWEVER...DEPENDING ON THE TIMING AND HOW ADVECTIVE INDIVIDUAL SHORT
WAVES ARE...THERE MIGHT BE A CHANCE FOR SOME ORGANIZED SEVERE
WEATHER WITH THE COOLING HEIGHTS.

&&

.AVIATION /19Z WEDNESDAY THROUGH MONDAY/...
KCLT AND ELSEWHERE...VFR. THE CENTER OF CANADIAN HIGH PRESSURE
LOCATED OVER THE GREAT LAKES REGION THIS AFTERNOON WILL LIKELY SPLIT
TONIGHT...WITH THE SOUTHERN CENTER REACHING THE CAROLINA COAST BY
18Z THURSDAY. THIS PATTERN WILL YIELD VEERING WINDS THROUGH THE
PERIOD...RANGING FROM NW THIS AFTERNOON TO SE BY THURSDAY AFTERNOON.
WIND SPEEDS MAY REMAIN AROUND 10 KTS UNTIL SUNSET THIS
EVENING...BECOMING LIGHT NE TO CALM TONIGHT...THEN INCREASING 5 TO
10 KTS THURSDAY MORNING. FEW CIRRUS CLOUDS AND CONTRAILS EXPECTED ON
THURSDAY.

OUTLOOK...ANOTHER COLD FRONT WITH POTENTIAL FOR SHOWERS/TSTMS IS
THEN EXPECTED TO CROSS THE REGION FRIDAY...DRYING OUT BY SATURDAY.

CONFIDENCE TABLE...

            19-01Z        01-07Z        07-13Z        13-19Z
KCLT       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KGSP       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KAVL       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KHKY       HIGH 100%     HIGH 100%     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_TABLES

&&

.FIRE WEATHER...
THE FIRE DANGER STATEMENT WILL REMAIN IN PLACE UNTIL EXPIRATION AS
THE VERY LOW RH VALUES AND LOW END WIND GUSTS CONTINUE INTO THE
EARLY EVENING. RH VALUES SHOULD RECOVER THU WITH LOWER TEMPS AND
INCREASED DEW POINTS.

&&

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

&&

$$
SYNOPSIS...DEO
NEAR TERM...NED
SHORT TERM...RWH
LONG TERM...MCAVOY
AVIATION...NED
FIRE WEATHER...RWH







000
FXUS62 KGSP 231745
AFDGSP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
145 PM EDT WED APR 23 2014

.SYNOPSIS...
DRY HIGH PRESSURE...CENTERED NEAR THE GREAT LAKES...WILL CONTROL OUR
WEATHER THROUGH THURSDAY. A WEAK COLD FRONT WILL CROSS THE
FORECAST AREA ON FRIDAY...WITH A REINFORCING FRONT STALLING IN THE
VICINITY OF THE REGION OVER THE WEEKEND. A WET AND POSSIBLY STORMY
PATTERN WILL SET UP FOR EARLY NEXT WEEK...FOLLOWED BY COOLER WEATHER.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 135 PM...WEAKENING PRESSURE GRADIENT HAS RESULTED IN WEAK WIND
GUSTS ACROSS THE MTNS AND NC FOOTHILLS/PIEDMONT EARLY THIS
AFTERNOON. IN ADDITION...TEMPERATURES HAVE TRENDED A LITTLE WARMER
THAN FORECAST. I WILL UPDATE TO TWEAK WINDS...TEMPS...AND DEWPOINTS
THROUGH THIS AFTERNOON.

AS OF 1050 AM...LATEST SATELLITE IMAGES AND VIEW OUT THE WINDOW
INDICATED THAT CIRRUS WAVE CLOUDS ACROSS CAROLINA FOOTHILLS AND
PIEDMONT. THESE CLOUDS WILL LIKELY REMAIN THROUGH MID DAY...THEN
DISSIPATE AS NW WINDS WEAKEN. I WILL UPDATE THE FORECAST TO MAKE
MINOR ADJUSTMENTS TO SKY...TEMPERATURE...AND DEWPOINTS. THE FIRE
DANGER STATEMENT APPEARS WELL PLACED AND TIMED.

AS OF 645 AM...THE COLD FRONT HAS JUST ABOUT PUSHED THRU THE ENTIRE
CWFA...RESULTING IN DIMINISHING FOG AND INCREASE IN WINDS.
AGAIN...JUST UPDATED THE T/TD/WIND/WX GRIDS TO KEEP UP WITH TRENDS.
OTHERWISE...NO OTHER CHANGES.

AS OF 430 AM...FOR THE 0830 UTC UPDATE...THE COLD FRONT HAS PUSHED
INTO THE FOOTHILLS...AND SHUD CROSS THE I-85 CORRIDOR WITHIN THE
NEXT HOUR OR SO. I UPDATED THE TEMP/DWPT/WIND/WX GRIDS THRU DAYBREAK
TO MATCH UP WITH THE TRENDS.

AS OF 300 AM...THE COLD FRONT IS FINALLY SHOWING SIGNS OF CROSSING
THE NC MTNS...AS KAVL HAS A NW WIND. EAST OF THE MTNS...PATCHY FOG
CONTINUES TO INCREASE IN COVERAGE...AND EVEN LOCALLY DENSE IN A
COUPLE SPOTS. I STILL EXPECT THE DRY AIR AND CAA TO WIN OUT...AND NO
WIDESPREAD DENSE FOG IS EXPECTED.

TODAY...DEEP LAYER NWLY FLOW WILL RESULT IN A SUNNY DAY WITH
SEASONABLE TEMPS. DRY SFC HIGH PRES FILTERS IN FROM THE
NORTH...WHICH WITH A LITTLE MIXING...WILL DROP DWPTS INTO THE 20 AND
30S...RESULTING IN CRITICAL RH ACRS MOST OF THE AREA. GUSTY NW WINDS
WILL LINGER INTO THE AFTN ACRS THE NC ZONES...SO THE FIRE DANGER
STATEMENT LOOKS GOOD.

TONIGHT...THE AXIS OF SFC HIGH PRES WILL SETTLE ACRS THE SOUTHERN
APPALACHIANS...WHILE A LITTLE BIT OF NE FLOW WILL LINGER ACRS THE
PIEDMONT. MOS GUIDANCE HINTS AT TEMPS IN THE MID 30S ACRS MUCH OF
THE NC MTNS AND NORTHERN FOOTHILLS. RADIATIONAL COOLING CONDITIONS
LOOK GOOD...SO FROST WILL BE MENTIONED IN THE THESE AREAS.
HOWEVER...THERE IS STILL ENUF UNCERTAINTY ON THESE MIN TEMPS TO HOLD
OFF ON A FROST ADVISORY UNTIL THE DAY SHIFT CAN ASSESS THE LATEST
GUIDANCE.

&&

.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 230 AM EDT WED...500 MB RIDGING WILL CROSS THE FORECAST AREA
ON THU AS WEAK SFC HIGH PRES MOVES OFFSHORE. SRLY RETURN FLOW
MOISTURE WILL GRADUALLY DEVELOP AT LOW LEVELS BY LATE DAY AND THEN
IMPROVE AND DEEPEN THROUGH THU NIGHT. MEANWHILE...A DEAMPLIFYING
UPPER WAVE EXTENDING SWD FROM A GREAT LAKES H5 LOW CENTER WILL SWING
EASTWARD AND CROSS THE APPALACHIANS FRI MORNING. A WEAK SURFACE COLD
FRONT ASSOCIATED WITH THIS SYSTEM WILL CROSS THE WRN HALF FRI
MORNING AND THEN GENERALLY CLEAR ERN SECTIONS MID AFTN. ALTHOUGH
MOISTURE AND LIFT WITH THE FRIDAY SYSTEM ARE EXPECTED TO DECAY EAST
OF THE MTNS...SFC BASED CAPE VALUES OF 1000 TO 1500 J/KG WILL BE
POSSIBLE ACROSS PIEDMONT SECTIONS FRI AFTN. SFC TO 3 KM SHEAR VALUES
SHOULD BE FAIRLY UNIMPRESSIVE AT 20 TO 30 KT...WHICH WOULD LIMIT THE
SEVERE THUNDERSTORM POTENTIAL. MAX TEMPS WILL BE A COUPLE OF DEGREES
BELOW CLIMO MOST AREAS THU AFTN...BUT ABOUT A CATEGORY OR BETTER
ABOVE CLIMO ON FRI.

&&

.LONG TERM /SATURDAY THROUGH TUESDAY/...
AS OF 240 AM EDT WED...A FLAT FLOW REGIME OVER THE CENTRAL/ERN CONUS
EARLY SAT WILL GIVE WAY TO AN AMPLIFIED FLOW PATTERN LATE IN THE
WEEKEND AS A CLOSED SYSTEM MOVES FROM THE ROCKIES TO THE PLAINS. A
BACKDOOR COLD FRONT APPROACHING FROM THE N ON SAT WILL LIKELY STALL
SOMEWHERE IN OR NEAR THE FORECAST AREA ON SUNDAY. W TO NW DOWNSLOPE
FLOW AHEAD OF THE BACKDOOR FRONT SHOULD KEEP MOST OF THE AREA DRY
SAT...BUT WITH MAINLY MTN POPS ENCROACHING ON SUNDAY AFTN IN
DEVELOPING SRLY FLOW. EXPECT MAXES TO RUN 1 TO 2 CATEGORIES ABOVE
NORMAL.

THE PINWHEELING PLAINS SYSTEM WILL GRADUALLY MIGRATE EWD MON THROUGH
TUE. IT DOES NOT APPEAR THAT THE LINGERING SFC HIGH TO THE N EARLY
IN THE WEEK WILL BE STRONG ENOUGH TO CREATE MUCH CAD UNDER THE
RETURNING MOISTURE. ANY WEAK CAD WOULD BE POSSIBLE MAINLY MON...BUT
WITH MOST OF THE REGION MORE SOLIDLY INTO THE WARM SECTOR BY
TUESDAY...WITH CONSIDERABLE INSTABILITY RESULTING. THE SLOWLY MOVING
BLOCKED PATTERN COULD PRODUCE ABUNDANT RAINFALL THROUGH MID WEEK.

&&

.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
KCLT AND ELSEWHERE...VFR. THE CENTER OF CANADIAN HIGH PRESSURE
LOCATED OVER THE GREAT LAKES REGION THIS AFTERNOON WILL LIKELY SPLIT
TONIGHT...WITH THE SOUTHERN CENTER REACHING THE CAROLINA COAST BY
18Z THURSDAY. THIS PATTERN WILL YIELD VEERING WINDS THROUGH THE
PERIOD...RANGING FROM NW THIS AFTERNOON TO SE BY THURSDAY AFTERNOON.
WIND SPEEDS MAY REMAIN AROUND 10 KTS UNTIL SUNSET THIS
EVENING...BECOMING LIGHT NE TO CALM TONIGHT...THEN INCREASING 5 TO
10 KTS THURSDAY MORNING. FEW CIRRUS CLOUDS AND CONTRAILS EXPECTED ON
THURSDAY.

OUTLOOK...ANOTHER COLD FRONT WITH POTENTIAL FOR SHOWERS/TSTMS IS
THEN EXPECTED TO CROSS THE REGION FRIDAY...DRYING OUT BY SATURDAY.

CONFIDENCE TABLE...

            17-23Z        23-05Z        05-11Z        11-17Z
KCLT       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KGSP       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KAVL       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KHKY       HIGH 100%     HIGH 100%     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_TABLES

&&

.FIRE WEATHER...
A DRY AND SEASONABLY WARM AIR MASS WILL MOVE INTO THE AREA TODAY
BEHIND A DEPARTING COLD FRONT. THE COMBINATION OF WARM TEMPERATURES
AND LOW DEW POINTS WILL LEAD TO RELATIVE HUMIDITY VALUES AT OR BELOW
25 PERCENT ACROSS MOST OF THE AREA. GUSTY NORTHWEST WINDS WILL
LINGER THIS MORNING INTO THE AFTN ACROSS THE MTNS NC PIEDMONT. WITH
ONLY LIGHT PRECIPITATION YESTERDAY...FUELS SHOULD QUICKLY DRY OUT
TODAY. A FIRE DANGER STATEMENT WAS COORDINATED WITH LAND MANAGERS
YESTERDAY...AND NO CHANGES WERE MADE TO THAT THIS MORNING.

&&

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

&&

$$
SYNOPSIS...HG
NEAR TERM...ARK/NED
SHORT TERM...HG
LONG TERM...HG
AVIATION...NED
FIRE WEATHER...








000
FXUS62 KGSP 231500
AFDGSP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
1100 AM EDT WED APR 23 2014

.SYNOPSIS...
DRY HIGH PRESSURE WILL BUILD OVER THE AREA TODAY AND LINGER THROUGH
THURSDAY. A WEAK COLD FRONT WILL CROSS THE FORECAST AREA ON
FRIDAY...WITH A REINFORCING FRONT STALLING IN THE VICINITY OF THE
REGION OVER THE WEEKEND. A WET AND POSSIBLY STORMY PATTERN WILL SET
UP FOR EARLY NEXT WEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 1050 AM...LATEST SATELLITE IMAGES AND VIEW OUT THE WINDOW
INDICATED THAT CIRRUS WAVE CLOUDS ACROSS CAROLINA FOOTHILLS AND
PIEDMONT. THESE CLOUDS WILL LIKELY REMAIN THROUGH MID DAY...THEN
DISSIPATE AS NW WINDS WEAKEN. I WILL UPDATE THE FORECAST TO MAKE
MINOR ADJUSTMENTS TO SKY...TEMPERATURE...AND DEWPOINTS. THE FIRE
DANGER STATEMENT APPEARS WELL PLACED AND TIMED.

AS OF 645 AM...THE COLD FRONT HAS JUST ABOUT PUSHED THRU THE ENTIRE
CWFA...RESULTING IN DIMINISHING FOG AND INCREASE IN WINDS.
AGAIN...JUST UPDATED THE T/TD/WIND/WX GRIDS TO KEEP UP WITH TRENDS.
OTHERWISE...NO OTHER CHANGES.

AS OF 430 AM...FOR THE 0830 UTC UPDATE...THE COLD FRONT HAS PUSHED
INTO THE FOOTHILLS...AND SHUD CROSS THE I-85 CORRIDOR WITHIN THE
NEXT HOUR OR SO. I UPDATED THE TEMP/DWPT/WIND/WX GRIDS THRU DAYBREAK
TO MATCH UP WITH THE TRENDS.

AS OF 300 AM...THE COLD FRONT IS FINALLY SHOWING SIGNS OF CROSSING
THE NC MTNS...AS KAVL HAS A NW WIND. EAST OF THE MTNS...PATCHY FOG
CONTINUES TO INCREASE IN COVERAGE...AND EVEN LOCALLY DENSE IN A
COUPLE SPOTS. I STILL EXPECT THE DRY AIR AND CAA TO WIN OUT...AND NO
WIDESPREAD DENSE FOG IS EXPECTED.

TODAY...DEEP LAYER NWLY FLOW WILL RESULT IN A SUNNY DAY WITH
SEASONABLE TEMPS. DRY SFC HIGH PRES FILTERS IN FROM THE
NORTH...WHICH WITH A LITTLE MIXING...WILL DROP DWPTS INTO THE 20 AND
30S...RESULTING IN CRITICAL RH ACRS MOST OF THE AREA. GUSTY NW WINDS
WILL LINGER INTO THE AFTN ACRS THE NC ZONES...SO THE FIRE DANGER
STATEMENT LOOKS GOOD.

TONIGHT...THE AXIS OF SFC HIGH PRES WILL SETTLE ACRS THE SOUTHERN
APPALACHIANS...WHILE A LITTLE BIT OF NE FLOW WILL LINGER ACRS THE
PIEDMONT. MOS GUIDANCE HINTS AT TEMPS IN THE MID 30S ACRS MUCH OF
THE NC MTNS AND NORTHERN FOOTHILLS. RADIATIONAL COOLING CONDITIONS
LOOK GOOD...SO FROST WILL BE MENTIONED IN THE THESE AREAS.
HOWEVER...THERE IS STILL ENUF UNCERTAINTY ON THESE MIN TEMPS TO HOLD
OFF ON A FROST ADVISORY UNTIL THE DAY SHIFT CAN ASSESS THE LATEST
GUIDANCE.

&&

.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 230 AM EDT WED...500 MB RIDGING WILL CROSS THE FORECAST AREA
ON THU AS WEAK SFC HIGH PRES MOVES OFFSHORE. SRLY RETURN FLOW
MOISTURE WILL GRADUALLY DEVELOP AT LOW LEVELS BY LATE DAY AND THEN
IMPROVE AND DEEPEN THROUGH THU NIGHT. MEANWHILE...A DEAMPLIFYING
UPPER WAVE EXTENDING SWD FROM A GREAT LAKES H5 LOW CENTER WILL SWING
EASTWARD AND CROSS THE APPALACHIANS FRI MORNING. A WEAK SURFACE COLD
FRONT ASSOCIATED WITH THIS SYSTEM WILL CROSS THE WRN HALF FRI
MORNING AND THEN GENERALLY CLEAR ERN SECTIONS MID AFTN. ALTHOUGH
MOISTURE AND LIFT WITH THE FRIDAY SYSTEM ARE EXPECTED TO DECAY EAST
OF THE MTNS...SFC BASED CAPE VALUES OF 1000 TO 1500 J/KG WILL BE
POSSIBLE ACROSS PIEDMONT SECTIONS FRI AFTN. SFC TO 3 KM SHEAR VALUES
SHOULD BE FAIRLY UNIMPRESSIVE AT 20 TO 30 KT...WHICH WOULD LIMIT THE
SEVERE THUNDERSTORM POTENTIAL. MAX TEMPS WILL BE A COUPLE OF DEGREES
BELOW CLIMO MOST AREAS THU AFTN...BUT ABOUT A CATEGORY OR BETTER
ABOVE CLIMO ON FRI.

&&

.LONG TERM /SATURDAY THROUGH TUESDAY/...
AS OF 240 AM EDT WED...A FLAT FLOW REGIME OVER THE CENTRAL/ERN CONUS
EARLY SAT WILL GIVE WAY TO AN AMPLIFIED FLOW PATTERN LATE IN THE
WEEKEND AS A CLOSED SYSTEM MOVES FROM THE ROCKIES TO THE PLAINS. A
BACKDOOR COLD FRONT APPROACHING FROM THE N ON SAT WILL LIKELY STALL
SOMEWHERE IN OR NEAR THE FORECAST AREA ON SUNDAY. W TO NW DOWNSLOPE
FLOW AHEAD OF THE BACKDOOR FRONT SHOULD KEEP MOST OF THE AREA DRY
SAT...BUT WITH MAINLY MTN POPS ENCROACHING ON SUNDAY AFTN IN
DEVELOPING SRLY FLOW. EXPECT MAXES TO RUN 1 TO 2 CATEGORIES ABOVE
NORMAL.

THE PINWHEELING PLAINS SYSTEM WILL GRADUALLY MIGRATE EWD MON THROUGH
TUE. IT DOES NOT APPEAR THAT THE LINGERING SFC HIGH TO THE N EARLY
IN THE WEEK WILL BE STRONG ENOUGH TO CREATE MUCH CAD UNDER THE
RETURNING MOISTURE. ANY WEAK CAD WOULD BE POSSIBLE MAINLY MON...BUT
WITH MOST OF THE REGION MORE SOLIDLY INTO THE WARM SECTOR BY
TUESDAY...WITH CONSIDERABLE INSTABILITY RESULTING. THE SLOWLY MOVING
BLOCKED PATTERN COULD PRODUCE ABUNDANT RAINFALL THROUGH MID WEEK.

&&

.AVIATION /15Z WEDNESDAY THROUGH SUNDAY/...
KCLT...THE COLD FRONT HAS PASSED BY THE TERMINAL...SO I THINK THE
THREAT OF GROUND FOG HAS ENDED THIS MORNING...AND A NLY WIND CAN BE
EXPECTED THRU THE PERIOD. SKIES LOOK TO BE CLEAR AND AIR MASS WILL
BE TOO DRY FOR FOG TONIGHT. WINDS WILL PICK UP TO ARND 8-10 KTS
WITHIN AN HOUR OR TWO AFTER SUNRISE...AND MAY BRIEFLY MIX A FEW
LOW-END GUSTS PER THE NAM BUFKIT. BUT BY EARLY AFTN...IT LOOKS LIKE
ANY GUSTS SHUD SUBSIDE. WINDS WILL DECREASE TO ABOUT 5-8 KTS AND
BACK TO NE THIS EVENING.

ELSEWHERE...AS WITH KCLT THE PASSAGE OF THE COLD FRONT SHUD PRECLUDE
ANY FURTHER FOG DEVELOPMENT EARLY THIS MORNING. N/NW WINDS THIS
MORNING...WITH CHANNELED GUSTY VALLEY WINDS AT KAVL...TODAY UNDER
CLEAR SKIES. WINDS WILL SUBSIDE TONIGHT...WITH A LIGHT NE WIND
LINGERING ACRS THE PIEDMONT SITES. AIR MASS LOOKS TOO DRY FOR ANY
FOG DEVELOPMENT.

OUTLOOK...DRY HIGH PRES WILL DOMINATE THRU THU. ANOTHER COLD FRONT
WITH POTENTIAL FOR SHOWERS/TSTMS IS THEN EXPECTED TO CROSS THE
REGION FRIDAY...DRYING OUT BY SATURDAY.

CONFIDENCE TABLE...

            15-21Z        21-03Z        03-09Z        09-15Z
KCLT       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KGSP       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KAVL       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KHKY       HIGH 100%     HIGH 100%     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_TABLES

&&

.FIRE WEATHER...
A DRY AND SEASONABLY WARM AIR MASS WILL MOVE INTO THE AREA TODAY
BEHIND A DEPARTING COLD FRONT. THE COMBINATION OF WARM TEMPERATURES
AND LOW DEW POINTS WILL LEAD TO RELATIVE HUMIDITY VALUES AT OR BELOW
25 PERCENT ACROSS MOST OF THE AREA. GUSTY NORTHWEST WINDS WILL
LINGER THIS MORNING INTO THE AFTN ACROSS THE MTNS NC PIEDMONT. WITH
ONLY LIGHT PRECIPITATION YESTERDAY...FUELS SHOULD QUICKLY DRY OUT
TODAY. A FIRE DANGER STATEMENT WAS COORDINATED WITH LAND MANAGERS
YESTERDAY...AND NO CHANGES WERE MADE TO THAT THIS MORNING.

&&

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

&&

$$
SYNOPSIS...HG
NEAR TERM...ARK/NED
SHORT TERM...HG
LONG TERM...HG
AVIATION...ARK
FIRE WEATHER...








000
FXUS62 KGSP 231051
AFDGSP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
651 AM EDT WED APR 23 2014

.SYNOPSIS...
DRY HIGH PRESSURE WILL BUILD OVER THE AREA TODAY AND LINGER THROUGH
THURSDAY. A WEAK COLD FRONT WILL CROSS THE FORECAST AREA ON
FRIDAY...WITH A REINFORCING FRONT STALLING IN THE VICINITY OF THE
REGION OVER THE WEEKEND. A WET AND POSSIBLY STORMY PATTERN WILL SET
UP FOR EARLY NEXT WEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 645 AM...THE COLD FRONT HAS JUST ABOUT PUSHED THRU THE ENTIRE
CWFA...RESULTING IN DIMINISHING FOG AND INCREASE IN WINDS.
AGAIN...JUST UPDATED THE T/TD/WIND/WX GRIDS TO KEEP UP WITH TRENDS.
OTHERWISE...NO OTHER CHANGES.

AS OF 430 AM...FOR THE 0830 UTC UPDATE...THE COLD FRONT HAS PUSHED
INTO THE FOOTHILLS...AND SHUD CROSS THE I-85 CORRIDOR WITHIN THE
NEXT HOUR OR SO. I UPDATED THE TEMP/DWPT/WIND/WX GRIDS THRU DAYBREAK
TO MATCH UP WITH THE TRENDS.

AS OF 300 AM...THE COLD FRONT IS FINALLY SHOWING SIGNS OF CROSSING
THE NC MTNS...AS KAVL HAS A NW WIND. EAST OF THE MTNS...PATCHY FOG
CONTINUES TO INCREASE IN COVERAGE...AND EVEN LOCALLY DENSE IN A
COUPLE SPOTS. I STILL EXPECT THE DRY AIR AND CAA TO WIN OUT...AND NO
WIDESPREAD DENSE FOG IS EXPECTED.

TODAY...DEEP LAYER NWLY FLOW WILL RESULT IN A SUNNY DAY WITH
SEASONABLE TEMPS. DRY SFC HIGH PRES FILTERS IN FROM THE
NORTH...WHICH WITH A LITTLE MIXING...WILL DROP DWPTS INTO THE 20 AND
30S...RESULTING IN CRITICAL RH ACRS MOST OF THE AREA. GUSTY NW WINDS
WILL LINGER INTO THE AFTN ACRS THE NC ZONES...SO THE FIRE DANGER
STATEMENT LOOKS GOOD.

TONIGHT...THE AXIS OF SFC HIGH PRES WILL SETTLE ACRS THE SOUTHERN
APPALACHIANS...WHILE A LITTLE BIT OF NE FLOW WILL LINGER ACRS THE
PIEDMONT. MOS GUIDANCE HINTS AT TEMPS IN THE MID 30S ACRS MUCH OF
THE NC MTNS AND NORTHERN FOOTHILLS. RADIATIONAL COOLING CONDITIONS
LOOK GOOD...SO FROST WILL BE MENTIONED IN THE THESE AREAS.
HOWEVER...THERE IS STILL ENUF UNCERTAINTY ON THESE MIN TEMPS TO HOLD
OFF ON A FROST ADVISORY UNTIL THE DAY SHIFT CAN ASSESS THE LATEST
GUIDANCE.

&&

.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 230 AM EDT WED...500 MB RIDGING WILL CROSS THE FORECAST AREA
ON THU AS WEAK SFC HIGH PRES MOVES OFFSHORE. SRLY RETURN FLOW
MOISTURE WILL GRADUALLY DEVELOP AT LOW LEVELS BY LATE DAY AND THEN
IMPROVE AND DEEPEN THROUGH THU NIGHT. MEANWHILE...A DEAMPLIFYING
UPPER WAVE EXTENDING SWD FROM A GREAT LAKES H5 LOW CENTER WILL SWING
EASTWARD AND CROSS THE APPALACHIANS FRI MORNING. A WEAK SURFACE COLD
FRONT ASSOCIATED WITH THIS SYSTEM WILL CROSS THE WRN HALF FRI
MORNING AND THEN GENERALLY CLEAR ERN SECTIONS MID AFTN. ALTHOUGH
MOISTURE AND LIFT WITH THE FRIDAY SYSTEM ARE EXPECTED TO DECAY EAST
OF THE MTNS...SFC BASED CAPE VALUES OF 1000 TO 1500 J/KG WILL BE
POSSIBLE ACROSS PIEDMONT SECTIONS FRI AFTN. SFC TO 3 KM SHEAR VALUES
SHOULD BE FAIRLY UNIMPRESSIVE AT 20 TO 30 KT...WHICH WOULD LIMIT THE
SEVERE THUNDERSTORM POTENTIAL. MAX TEMPS WILL BE A COUPLE OF DEGREES
BELOW CLIMO MOST AREAS THU AFTN...BUT ABOUT A CATEGORY OR BETTER
ABOVE CLIMO ON FRI.

&&

.LONG TERM /SATURDAY THROUGH TUESDAY/...
AS OF 240 AM EDT WED...A FLAT FLOW REGIME OVER THE CENTRAL/ERN CONUS
EARLY SAT WILL GIVE WAY TO AN AMPLIFIED FLOW PATTERN LATE IN THE
WEEKEND AS A CLOSED SYSTEM MOVES FROM THE ROCKIES TO THE PLAINS. A
BACKDOOR COLD FRONT APPROACHING FROM THE N ON SAT WILL LIKELY STALL
SOMEWHERE IN OR NEAR THE FORECAST AREA ON SUNDAY. W TO NW DOWNSLOPE
FLOW AHEAD OF THE BACKDOOR FRONT SHOULD KEEP MOST OF THE AREA DRY
SAT...BUT WITH MAINLY MTN POPS ENCROACHING ON SUNDAY AFTN IN
DEVELOPING SRLY FLOW. EXPECT MAXES TO RUN 1 TO 2 CATEGORIES ABOVE
NORMAL.

THE PINWHEELING PLAINS SYSTEM WILL GRADUALLY MIGRATE EWD MON THROUGH
TUE. IT DOES NOT APPEAR THAT THE LINGERING SFC HIGH TO THE N EARLY
IN THE WEEK WILL BE STRONG ENOUGH TO CREATE MUCH CAD UNDER THE
RETURNING MOISTURE. ANY WEAK CAD WOULD BE POSSIBLE MAINLY MON...BUT
WITH MOST OF THE REGION MORE SOLIDLY INTO THE WARM SECTOR BY
TUESDAY...WITH CONSIDERABLE INSTABILITY RESULTING. THE SLOWLY MOVING
BLOCKED PATTERN COULD PRODUCE ABUNDANT RAINFALL THROUGH MID WEEK.

&&

.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
KCLT...THE COLD FRONT HAS PASSED BY THE TERMINAL...SO I THINK THE
THREAT OF GROUND FOG HAS ENDED THIS MORNING...AND A NLY WIND CAN BE
EXPECTED THRU THE PERIOD. SKIES LOOK TO BE CLEAR AND AIR MASS WILL
BE TOO DRY FOR FOG TONIGHT. WINDS WILL PICK UP TO ARND 8-10 KTS
WITHIN AN HOUR OR TWO AFTER SUNRISE...AND MAY BRIEFLY MIX A FEW
LOW-END GUSTS PER THE NAM BUFKIT. BUT BY EARLY AFTN...IT LOOKS LIKE
ANY GUSTS SHUD SUBSIDE. WINDS WILL DECREASE TO ABOUT 5-8 KTS AND
BACK TO NE THIS EVENING.

ELSEWHERE...AS WITH KCLT THE PASSAGE OF THE COLD FRONT SHUD PRECLUDE
ANY FURTHER FOG DEVELOPMENT EARLY THIS MORNING. N/NW WINDS THIS
MORNING...WITH CHANNELED GUSTY VALLEY WINDS AT KAVL...TODAY UNDER
CLEAR SKIES. WINDS WILL SUBSIDE TONIGHT...WITH A LIGHT NE WIND
LINGERING ACRS THE PIEDMONT SITES. AIR MASS LOOKS TOO DRY FOR ANY
FOG DEVELOPMENT.

OUTLOOK...DRY HIGH PRES WILL DOMINATE THRU THU. ANOTHER COLD FRONT
WITH POTENTIAL FOR SHOWERS/TSTMS IS THEN EXPECTED TO CROSS THE
REGION FRIDAY...DRYING OUT BY SATURDAY.

CONFIDENCE TABLE...

            11-17Z        17-23Z        23-05Z        05-11Z
KCLT       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KGSP       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KAVL       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KHKY       HIGH 100%     HIGH 100%     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_TABLES

&&

.FIRE WEATHER...
A DRY AND SEASONABLY WARM AIR MASS WILL MOVE INTO THE AREA TODAY
BEHIND A DEPARTING COLD FRONT. THE COMBINATION OF WARM TEMPERATURES
AND LOW DEW POINTS WILL LEAD TO RELATIVE HUMIDITY VALUES AT OR BELOW
25 PERCENT ACROSS MOST OF THE AREA. GUSTY NORTHWEST WINDS WILL
LINGER THIS MORNING INTO THE AFTN ACROSS THE MTNS NC PIEDMONT. WITH
ONLY LIGHT PRECIPITATION YESTERDAY...FUELS SHOULD QUICKLY DRY OUT
TODAY. A FIRE DANGER STATEMENT WAS COORDINATED WITH LAND MANAGERS
YESTERDAY...AND NO CHANGES WERE MADE TO THAT THIS MORNING.

&&

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

&&

$$
SYNOPSIS...HG
NEAR TERM...ARK
SHORT TERM...HG
LONG TERM...HG
AVIATION...ARK
FIRE WEATHER...








000
FXUS62 KGSP 230830
AFDGSP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
430 AM EDT WED APR 23 2014

.SYNOPSIS...
DRY HIGH PRESSURE WILL BUILD OVER THE AREA TODAY AND LINGER THROUGH
THURSDAY. A WEAK COLD FRONT WILL CROSS THE FORECAST AREA ON
FRIDAY...WITH A REINFORCING FRONT STALLING IN THE VICINITY OF THE
REGION OVER THE WEEKEND. A WET AND POSSIBLY STORMY PATTERN WILL SET
UP FOR EARLY NEXT WEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 430 AM...FOR THE 0830 UTC UPDATE...THE COLD FRONT HAS PUSHED
INTO THE FOOTHILLS...AND SHUD CROSS THE I-85 CORRIDOR WITHIN THE
NEXT HOUR OR SO. I UPDATED THE TEMP/DWPT/WIND/WX GRIDS THRU DAYBREAK
TO MATCH UP WITH THE TRENDS.

AS OF 300 AM...THE COLD FRONT IS FINALLY SHOWING SIGNS OF CROSSING
THE NC MTNS...AS KAVL HAS A NW WIND. EAST OF THE MTNS...PATCHY FOG
CONTINUES TO INCREASE IN COVERAGE...AND EVEN LOCALLY DENSE IN A
COUPLE SPOTS. I STILL EXPECT THE DRY AIR AND CAA TO WIN OUT...AND NO
WIDESPREAD DENSE FOG IS EXPECTED.

TODAY...DEEP LAYER NWLY FLOW WILL RESULT IN A SUNNY DAY WITH
SEASONABLE TEMPS. DRY SFC HIGH PRES FILTERS IN FROM THE
NORTH...WHICH WITH A LITTLE MIXING...WILL DROP DWPTS INTO THE 20 AND
30S...RESULTING IN CRITICAL RH ACRS MOST OF THE AREA. GUSTY NW WINDS
WILL LINGER INTO THE AFTN ACRS THE NC ZONES...SO THE FIRE DANGER
STATEMENT LOOKS GOOD.

TONIGHT...THE AXIS OF SFC HIGH PRES WILL SETTLE ACRS THE SOUTHERN
APPALACHIANS...WHILE A LITTLE BIT OF NE FLOW WILL LINGER ACRS THE
PIEDMONT. MOS GUIDANCE HINTS AT TEMPS IN THE MID 30S ACRS MUCH OF
THE NC MTNS AND NORTHERN FOOTHILLS. RADIATIONAL COOLING CONDITIONS
LOOK GOOD...SO FROST WILL BE MENTIONED IN THE THESE AREAS.
HOWEVER...THERE IS STILL ENUF UNCERTAINTY ON THESE MIN TEMPS TO HOLD
OFF ON A FROST ADVISORY UNTIL THE DAY SHIFT CAN ASSESS THE LATEST
GUIDANCE.

&&

.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 230 AM EDT WED...500 MB RIDGING WILL CROSS THE FORECAST AREA
ON THU AS WEAK SFC HIGH PRES MOVES OFFSHORE. SRLY RETURN FLOW
MOISTURE WILL GRADUALLY DEVELOP AT LOW LEVELS BY LATE DAY AND THEN
IMPROVE AND DEEPEN THROUGH THU NIGHT. MEANWHILE...A DEAMPLIFYING
UPPER WAVE EXTENDING SWD FROM A GREAT LAKES H5 LOW CENTER WILL SWING
EASTWARD AND CROSS THE APPALACHIANS FRI MORNING. A WEAK SURFACE COLD
FRONT ASSOCIATED WITH THIS SYSTEM WILL CROSS THE WRN HALF FRI
MORNING AND THEN GENERALLY CLEAR ERN SECTIONS MID AFTN. ALTHOUGH
MOISTURE AND LIFT WITH THE FRIDAY SYSTEM ARE EXPECTED TO DECAY EAST
OF THE MTNS...SFC BASED CAPE VALUES OF 1000 TO 1500 J/KG WILL BE
POSSIBLE ACROSS PIEDMONT SECTIONS FRI AFTN. SFC TO 3 KM SHEAR VALUES
SHOULD BE FAIRLY UNIMPRESSIVE AT 20 TO 30 KT...WHICH WOULD LIMIT THE
SEVERE THUNDERSTORM POTENTIAL. MAX TEMPS WILL BE A COUPLE OF DEGREES
BELOW CLIMO MOST AREAS THU AFTN...BUT ABOUT A CATEGORY OR BETTER
ABOVE CLIMO ON FRI.

&&

.LONG TERM /SATURDAY THROUGH TUESDAY/...
AS OF 240 AM EDT WED...A FLAT FLOW REGIME OVER THE CENTRAL/ERN CONUS
EARLY SAT WILL GIVE WAY TO AN AMPLIFIED FLOW PATTERN LATE IN THE
WEEKEND AS A CLOSED SYSTEM MOVES FROM THE ROCKIES TO THE PLAINS. A
BACKDOOR COLD FRONT APPROACHING FROM THE N ON SAT WILL LIKELY STALL
SOMEWHERE IN OR NEAR THE FORECAST AREA ON SUNDAY. W TO NW DOWNSLOPE
FLOW AHEAD OF THE BACKDOOR FRONT SHOULD KEEP MOST OF THE AREA DRY
SAT...BUT WITH MAINLY MTN POPS ENCROACHING ON SUNDAY AFTN IN
DEVELOPING SRLY FLOW. EXPECT MAXES TO RUN 1 TO 2 CATEGORIES ABOVE
NORMAL.

THE PINWHEELING PLAINS SYSTEM WILL GRADUALLY MIGRATE EWD MON THROUGH
TUE. IT DOES NOT APPEAR THAT THE LINGERING SFC HIGH TO THE N EARLY
IN THE WEEK WILL BE STRONG ENOUGH TO CREATE MUCH CAD UNDER THE
RETURNING MOISTURE. ANY WEAK CAD WOULD BE POSSIBLE MAINLY MON...BUT
WITH MOST OF THE REGION MORE SOLIDLY INTO THE WARM SECTOR BY
TUESDAY...WITH CONSIDERABLE INSTABILITY RESULTING. THE SLOWLY MOVING
BLOCKED PATTERN COULD PRODUCE ABUNDANT RAINFALL THROUGH MID WEEK.

&&

.AVIATION /09Z WEDNESDAY THROUGH SUNDAY/...
KCLT...ONLY A TRACE OF RAIN WAS REPORTED AT THE TERMINAL ASOS THIS
EVENING...SO CONFIDENCE ON GROUND FOG DEVELOPMENT IS LOW. THE DEWPT
DEPRESSION AT TIME OF 06Z TAF ISSUANCE WAS 2F...AND WINDS ARE LIGHT
WITH CLEAR SKIES. WITH THAT SAID...DRIER AIR IS WORKING IN ACRS THE
NC PIEDMONT...AND A COLD FRONT SHUD PUSH THRU BEFORE DAYBREAK. SO
WHILE FOG IS POSSIBLE...I THINK CHANCES ARE TOO LOW TO PUT IN THE
TAF. TRENDS WILL BE MONITORED CLOSELY...HOWEVER. OTHERWISE...IT SHUD
BE A QUIET TAF PERIOD...WITH CLEAR SKIES AND A LIGHT NW WIND THAT
MAY APPROACH 10 KTS THIS AFTN.

ELSEWHERE...BASED ON THE LIGHT RAIN THAT FELL YESTERDAY...ONLY KGSP
SEEMS TO HAVE THE RIGHT CONDITIONS FOR GROUND FOG AT THE TERMINAL.
THE OTHER SITES HAVE DEWPT DEPRESSIONS 4-10F...EXCEPT 2F AT KAVL.
HOWEVER...A COLD FRONT SHUD PUSH THRU OVERNIGHT...AND ADVECT DRY AIR
AND SOME MIXING...ESP AT KAVL WHERE CHANNELED VALLEY WINDS SHUD PICK
UP TO ABOUT 10 KTS WITH GUSTS BY DAYBREAK. KAVL WAS CALM AT TIME OF
TAF ISSUANCE...SO A BRIEF PERIOD OF FOG CANNOT BE RULED OUT...BUT
CONFIDENCE TOO LOW TO MENTION IN THE TAF. OTHERWISE...VFR CONDITIONS
ARE EXPECTED WITH NW WINDS.

OUTLOOK...DRY HIGH PRES WILL DOMINATE THRU THU. ANOTHER COLD FRONT
WITH POTENTIAL FOR SHOWERS/TSTMS IS THEN EXPECTED TO CROSS THE
REGION FRIDAY...DRYING OUT BY SATURDAY.

CONFIDENCE TABLE...

            08-14Z        14-20Z        20-02Z        02-08Z
KCLT       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KGSP       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KAVL       HIGH  85%     HIGH 100%     HIGH 100%     HIGH 100%
KHKY       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KGMU       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KAND       HIGH  83%     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_TABLES

&&

.FIRE WEATHER...
A DRY AND SEASONABLY WARM AIR MASS WILL MOVE INTO THE AREA TODAY
BEHIND A DEPARTING COLD FRONT. THE COMBINATION OF WARM TEMPERATURES
AND LOW DEW POINTS WILL LEAD TO RELATIVE HUMIDITY VALUES AT OR BELOW
25 PERCENT ACROSS MOST OF THE AREA. GUSTY NORTHWEST WINDS WILL
LINGER THIS MORNING INTO THE AFTN ACROSS THE MTNS NC PIEDMONT. WITH
ONLY LIGHT PRECIPITATION YESTERDAY...FUELS SHOULD QUICKLY DRY OUT
TODAY. A FIRE DANGER STATEMENT WAS COORDINATED WITH LAND MANAGERS
YESTERDAY...AND NO CHANGES WERE MADE TO THAT THIS MORNING.

&&

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

&&

$$
SYNOPSIS...HG
NEAR TERM...ARK
SHORT TERM...HG
LONG TERM...HG
AVIATION...ARK
FIRE WEATHER...








000
FXUS62 KGSP 230710
AFDGSP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
310 AM EDT WED APR 23 2014

.SYNOPSIS...
DRY HIGH PRESSURE WILL BUILD OVER THE AREA TODAY AND LINGER THROUGH
THURSDAY. A WEAK COLD FRONT WILL CROSS THE FORECAST AREA ON
FRIDAY...WITH A REINFORCING FRONT STALLING IN THE VICINITY OF THE
REGION OVER THE WEEKEND. A WET AND POSSIBLY STORMY PATTERN WILL SET
UP FOR EARLY NEXT WEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 300 AM...THE COLD FRONT IS FINALLY SHOWING SIGNS OF CROSSING
THE NC MTNS...AS KAVL HAS A NW WIND. EAST OF THE MTNS...PATCHY FOG
CONTINUES TO INCREASE IN COVERAGE...AND EVEN LOCALLY DENSE IN A
COUPLE SPOTS. I STILL EXPECT THE DRY AIR AND CAA TO WIN OUT...AND NO
WIDESPREAD DENSE FOG IS EXPECTED.

TODAY...DEEP LAYER NWLY FLOW WILL RESULT IN A SUNNY DAY WITH
SEASONABLE TEMPS. DRY SFC HIGH PRES FILTERS IN FROM THE
NORTH...WHICH WITH A LITTLE MIXING...WILL DROP DWPTS INTO THE 20 AND
30S...RESULTING IN CRITICAL RH ACRS MOST OF THE AREA. GUSTY NW WINDS
WILL LINGER INTO THE AFTN ACRS THE NC ZONES...SO THE FIRE DANGER
STATEMENT LOOKS GOOD.

TONIGHT...THE AXIS OF SFC HIGH PRES WILL SETTLE ACRS THE SOUTHERN
APPALACHIANS...WHILE A LITTLE BIT OF NE FLOW WILL LINGER ACRS THE
PIEDMONT. MOS GUIDANCE HINTS AT TEMPS IN THE MID 30S ACRS MUCH OF
THE NC MTNS AND NORTHERN FOOTHILLS. RADIATIONAL COOLING CONDITIONS
LOOK GOOD...SO FROST WILL BE MENTIONED IN THE THESE AREAS.
HOWEVER...THERE IS STILL ENUF UNCERTAINTY ON THESE MIN TEMPS TO HOLD
OFF ON A FROST ADVISORY UNTIL THE DAY SHIFT CAN ASSESS THE LATEST
GUIDANCE.

&&

.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 230 AM EDT WED...500 MB RIDGING WILL CROSS THE FORECAST AREA
ON THU AS WEAK SFC HIGH PRES MOVES OFFSHORE. SRLY RETURN FLOW
MOISTURE WILL GRADUALLY DEVELOP AT LOW LEVELS BY LATE DAY AND THEN
IMPROVE AND DEEPEN THROUGH THU NIGHT. MEANWHILE...A DEAMPLIFYING
UPPER WAVE EXTENDING SWD FROM A GREAT LAKES H5 LOW CENTER WILL SWING
EASTWARD AND CROSS THE APPALACHIANS FRI MORNING. A WEAK SURFACE COLD
FRONT ASSOCIATED WITH THIS SYSTEM WILL CROSS THE WRN HALF FRI
MORNING AND THEN GENERALLY CLEAR ERN SECTIONS MID AFTN. ALTHOUGH
MOISTURE AND LIFT WITH THE FRIDAY SYSTEM ARE EXPECTED TO DECAY EAST
OF THE MTNS...SFC BASED CAPE VALUES OF 1000 TO 1500 J/KG WILL BE
POSSIBLE ACROSS PIEDMONT SECTIONS FRI AFTN. SFC TO 3 KM SHEAR VALUES
SHOULD BE FAIRLY UNIMPRESSIVE AT 20 TO 30 KT...WHICH WOULD LIMIT THE
SEVERE THUNDERSTORM POTENTIAL. MAX TEMPS WILL BE A COUPLE OF DEGREES
BELOW CLIMO MOST AREAS THU AFTN...BUT ABOUT A CATEGORY OR BETTER
ABOVE CLIMO ON FRI.

&&

.LONG TERM /SATURDAY THROUGH TUESDAY/...
AS OF 240 AM EDT WED...A FLAT FLOW REGIME OVER THE CENTRAL/ERN CONUS
EARLY SAT WILL GIVE WAY TO AN AMPLIFIED FLOW PATTERN LATE IN THE
WEEKEND AS A CLOSED SYSTEM MOVES FROM THE ROCKIES TO THE PLAINS. A
BACKDOOR COLD FRONT APPROACHING FROM THE N ON SAT WILL LIKELY STALL
SOMEWHERE IN OR NEAR THE FORECAST AREA ON SUNDAY. W TO NW DOWNSLOPE
FLOW AHEAD OF THE BACKDOOR FRONT SHOULD KEEP MOST OF THE AREA DRY
SAT...BUT WITH MAINLY MTN POPS ENCROACHING ON SUNDAY AFTN IN
DEVELOPING SRLY FLOW. EXPECT MAXES TO RUN 1 TO 2 CATEGORIES ABOVE
NORMAL.

THE PINWHEELING PLAINS SYSTEM WILL GRADUALLY MIGRATE EWD MON THROUGH
TUE. IT DOES NOT APPEAR THAT THE LINGERING SFC HIGH TO THE N EARLY
IN THE WEEK WILL BE STRONG ENOUGH TO CREATE MUCH CAD UNDER THE
RETURNING MOISTURE. ANY WEAK CAD WOULD BE POSSIBLE MAINLY MON...BUT
WITH MOST OF THE REGION MORE SOLIDLY INTO THE WARM SECTOR BY
TUESDAY...WITH CONSIDERABLE INSTABILITY RESULTING. THE SLOWLY MOVING
BLOCKED PATTERN COULD PRODUCE ABUNDANT RAINFALL THROUGH MID WEEK.

&&

.AVIATION /07Z WEDNESDAY THROUGH SUNDAY/...
KCLT...ONLY A TRACE OF RAIN WAS REPORTED AT THE TERMINAL ASOS THIS
EVENING...SO CONFIDENCE ON GROUND FOG DEVELOPMENT IS LOW. THE DEWPT
DEPRESSION AT TIME OF 06Z TAF ISSUANCE WAS 2F...AND WINDS ARE LIGHT
WITH CLEAR SKIES. WITH THAT SAID...DRIER AIR IS WORKING IN ACRS THE
NC PIEDMONT...AND A COLD FRONT SHUD PUSH THRU BEFORE DAYBREAK. SO
WHILE FOG IS POSSIBLE...I THINK CHANCES ARE TOO LOW TO PUT IN THE
TAF. TRENDS WILL BE MONITORED CLOSELY...HOWEVER. OTHERWISE...IT SHUD
BE A QUIET TAF PERIOD...WITH CLEAR SKIES AND A LIGHT NW WIND THAT
MAY APPROACH 10 KTS THIS AFTN.

ELSEWHERE...BASED ON THE LIGHT RAIN THAT FELL YESTERDAY...ONLY KGSP
SEEMS TO HAVE THE RIGHT CONDITIONS FOR GROUND FOG AT THE TERMINAL.
THE OTHER SITES HAVE DEWPT DEPRESSIONS 4-10F...EXCEPT 2F AT KAVL.
HOWEVER...A COLD FRONT SHUD PUSH THRU OVERNIGHT...AND ADVECT DRY AIR
AND SOME MIXING...ESP AT KAVL WHERE CHANNELED VALLEY WINDS SHUD PICK
UP TO ABOUT 10 KTS WITH GUSTS BY DAYBREAK. KAVL WAS CALM AT TIME OF
TAF ISSUANCE...SO A BRIEF PERIOD OF FOG CANNOT BE RULED OUT...BUT
CONFIDENCE TOO LOW TO MENTION IN THE TAF. OTHERWISE...VFR CONDITIONS
ARE EXPECTED WITH NW WINDS.

OUTLOOK...DRY HIGH PRES WILL DOMINATE THRU THU. ANOTHER COLD FRONT
WITH POTENTIAL FOR SHOWERS/TSTMS IS THEN EXPECTED TO CROSS THE
REGION FRIDAY...DRYING OUT BY SATURDAY.

CONFIDENCE TABLE...

            07-13Z        13-19Z        19-01Z        01-07Z
KCLT       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KGSP       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KAVL       HIGH  85%     HIGH 100%     HIGH 100%     HIGH 100%
KHKY       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KGMU       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KAND       HIGH  83%     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_TABLES

&&

.FIRE WEATHER...
A DRY AND SEASONABLY WARM AIR MASS WILL MOVE INTO THE AREA TODAY
BEHIND A DEPARTING COLD FRONT. THE COMBINATION OF WARM TEMPERATURES
AND LOW DEW POINTS WILL LEAD TO RELATIVE HUMIDITY VALUES AT OR BELOW
25 PERCENT ACROSS MOST OF THE AREA. GUSTY NORTHWEST WINDS WILL
LINGER THIS MORNING INTO THE AFTN ACROSS THE MTNS NC PIEDMONT. WITH
ONLY LIGHT PRECIPITATION YESTERDAY...FUELS SHOULD QUICKLY DRY OUT
TODAY. A FIRE DANGER STATEMENT WAS COORDINATED WITH LAND MANAGERS
YESTERDAY...AND NO CHANGES WERE MADE TO THAT THIS MORNING.

&&

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

&&

$$
SYNOPSIS...HG
NEAR TERM...ARK
SHORT TERM...HG
LONG TERM...HG
AVIATION...ARK
FIRE WEATHER...ARK








000
FXUS62 KGSP 230550
AFDGSP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
150 AM EDT WED APR 23 2014

.SYNOPSIS...
A COLD FRONT WILL MOVE OFF THE CAROLINA COAST TONIGHT AS HIGH
PRESSURE CONTROLS OUR WEATHER THROUGH THURSDAY.  A WEAK COLD FRONT
CROSSES OUR AREA ON FRIDAY...WITH A REINFORCING FRONT STALLING TO
THE NORTH OF THE AREA OVER THE WEEKEND. COOLER WEATHER MAY ARRIVE
IN THE MIDDLE OF NEXT WEEK.

&&

.NEAR TERM /THROUGH TODAY/...
AS OF 145 AM...THE COLD FRONT LOOKS TO FINALLY CROSSED THE TENN
VALLEY...AND SHUD PUSH THRU THE MTNS OVERNIGHT. IN THE
MEANTIME...THERE IS ALREADY SOME DRY ADVECTION/MIXING AHEAD OF THE
FRONT TO LIMIT FOG DEVELOPMENT...BUT THERE IS STILL PATCHY FOG OUT
THERE. I UPDATED THE NEAR TERM GRIDS FOR THE 06Z TAFS...PERHAPS
BUMPING UP FOG COVERAGE/WORDING OVERNIGHT. OTHERWISE...NO
SIGNIFICANT CHANGES RESULTED FROM THIS UPDATE.

AS OF 1035 PM...THE COLD FRONT CONTINUES TO TAKE ITS TIME DROPPING
SOUTHEAST ACROSS THE TENN VALLEY. IN FACT...THE REAL PUSH OF SURFACE
DRY AIR IS REALLY JUST NOW BEGINNING ACROSS EAST TENN. IN ADVANCE OF
THIS AREA OF DRY AIR ADVECTION...THE AIR MASS IS QUITE MOIST LATE
THIS EVENING...WITH DEWPOINTS AS HIGH AS 60 ACROSS PORTIONS OF THE
PIEDMONT. MEANWHILE...WINDS HAVE BECOME LIGHT JUST ABOUT
EVERYWHERE...AND WITH MID/UPPER LEVEL DRIER AIR PUNCHING INTO THE
AREA...SOME POCKETS OF FOG HAVE BEGUN TO FORM. SINCE IT/S GOING TO
BE A FEW MORE HOURS BEFORE THE LOW LEVEL DRYING COMMENCES...WE HAVE
ADDED QUITE A BIT MORE FOG TO THE FORECAST SUITE...PRETTY MUCH
ENCOMPASSING THE ENTIRE FORECAST AREA WITH SOME AMOUNT OF RESTRICTED
VISIBILITY. FOG COULD BECOME DENSE IN A FEW AREAS...PARTICULARLY
SHELTERED MOUNTAIN VALLEYS. WE WOULD THEN EXPECT AN IMPROVEMENT IN
VISBY AFTER 06Z...SUCH THAT LITTLE FOG IS ANTICIPATED BY SUNRISE.
INCREASING COLD ADVECTION SHOULD ALLOW TEMPS TO COOL TO NEAR CLIMO
IN MOST AREAS BY SUNRISE.

AS OF 745 PM...POPS HAVE BEEN ALL BUT REMOVED FROM THE FORECAST FOR
THIS EVENING...AS THE MAIN AREA OF SHOWERS HAS SHIFTED EAST OF THE
FORECAST AREA. THE ACTUAL FRONT IS STILL PUSHING ITS WAY ACROSS THE
GREAT TN VALLEY/NORTH GEORGIA ATTM...ALONG WHICH REMAINS A DECENT
AREA OF LOW LEVEL CONVERGENCE AND SOME RESPECTABLE INSTABILITY.
HOWEVER...COVERAGE OF SHOWERS ALONG THE BOUNDARY IS UNINSPIRED TO
SAY THE LEAST. WILL NEVERTHELESS CARRY SOME TOKEN CHANCES ALONG THE
TENN BORDER...WHERE A BRIEF FLARE UP IN SHOWERS IS POSSIBLE AS THE
FRONT MOVES INTO THE SOUTHERN APPALACHIANS...AND RECEIVES SOME
ASSISTANCE FROM A NW UPSLOPE FLOW.

AS OF 245 PM...RECENT KGSP AND TCLT RADAR IMAGES INDICATED CLUSTERS
OF SHRA ACROSS THE MOUNTAINS AND FOOTHILLS...MOVING EAST BETWEEN 20
TO 25 MPH. THE SHOWERS WILL ENCOUNTER GREATER INSTABILITY ACROSS THE
PIEDMONT...BUT VALUES SHOULD RANGE BETWEEN 500-1000 J/KG. A FEW TSRA
MAY DEVELOP...BUT THE ENVIRONMENT WILL NOT SUPPORT SVR STORMS. THE
MAJORITY OF THE SHRA ARE TIMED TO MOVE EAST OF THE CWA BETWEEN
22-00Z...WITH A FEW UPSLOPE SHRA REMAINING NEAR THE TN LINE WELL
INTO THE EVENING. IN THE WAKE OF THE WEAK COLD FRONT...SKY COVER
WILL DECREASE STEADILY OVERNIGHT. GUSTY NW WINDS SHOULD RESULT IN
WEAK CAA ACROSS THE MTNS OVERNIGHT. A BLEND OF PREFERRED MOS
SUPPORTS MIN TEMPERATURES WITHIN A DEGREE OR TWO OF NORMAL.

ON WEDNESDAY...DRY CANADIAN SFC HIGH PRESSURE WILL BUILD ACROSS THE
SOUTHERN APPALACHIAN REGION. AS THE HIGH ARRIVES...GUSTY NW WINDS
ACROSS THE MTNS MAY YIELD A SMALL PATCH OF HIGH WAVE CLOUDS ACROSS
THE NC FOOTHILLS AROUND SUNRISE. OTHERWISE...SKY SHOULD REMAIN SUNNY
ACROSS THE REGION. HIGH TEMPERATURES ARE FORECAST TO RANGE FROM THE
U60S ACROSS THE MTNS TO MID 70S ACROSS THE UPPER SAVANNAH RIVER
VALLEY. THE SEASONABLE TEMPERATURE ABOVE DEWPOINTS IN THE 20S AND
30S SHOULD RESULT IN RH VALUES IN THE LOWER 20S.

&&

.SHORT TERM /TONIGHT THROUGH FRIDAY NIGHT/...
AS OF 240 PM TUESDAY...UPPER RIDGE BUILDS IN WED NITE AND THU AS SFC
HIGH PRESSURE NOSES IN FROM THE NORTH WED NITE THEN SLIDES OFF SHORE
THU. EXPECT LOWS WED NITE AS MUCH AS 5 DEGREES BELOW NORMAL AS GOOD
RADIATIONAL CONDITIONS DEVELOP. HAVE INCLUDED PATCHY FROST ACROSS
THE NC MTNS AND NRN FOOTHILLS WHERE TEMPS ARE COLD ENUF FOR FROST.
MOISTURE RETURN IN THE SLY FLOW AROUND THE DEPARTING HIGH PRESSURE
CENTER WILL LEAD TO INCREASING CLOUDINESS THU. HIGHS WILL END UP NEAR
TO SLIGHTLY ABOVE NORMAL.

A SERIES OF SHORT WAVES CROSS THE AREA IN THE FLAT TROF MOVING INTO
THE ERN CONUS LATE THU NITE AND FRI. GUIDANCE...IN GENERAL...HAS
INCREASED THE SPEED OF THIS SYSTEM AS IT MOVES EAST ACROSS THE AREA.
THEREFORE...BRING CHC POP INTO THE MTNS AND SLIGHT CHC ELSEWHERE
LATE THU NITE. STILL KEEP LIKELY POP LIMITED TO THE TN BORDER FRI
MORNING...BUT BRING GOOD CHC POP ACROSS THE CWFA DURING THAT TIME.
TAPER POP FROM WEST TO EAST DURING THE AFTERNOON...WITH ONLY A SMALL
PERIOD OF LINGERING SLIGHT CHC POP ACROSS THE I-77 CORRIDOR EARLY
FRI EVENING. SHEAR LOOKS BETTER WITH THIS SYSTEM...BUT STILL DOES
NOT REACH THE STRONG CATEGORY. OPS GUIDANCE SHOWS MODERATE
INSTABILITY POSSIBLE OVER THE ERN CWFA DURING THE AFTERNOON...BUT
ENSEMBLE MEAN SHOWS ONLY WEAK VALUES...EVEN IN MUCAPE. THEREFORE...
EXPECT TSRA TO DEVELOP...BUT ONLY A LOW CHC...AT BEST...FOR ANY
SEVERE STORMS. RIGHT NOW...PRECIP AMOUNTS DO NOT LOOK TO BE
EXCESSIVE EITHER. LOWS THU NITE 5 TO 10 DEGREES ABOVE NORMAL. HIGHS
FRI AROUND 5 DEGREES ABOVE NORMAL.

DRY HIGH PRESSURE BUILDS IN FRI NITE WITH LOWS AROUND 5 DEGREES
ABOVE NORMAL.

&&

.LONG TERM /SATURDAY THROUGH TUESDAY/...
AS OF 100 PM EDT TUESDAY...THE EXTENDED RANGE PERIOD INITIALIZES
SATURDAY MORNING IN THE WAKE OF A PASSING FRONTAL BOUNDARY.  HIGH
PRESSURE DIVING SOUTHWARD FROM CENTRAL CANADA WILL SPREAD ACROSS THE
OHIO VALLEY WITH A REINFORCING BACK DOOR COLD FRONT PUSHING INTO THE
SOUTHERN APPALACHIANS SATURDAY EVENING.  FORECAST WILL REMAIN DRY
INTO LATE SUNDAY MORNING BEFORE POPS RAMP UP AHEAD OF AN APPROACHING
WARM FRONT WHICH WILL INTERACT WITH THE QUASI STATIONARY BACK DOOR
FRONT DRAPED ACROSS THE AREA.

THIS WARM FRONTAL INTRUSION WILL BE IN RESPONSE TO SURFACE
CYCLOGENESIS ACROSS THE CENTRAL PLAINS BEING DRIVEN BY AN EASTWARD
MIGRATING BROAD NEGATIVELY TILTED UPPER TROF.  MODEL DISCONTINUITY
REMAINS PREVALENT REGARDING THIS SYSTEM AND ITS IMPACTS ACROSS
NORTHEAST GA AND THE WESTERN CAROLINAS.  THE GFS SOLUTION HAS THE
ABOVE MENTIONED SURFACE RIDGE TRANSITIONING TO A BERMUDA TYPE HIGH
WITH A PROGRESSIVELY DEEPENING SURFACE LOW PASSING THROUGH THE OHIO
VALLEY.  THE ECMWF ON THE OTHER HAND SHIFTS THE ABOVE MENTIONED OHIO
VALLEY RIDGE OVER NEW ENGLAND SETTING UP A WEDGE CONFIGURATION ALONG
THE APPALACHIANS.  THE GFS SOLUTION FAVORS A MORE ROBUST AND DYNAMIC
EVENT WHILE THE ECMWF LEANS TOWARDS A LESS FAVORABLE THUNDERSTORM
ENVIRONMENT AS CAD LIKE REGIME INHIBITS WARM FRONTAL SURGE.
THUS...AT THIS RANGE DECIDED TO RAMP POPS UP TO SOLID CHANCE LEVELS
WITH MENTION OF A CHANCE OF THUNDER FOR MONDAY AND TUESDAY.
TEMPERATURES THROUGH THE PERIOD WILL GENERALLY REMAIN ABOVE NORMAL
THROUGH SUNDAY WITH SLIGHTLY COOLER TEMPERATURES POSSIBLE ON MONDAY
AND TUESDAY AS SKY COVER INCREASES ASSOCIATED WITH WARM FRONTAL
ACTIVATION AND POTENTIAL PRECIPIATION.

&&

.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
KCLT...ONLY A TRACE OF RAIN WAS REPORTED AT THE TERMINAL ASOS THIS
EVENING...SO CONFIDENCE ON GROUND FOG DEVELOPMENT IS LOW. THE DEWPT
DEPRESSION AT TIME OF 06Z TAF ISSUANCE WAS 2F...AND WINDS ARE LIGHT
WITH CLEAR SKIES. WITH THAT SAID...DRIER AIR IS WORKING IN ACRS THE
NC PIEDMONT...AND A COLD FRONT SHUD PUSH THRU BEFORE DAYBREAK. SO
WHILE FOG IS POSSIBLE...I THINK CHANCES ARE TOO LOW TO PUT IN THE
TAF. TRENDS WILL BE MONITORED CLOSELY...HOWEVER. OTHERWISE...IT SHUD
BE A QUIET TAF PERIOD...WITH CLEAR SKIES AND A LIGHT NW WIND THAT
MAY APPROACH 10 KTS THIS AFTN.

ELSEWHERE...BASED ON THE LIGHT RAIN THAT FELL YESTERDAY...ONLY KGSP
SEEMS TO HAVE THE RIGHT CONDITIONS FOR GROUND FOG AT THE TERMINAL.
THE OTHER SITES HAVE DEWPT DEPRESSIONS 4-10F...EXCEPT 2F AT KAVL.
HOWEVER...A COLD FRONT SHUD PUSH THRU OVERNIGHT...AND ADVECT DRY AIR
AND SOME MIXING...ESP AT KAVL WHERE CHANNELED VALLEY WINDS SHUD PICK
UP TO ABOUT 10 KTS WITH GUSTS BY DAYBREAK. KAVL WAS CALM AT TIME OF
TAF ISSUANCE...SO A BRIEF PERIOD OF FOG CANNOT BE RULED OUT...BUT
CONFIDENCE TOO LOW TO MENTION IN THE TAF. OTHERWISE...VFR CONDITIONS
ARE EXPECTED WITH NW WINDS.

OUTLOOK...DRY HIGH PRES WILL DOMINATE THRU THU. ANOTHER COLD FRONT
WITH POTENTIAL FOR SHOWERS/TSTMS IS THEN EXPECTED TO CROSS THE
REGION FRIDAY...DRYING OUT BY SATURDAY.

CONFIDENCE TABLE...

            05-11Z        11-17Z        17-23Z        23-05Z
KCLT       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KGSP       HIGH  94%     HIGH  91%     HIGH 100%     HIGH 100%
KAVL       MED   77%     HIGH 100%     HIGH 100%     HIGH 100%
KHKY       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KGMU       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KAND       HIGH  94%     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_TABLES

&&

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

&&

$$
SYNOPSIS...DEO
NEAR TERM...ARK/JDL/NED
SHORT TERM...RWH
LONG TERM...CDG
AVIATION...ARK








000
FXUS62 KGSP 230244
AFDGSP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
1044 PM EDT TUE APR 22 2014

.SYNOPSIS...
A COLD FRONT WILL MOVE OFF THE CAROLINA COAST TONIGHT AS HIGH
PRESSURE CONTROLS OUR WEATHER THROUGH THURSDAY.  A WEAK COLD FRONT
CROSSES OUR AREA ON FRIDAY...WITH A REINFORCING FRONT STALLING TO
THE NORTH OF THE AREA OVER THE WEEKEND. COOLER WEATHER MAY ARRIVE
IN THE MIDDLE OF NEXT WEEK.

&&

.NEAR TERM /THROUGH WEDNESDAY/...
AS OF 1035 PM...THE COLD FRONT CONTINUES TO TAKE ITS TIME DROPPING
SOUTHEAST ACROSS THE TENN VALLEY. IN FACT...THE REAL PUSH OF SURFACE
DRY AIR IS REALLY JUST NOW BEGINNING ACROSS EAST TENN. IN ADVANCE OF
THIS AREA OF DRY AIR ADVECTION...THE AIR MASS IS QUITE MOIST LATE
THIS EVENING...WITH DEWPOINTS AS HIGH AS 60 ACROSS PORTIONS OF THE
PIEDMONT. MEANWHILE...WINDS HAVE BECOME LIGHT JUST ABOUT
EVERYWHERE...AND WITH MID/UPPER LEVEL DRIER AIR PUNCHING INTO THE
AREA...SOME POCKETS OF FOG HAVE BEGUN TO FORM. SINCE IT/S GOING TO
BE A FEW MORE HOURS BEFORE THE LOW LEVEL DRYING COMMENCES...WE HAVE
ADDED QUITE A BIT MORE FOG TO THE FORECAST SUITE...PRETTY MUCH
ENCOMPASSING THE ENTIRE FORECAST AREA WITH SOME AMOUNT OF RESTRICTED
VISIBILITY. FOG COULD BECOME DENSE IN A FEW AREAS...PARTICULARLY
SHELTERED MOUNTAIN VALLEYS. WE WOULD THEN EXPECT AN IMPROVEMENT IN
VISBY AFTER 06Z...SUCH THAT LITTLE FOG IS ANTICIPATED BY SUNRISE.
INCREASING COLD ADVECTION SHOULD ALLOW TEMPS TO COOL TO NEAR CLIMO
IN MOST AREAS BY SUNRISE.

AS OF 745 PM...POPS HAVE BEEN ALL BUT REMOVED FROM THE FORECAST FOR
THIS EVENING...AS THE MAIN AREA OF SHOWERS HAS SHIFTED EAST OF THE
FORECAST AREA. THE ACTUAL FRONT IS STILL PUSHING ITS WAY ACROSS THE
GREAT TN VALLEY/NORTH GEORGIA ATTM...ALONG WHICH REMAINS A DECENT
AREA OF LOW LEVEL CONVERGENCE AND SOME RESPECTABLE INSTABILITY.
HOWEVER...COVERAGE OF SHOWERS ALONG THE BOUNDARY IS UNINSPIRED TO
SAY THE LEAST. WILL NEVERTHELESS CARRY SOME TOKEN CHANCES ALONG THE
TENN BORDER...WHERE A BRIEF FLARE UP IN SHOWERS IS POSSIBLE AS THE
FRONT MOVES INTO THE SOUTHERN APPALACHIANS...AND RECEIVES SOME
ASSISTANCE FROM A NW UPSLOPE FLOW.

AS OF 245 PM...RECENT KGSP AND TCLT RADAR IMAGES INDICATED CLUSTERS
OF SHRA ACROSS THE MOUNTAINS AND FOOTHILLS...MOVING EAST BETWEEN 20
TO 25 MPH. THE SHOWERS WILL ENCOUNTER GREATER INSTABILITY ACROSS THE
PIEDMONT...BUT VALUES SHOULD RANGE BETWEEN 500-1000 J/KG. A FEW TSRA
MAY DEVELOP...BUT THE ENVIRONMENT WILL NOT SUPPORT SVR STORMS. THE
MAJORITY OF THE SHRA ARE TIMED TO MOVE EAST OF THE CWA BETWEEN
22-00Z...WITH A FEW UPSLOPE SHRA REMAINING NEAR THE TN LINE WELL
INTO THE EVENING. IN THE WAKE OF THE WEAK COLD FRONT...SKY COVER
WILL DECREASE STEADILY OVERNIGHT. GUSTY NW WINDS SHOULD RESULT IN
WEAK CAA ACROSS THE MTNS OVERNIGHT. A BLEND OF PREFERRED MOS
SUPPORTS MIN TEMPERATURES WITHIN A DEGREE OR TWO OF NORMAL.

ON WEDNESDAY...DRY CANADIAN SFC HIGH PRESSURE WILL BUILD ACROSS THE
SOUTHERN APPALACHIAN REGION. AS THE HIGH ARRIVES...GUSTY NW WINDS
ACROSS THE MTNS MAY YIELD A SMALL PATCH OF HIGH WAVE CLOUDS ACROSS
THE NC FOOTHILLS AROUND SUNRISE. OTHERWISE...SKY SHOULD REMAIN SUNNY
ACROSS THE REGION. HIGH TEMPERATURES ARE FORECAST TO RANGE FROM THE
U60S ACROSS THE MTNS TO MID 70S ACROSS THE UPPER SAVANNAH RIVER
VALLEY. THE SEASONABLE TEMPERATURE ABOVE DEWPOINTS IN THE 20S AND
30S SHOULD RESULT IN RH VALUES IN THE LOWER 20S.

&&

.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY NIGHT/...
AS OF 240 PM TUESDAY...UPPER RIDGE BUILDS IN WED NITE AND THU AS SFC
HIGH PRESSURE NOSES IN FROM THE NORTH WED NITE THEN SLIDES OFF SHORE
THU. EXPECT LOWS WED NITE AS MUCH AS 5 DEGREES BELOW NORMAL AS GOOD
RADIATIONAL CONDITIONS DEVELOP. HAVE INCLUDED PATCHY FROST ACROSS
THE NC MTNS AND NRN FOOTHILLS WHERE TEMPS ARE COLD ENUF FOR FROST.
MOISTURE RETURN IN THE SLY FLOW AROUND THE DEPARTING HIGH PRESSURE
CENTER WILL LEAD TO INCREASING CLOUDINESS THU. HIGHS WILL END UP NEAR
TO SLIGHTLY ABOVE NORMAL.

A SERIES OF SHORT WAVES CROSS THE AREA IN THE FLAT TROF MOVING INTO
THE ERN CONUS LATE THU NITE AND FRI. GUIDANCE...IN GENERAL...HAS
INCREASED THE SPEED OF THIS SYSTEM AS IT MOVES EAST ACROSS THE AREA.
THEREFORE...BRING CHC POP INTO THE MTNS AND SLIGHT CHC ELSEWHERE
LATE THU NITE. STILL KEEP LIKELY POP LIMITED TO THE TN BORDER FRI
MORNING...BUT BRING GOOD CHC POP ACROSS THE CWFA DURING THAT TIME.
TAPER POP FROM WEST TO EAST DURING THE AFTERNOON...WITH ONLY A SMALL
PERIOD OF LINGERING SLIGHT CHC POP ACROSS THE I-77 CORRIDOR EARLY
FRI EVENING. SHEAR LOOKS BETTER WITH THIS SYSTEM...BUT STILL DOES
NOT REACH THE STRONG CATEGORY. OPS GUIDANCE SHOWS MODERATE
INSTABILITY POSSIBLE OVER THE ERN CWFA DURING THE AFTERNOON...BUT
ENSEMBLE MEAN SHOWS ONLY WEAK VALUES...EVEN IN MUCAPE. THEREFORE...
EXPECT TSRA TO DEVELOP...BUT ONLY A LOW CHC...AT BEST...FOR ANY
SEVERE STORMS. RIGHT NOW...PRECIP AMOUNTS DO NOT LOOK TO BE
EXCESSIVE EITHER. LOWS THU NITE 5 TO 10 DEGREES ABOVE NORMAL. HIGHS
FRI AROUND 5 DEGREES ABOVE NORMAL.

DRY HIGH PRESSURE BUILDS IN FRI NITE WITH LOWS AROUND 5 DEGREES
ABOVE NORMAL.

&&

.LONG TERM /SATURDAY THROUGH TUESDAY/...
AS OF 100 PM EDT TUESDAY...THE EXTENDED RANGE PERIOD INITIALIZES
SATURDAY MORNING IN THE WAKE OF A PASSING FRONTAL BOUNDARY.  HIGH
PRESSURE DIVING SOUTHWARD FROM CENTRAL CANADA WILL SPREAD ACROSS THE
OHIO VALLEY WITH A REINFORCING BACK DOOR COLD FRONT PUSHING INTO THE
SOUTHERN APPALACHIANS SATURDAY EVENING.  FORECAST WILL REMAIN DRY
INTO LATE SUNDAY MORNING BEFORE POPS RAMP UP AHEAD OF AN APPROACHING
WARM FRONT WHICH WILL INTERACT WITH THE QUASI STATIONARY BACK DOOR
FRONT DRAPED ACROSS THE AREA.

THIS WARM FRONTAL INTRUSION WILL BE IN RESPONSE TO SURFACE
CYCLOGENESIS ACROSS THE CENTRAL PLAINS BEING DRIVEN BY AN EASTWARD
MIGRATING BROAD NEGATIVELY TILTED UPPER TROF.  MODEL DISCONTINUITY
REMAINS PREVALENT REGARDING THIS SYSTEM AND ITS IMPACTS ACROSS
NORTHEAST GA AND THE WESTERN CAROLINAS.  THE GFS SOLUTION HAS THE
ABOVE MENTIONED SURFACE RIDGE TRANSITIONING TO A BERMUDA TYPE HIGH
WITH A PROGRESSIVELY DEEPENING SURFACE LOW PASSING THROUGH THE OHIO
VALLEY.  THE ECMWF ON THE OTHER HAND SHIFTS THE ABOVE MENTIONED OHIO
VALLEY RIDGE OVER NEW ENGLAND SETTING UP A WEDGE CONFIGURATION ALONG
THE APPALACHIANS.  THE GFS SOLUTION FAVORS A MORE ROBUST AND DYNAMIC
EVENT WHILE THE ECMWF LEANS TOWARDS A LESS FAVORABLE THUNDERSTORM
ENVIRONMENT AS CAD LIKE REGIME INHIBITS WARM FRONTAL SURGE.
THUS...AT THIS RANGE DECIDED TO RAMP POPS UP TO SOLID CHANCE LEVELS
WITH MENTION OF A CHANCE OF THUNDER FOR MONDAY AND TUESDAY.
TEMPERATURES THROUGH THE PERIOD WILL GENERALLY REMAIN ABOVE NORMAL
THROUGH SUNDAY WITH SLIGHTLY COOLER TEMPERATURES POSSIBLE ON MONDAY
AND TUESDAY AS SKY COVER INCREASES ASSOCIATED WITH WARM FRONTAL
ACTIVATION AND POTENTIAL PRECIPITATION.

&&

.AVIATION /03Z WEDNESDAY THROUGH SUNDAY/...
KCLT...SHOWERS HAVE MOVED EAST OF THE TERMINAL...AND EXPECT THE
LINGERING MID/HIGH CLOUDS TO CLEAR THROUGH THE EVENING. WINDS
CONTINUE OUT OF THE W/SW...BUT ARE EXPECTED TO VEER TOWARD THE NW
AND REMAIN LIGHT OVERNIGHT...BEFORE INCREASING TO NEAR 10 KTS AFTER
SUNRISE. THE ACTUAL FRONT AND DRIER LOW LEVEL AIR IS STILL BACK
ACROSS THE TENN VALLEY AS OF EARLY EVENING...SO THERE IS SOME
CONCERN THAT AREAS OF FOG COULD DEVELOP LATER THIS EVENING/EARLY IN
THE OVERNIGHT...ESP IN LIGHT OF THE LIGHT WINDS. THIS APPEARS TO BE
A LOW PROBABILITY EVENT ATTM...SO HAVE OMITTED ANY FOG MENTION IN
THE FORECAST...BUT WILL HAVE TO KEEP AN EYE ON TRENDS.

ELSEWHERE...SIMILAR TO CLT...ALTHOUGH FOG IS LESS OF A CONCERN AT
KAVL...AS WINDS SHOULD CHANNEL UP THE VALLEY AT AROUND 10 KTS FOR
MUCH OF THE OVERNIGHT. HOWEVER...A BRIEF MVFR CIG CANNOT BE RULED
OUT THERE THIS EVENING. OTHERWISE...THERE WAS ENOUGH OF A HINT AMONG
GUIDANCE PACKAGES OF THE FOG POTENTIAL AT KAND THAT A 6SM WAS
INTRODUCED THERE PRIOR TO SUNRISE...BUT WOULD NOT BE SURPRISED IF
LOWER VISBY DEVELOPS THERE...OR ANYWHERE ELSE (OTHER THAN KAVL) FOR
THAT MATTER.

OUTLOOK...DRY HIGH PRES WILL DOMINATE WED THRU THU. ANOTHER COLD
FRONT WITH POTENTIAL FOR SHOWERS/TSTMS IS THEN EXPECTED TO CROSS THE
REGION FRIDAY...DRYING OUT BY SATURDAY.

CONFIDENCE TABLE...

            02-08Z        08-14Z        14-20Z        20-02Z
KCLT       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KGSP       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KAVL       HIGH  99%     HIGH 100%     HIGH 100%     HIGH 100%
KHKY       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KGMU       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KAND       HIGH 100%     HIGH  94%     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_TABLES

&&

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

&&

$$
SYNOPSIS...DEO
NEAR TERM...JDL/NED
SHORT TERM...RWH
LONG TERM...CDG
AVIATION...JDL








000
FXUS62 KGSP 222353
AFDGSP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
753 PM EDT TUE APR 22 2014

.SYNOPSIS...
A COLD FRONT WILL MOVE OFF THE CAROLINA COAST TONIGHT AS HIGH
PRESSURE CONTROLS OUR WEATHER THROUGH THURSDAY.  A WEAK COLD FRONT
CROSSES OUR AREA ON FRIDAY...WITH A REINFORCING FRONT STALLING TO
THE NORTH OF THE AREA OVER THE WEEKEND. COOLER WEATHER MAY ARRIVE
IN THE MIDDLE OF NEXT WEEK.

&&

.NEAR TERM /THROUGH WEDNESDAY/...
AS OF 745 PM...POPS HAVE BEEN ALL BUT REMOVED FROM THE FORECAST FOR
THIS EVENING...AS THE MAIN AREA OF SHOWERS HAS SHIFTED EAST OF THE
FORECAST AREA. THE ACTUAL FRONT IS STILL PUSHING ITS WAY ACROSS THE
GREAT TN VALLEY/NORTH GEORGIA ATTM...ALONG WHICH REMAINS A DECENT
AREA OF LOW LEVEL CONVERGENCE AND SOME RESPECTABLE INSTABILITY.
HOWEVER...COVERAGE OF SHOWERS ALONG THE BOUNDARY IS UNINSPIRED TO
SAY THE LEAST. WILL NEVERTHELESS CARRY SOME TOKEN CHANCES ALONG THE
TENN BORDER...WHERE A BRIEF FLARE UP IN SHOWERS IS POSSIBLE AS THE
FRONT MOVES INTO THE SOUTHERN APPALACHIANS...AND RECEIVES SOME
ASSISTANCE FROM A NW UPSLOPE FLOW.

AS OF 245 PM...RECENT KGSP AND TCLT RADAR IMAGES INDICATED CLUSTERS
OF SHRA ACROSS THE MOUNTAINS AND FOOTHILLS...MOVING EAST BETWEEN 20
TO 25 MPH. THE SHOWERS WILL ENCOUNTER GREATER INSTABILITY ACROSS THE
PIEDMONT...BUT VALUES SHOULD RANGE BETWEEN 500-1000 J/KG. A FEW TSRA
MAY DEVELOP...BUT THE ENVIRONMENT WILL NOT SUPPORT SVR STORMS. THE
MAJORITY OF THE SHRA ARE TIMED TO MOVE EAST OF THE CWA BETWEEN
22-00Z...WITH A FEW UPSLOPE SHRA REMAINING NEAR THE TN LINE WELL
INTO THE EVENING. IN THE WAKE OF THE WEAK COLD FRONT...SKY COVER
WILL DECREASE STEADILY OVERNIGHT. GUSTY NW WINDS SHOULD RESULT IN
WEAK CAA ACROSS THE MTNS OVERNIGHT. A BLEND OF PREFERRED MOS
SUPPORTS MIN TEMPERATURES WITHIN A DEGREE OR TWO OF NORMAL.

ON WEDNESDAY...DRY CANADIAN SFC HIGH PRESSURE WILL BUILD ACROSS THE
SOUTHERN APPALACHIAN REGION. AS THE HIGH ARRIVES...GUSTY NW WINDS
ACROSS THE MTNS MAY YIELD A SMALL PATCH OF HIGH WAVE CLOUDS ACROSS
THE NC FOOTHILLS AROUND SUNRISE. OTHERWISE...SKY SHOULD REMAIN SUNNY
ACROSS THE REGION. HIGH TEMPERATURES ARE FORECAST TO RANGE FROM THE
U60S ACROSS THE MTNS TO MID 70S ACROSS THE UPPER SAVANNAH RIVER
VALLEY. THE SEASONABLE TEMPERATURE ABOVE DEWPOINTS IN THE 20S AND
30S SHOULD RESULT IN RH VALUES IN THE LOWER 20S.

&&

.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY NIGHT/...
AS OF 240 PM TUESDAY...UPPER RIDGE BUILDS IN WED NITE AND THU AS SFC
HIGH PRESSURE NOSES IN FROM THE NORTH WED NITE THEN SLIDES OFF SHORE
THU. EXPECT LOWS WED NITE AS MUCH AS 5 DEGREES BELOW NORMAL AS GOOD
RADIATIONAL CONDITIONS DEVELOP. HAVE INCLUDED PATCHY FROST ACROSS
THE NC MTNS AND NRN FOOTHILLS WHERE TEMPS ARE COLD ENUF FOR FROST.
MOISTURE RETURN IN THE SLY FLOW AROUND THE DEPARTING HIGH PRESSURE
CENTER WILL LEAD TO INCREASING CLOUDINESS THU. HIGHS WILL END UP NEAR
TO SLIGHTLY ABOVE NORMAL.

A SERIES OF SHORT WAVES CROSS THE AREA IN THE FLAT TROF MOVING INTO
THE ERN CONUS LATE THU NITE AND FRI. GUIDANCE...IN GENERAL...HAS
INCREASED THE SPEED OF THIS SYSTEM AS IT MOVES EAST ACROSS THE AREA.
THEREFORE...BRING CHC POP INTO THE MTNS AND SLIGHT CHC ELSEWHERE
LATE THU NITE. STILL KEEP LIKELY POP LIMITED TO THE TN BORDER FRI
MORNING...BUT BRING GOOD CHC POP ACROSS THE CWFA DURING THAT TIME.
TAPER POP FROM WEST TO EAST DURING THE AFTERNOON...WITH ONLY A SMALL
PERIOD OF LINGERING SLIGHT CHC POP ACROSS THE I-77 CORRIDOR EARLY
FRI EVENING. SHEAR LOOKS BETTER WITH THIS SYSTEM...BUT STILL DOES
NOT REACH THE STRONG CATEGORY. OPS GUIDANCE SHOWS MODERATE
INSTABILITY POSSIBLE OVER THE ERN CWFA DURING THE AFTERNOON...BUT
ENSEMBLE MEAN SHOWS ONLY WEAK VALUES...EVEN IN MUCAPE. THEREFORE...
EXPECT TSRA TO DEVELOP...BUT ONLY A LOW CHC...AT BEST...FOR ANY
SEVERE STORMS. RIGHT NOW...PRECIP AMOUNTS DO NOT LOOK TO BE
EXCESSIVE EITHER. LOWS THU NITE 5 TO 10 DEGREES ABOVE NORMAL. HIGHS
FRI AROUND 5 DEGREES ABOVE NORMAL.

DRY HIGH PRESSURE BUILDS IN FRI NITE WITH LOWS AROUND 5 DEGREES
ABOVE NORMAL.

&&

.LONG TERM /SATURDAY THROUGH TUESDAY/...
AS OF 100 PM EDT TUESDAY...THE EXTENDED RANGE PERIOD INITIALIZES
SATURDAY MORNING IN THE WAKE OF A PASSING FRONTAL BOUNDARY.  HIGH
PRESSURE DIVING SOUTHWARD FROM CENTRAL CANADA WILL SPREAD ACROSS THE
OHIO VALLEY WITH A REINFORCING BACK DOOR COLD FRONT PUSHING INTO THE
SOUTHERN APPALACHIANS SATURDAY EVENING.  FORECAST WILL REMAIN DRY
INTO LATE SUNDAY MORNING BEFORE POPS RAMP UP AHEAD OF AN APPROACHING
WARM FRONT WHICH WILL INTERACT WITH THE QUASI STATIONARY BACK DOOR
FRONT DRAPED ACROSS THE AREA.

THIS WARM FRONTAL INTRUSION WILL BE IN RESPONSE TO SURFACE
CYCLOGENESIS ACROSS THE CENTRAL PLAINS BEING DRIVEN BY AN EASTWARD
MIGRATING BROAD NEGATIVELY TILTED UPPER TROF.  MODEL DISCONTINUITY
REMAINS PREVALENT REGARDING THIS SYSTEM AND ITS IMPACTS ACROSS
NORTHEAST GA AND THE WESTERN CAROLINAS.  THE GFS SOLUTION HAS THE
ABOVE MENTIONED SURFACE RIDGE TRANSITIONING TO A BERMUDA TYPE HIGH
WITH A PROGRESSIVELY DEEPENING SURFACE LOW PASSING THROUGH THE OHIO
VALLEY.  THE ECMWF ON THE OTHER HAND SHIFTS THE ABOVE MENTIONED OHIO
VALLEY RIDGE OVER NEW ENGLAND SETTING UP A WEDGE CONFIGURATION ALONG
THE APPALACHIANS.  THE GFS SOLUTION FAVORS A MORE ROBUST AND DYNAMIC
EVENT WHILE THE ECMWF LEANS TOWARDS A LESS FAVORABLE THUNDERSTORM
ENVIRONMENT AS CAD LIKE REGIME INHIBITS WARM FRONTAL SURGE.
THUS...AT THIS RANGE DECIDED TO RAMP POPS UP TO SOLID CHANCE LEVELS
WITH MENTION OF A CHANCE OF THUNDER FOR MONDAY AND TUESDAY.
TEMPERATURES THROUGH THE PERIOD WILL GENERALLY REMAIN ABOVE NORMAL
THROUGH SUNDAY WITH SLIGHTLY COOLER TEMPERATURES POSSIBLE ON MONDAY
AND TUESDAY AS SKY COVER INCREASES ASSOCIATED WITH WARM FRONTAL
ACTIVATION AND POTENTIAL PRECIPITATION.

&&

.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
KCLT...SHOWERS HAVE MOVED EAST OF THE TERMINAL...AND EXPECT THE
LINGERING MID/HIGH CLOUDS TO CLEAR THROUGH THE EVENING. WINDS
CONTINUE OUT OF THE W/SW...BUT ARE EXPECTED TO VEER TOWARD THE NW
AND REMAIN LIGHT OVERNIGHT...BEFORE INCREASING TO NEAR 10 KTS AFTER
SUNRISE. THE ACTUAL FRONT AND DRIER LOW LEVEL AIR IS STILL BACK
ACROSS THE TENN VALLEY AS OF EARLY EVENING...SO THERE IS SOME
CONCERN THAT AREAS OF FOG COULD DEVELOP LATER THIS EVENING/EARLY IN
THE OVERNIGHT...ESP IN LIGHT OF THE LIGHT WINDS. THIS APPEARS TO BE
A LOW PROBABILITY EVENT ATTM...SO HAVE OMITTED ANY FOG MENTION IN
THE FORECAST...BUT WILL HAVE TO KEEP AN EYE ON TRENDS.

ELSEWHERE...SIMILAR TO CLT...ALTHOUGH FOG IS LESS OF A CONCERN AT
KAVL...AS WINDS SHOULD CHANNEL UP THE VALLEY AT AROUND 10 KTS FOR
MUCH OF THE OVERNIGHT. HOWEVER...A BRIEF MVFR CIG CANNOT BE RULED
OUT THERE THIS EVENING. OTHERWISE...THERE WAS ENOUGH OF A HINT AMONG
GUIDANCE PACKAGES OF THE FOG POTENTIAL AT KAND THAT A 6SM WAS
INTRODUCED THERE PRIOR TO SUNRISE...BUT WOULD NOT BE SURPRISED IF
LOWER VISBY DEVELOPS THERE...OR ANYWHERE ELSE (OTHER THAN KAVL) FOR
THAT MATTER.

OUTLOOK...DRY HIGH PRES WILL DOMINATE WED THRU THU. ANOTHER COLD
FRONT WITH POTENTIAL FOR SHOWERS/TSTMS IS THEN EXPECTED TO CROSS THE
REGION FRIDAY...DRYING OUT BY SATURDAY.

CONFIDENCE TABLE...

            00-06Z        06-12Z        12-18Z        18-24Z
KCLT       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KGSP       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KAVL       HIGH  99%     HIGH 100%     HIGH 100%     HIGH 100%
KHKY       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KGMU       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KAND       HIGH 100%     HIGH  97%     HIGH  97%     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_TABLES

&&

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

&&

$$
SYNOPSIS...DEO
NEAR TERM...JDL/NED
SHORT TERM...RWH
LONG TERM...CDG
AVIATION...JDL








000
FXUS62 KGSP 221851
AFDGSP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
251 PM EDT TUE APR 22 2014

.SYNOPSIS...
A COLD FRONT WILL MOVE OFF THE CAROLINA COAST TONIGHT AS HIGH
PRESSURE CONTROLS OUR WEATHER THROUGH THURSDAY.  A WEAK COLD FRONT
CROSSES OUR AREA ON FRIDAY...WITH A REINFORCING FRONT STALLING TO
THE NORTH OF THE AREA OVER THE WEEKEND. COOLER WEATHER MAY ARRIVE
IN THE MIDDLE OF NEXT WEEK.

&&

.NEAR TERM /THROUGH WEDNESDAY/...
AS OF 245 PM...RECENT KGSP AND TCLT RADAR IMAGES INDICATED CLUSTERS
OF SHRA ACROSS THE MOUNTAINS AND FOOTHILLS...MOVING EAST BETWEEN 20
TO 25 MPH. THE SHOWERS WILL ENCOUNTER GREATER INSTABILITY ACROSS THE
PIEDMONT...BUT VALUES SHOULD RANGE BETWEEN 500-1000 J/KG. A FEW TSRA
MAY DEVELOP...BUT THE ENVIRONMENT WILL NOT SUPPORT SVR STORMS. THE
MAJORITY OF THE SHRA ARE TIMED TO MOVE EAST OF THE CWA BETWEEN
22-00Z...WITH A FEW UPSLOPE SHRA REMAINING NEAR THE TN LINE WELL
INTO THE EVENING. IN THE WAKE OF THE WEAK COLD FRONT...SKY COVER
WILL DECREASE STEADILY OVERNIGHT. GUSTY NW WINDS SHOULD RESULT IN
WEAK CAA ACROSS THE MTNS OVERNIGHT. A BLEND OF PREFERRED MOS
SUPPORTS MIN TEMPERATURES WITHIN A DEGREE OR TWO OF NORMAL.

ON WEDNESDAY...DRY CANADIAN SFC HIGH PRESSURE WILL BUILD ACROSS THE
SOUTHERN APPALACHIAN REGION. AS THE HIGH ARRIVES...GUSTY NW WINDS
ACROSS THE MTNS MAY YIELD A SMALL PATCH OF HIGH WAVE CLOUDS ACROSS
THE NC FOOTHILLS AROUND SUNRISE. OTHERWISE...SKY SHOULD REMAIN SUNNY
ACROSS THE REGION. HIGH TEMPERATURES ARE FORECAST TO RANGE FROM THE
U60S ACROSS THE MTNS TO MID 70S ACROSS THE UPPER SAVANNAH RIVER
VALLEY. THE SEASONABLE TEMPERATURE ABOVE DEWPOINTS IN THE 20S AND
30S SHOULD RESULT IN RH VALUES IN THE LOWER 20S.

&&

.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY NIGHT/...
AS OF 240 PM TUESDAY...UPPER RIDGE BUILDS IN WED NITE AND THU AS SFC
HIGH PRESSURE NOSES IN FROM THE NORTH WED NITE THEN SLIDES OFF SHORE
THU. EXPECT LOWS WED NITE AS MUCH AS 5 DEGREES BELOW NORMAL AS GOOD
RADIATIONAL CONDITIONS DEVELOP. HAVE INCLUDED PATCHY FROST ACROSS
THE NC MTNS AND NRN FOOTHILLS WHERE TEMPS ARE COLD ENUF FOR FROST.
MOISTURE RETURN IN THE SLY FLOW AROUND THE DEPARTING HIGH PRESSURE
CENTER WILL LEAD TO INCREASING CLOUDINESS THU. HIGHS WILL END UP NEAR
TO SLIGHTLY ABOVE NORMAL.

A SERIES OF SHORT WAVES CROSS THE AREA IN THE FLAT TROF MOVING INTO
THE ERN CONUS LATE THU NITE AND FRI. GUIDANCE...IN GENERAL...HAS
INCREASED THE SPEED OF THIS SYSTEM AS IT MOVES EAST ACROSS THE AREA.
THEREFORE...BRING CHC POP INTO THE MTNS AND SLIGHT CHC ELSEWHERE
LATE THU NITE. STILL KEEP LIKELY POP LIMITED TO THE TN BORDER FRI
MORNING...BUT BRING GOOD CHC POP ACROSS THE CWFA DURING THAT TIME.
TAPER POP FROM WEST TO EAST DURING THE AFTERNOON...WITH ONLY A SMALL
PERIOD OF LINGERING SLIGHT CHC POP ACROSS THE I-77 CORRIDOR EARLY
FRI EVENING. SHEAR LOOKS BETTER WITH THIS SYSTEM...BUT STILL DOES
NOT REACH THE STRONG CATEGORY. OPS GUIDANCE SHOWS MODERATE
INSTABILITY POSSIBLE OVER THE ERN CWFA DURING THE AFTERNOON...BUT
ENSEMBLE MEAN SHOWS ONLY WEAK VALUES...EVEN IN MUCAPE. THEREFORE...
EXPECT TSRA TO DEVELOP...BUT ONLY A LOW CHC...AT BEST...FOR ANY
SEVERE STORMS. RIGHT NOW...PRECIP AMOUNTS DO NOT LOOK TO BE
EXCESSIVE EITHER. LOWS THU NITE 5 TO 10 DEGREES ABOVE NORMAL. HIGHS
FRI AROUND 5 DEGREES ABOVE NORMAL.

DRY HIGH PRESSURE BUILDS IN FRI NITE WITH LOWS AROUND 5 DEGREES
ABOVE NORMAL.

&&

.LONG TERM /SATURDAY THROUGH TUESDAY/...
AS OF 100 PM EDT TUESDAY...THE EXTENDED RANGE PERIOD INITIALIZES
SATURDAY MORNING IN THE WAKE OF A PASSING FRONTAL BOUNDARY.  HIGH
PRESSURE DIVING SOUTHWARD FROM CENTRAL CANADA WILL SPREAD ACROSS THE
OHIO VALLEY WITH A REINFORCING BACK DOOR COLD FRONT PUSHING INTO THE
SOUTHERN APPALACHIANS SATURDAY EVENING.  FORECAST WILL REMAIN DRY
INTO LATE SUNDAY MORNING BEFORE POPS RAMP UP AHEAD OF AN APPROACHING
WARM FRONT WHICH WILL INTERACT WITH THE QUASI STATIONARY BACK DOOR
FRONT DRAPED ACROSS THE AREA.

THIS WARM FRONTAL INTRUSION WILL BE IN RESPONSE TO SURFACE
CYCLOGENESIS ACROSS THE CENTRAL PLAINS BEING DRIVEN BY AN EASTWARD
MIGRATING BROAD NEGATIVELY TILTED UPPER TROF.  MODEL DISCONTINUITY
REMAINS PREVALENT REGARDING THIS SYSTEM AND ITS IMPACTS ACROSS
NORTHEAST GA AND THE WESTERN CAROLINAS.  THE GFS SOLUTION HAS THE
ABOVE MENTIONED SURFACE RIDGE TRANSITIONING TO A BERMUDA TYPE HIGH
WITH A PROGRESSIVELY DEEPENING SURFACE LOW PASSING THROUGH THE OHIO
VALLEY.  THE ECMWF ON THE OTHER HAND SHIFTS THE ABOVE MENTIONED OHIO
VALLEY RIDGE OVER NEW ENGLAND SETTING UP A WEDGE CONFIGURATION ALONG
THE APPALACHIANS.  THE GFS SOLUTION FAVORS A MORE ROBUST AND DYNAMIC
EVENT WHILE THE ECMWF LEANS TOWARDS A LESS FAVORABLE THUNDERSTORM
ENVIRONMENT AS CAD LIKE REGIME INHIBITS WARM FRONTAL SURGE.
THUS...AT THIS RANGE DECIDED TO RAMP POPS UP TO SOLID CHANCE LEVELS
WITH MENTION OF A CHANCE OF THUNDER FOR MONDAY AND TUESDAY.
TEMPERATURES THROUGH THE PERIOD WILL GENERALLY REMAIN ABOVE NORMAL
THROUGH SUNDAY WITH SLIGHTLY COOLER TEMPERATURES POSSIBLE ON MONDAY
AND TUESDAY AS SKY COVER INCREASES ASSOCIATED WITH WARM FRONTAL
ACTIVATION AND POTENTIAL PRECIPIATION.

&&

.AVIATION /19Z TUESDAY THROUGH SUNDAY/...
KCLT...AT 2 PM...LATEST KGSP RADAR IMAGES INDICATED SEVERAL
CLUSTERS OF SHRA ACROSS THE MTNS AND FOOTHILLS...TRACKING EAST
AROUND 25 MPH. LATEST MESOSCALE ANALYSIS HAD AN AREA OF 500-1000
J/JG OF CAPE ACROSS THE UPSTATE...DROPPING OFF TO 250 J/KG ACROSS
KCLT. CONVECTIVE ALLOWING MODELS INDICATE THAT CONVECTION SHOULD
STRENGTHEN AS IT MOVES ACROSS THE PIEDMONT LATER THIS AFTERNOON. I
WILL CONTINUE TO HIGHLIGHT THE PERIOD FOR TSRA WITH A TEMPO FROM
19Z-22Z...WITH NW WIND GUSTS TO 20 KTS. BY 22Z...THE CLUSTER/BANDS
OF CONVECTION SHOULD MOVE EAST OF THE REGION...FOLLOWED WITH FROPA
BY 0Z. THE REMAINDER OF THE TAF PERIOD WILL FEATURE VEERING WINDS AND
VFR CONDITIONS. WINDS SHOULD BECOME NW BY 9Z.

ELSEWHERE...SHRA TO VCSH WILL IMPACT THE TERMINALS THROUGH LATE THIS
AFTERNOON. INSTABILITY HAS LIKELY PEAKED ACROSS THE
REGION...HOWEVER...KAND NE TO KGSP COULD SEE VCTS BETWEEN 20-22Z.
FROPA WILL LIKELY OCCUR DURING THE EARLY EVENING...FOLLOWED BE
VEERING WINDS. GUSTY NNW WINDS IS EXPECTED TO DEVELOP AT KAVL BY
8Z...REMAINING THROUGH THE REST OF THE TAF PERIOD. EAST OF THE
MTNS...WINDS WILL INCREASE FROM THE NNW TO AROUND 10 KTS BY
15Z...KHKY COULD SEE SOME MORNING MTN CIRRUS.

OUTLOOK...DRY HIGH PRES WILL REMAIN FOR THURSDAY. ANOTHER COLD FRONT
WITH POTENTIAL FOR SHOWERS/TSTMS IS THEN EXPECTED TO CROSS THE
REGION FRIDAY.

CONFIDENCE TABLE...

            19-01Z        01-07Z        07-13Z        13-19Z
KCLT       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KGSP       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KAVL       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KHKY       HIGH 100%     HIGH 100%     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_TABLES

&&

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

&&

$$
SYNOPSIS...DEO
NEAR TERM...NED
SHORT TERM...RWH
LONG TERM...CDG
AVIATION...NED








000
FXUS62 KGSP 221814
AFDGSP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
214 PM EDT TUE APR 22 2014

.SYNOPSIS...
A COLD FRONT WILL MOVE OFF THE CAROLINA COAST TONIGHT AS HIGH
PRESSURE CONTROLS OUR WEATHER THROUGH THURSDAY.  A WEAK COLD FRONT
CROSSES OUR AREA ON FRIDAY...WITH A REINFORCING FRONT STALLING TO
THE NORTH OF THE AREA OVER THE WEEKEND. COOLER WEATHER MAY ARRIVE
IN THE MIDDLE OF NEXT WEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 2 PM...LATEST KGSP RADAR IMAGES INDICATED SEVERAL CLUSTERS OF
SHRA ACROSS THE MTNS AND FOOTHILLS...TRACKING EAST AROUND 25 MPH.
LATEST MESOSCALE ANALYSIS HAD AN AREA OF 500-1000 J/JG OF CAPE
ACROSS THE UPSTATE...DROPPING OFF TO 250 J/KG ACROSS KCLT.
CONVECTIVE ALLOWING MODELS INDICATE THAT CONVECTION SHOULD
STRENGTHEN AS IT MOVES ACROSS THE PIEDMONT LATER THIS AFTERNOON.

AS OF NOON...LATEST MESOSCALE ANALYSIS INDICATES THAT WEAK CAPE HAS
DEVELOPED ACROSS THE UPPER SAVANNAH RIVER VALLEY AND UPSTATE...WITH
SHALLOW CIN ACROSS THE MAJORITY OF THE NC ZONES. RECENT RADAR
INDICATED THAT SHRA WERE DRIFTING EAST ACROSS THE MTNS. I WILL
UPDATE THE FORECAST TO FINE TUNE POPS INTO THIS EVENING. IN
ADDITION...TEMPS UNDER LIMITED CLOUD COVER HAVE SURGED WELL ABOVE
THE FORECAST...I WILL UPDATE TO AGREE WITH OBS AND LATEST MOS.

AS OF 940 AM...SUNNY CONDITIONS EAST OF THE MTNS HAVE RESULTED IN
RAPID WARMING THIS MORNING. KGSP LATEST READING WAS 70 DEGREES. I
WILL ISSUE A QUICK UPDATE TO ADJUST SKY TO SATELLITE OBSERVATIONS. I
WILL ALSO UPDATE TEMPERATURE AND DEWPOINTS TO ALIGN WITH RECENT OBS
TRENDS. POPS APPEAR ON TRACK.

AS OF 645 AM...SHWRS ARE JUST ENTERING WESTERN GRAHAM COUNTY ON
SCHEDULE...ALTHO THEY ARE VERY LIGHT PER MRX RADAR. MID CLOUDS
AROUND 10000 FT ARE INCREASING IN COVERAGE ACRS THE MTNS AND
ADJACENT FOOTHILLS EARLIER THAN EXPECTED. THEY ARE STILL SPLOTCHY IN
NATURE ON IR SAT IMAGERY...SO NOT SURE HOW MUCH IMPACT THEY WILL
HAVE ON DAYTIME HEATING/MAX TEMPS AND RESULTANT SBCAPE THIS AFTN.
WITH PREVIOUS UPDATE I BLENDED IN CONSHORT TEMP GRIDS...WHICH
RATCHETED BACK MAX TEMPS ACRS THE WRN 2/3RDS OF THE CWFA FOR THIS
AFTN. CONFIDENCE IN ROBUST CONVECTION AND SEVERE THIS AFTN IS
DECREASING BASED ON THESE TRENDS.

AS OF 500 AM...FOR THE 0830 UTC UPDATE...I TWEAKED TEMP/DWPT TO
MATCH UP WITH LATEST OBS. THE RADAR MOSAIC SHOWS AN AREA OF SHOWERS
CROSSING CENTRAL TN AND NRN AL. THE LEADING EDGE LOOKS TO REACH THE
SMOKIES AROUND 7 AM. THE POPS LOOK ON TARGET...BUT IF THE COVERAGE
CONTINUES TO BE AS HIGH AS IT IS NOW...I MAY BUMP THEM UP A LITTLE
WITH NEXT UPDATE.

AS OF 245 AM...A FULL LATITUDINAL TROF WITH SEVERAL EMBEDDED VORT
MAXES WILL CROSS THE CWFA TODAY. ONE OF THE LEADING VORT MAXES IS
ALREADY CROSSING THE AREA EARLY THIS MORNING...WITH INCREASING
MID-HIGH CLOUDINESS. AT THE SFC...A COLD FRONT IS CURRENTLY ENTERING
THE OH VLY...AND WILL CROSS THE AREA THIS EVENING. DISORGANIZED
PRE-FRONTAL SHOWERS ACRS THE OH/TN VLYS SHUD START TO ENTER THE NC
MTNS RIGHT AROUND DAYBREAK THIS MORNING.

FOR TODAY...GUIDANCE SEEMS TO BE BACKING OFF POPS A TAD...WHICH
ISN/T TOO SURPRISING...AS LLVL FLOW VEERS TO WLY BEFORE THE FRONT
ARRIVES. THERE IS SOME Q-VECTOR CONVERGENCE AND UPR JET DIVERGENCE
AROUND 18Z ACRS WRN NC. BUT EVEN THAT IS NOT THAT IMPRESSIVE IN ANY
OF THE PROGS. BLENDING IN THE 00Z NAM/GFS...I ACTUALLY GET A
DECREASE IN POPS EAST OF THE MTNS...IN THE HIGH-END CHC TO LOW-END
LIKELY RANGE. TEMPS SHUD BE ABLE TO WARM INTO THE MID-UPR 70S.
HOWEVER...WITH LEADING SHORTWAVE ENERGY WORKING IN THIS
MORNING...MID LVL CLOUDINESS MAY HAMPER DIURNAL HEATING SOMEWHAT. AS
FOR SEVERE POTENTIAL...IT STILL DOES NOT LOOK GOOD. FCST SNDGS SHOW
MOIST MID LVLS WITH WEAK LAPSE RATES AND GENERALLY LESS THAN 25 KTS
OF 0-6KM BULK SHEAR. HIGH RES MODELS SHOW SORT OF SHOTGUN CONVECTIVE
COVERAGE WITH A FEW STRONGER CELLS...PRIMARILY ACRS THE NC PIEDMONT.
SO I THINK WE WILL SEE MAINLY SCATTERED TO NUMEROUS SHWRS WITH
SCATTERED TSTMS...A FEW OF WHICH MAY APPROACH SEVERE LIMITS IF WE
CAN MANAGE TO DESTABILIZE TO 1500-2000 J/KG OF SBCAPE (AS THE GFS
SHOWS). BUT THE GFS SEEMS TOO HIGH WITH SFC DWPTS ACRS MUCH OF THE
WARM SECTOR...SO MAY BE AN OUTLIER. THE NEW DAY ONE CONVECTIVE
OUTLOOK STILL HAS ONLY GENERAL THUNDER TODAY ACRS THE REGION. WILL
MENTION THUNDER THREAT IN THE HWO...BUT IF ANY MENTION OF
SEVERE...JUST THAT IT CANNOT BE RULED OUT.

TONIGHT...GUIDANCE IN GOOD AGREEMENT ON DRY AIR AND CAA WORKING INTO
THE AREA QUICKLY THIS EVENING. SO POPS PRETTY MUCH END BY 00Z THIS
EVENING...SAVE FOR A FEW SHWRS LINGERING ALONG THE TN/NC BORDER WITH
HELP FROM NW UPSLOPE FLOW. FLOW STRENGTHENS TO 40-50 KTS AT 850 MB
IN THE NC MTNS WITH A STRONG BUT LOW INVERSION...HELPING PRODUCE
STRONG CHANNELED VALLEY WINDS. RIGHT NOW...IT LOOKS LIKE WINDS SHUD
GENERALLY STAY SUB-ADVISORY LEVELS. TEMPS SHUD BE ABLE TO FALL INTO
THE UPR 30S TO LWR 40S IN THE MTNS AND MID-UPR 40S ACRS THE PIEDMONT
BEHIND THE FRONT.

&&

.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 225 AM TUESDAY...DRY HIGH PRESSURE WILL BEGIN TO BUILD DOWN
OVER THE FORECAST AREA ON WEDNESDAY...WITH RESIDUAL BRISK NW FLOW
LINGERING THROUGH AT LEAST THE MORNING HOURS. THERE IS SOME
POTENTIAL FOR AN OROGRAPHICALLY INDUCED CIRRUS SHIELD TO FORM IN THE
MTN WAVE FLOW OVER WRN NC WED MORNING...BUT UPSTREAM MOISTURE
REMAINS A QUESTION MARK. OTHERWISE...EXPECT DRY CONDITIONS WED WITH
MAX TEMPS NEAR CLIMO IN THE SRN TIER AND ONE TO TWO CATEGORIES BELOW
NORMAL IN THE NRN TIER.

FLAT UPPER RIDGING WILL THEN BUILD IN FROM THE WEST LATE WED AND
LINGER THROUGH THU. SPOTTY 30S FOR OVERNIGHT LOWS WILL BE POSSIBLE
IN THE NC MTNS THU MORNING WITH GOOD RADIATION...BUT WITH TEMPS
PROBABLY A LITTLE TOO WARM FOR FROST. RETURN FLOW MOISTURE WILL
START TO SET UP FROM THE SW THU AFTN AND EVENING. THIS MIGHT
CONTRIBUTE A FEW MORE CLOUDS...BUT POPS STILL LOOK UNLIKELY. TEMPS
WILL HOVER NEAR CLIMATE NORMS.

&&

.LONG TERM /FRIDAY THROUGH MONDAY/...
AS OF 100 PM EDT TUESDAY...THE EXTENDED RANGE PERIOD INITIALIZES
SATURDAY MORNING IN THE WAKE OF A PASSING FRONTAL BOUNDARY.  HIGH
PRESSURE DIVING SOUTHWARD FROM CENTRAL CANADA WILL SPREAD ACROSS THE
OHIO VALLEY WITH A REINFORCING BACK DOOR COLD FRONT PUSHING INTO THE
SOUTHERN APPALACHIANS SATURDAY EVENING.  FORECAST WILL REMAIN DRY
INTO LATE SUNDAY MORNING BEFORE POPS RAMP UP AHEAD OF AN APPROACHING
WARM FRONT WHICH WILL INTERACT WITH THE QUASI STATIONARY BACK DOOR
FRONT DRAPED ACROSS THE AREA.

THIS WARM FRONTAL INTRUSION WILL BE IN RESPONSE TO SURFACE
CYCLOGENESIS ACROSS THE CENTRAL PLAINS BEING DRIVEN BY AN EASTWARD
MIGRATING BROAD NEGATIVELY TILTED UPPER TROF.  MODEL DISCONTINUITY
REMAINS PREVALENT REGARDING THIS SYSTEM AND ITS IMPACTS ACROSS
NORTHEAST GA AND THE WESTERN CAROLINAS.  THE GFS SOLUTION HAS THE
ABOVE MENTIONED SURFACE RIDGE TRANSITIONING TO A BERMUDA TYPE HIGH
WITH A PROGRESSIVELY DEEPENING SURFACE LOW PASSING THROUGH THE OHIO
VALLEY.  THE ECMWF ON THE OTHER HAND SHIFTS THE ABOVE MENTIONED OHIO
VALLEY RIDGE OVER NEW ENGLAND SETTING UP A WEDGE CONFIGURATION ALONG
THE APPALACHIANS.  THE GFS SOLUTION FAVORS A MORE ROBUST AND DYNAMIC
EVENT WHILE THE ECMWF LEANS TOWARDS A LESS FAVORABLE THUNDERSTORM
ENVIRONMENT AS CAD LIKE REGIME INHIBITS WARM FRONTAL SURGE.
THUS...AT THIS RANGE DECIDED TO RAMP POPS UP TO SOLID CHANCE LEVELS
WITH MENTION OF A CHANCE OF THUNDER FOR MONDAY AND TUESDAY.
TEMPERATURES THROUGH THE PERIOD WILL GENERALLY REMAIN ABOVE NORMAL
THROUGH SUNDAY WITH SLIGHTLY COOLER TEMPERATURES POSSIBLE ON MONDAY
AND TUESDAY AS SKY COVER INCREASES ASSOCIATED WITH WARM FRONTAL
ACTIVATION AND POTENTIAL PRECIPIATION.

&&

.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
KCLT...AT 2 PM...LATEST KGSP RADAR IMAGES INDICATED SEVERAL
CLUSTERS OF SHRA ACROSS THE MTNS AND FOOTHILLS...TRACKING EAST
AROUND 25 MPH. LATEST MESOSCALE ANALYSIS HAD AN AREA OF 500-1000
J/JG OF CAPE ACROSS THE UPSTATE...DROPPING OFF TO 250 J/KG ACROSS
KCLT. CONVECTIVE ALLOWING MODELS INDICATE THAT CONVECTION SHOULD
STRENGTHEN AS IT MOVES ACROSS THE PIEDMONT LATER THIS AFTERNOON. I
WILL CONTINUE TO HIGHLIGHT THE PERIOD FOR TSRA WITH A TEMPO FROM
19Z-22Z...WITH NW WIND GUSTS TO 20 KTS. BY 22Z...THE CLUSTER/BANDS
OF CONVECTION SHOULD MOVE EAST OF THE REGION...FOLLOWED WITH FROPA
BY 0Z. THE REMAINDER OF THE TAF PERIOD WILL FEATURE VEERING WINDS AND
VFR CONDITIONS. WINDS SHOULD BECOME NW BY 9Z.

ELSEWHERE...SHRA TO VCSH WILL IMPACT THE TERMINALS THROUGH LATE THIS
AFTERNOON. INSTABILITY HAS LIKELY PEAKED ACROSS THE
REGION...HOWEVER...KAND NE TO KGSP COULD SEE VCTS BETWEEN 20-22Z.
FROPA WILL LIKELY OCCUR DURING THE EARLY EVENING...FOLLOWED BE
VEERING WINDS. GUSTY NNW WINDS IS EXPECTED TO DEVELOP AT KAVL BY
8Z...REMAINING THROUGH THE REST OF THE TAF PERIOD. EAST OF THE
MTNS...WINDS WILL INCREASE FROM THE NNW TO AROUND 10 KTS BY
15Z...KHKY COULD SEE SOME MORNING MTN CIRRUS.

OUTLOOK...DRY HIGH PRES WILL REMAIN FOR THURSDAY. ANOTHER COLD FRONT
WITH POTENTIAL FOR SHOWERS/TSTMS IS THEN EXPECTED TO CROSS THE
REGION FRIDAY.

CONFIDENCE TABLE...

            18-24Z        00-06Z        06-12Z        12-18Z
KCLT       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KGSP       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KAVL       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KHKY       HIGH 100%     HIGH 100%     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_TABLES

&&

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

&&

$$
SYNOPSIS...HG
NEAR TERM...ARK/NED
SHORT TERM...HG
LONG TERM...HG
AVIATION...NED








000
FXUS62 KGSP 221613
AFDGSP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
1213 PM EDT TUE APR 22 2014

.SYNOPSIS...
A COLD FRONT WILL CROSS THE REGION FROM THE WEST TODAY. DRY HIGH
PRESSURE WILL THEN RETURN WEDNESDAY THROUGH THURSDAY. A WEAK COLD
FRONT WILL MOVE THROUGH THE AREA ON FRIDAY...WITH A REINFORCING
FRONT STALLING TO THE NORTH OF THE AREA OVER THE WEEKEND.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF NOON...LATEST MESOSCALE ANALYSIS INDICATES THAT WEAK CAPE HAS
DEVELOPED ACROSS THE UPPER SAVANNAH RIVER VALLEY AND UPSTATE...WITH
SHALLOW CIN ACROSS THE MAJORITY OF THE NC ZONES. RECENT RADAR
INDICATED THAT SHRA WERE DRIFTING EAST ACROSS THE MTNS. I WILL
UPDATE THE FORECAST TO FINE TUNE POPS INTO THIS EVENING. IN
ADDITION...TEMPS UNDER LIMITED CLOUD COVER HAVE SURGED WELL ABOVE
THE FORECAST...I WILL UPDATE TO AGREE WITH OBS AND LATEST MOS.

AS OF 940 AM...SUNNY CONDITIONS EAST OF THE MTNS HAVE RESULTED IN
RAPID WARMING THIS MORNING. KGSP LATEST READING WAS 70 DEGREES. I
WILL ISSUE A QUICK UPDATE TO ADJUST SKY TO SATELLITE OBSERVATIONS. I
WILL ALSO UPDATE TEMPERATURE AND DEWPOINTS TO ALIGN WITH RECENT OBS
TRENDS. POPS APPEAR ON TRACK.

AS OF 645 AM...SHWRS ARE JUST ENTERING WESTERN GRAHAM COUNTY ON
SCHEDULE...ALTHO THEY ARE VERY LIGHT PER MRX RADAR. MID CLOUDS
AROUND 10000 FT ARE INCREASING IN COVERAGE ACRS THE MTNS AND
ADJACENT FOOTHILLS EARLIER THAN EXPECTED. THEY ARE STILL SPLOTCHY IN
NATURE ON IR SAT IMAGERY...SO NOT SURE HOW MUCH IMPACT THEY WILL
HAVE ON DAYTIME HEATING/MAX TEMPS AND RESULTANT SBCAPE THIS AFTN.
WITH PREVIOUS UPDATE I BLENDED IN CONSHORT TEMP GRIDS...WHICH
RATCHETED BACK MAX TEMPS ACRS THE WRN 2/3RDS OF THE CWFA FOR THIS
AFTN. CONFIDENCE IN ROBUST CONVECTION AND SEVERE THIS AFTN IS
DECREASING BASED ON THESE TRENDS.

AS OF 500 AM...FOR THE 0830 UTC UPDATE...I TWEAKED TEMP/DWPT TO
MATCH UP WITH LATEST OBS. THE RADAR MOSAIC SHOWS AN AREA OF SHOWERS
CROSSING CENTRAL TN AND NRN AL. THE LEADING EDGE LOOKS TO REACH THE
SMOKIES AROUND 7 AM. THE POPS LOOK ON TARGET...BUT IF THE COVERAGE
CONTINUES TO BE AS HIGH AS IT IS NOW...I MAY BUMP THEM UP A LITTLE
WITH NEXT UPDATE.

AS OF 245 AM...A FULL LATITUDINAL TROF WITH SEVERAL EMBEDDED VORT
MAXES WILL CROSS THE CWFA TODAY. ONE OF THE LEADING VORT MAXES IS
ALREADY CROSSING THE AREA EARLY THIS MORNING...WITH INCREASING
MID-HIGH CLOUDINESS. AT THE SFC...A COLD FRONT IS CURRENTLY ENTERING
THE OH VLY...AND WILL CROSS THE AREA THIS EVENING. DISORGANIZED
PRE-FRONTAL SHOWERS ACRS THE OH/TN VLYS SHUD START TO ENTER THE NC
MTNS RIGHT AROUND DAYBREAK THIS MORNING.

FOR TODAY...GUIDANCE SEEMS TO BE BACKING OFF POPS A TAD...WHICH
ISN/T TOO SURPRISING...AS LLVL FLOW VEERS TO WLY BEFORE THE FRONT
ARRIVES. THERE IS SOME Q-VECTOR CONVERGENCE AND UPR JET DIVERGENCE
AROUND 18Z ACRS WRN NC. BUT EVEN THAT IS NOT THAT IMPRESSIVE IN ANY
OF THE PROGS. BLENDING IN THE 00Z NAM/GFS...I ACTUALLY GET A
DECREASE IN POPS EAST OF THE MTNS...IN THE HIGH-END CHC TO LOW-END
LIKELY RANGE. TEMPS SHUD BE ABLE TO WARM INTO THE MID-UPR 70S.
HOWEVER...WITH LEADING SHORTWAVE ENERGY WORKING IN THIS
MORNING...MID LVL CLOUDINESS MAY HAMPER DIURNAL HEATING SOMEWHAT. AS
FOR SEVERE POTENTIAL...IT STILL DOES NOT LOOK GOOD. FCST SNDGS SHOW
MOIST MID LVLS WITH WEAK LAPSE RATES AND GENERALLY LESS THAN 25 KTS
OF 0-6KM BULK SHEAR. HIGH RES MODELS SHOW SORT OF SHOTGUN CONVECTIVE
COVERAGE WITH A FEW STRONGER CELLS...PRIMARILY ACRS THE NC PIEDMONT.
SO I THINK WE WILL SEE MAINLY SCATTERED TO NUMEROUS SHWRS WITH
SCATTERED TSTMS...A FEW OF WHICH MAY APPROACH SEVERE LIMITS IF WE
CAN MANAGE TO DESTABILIZE TO 1500-2000 J/KG OF SBCAPE (AS THE GFS
SHOWS). BUT THE GFS SEEMS TOO HIGH WITH SFC DWPTS ACRS MUCH OF THE
WARM SECTOR...SO MAY BE AN OUTLIER. THE NEW DAY ONE CONVECTIVE
OUTLOOK STILL HAS ONLY GENERAL THUNDER TODAY ACRS THE REGION. WILL
MENTION THUNDER THREAT IN THE HWO...BUT IF ANY MENTION OF
SEVERE...JUST THAT IT CANNOT BE RULED OUT.

TONIGHT...GUIDANCE IN GOOD AGREEMENT ON DRY AIR AND CAA WORKING INTO
THE AREA QUICKLY THIS EVENING. SO POPS PRETTY MUCH END BY 00Z THIS
EVENING...SAVE FOR A FEW SHWRS LINGERING ALONG THE TN/NC BORDER WITH
HELP FROM NW UPSLOPE FLOW. FLOW STRENGTHENS TO 40-50 KTS AT 850 MB
IN THE NC MTNS WITH A STRONG BUT LOW INVERSION...HELPING PRODUCE
STRONG CHANNELED VALLEY WINDS. RIGHT NOW...IT LOOKS LIKE WINDS SHUD
GENERALLY STAY SUB-ADVISORY LEVELS. TEMPS SHUD BE ABLE TO FALL INTO
THE UPR 30S TO LWR 40S IN THE MTNS AND MID-UPR 40S ACRS THE PIEDMONT
BEHIND THE FRONT.

&&

.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 225 AM TUESDAY...DRY HIGH PRESSURE WILL BEGIN TO BUILD DOWN
OVER THE FORECAST AREA ON WEDNESDAY...WITH RESIDUAL BRISK NW FLOW
LINGERING THROUGH AT LEAST THE MORNING HOURS. THERE IS SOME
POTENTIAL FOR AN OROGRAPHICALLY INDUCED CIRRUS SHIELD TO FORM IN THE
MTN WAVE FLOW OVER WRN NC WED MORNING...BUT UPSTREAM MOISTURE
REMAINS A QUESTION MARK. OTHERWISE...EXPECT DRY CONDITIONS WED WITH
MAX TEMPS NEAR CLIMO IN THE SRN TIER AND ONE TO TWO CATEGORIES BELOW
NORMAL IN THE NRN TIER.

FLAT UPPER RIDGING WILL THEN BUILD IN FROM THE WEST LATE WED AND
LINGER THROUGH THU. SPOTTY 30S FOR OVERNIGHT LOWS WILL BE POSSIBLE
IN THE NC MTNS THU MORNING WITH GOOD RADIATION...BUT WITH TEMPS
PROBABLY A LITTLE TOO WARM FOR FROST. RETURN FLOW MOISTURE WILL
START TO SET UP FROM THE SW THU AFTN AND EVENING. THIS MIGHT
CONTRIBUTE A FEW MORE CLOUDS...BUT POPS STILL LOOK UNLIKELY. TEMPS
WILL HOVER NEAR CLIMATE NORMS.

&&

.LONG TERM /FRIDAY THROUGH MONDAY/...
AS OF 230 AM EDT TUESDAY...A DEAMPLIFYING SHORTWAVE WILL CROSS THE
REGION EARLY FRI. THE ASSOCIATED SFC FRONT/TROUGH SHOULD ALSO CROSS
THE REGION BY EARLY AFTN...WITH THIS TIMING LIMITING INSTABILITY
SOMEWHAT. HOWEVER...ANY SLOWING OF THE FORWARD PROGRESS OF THE WEAK
FROPA COULD ALLOW CONVECTION TO CONTINUE THROUGH MID AFTN...WHEN SFC
BASED CAPE VALUES SHOULD BE 1000 TO 1500 J/KG ALONG THE SE PIEDMONT.
WILL FEATURE CHANCE POPS THROUGHOUT FOR SHOWERS AND THUNDERSTORMS
BUT SEVERE WEATHER PROBABILITIES REMAIN LOW.

A BROAD UPPER RIDGE SHOULD BE IN PLACE OVER THE SE THROUGH THE
WEEKEND. UNDER THE RIDGE...A BACKDOOR SFC COLD FRONT WILL STALL
NORTH OF THE FORECAST AREA SAT INTO SAT NIGHT. THIS WILL KEEP THE
REGION IN THE WARM SECTOR SUN THROUGH MON AS LOW PRES RIDES EAST
ALONG THE STALLED BOUNDARY TOWARD THE APPALACHIANS. DIURNAL SHOWER
CHANCES WILL STEADILY INCREASE SUNDAY THROUGH MONDAY AS MOISTURE AND
INSTABILITY BUILD IN THE SW FLOW.

&&

.AVIATION /16Z TUESDAY THROUGH SATURDAY/...
KCLT...THE MAIN CONCERN FOR THE 12Z TAFS WILL BE CONVECTION THIS
AFTN AHEAD OF AN APPROACHING COLD FRONT. GUIDANCE IN DECENT
AGREEMENT ON SCATTERED TO NUMEROUS SHRA ACROSS THE REGION FROM ABOUT
18Z TO 23Z...WITH AT LEAST A CHC OF TSTMS. SO WILL GO WITH
PREVAILING SHRA AND TEMPO TSRA FROM 19-22Z WHICH IS THE TIME FRAME
OF BEST CHC. THE BASES OF THE CLOUDS ARE HIGH (AROUND 7000-9000
FT)...SO EVEN ORDINARY SHRA MAY PRODUCE GUSTY WINDS. WILL INCLUDE
GUSTS IN THE TEMPO. OTHERWISE...GENERALLY BKN070-100 WITH A WSW WIND
(EXCEPT IN CONVECTION). THE ACTUAL FRONT SHUD PUSH THRU THIS EVENING
AFTER THE SHRA HAVE PUSHED OFF TO THE EAST...SO WIND DIR IS LOW
CONFIDENCE UNTIL THE FRONT IS THRU (AROUND 5Z WITH A NW WIND). SKIES
WILL CLEAR OUT...BUT OROGRAPHIC CIRRUS MAY DEVELOP AS UPPER JET
NOSES IN FROM THE NW TOWARD DAYBREAK WEDNESDAY.

ELSEWHERE...STILL LITTLE CHANGE IN THINKING FOR THE 12Z TAFS.
SCATTERED TO NUMEROUS SHRA EXPECTED WITH JUST A FEW EMBEDDED TSTMS
PRIMARILY ACRS THE PIEDMONT THIS AFTN. OTHER THAN A DIRECT IMPACT
FROM SHRA/TSRA...EXPECT VFR CONDITIONS WITH WSW WIND INCREASING TO
ABOUT 8-10 KTS. CONVECTION WILL EXIT TO THE EAST QUICKLY THIS
EVENING...THEN THE SFC COLD FRONT WILL PUSH THRU...CLEARING OUT THE
SKIES AND SWITCHING THE WINDS TO NW. WINDS MAY GET GUSTY AT KAVL
BEFORE DAYBREAK WEDNESDAY...AS PROFILES SUPPORT STRONG CHANNELED
VALLEY WINDS IN NW FLOW.

OUTLOOK...DRY HIGH PRES RETURNS FOR WEDNESDAY/THURSDAY. ANOTHER COLD
FRONT WITH POTENTIAL FOR SHOWERS/TSTMS IS THEN EXPECTED TO CROSS THE
REGION FRIDAY.

CONFIDENCE TABLE...

            16-22Z        22-04Z        04-10Z        10-16Z
KCLT       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KGSP       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KAVL       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KHKY       HIGH 100%     HIGH 100%     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_TABLES

&&

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

&&

$$
SYNOPSIS...HG
NEAR TERM...ARK/NED
SHORT TERM...HG
LONG TERM...HG
AVIATION...ARK








000
FXUS62 KGSP 221343
AFDGSP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
943 AM EDT TUE APR 22 2014

.SYNOPSIS...
A COLD FRONT WILL CROSS THE REGION FROM THE WEST TODAY. DRY HIGH
PRESSURE WILL THEN RETURN WEDNESDAY THROUGH THURSDAY. A WEAK COLD
FRONT WILL MOVE THROUGH THE AREA ON FRIDAY...WITH A REINFORCING
FRONT STALLING TO THE NORTH OF THE AREA OVER THE WEEKEND.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 940 AM...SUNNY CONDITIONS EAST OF THE MTNS HAVE RESULTED IN
RAPID WARMING THIS MORNING. KGSP LATEST READING WAS 70 DEGREES. I
WILL ISSUE A QUICK UPDATE TO ADJUST SKY TO SATELLITE OBSERVATIONS. I
WILL ALSO UPDATE TEMPERATURE AND DEWPOINTS TO ALIGN WITH RECENT OBS
TRENDS. POPS APPEAR ON TRACK.

AS OF 645 AM...SHWRS ARE JUST ENTERING WESTERN GRAHAM COUNTY ON
SCHEDULE...ALTHO THEY ARE VERY LIGHT PER MRX RADAR. MID CLOUDS
AROUND 10000 FT ARE INCREASING IN COVERAGE ACRS THE MTNS AND
ADJACENT FOOTHILLS EARLIER THAN EXPECTED. THEY ARE STILL SPLOTCHY IN
NATURE ON IR SAT IMAGERY...SO NOT SURE HOW MUCH IMPACT THEY WILL
HAVE ON DAYTIME HEATING/MAX TEMPS AND RESULTANT SBCAPE THIS AFTN.
WITH PREVIOUS UPDATE I BLENDED IN CONSHORT TEMP GRIDS...WHICH
RATCHETED BACK MAX TEMPS ACRS THE WRN 2/3RDS OF THE CWFA FOR THIS
AFTN. CONFIDENCE IN ROBUST CONVECTION AND SEVERE THIS AFTN IS
DECREASING BASED ON THESE TRENDS.

AS OF 500 AM...FOR THE 0830 UTC UPDATE...I TWEAKED TEMP/DWPT TO
MATCH UP WITH LATEST OBS. THE RADAR MOSAIC SHOWS AN AREA OF SHOWERS
CROSSING CENTRAL TN AND NRN AL. THE LEADING EDGE LOOKS TO REACH THE
SMOKIES AROUND 7 AM. THE POPS LOOK ON TARGET...BUT IF THE COVERAGE
CONTINUES TO BE AS HIGH AS IT IS NOW...I MAY BUMP THEM UP A LITTLE
WITH NEXT UPDATE.

AS OF 245 AM...A FULL LATITUDINAL TROF WITH SEVERAL EMBEDDED VORT
MAXES WILL CROSS THE CWFA TODAY. ONE OF THE LEADING VORT MAXES IS
ALREADY CROSSING THE AREA EARLY THIS MORNING...WITH INCREASING
MID-HIGH CLOUDINESS. AT THE SFC...A COLD FRONT IS CURRENTLY ENTERING
THE OH VLY...AND WILL CROSS THE AREA THIS EVENING. DISORGANIZED
PRE-FRONTAL SHOWERS ACRS THE OH/TN VLYS SHUD START TO ENTER THE NC
MTNS RIGHT AROUND DAYBREAK THIS MORNING.

FOR TODAY...GUIDANCE SEEMS TO BE BACKING OFF POPS A TAD...WHICH
ISN/T TOO SURPRISING...AS LLVL FLOW VEERS TO WLY BEFORE THE FRONT
ARRIVES. THERE IS SOME Q-VECTOR CONVERGENCE AND UPR JET DIVERGENCE
AROUND 18Z ACRS WRN NC. BUT EVEN THAT IS NOT THAT IMPRESSIVE IN ANY
OF THE PROGS. BLENDING IN THE 00Z NAM/GFS...I ACTUALLY GET A
DECREASE IN POPS EAST OF THE MTNS...IN THE HIGH-END CHC TO LOW-END
LIKELY RANGE. TEMPS SHUD BE ABLE TO WARM INTO THE MID-UPR 70S.
HOWEVER...WITH LEADING SHORTWAVE ENERGY WORKING IN THIS
MORNING...MID LVL CLOUDINESS MAY HAMPER DIURNAL HEATING SOMEWHAT. AS
FOR SEVERE POTENTIAL...IT STILL DOES NOT LOOK GOOD. FCST SNDGS SHOW
MOIST MID LVLS WITH WEAK LAPSE RATES AND GENERALLY LESS THAN 25 KTS
OF 0-6KM BULK SHEAR. HIGH RES MODELS SHOW SORT OF SHOTGUN CONVECTIVE
COVERAGE WITH A FEW STRONGER CELLS...PRIMARILY ACRS THE NC PIEDMONT.
SO I THINK WE WILL SEE MAINLY SCATTERED TO NUMEROUS SHWRS WITH
SCATTERED TSTMS...A FEW OF WHICH MAY APPROACH SEVERE LIMITS IF WE
CAN MANAGE TO DESTABILIZE TO 1500-2000 J/KG OF SBCAPE (AS THE GFS
SHOWS). BUT THE GFS SEEMS TOO HIGH WITH SFC DWPTS ACRS MUCH OF THE
WARM SECTOR...SO MAY BE AN OUTLIER. THE NEW DAY ONE CONVECTIVE
OUTLOOK STILL HAS ONLY GENERAL THUNDER TODAY ACRS THE REGION. WILL
MENTION THUNDER THREAT IN THE HWO...BUT IF ANY MENTION OF
SEVERE...JUST THAT IT CANNOT BE RULED OUT.

TONIGHT...GUIDANCE IN GOOD AGREEMENT ON DRY AIR AND CAA WORKING INTO
THE AREA QUICKLY THIS EVENING. SO POPS PRETTY MUCH END BY 00Z THIS
EVENING...SAVE FOR A FEW SHWRS LINGERING ALONG THE TN/NC BORDER WITH
HELP FROM NW UPSLOPE FLOW. FLOW STRENGTHENS TO 40-50 KTS AT 850 MB
IN THE NC MTNS WITH A STRONG BUT LOW INVERSION...HELPING PRODUCE
STRONG CHANNELED VALLEY WINDS. RIGHT NOW...IT LOOKS LIKE WINDS SHUD
GENERALLY STAY SUB-ADVISORY LEVELS. TEMPS SHUD BE ABLE TO FALL INTO
THE UPR 30S TO LWR 40S IN THE MTNS AND MID-UPR 40S ACRS THE PIEDMONT
BEHIND THE FRONT.

&&

.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 225 AM TUESDAY...DRY HIGH PRESSURE WILL BEGIN TO BUILD DOWN
OVER THE FORECAST AREA ON WEDNESDAY...WITH RESIDUAL BRISK NW FLOW
LINGERING THROUGH AT LEAST THE MORNING HOURS. THERE IS SOME
POTENTIAL FOR AN OROGRAPHICALLY INDUCED CIRRUS SHIELD TO FORM IN THE
MTN WAVE FLOW OVER WRN NC WED MORNING...BUT UPSTREAM MOISTURE
REMAINS A QUESTION MARK. OTHERWISE...EXPECT DRY CONDITIONS WED WITH
MAX TEMPS NEAR CLIMO IN THE SRN TIER AND ONE TO TWO CATEGORIES BELOW
NORMAL IN THE NRN TIER.

FLAT UPPER RIDGING WILL THEN BUILD IN FROM THE WEST LATE WED AND
LINGER THROUGH THU. SPOTTY 30S FOR OVERNIGHT LOWS WILL BE POSSIBLE
IN THE NC MTNS THU MORNING WITH GOOD RADIATION...BUT WITH TEMPS
PROBABLY A LITTLE TOO WARM FOR FROST. RETURN FLOW MOISTURE WILL
START TO SET UP FROM THE SW THU AFTN AND EVENING. THIS MIGHT
CONTRIBUTE A FEW MORE CLOUDS...BUT POPS STILL LOOK UNLIKELY. TEMPS
WILL HOVER NEAR CLIMATE NORMS.

&&

.LONG TERM /FRIDAY THROUGH MONDAY/...
AS OF 230 AM EDT TUESDAY...A DEAMPLIFYING SHORTWAVE WILL CROSS THE
REGION EARLY FRI. THE ASSOCIATED SFC FRONT/TROUGH SHOULD ALSO CROSS
THE REGION BY EARLY AFTN...WITH THIS TIMING LIMITING INSTABILITY
SOMEWHAT. HOWEVER...ANY SLOWING OF THE FORWARD PROGRESS OF THE WEAK
FROPA COULD ALLOW CONVECTION TO CONTINUE THROUGH MID AFTN...WHEN SFC
BASED CAPE VALUES SHOULD BE 1000 TO 1500 J/KG ALONG THE SE PIEDMONT.
WILL FEATURE CHANCE POPS THROUGHOUT FOR SHOWERS AND THUNDERSTORMS
BUT SEVERE WEATHER PROBABILITIES REMAIN LOW.

A BROAD UPPER RIDGE SHOULD BE IN PLACE OVER THE SE THROUGH THE
WEEKEND. UNDER THE RIDGE...A BACKDOOR SFC COLD FRONT WILL STALL
NORTH OF THE FORECAST AREA SAT INTO SAT NIGHT. THIS WILL KEEP THE
REGION IN THE WARM SECTOR SUN THROUGH MON AS LOW PRES RIDES EAST
ALONG THE STALLED BOUNDARY TOWARD THE APPALACHIANS. DIURNAL SHOWER
CHANCES WILL STEADILY INCREASE SUNDAY THROUGH MONDAY AS MOISTURE AND
INSTABILITY BUILD IN THE SW FLOW.

&&

.AVIATION /14Z TUESDAY THROUGH SATURDAY/...
KCLT...THE MAIN CONCERN FOR THE 12Z TAFS WILL BE CONVECTION THIS
AFTN AHEAD OF AN APPROACHING COLD FRONT. GUIDANCE IN DECENT
AGREEMENT ON SCATTERED TO NUMEROUS SHRA ACROSS THE REGION FROM ABOUT
18Z TO 23Z...WITH AT LEAST A CHC OF TSTMS. SO WILL GO WITH
PREVAILING SHRA AND TEMPO TSRA FROM 19-22Z WHICH IS THE TIME FRAME
OF BEST CHC. THE BASES OF THE CLOUDS ARE HIGH (AROUND 7000-9000
FT)...SO EVEN ORDINARY SHRA MAY PRODUCE GUSTY WINDS. WILL INCLUDE
GUSTS IN THE TEMPO. OTHERWISE...GENERALLY BKN070-100 WITH A WSW WIND
(EXCEPT IN CONVECTION). THE ACTUAL FRONT SHUD PUSH THRU THIS EVENING
AFTER THE SHRA HAVE PUSHED OFF TO THE EAST...SO WIND DIR IS LOW
CONFIDENCE UNTIL THE FRONT IS THRU (AROUND 5Z WITH A NW WIND). SKIES
WILL CLEAR OUT...BUT OROGRAPHIC CIRRUS MAY DEVELOP AS UPPER JET
NOSES IN FROM THE NW TOWARD DAYBREAK WEDNESDAY.

ELSEWHERE...STILL LITTLE CHANGE IN THINKING FOR THE 12Z TAFS.
SCATTERED TO NUMEROUS SHRA EXPECTED WITH JUST A FEW EMBEDDED TSTMS
PRIMARILY ACRS THE PIEDMONT THIS AFTN. OTHER THAN A DIRECT IMPACT
FROM SHRA/TSRA...EXPECT VFR CONDITIONS WITH WSW WIND INCREASING TO
ABOUT 8-10 KTS. CONVECTION WILL EXIT TO THE EAST QUICKLY THIS
EVENING...THEN THE SFC COLD FRONT WILL PUSH THRU...CLEARING OUT THE
SKIES AND SWITCHING THE WINDS TO NW. WINDS MAY GET GUSTY AT KAVL
BEFORE DAYBREAK WEDNESDAY...AS PROFILES SUPPORT STRONG CHANNELED
VALLEY WINDS IN NW FLOW.

OUTLOOK...DRY HIGH PRES RETURNS FOR WEDNESDAY/THURSDAY. ANOTHER COLD
FRONT WITH POTENTIAL FOR SHOWERS/TSTMS IS THEN EXPECTED TO CROSS THE
REGION FRIDAY.

CONFIDENCE TABLE...

            13-19Z        19-01Z        01-07Z        07-13Z
KCLT       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KGSP       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KAVL       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KHKY       HIGH 100%     HIGH 100%     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_TABLES

&&

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

&&

$$
SYNOPSIS...HG
NEAR TERM...ARK/NED
SHORT TERM...HG
LONG TERM...HG
AVIATION...ARK








000
FXUS62 KGSP 221115
AFDGSP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
715 AM EDT TUE APR 22 2014

.SYNOPSIS...
A COLD FRONT WILL CROSS THE REGION FROM THE WEST TODAY. DRY HIGH
PRESSURE WILL THEN RETURN WEDNESDAY THROUGH THURSDAY. A WEAK COLD
FRONT WILL MOVE THROUGH THE AREA ON FRIDAY...WITH A REINFORCING
FRONT STALLING TO THE NORTH OF THE AREA OVER THE WEEKEND.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 645 AM...SHWRS ARE JUST ENTERING WESTERN GRAHAM COUNTY ON
SCHEDULE...ALTHO THEY ARE VERY LIGHT PER MRX RADAR. MID CLOUDS
AROUND 10000 FT ARE INCREASING IN COVERAGE ACRS THE MTNS AND
ADJACENT FOOTHILLS EARLIER THAN EXPECTED. THEY ARE STILL SPLOTCHY IN
NATURE ON IR SAT IMAGERY...SO NOT SURE HOW MUCH IMPACT THEY WILL
HAVE ON DAYTIME HEATING/MAX TEMPS AND RESULTANT SBCAPE THIS AFTN.
WITH PREVIOUS UPDATE I BLENDED IN CONSHORT TEMP GRIDS...WHICH
RATCHETED BACK MAX TEMPS ACRS THE WRN 2/3RDS OF THE CWFA FOR THIS
AFTN. CONFIDENCE IN ROBUST CONVECTION AND SEVERE THIS AFTN IS
DECREASING BASED ON THESE TRENDS.

AS OF 500 AM...FOR THE 0830 UTC UPDATE...I TWEAKED TEMP/DWPT TO
MATCH UP WITH LATEST OBS. THE RADAR MOSAIC SHOWS AN AREA OF SHOWERS
CROSSING CENTRAL TN AND NRN AL. THE LEADING EDGE LOOKS TO REACH THE
SMOKIES AROUND 7 AM. THE POPS LOOK ON TARGET...BUT IF THE COVERAGE
CONTINUES TO BE AS HIGH AS IT IS NOW...I MAY BUMP THEM UP A LITTLE
WITH NEXT UPDATE.

AS OF 245 AM...A FULL LATITUDINAL TROF WITH SEVERAL EMBEDDED VORT
MAXES WILL CROSS THE CWFA TODAY. ONE OF THE LEADING VORT MAXES IS
ALREADY CROSSING THE AREA EARLY THIS MORNING...WITH INCREASING
MID-HIGH CLOUDINESS. AT THE SFC...A COLD FRONT IS CURRENTLY ENTERING
THE OH VLY...AND WILL CROSS THE AREA THIS EVENING. DISORGANIZED
PRE-FRONTAL SHOWERS ACRS THE OH/TN VLYS SHUD START TO ENTER THE NC
MTNS RIGHT AROUND DAYBREAK THIS MORNING.

FOR TODAY...GUIDANCE SEEMS TO BE BACKING OFF POPS A TAD...WHICH
ISN/T TOO SURPRISING...AS LLVL FLOW VEERS TO WLY BEFORE THE FRONT
ARRIVES. THERE IS SOME Q-VECTOR CONVERGENCE AND UPR JET DIVERGENCE
AROUND 18Z ACRS WRN NC. BUT EVEN THAT IS NOT THAT IMPRESSIVE IN ANY
OF THE PROGS. BLENDING IN THE 00Z NAM/GFS...I ACTUALLY GET A
DECREASE IN POPS EAST OF THE MTNS...IN THE HIGH-END CHC TO LOW-END
LIKELY RANGE. TEMPS SHUD BE ABLE TO WARM INTO THE MID-UPR 70S.
HOWEVER...WITH LEADING SHORTWAVE ENERGY WORKING IN THIS
MORNING...MID LVL CLOUDINESS MAY HAMPER DIURNAL HEATING SOMEWHAT. AS
FOR SEVERE POTENTIAL...IT STILL DOES NOT LOOK GOOD. FCST SNDGS SHOW
MOIST MID LVLS WITH WEAK LAPSE RATES AND GENERALLY LESS THAN 25 KTS
OF 0-6KM BULK SHEAR. HIGH RES MODELS SHOW SORT OF SHOTGUN CONVECTIVE
COVERAGE WITH A FEW STRONGER CELLS...PRIMARILY ACRS THE NC PIEDMONT.
SO I THINK WE WILL SEE MAINLY SCATTERED TO NUMEROUS SHWRS WITH
SCATTERED TSTMS...A FEW OF WHICH MAY APPROACH SEVERE LIMITS IF WE
CAN MANAGE TO DESTABILIZE TO 1500-2000 J/KG OF SBCAPE (AS THE GFS
SHOWS). BUT THE GFS SEEMS TOO HIGH WITH SFC DWPTS ACRS MUCH OF THE
WARM SECTOR...SO MAY BE AN OUTLIER. THE NEW DAY ONE CONVECTIVE
OUTLOOK STILL HAS ONLY GENERAL THUNDER TODAY ACRS THE REGION. WILL
MENTION THUNDER THREAT IN THE HWO...BUT IF ANY MENTION OF
SEVERE...JUST THAT IT CANNOT BE RULED OUT.

TONIGHT...GUIDANCE IN GOOD AGREEMENT ON DRY AIR AND CAA WORKING INTO
THE AREA QUICKLY THIS EVENING. SO POPS PRETTY MUCH END BY 00Z THIS
EVENING...SAVE FOR A FEW SHWRS LINGERING ALONG THE TN/NC BORDER WITH
HELP FROM NW UPSLOPE FLOW. FLOW STRENGTHENS TO 40-50 KTS AT 850 MB
IN THE NC MTNS WITH A STRONG BUT LOW INVERSION...HELPING PRODUCE
STRONG CHANNELED VALLEY WINDS. RIGHT NOW...IT LOOKS LIKE WINDS SHUD
GENERALLY STAY SUB-ADVISORY LEVELS. TEMPS SHUD BE ABLE TO FALL INTO
THE UPR 30S TO LWR 40S IN THE MTNS AND MID-UPR 40S ACRS THE PIEDMONT
BEHIND THE FRONT.

&&

.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 225 AM TUESDAY...DRY HIGH PRESSURE WILL BEGIN TO BUILD DOWN
OVER THE FORECAST AREA ON WEDNESDAY...WITH RESIDUAL BRISK NW FLOW
LINGERING THROUGH AT LEAST THE MORNING HOURS. THERE IS SOME
POTENTIAL FOR AN OROGRAPHICALLY INDUCED CIRRUS SHIELD TO FORM IN THE
MTN WAVE FLOW OVER WRN NC WED MORNING...BUT UPSTREAM MOISTURE
REMAINS A QUESTION MARK. OTHERWISE...EXPECT DRY CONDITIONS WED WITH
MAX TEMPS NEAR CLIMO IN THE SRN TIER AND ONE TO TWO CATEGORIES BELOW
NORMAL IN THE NRN TIER.

FLAT UPPER RIDGING WILL THEN BUILD IN FROM THE WEST LATE WED AND
LINGER THROUGH THU. SPOTTY 30S FOR OVERNIGHT LOWS WILL BE POSSIBLE
IN THE NC MTNS THU MORNING WITH GOOD RADIATION...BUT WITH TEMPS
PROBABLY A LITTLE TOO WARM FOR FROST. RETURN FLOW MOISTURE WILL
START TO SET UP FROM THE SW THU AFTN AND EVENING. THIS MIGHT
CONTRIBUTE A FEW MORE CLOUDS...BUT POPS STILL LOOK UNLIKELY. TEMPS
WILL HOVER NEAR CLIMATE NORMS.

&&

.LONG TERM /FRIDAY THROUGH MONDAY/...
AS OF 230 AM EDT TUESDAY...A DEAMPLIFYING SHORTWAVE WILL CROSS THE
REGION EARLY FRI. THE ASSOCIATED SFC FRONT/TROUGH SHOULD ALSO CROSS
THE REGION BY EARLY AFTN...WITH THIS TIMING LIMITING INSTABILITY
SOMEWHAT. HOWEVER...ANY SLOWING OF THE FORWARD PROGRESS OF THE WEAK
FROPA COULD ALLOW CONVECTION TO CONTINUE THROUGH MID AFTN...WHEN SFC
BASED CAPE VALUES SHOULD BE 1000 TO 1500 J/KG ALONG THE SE PIEDMONT.
WILL FEATURE CHANCE POPS THROUGHOUT FOR SHOWERS AND THUNDERSTORMS
BUT SEVERE WEATHER PROBABILITIES REMAIN LOW.

A BROAD UPPER RIDGE SHOULD BE IN PLACE OVER THE SE THROUGH THE
WEEKEND. UNDER THE RIDGE...A BACKDOOR SFC COLD FRONT WILL STALL
NORTH OF THE FORECAST AREA SAT INTO SAT NIGHT. THIS WILL KEEP THE
REGION IN THE WARM SECTOR SUN THROUGH MON AS LOW PRES RIDES EAST
ALONG THE STALLED BOUNDARY TOWARD THE APPALACHIANS. DIURNAL SHOWER
CHANCES WILL STEADILY INCREASE SUNDAY THROUGH MONDAY AS MOISTURE AND
INSTABILITY BUILD IN THE SW FLOW.

&&

.AVIATION /11Z TUESDAY THROUGH SATURDAY/...
KCLT...THE MAIN CONCERN FOR THE 12Z TAFS WILL BE CONVECTION THIS
AFTN AHEAD OF AN APPROACHING COLD FRONT. GUIDANCE IN DECENT
AGREEMENT ON SCATTERED TO NUMEROUS SHRA ACROSS THE REGION FROM ABOUT
18Z TO 23Z...WITH AT LEAST A CHC OF TSTMS. SO WILL GO WITH
PREVAILING SHRA AND TEMPO TSRA FROM 19-22Z WHICH IS THE TIME FRAME
OF BEST CHC. THE BASES OF THE CLOUDS ARE HIGH (AROUND 7000-9000
FT)...SO EVEN ORDINARY SHRA MAY PRODUCE GUSTY WINDS. WILL INCLUDE
GUSTS IN THE TEMPO. OTHERWISE...GENERALLY BKN070-100 WITH A WSW WIND
(EXCEPT IN CONVECTION). THE ACTUAL FRONT SHUD PUSH THRU THIS EVENING
AFTER THE SHRA HAVE PUSHED OFF TO THE EAST...SO WIND DIR IS LOW
CONFIDENCE UNTIL THE FRONT IS THRU (AROUND 5Z WITH A NW WIND). SKIES
WILL CLEAR OUT...BUT OROGRAPHIC CIRRUS MAY DEVELOP AS UPPER JET
NOSES IN FROM THE NW TOWARD DAYBREAK WEDNESDAY.

ELSEWHERE...STILL LITTLE CHANGE IN THINKING FOR THE 12Z TAFS.
SCATTERED TO NUMEROUS SHRA EXPECTED WITH JUST A FEW EMBEDDED TSTMS
PRIMARILY ACRS THE PIEDMONT THIS AFTN. OTHER THAN A DIRECT IMPACT
FROM SHRA/TSRA...EXPECT VFR CONDITIONS WITH WSW WIND INCREASING TO
ABOUT 8-10 KTS. CONVECTION WILL EXIT TO THE EAST QUICKLY THIS
EVENING...THEN THE SFC COLD FRONT WILL PUSH THRU...CLEARING OUT THE
SKIES AND SWITCHING THE WINDS TO NW. WINDS MAY GET GUSTY AT KAVL
BEFORE DAYBREAK WEDNESDAY...AS PROFILES SUPPORT STRONG CHANNELED
VALLEY WINDS IN NW FLOW.

OUTLOOK...DRY HIGH PRES RETURNS FOR WEDNESDAY/THURSDAY. ANOTHER COLD
FRONT WITH POTENTIAL FOR SHOWERS/TSTMS IS THEN EXPECTED TO CROSS THE
REGION FRIDAY.

CONFIDENCE TABLE...

            11-17Z        17-23Z        23-05Z        05-11Z
KCLT       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KGSP       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KAVL       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KHKY       HIGH 100%     HIGH 100%     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_TABLES

&&

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

&&

$$
SYNOPSIS...HG
NEAR TERM...ARK
SHORT TERM...HG
LONG TERM...HG
AVIATION...ARK








000
FXUS62 KGSP 220920
AFDGSP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
520 AM EDT TUE APR 22 2014

.SYNOPSIS...
A COLD FRONT WILL CROSS THE REGION FROM THE WEST TODAY. DRY HIGH
PRESSURE WILL THEN RETURN WEDNESDAY THROUGH THURSDAY. A WEAK COLD
FRONT WILL MOVE THROUGH THE AREA ON FRIDAY...WITH A REINFORCING
FRONT STALLING TO THE NORTH OF THE AREA OVER THE WEEKEND.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 500 AM...FOR THE 0830 UTC UPDATE...I TWEAKED TEMP/DWPT TO
MATCH UP WITH LATEST OBS. THE RADAR MOSAIC SHOWS AN AREA OF SHOWERS
CROSSING CENTRAL TN AND NRN AL. THE LEADING EDGE LOOKS TO REACH THE
SMOKIES AROUND 7 AM. THE POPS LOOK ON TARGET...BUT IF THE COVERAGE
CONTINUES TO BE AS HIGH AS IT IS NOW...I MAY BUMP THEM UP A LITTLE
WITH NEXT UPDATE.

AS OF 245 AM...A FULL LATITUDINAL TROF WITH SEVERAL EMBEDDED VORT
MAXES WILL CROSS THE CWFA TODAY. ONE OF THE LEADING VORT MAXES IS
ALREADY CROSSING THE AREA EARLY THIS MORNING...WITH INCREASING
MID-HIGH CLOUDINESS. AT THE SFC...A COLD FRONT IS CURRENTLY ENTERING
THE OH VLY...AND WILL CROSS THE AREA THIS EVENING. DISORGANIZED
PRE-FRONTAL SHOWERS ACRS THE OH/TN VLYS SHUD START TO ENTER THE NC
MTNS RIGHT AROUND DAYBREAK THIS MORNING.

FOR TODAY...GUIDANCE SEEMS TO BE BACKING OFF POPS A TAD...WHICH
ISN/T TOO SURPRISING...AS LLVL FLOW VEERS TO WLY BEFORE THE FRONT
ARRIVES. THERE IS SOME Q-VECTOR CONVERGENCE AND UPR JET DIVERGENCE
AROUND 18Z ACRS WRN NC. BUT EVEN THAT IS NOT THAT IMPRESSIVE IN ANY
OF THE PROGS. BLENDING IN THE 00Z NAM/GFS...I ACTUALLY GET A
DECREASE IN POPS EAST OF THE MTNS...IN THE HIGH-END CHC TO LOW-END
LIKELY RANGE. TEMPS SHUD BE ABLE TO WARM INTO THE MID-UPR 70S.
HOWEVER...WITH LEADING SHORTWAVE ENERGY WORKING IN THIS
MORNING...MID LVL CLOUDINESS MAY HAMPER DIURNAL HEATING SOMEWHAT. AS
FOR SEVERE POTENTIAL...IT STILL DOES NOT LOOK GOOD. FCST SNDGS SHOW
MOIST MID LVLS WITH WEAK LAPSE RATES AND GENERALLY LESS THAN 25 KTS
OF 0-6KM BULK SHEAR. HIGH RES MODELS SHOW SORT OF SHOTGUN CONVECTIVE
COVERAGE WITH A FEW STRONGER CELLS...PRIMARILY ACRS THE NC PIEDMONT.
SO I THINK WE WILL SEE MAINLY SCATTERED TO NUMEROUS SHWRS WITH
SCATTERED TSTMS...A FEW OF WHICH MAY APPROACH SEVERE LIMITS IF WE
CAN MANAGE TO DESTABILIZE TO 1500-2000 J/KG OF SBCAPE (AS THE GFS
SHOWS). BUT THE GFS SEEMS TOO HIGH WITH SFC DWPTS ACRS MUCH OF THE
WARM SECTOR...SO MAY BE AN OUTLIER. THE NEW DAY ONE CONVECTIVE
OUTLOOK STILL HAS ONLY GENERAL THUNDER TODAY ACRS THE REGION. WILL
MENTION THUNDER THREAT IN THE HWO...BUT IF ANY MENTION OF
SEVERE...JUST THAT IT CANNOT BE RULED OUT.

TONIGHT...GUIDANCE IN GOOD AGREEMENT ON DRY AIR AND CAA WORKING INTO
THE AREA QUICKLY THIS EVENING. SO POPS PRETTY MUCH END BY 00Z THIS
EVENING...SAVE FOR A FEW SHWRS LINGERING ALONG THE TN/NC BORDER WITH
HELP FROM NW UPSLOPE FLOW. FLOW STRENGTHENS TO 40-50 KTS AT 850 MB
IN THE NC MTNS WITH A STRONG BUT LOW INVERSION...HELPING PRODUCE
STRONG CHANNELED VALLEY WINDS. RIGHT NOW...IT LOOKS LIKE WINDS SHUD
GENERALLY STAY SUB-ADVISORY LEVELS. TEMPS SHUD BE ABLE TO FALL INTO
THE UPR 30S TO LWR 40S IN THE MTNS AND MID-UPR 40S ACRS THE PIEDMONT
BEHIND THE FRONT.

&&

.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 225 AM TUESDAY...DRY HIGH PRESSURE WILL BEGIN TO BUILD DOWN
OVER THE FORECAST AREA ON WEDNESDAY...WITH RESIDUAL BRISK NW FLOW
LINGERING THROUGH AT LEAST THE MORNING HOURS. THERE IS SOME
POTENTIAL FOR AN OROGRAPHICALLY INDUCED CIRRUS SHIELD TO FORM IN THE
MTN WAVE FLOW OVER WRN NC WED MORNING...BUT UPSTREAM MOISTURE
REMAINS A QUESTION MARK. OTHERWISE...EXPECT DRY CONDITIONS WED WITH
MAX TEMPS NEAR CLIMO IN THE SRN TIER AND ONE TO TWO CATEGORIES BELOW
NORMAL IN THE NRN TIER.

FLAT UPPER RIDGING WILL THEN BUILD IN FROM THE WEST LATE WED AND
LINGER THROUGH THU. SPOTTY 30S FOR OVERNIGHT LOWS WILL BE POSSIBLE
IN THE NC MTNS THU MORNING WITH GOOD RADIATION...BUT WITH TEMPS
PROBABLY A LITTLE TOO WARM FOR FROST. RETURN FLOW MOISTURE WILL
START TO SET UP FROM THE SW THU AFTN AND EVENING. THIS MIGHT
CONTRIBUTE A FEW MORE CLOUDS...BUT POPS STILL LOOK UNLIKELY. TEMPS
WILL HOVER NEAR CLIMATE NORMS.

&&

.LONG TERM /FRIDAY THROUGH MONDAY/...
AS OF 230 AM EDT TUESDAY...A DEAMPLIFYING SHORTWAVE WILL CROSS THE
REGION EARLY FRI. THE ASSOCIATED SFC FRONT/TROUGH SHOULD ALSO CROSS
THE REGION BY EARLY AFTN...WITH THIS TIMING LIMITING INSTABILITY
SOMEWHAT. HOWEVER...ANY SLOWING OF THE FORWARD PROGRESS OF THE WEAK
FROPA COULD ALLOW CONVECTION TO CONTINUE THROUGH MID AFTN...WHEN SFC
BASED CAPE VALUES SHOULD BE 1000 TO 1500 J/KG ALONG THE SE PIEDMONT.
WILL FEATURE CHANCE POPS THROUGHOUT FOR SHOWERS AND THUNDERSTORMS
BUT SEVERE WEATHER PROBABILITIES REMAIN LOW.

A BROAD UPPER RIDGE SHOULD BE IN PLACE OVER THE SE THROUGH THE
WEEKEND. UNDER THE RIDGE...A BACKDOOR SFC COLD FRONT WILL STALL
NORTH OF THE FORECAST AREA SAT INTO SAT NIGHT. THIS WILL KEEP THE
REGION IN THE WARM SECTOR SUN THROUGH MON AS LOW PRES RIDES EAST
ALONG THE STALLED BOUNDARY TOWARD THE APPALACHIANS. DIURNAL SHOWER
CHANCES WILL STEADILY INCREASE SUNDAY THROUGH MONDAY AS MOISTURE AND
INSTABILITY BUILD IN THE SW FLOW.

&&

.AVIATION /09Z TUESDAY THROUGH SATURDAY/...
KCLT AND ELSEWHERE...LITTLE CHANGE IN THINKING FROM PREVIOUS TAFS.
INCREASING MID-HIGH CLOUDS THRU THE MORNING HOURS AHEAD OF AN
APPROACHING COLD FRONT. THE FRONT WILL CROSS THE AREA THIS
AFTN...WITH SCATTERED TO NUMEROUS SHWRS AND A FEW TSTMS. WILL
CONTINUE WITH PROB30 AND A PERIOD OF VCTS OR PREVAILING TSRA WHEN
EXPECT BEST CHC OF IMPACTS...MAINLY EARLY TO MID AFTN. ANY VSBY/CIG
RESTRICTIONS SHUD BE BRIEF WHERE PRECIP DIRECTLY AFFECTS THE
TERMINALS. DRY AIR AND CAA SHUD CUT OFF SHRA ACTIVITY AND SCOUR OUT
LOW VFR CLOUDS QUICKLY THIS EVENING...WITH NW WINDS LINGERING THRU
THE NIGHT. EXPECT STRONGEST WINDS AT KAVL WITH GUSTS IN THE 20-25 KT
RANGE OVERNIGHT.

OUTLOOK...DRY HIGH PRES RETURNS FOR WEDNESDAY/THURSDAY. ANOTHER COLD
FRONT WITH POTENTIAL FOR SHOWERS/TSTMS IS THEN EXPECTED TO CROSS THE
REGION FRIDAY.

CONFIDENCE TABLE...

            09-15Z        15-21Z        21-03Z        03-09Z
KCLT       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KGSP       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KAVL       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KHKY       HIGH 100%     HIGH 100%     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_TABLES

&&

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

&&

$$
SYNOPSIS...HG
NEAR TERM...ARK
SHORT TERM...HG
LONG TERM...HG
AVIATION...ARK








000
FXUS62 KGSP 220705
AFDGSP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
305 AM EDT TUE APR 22 2014

.SYNOPSIS...
A COLD FRONT WILL CROSS THE REGION FROM THE WEST TODAY. DRY HIGH
PRESSURE WILL THEN RETURN WEDNESDAY THROUGH THURSDAY. A WEAK COLD
FRONT WILL MOVE THROUGH THE AREA ON FRIDAY...WITH A REINFORCING
FRONT STALLING TO THE NORTH OF THE AREA OVER THE WEEKEND.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 245 AM...A FULL LATITUDINAL TROF WITH SEVERAL EMBEDDED VORT
MAXES WILL CROSS THE CWFA TODAY. ONE OF THE LEADING VORT MAXES IS
ALREADY CROSSING THE AREA EARLY THIS MORNING...WITH INCREASING
MID-HIGH CLOUDINESS. AT THE SFC...A COLD FRONT IS CURRENTLY ENTERING
THE OH VLY...AND WILL CROSS THE AREA THIS EVENING. DISORGANIZED
PRE-FRONTAL SHOWERS ACRS THE OH/TN VLYS SHUD START TO ENTER THE NC
MTNS RIGHT AROUND DAYBREAK THIS MORNING.

FOR TODAY...GUIDANCE SEEMS TO BE BACKING OFF POPS A TAD...WHICH
ISN/T TOO SURPRISING...AS LLVL FLOW VEERS TO WLY BEFORE THE FRONT
ARRIVES. THERE IS SOME Q-VECTOR CONVERGENCE AND UPR JET DIVERGENCE
AROUND 18Z ACRS WRN NC. BUT EVEN THAT IS NOT THAT IMPRESSIVE IN ANY
OF THE PROGS. BLENDING IN THE 00Z NAM/GFS...I ACTUALLY GET A
DECREASE IN POPS EAST OF THE MTNS...IN THE HIGH-END CHC TO LOW-END
LIKELY RANGE. TEMPS SHUD BE ABLE TO WARM INTO THE MID-UPR 70S.
HOWEVER...WITH LEADING SHORTWAVE ENERGY WORKING IN THIS
MORNING...MID LVL CLOUDINESS MAY HAMPER DIURNAL HEATING SOMEWHAT. AS
FOR SEVERE POTENTIAL...IT STILL DOES NOT LOOK GOOD. FCST SNDGS SHOW
MOIST MID LVLS WITH WEAK LAPSE RATES AND GENERALLY LESS THAN 25 KTS
OF 0-6KM BULK SHEAR. HIGH RES MODELS SHOW SORT OF SHOTGUN CONVECTIVE
COVERAGE WITH A FEW STRONGER CELLS...PRIMARILY ACRS THE NC PIEDMONT.
SO I THINK WE WILL SEE MAINLY SCATTERED TO NUMEROUS SHWRS WITH
SCATTERED TSTMS...A FEW OF WHICH MAY APPROACH SEVERE LIMITS IF WE
CAN MANAGE TO DESTABILIZE TO 1500-2000 J/KG OF SBCAPE (AS THE GFS
SHOWS). BUT THE GFS SEEMS TOO HIGH WITH SFC DWPTS ACRS MUCH OF THE
WARM SECTOR...SO MAY BE AN OUTLIER. THE NEW DAY ONE CONVECTIVE
OUTLOOK STILL HAS ONLY GENERAL THUNDER TODAY ACRS THE REGION. WILL
MENTION THUNDER THREAT IN THE HWO...BUT IF ANY MENTION OF
SEVERE...JUST THAT IT CANNOT BE RULED OUT.

TONIGHT...GUIDANCE IN GOOD AGREEMENT ON DRY AIR AND CAA WORKING INTO
THE AREA QUICKLY THIS EVENING. SO POPS PRETTY MUCH END BY 00Z THIS
EVENING...SAVE FOR A FEW SHWRS LINGERING ALONG THE TN/NC BORDER WITH
HELP FROM NW UPSLOPE FLOW. FLOW STRENGTHENS TO 40-50 KTS AT 850 MB
IN THE NC MTNS WITH A STRONG BUT LOW INVERSION...HELPING PRODUCE
STRONG CHANNELED VALLEY WINDS. RIGHT NOW...IT LOOKS LIKE WINDS SHUD
GENERALLY STAY SUB-ADVISORY LEVELS. TEMPS SHUD BE ABLE TO FALL INTO
THE UPR 30S TO LWR 40S IN THE MTNS AND MID-UPR 40S ACRS THE PIEDMONT
BEHIND THE FRONT.

&&

.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 225 AM TUESDAY...DRY HIGH PRESSURE WILL BEGIN TO BUILD DOWN
OVER THE FORECAST AREA ON WEDNESDAY...WITH RESIDUAL BRISK NW FLOW
LINGERING THROUGH AT LEAST THE MORNING HOURS. THERE IS SOME
POTENTIAL FOR AN OROGRAPHICALLY INDUCED CIRRUS SHIELD TO FORM IN THE
MTN WAVE FLOW OVER WRN NC WED MORNING...BUT UPSTREAM MOISTURE
REMAINS A QUESTION MARK. OTHERWISE...EXPECT DRY CONDITIONS WED WITH
MAX TEMPS NEAR CLIMO IN THE SRN TIER AND ONE TO TWO CATEGORIES BELOW
NORMAL IN THE NRN TIER.

FLAT UPPER RIDGING WILL THEN BUILD IN FROM THE WEST LATE WED AND
LINGER THROUGH THU. SPOTTY 30S FOR OVERNIGHT LOWS WILL BE POSSIBLE
IN THE NC MTNS THU MORNING WITH GOOD RADIATION...BUT WITH TEMPS
PROBABLY A LITTLE TOO WARM FOR FROST. RETURN FLOW MOISTURE WILL
START TO SET UP FROM THE SW THU AFTN AND EVENING. THIS MIGHT
CONTRIBUTE A FEW MORE CLOUDS...BUT POPS STILL LOOK UNLIKELY. TEMPS
WILL HOVER NEAR CLIMATE NORMS.

&&

.LONG TERM /FRIDAY THROUGH MONDAY/...
AS OF 230 AM EDT TUESDAY...A DEAMPLIFYING SHORTWAVE WILL CROSS THE
REGION EARLY FRI. THE ASSOCIATED SFC FRONT/TROUGH SHOULD ALSO CROSS
THE REGION BY EARLY AFTN...WITH THIS TIMING LIMITING INSTABILITY
SOMEWHAT. HOWEVER...ANY SLOWING OF THE FORWARD PROGRESS OF THE WEAK
FROPA COULD ALLOW CONVECTION TO CONTINUE THROUGH MID AFTN...WHEN SFC
BASED CAPE VALUES SHOULD BE 1000 TO 1500 J/KG ALONG THE SE PIEDMONT.
WILL FEATURE CHANCE POPS THROUGHOUT FOR SHOWERS AND THUNDERSTORMS
BUT SEVERE WEATHER PROBABILITIES REMAIN LOW.

A BROAD UPPER RIDGE SHOULD BE IN PLACE OVER THE SE THROUGH THE
WEEKEND. UNDER THE RIDGE...A BACKDOOR SFC COLD FRONT WILL STALL
NORTH OF THE FORECAST AREA SAT INTO SAT NIGHT. THIS WILL KEEP THE
REGION IN THE WARM SECTOR SUN THROUGH MON AS LOW PRES RIDES EAST
ALONG THE STALLED BOUNDARY TOWARD THE APPALACHIANS. DIURNAL SHOWER
CHANCES WILL STEADILY INCREASE SUNDAY THROUGH MONDAY AS MOISTURE AND
INSTABILITY BUILD IN THE SW FLOW.

&&

.AVIATION /07Z TUESDAY THROUGH SATURDAY/...
KCLT AND ELSEWHERE...LITTLE CHANGE IN THINKING FROM PREVIOUS TAFS.
INCREASING MID-HIGH CLOUDS THRU THE MORNING HOURS AHEAD OF AN
APPROACHING COLD FRONT. THE FRONT WILL CROSS THE AREA THIS
AFTN...WITH SCATTERED TO NUMEROUS SHWRS AND A FEW TSTMS. WILL
CONTINUE WITH PROB30 AND A PERIOD OF VCTS OR PREVAILING TSRA WHEN
EXPECT BEST CHC OF IMPACTS...MAINLY EARLY TO MID AFTN. ANY VSBY/CIG
RESTRICTIONS SHUD BE BRIEF WHERE PRECIP DIRECTLY AFFECTS THE
TERMINALS. DRY AIR AND CAA SHUD CUT OFF SHRA ACTIVITY AND SCOUR OUT
LOW VFR CLOUDS QUICKLY THIS EVENING...WITH NW WINDS LINGERING THRU
THE NIGHT. EXPECT STRONGEST WINDS AT KAVL WITH GUSTS IN THE 20-25 KT
RANGE OVERNIGHT.

OUTLOOK...DRY HIGH PRES RETURNS FOR WEDNESDAY/THURSDAY. ANOTHER COLD
FRONT WITH POTENTIAL FOR SHOWERS/TSTMS IS THEN EXPECTED TO CROSS THE
REGION FRIDAY.

CONFIDENCE TABLE...

            07-13Z        13-19Z        19-01Z        01-07Z
KCLT       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KGSP       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KAVL       HIGH 100%     HIGH 100%     HIGH  98%     HIGH 100%
KHKY       HIGH 100%     HIGH 100%     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_TABLES

&&

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

&&

$$
SYNOPSIS...HG
NEAR TERM...ARK
SHORT TERM...HG
LONG TERM...HG
AVIATION...ARK








000
FXUS62 KGSP 220549
AFDGSP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
149 AM EDT TUE APR 22 2014

.SYNOPSIS...
HIGH PRESSURE WILL WEAKEN AND SHIFT EAST BEFORE A COLD FRONT
CROSSES THE REGION ON TUESDAY. DRY HIGH PRESSURE WILL RETURN
WEDNESDAY AND THURSDAY...WITH ANOTHER COLD FRONT REACHING THE
CAROLINAS AND NORTHEAST GEORGIA FRIDAY.

&&

.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 1245 AM...NO SIGNIFICANT CHANGES TO THE NEAR TERM GRIDS WITH
THIS UPDATE. TEMPS/DWPTS/SKY/WIND WERE TWEAKED WITH LATEST OBS AND
GUIDANCE...BUT OVERALL THE FCST IS ON TRACK.

AS OF 1025 PM...HIGH CLOUDS CONTINUE TO STREAM OVER THE AREA THIS
EVENING...AND WILL CONTINUE TO DO SO THROUGH THE OVERNIGHT. WE
CONTINUE TO SEE SPOTTY RETURNS ON REGIONAL RADAR IMAGERY...BUT HAVE
THUS FAR SEEN NO REPORTS OF CLOUDS BELOW 12 KFT...AND WITH THE
RELATIVELY DRY SUB-CLOUD LAYER...DOUBT WE/LL EVEN SEE SPRINKLES FROM
THESE RADAR ECHOES. THE LATEST MESOSCALE MODELS APPEAR TO HAVE
SLOWED THE TIMING OF PRE-FRONTAL SHOWERS INTO THE AREA EARLY
TUESDAY. HOWEVER...A GLANCE AT RADAR DATA FROM WAY UPSTREAM (I.E.
THE MISS VALLEY)...SUGGESTS CONVECTION MAY BE OUTPACING THESE MODEL
SOLUTIONS...SO WILL NOT MAKE SIGNIFICANT ADJUSTMENTS TO TIMING OF
POPS ATTM...WITH ISLD/SCT COVERAGE OF SHOWERS EXPECTED NEAR THE
ACROSS THE FAR WESTERN MTNS BY 12Z. OCCL HIGH CLOUDS AND LIGHT WIND
MAY LIMIT NOCTURNAL COOLING SOMEWHAT...ALTHOUGH PROBABLY NOT
SIGNIFICANTLY SO UNTIL MID-LEVEL CLOUDS ARRIVE PRIOR TO DAYBREAK.
TEMPS SHOULD COOL TO WITHIN A FEW DEGREES OF THE WARM SIDE OF
CLIMO.

AS OF 755 PM...WIDESPREAD HIGH CLOUDS CONTINUE OVER THE AREA THIS
EVENING. SOME LIGHT RETURNS ARE APPEARING ON REGIONAL RADARS...BUT
MUCH OF ANY (IF NOT ALL) PRECIP IS LIKELY EVAPORATING IN DRY
SUB-CLOUD AIR. OTHERWISE...SKIES WILL REMAIN MOSTLY/PARTLY CLOUDY
TONIGHT THROUGH THE EVENING...AND INDEED THE OVERNIGHT...WITH POPS
GRADUALLY RAMPING UP ACROSS THE MTNS TOWARD DAYBREAK IN ADVANCE OF
APPROACHING FRONTAL ZONE.

AS OF 245 PM...THROUGH TONIGHT...WEAK HIGH PRESSURE WILL GRADUALLY
ERODE AS A COLD FRONT SLIDES ACROSS THE MISSISSIPPI RIVER VALLEY.
MODEL FORECAST SOUNDINGS AND SATELLITE TRENDS INDICATE THAT MID TO
HIGH CLOUD COVER WILL LIKELY GRADUALLY INCREASE DAYBREAK. LIGHT SW
WINDS AND INCREASING SKY COVER SHOULD FAVOR LOW TEMPERATURES AROUND
5 DEGREES ABOVE NORMAL...OR FROM THE UPPER 40S ACROSS THE MTNS TO
MID 50S ALONG AND EAST OF I-85. BOTH THE NAM AND GFS INDICATE THAT
PRE-FRONTAL SHOWERS WILL REACH THE NC/TN LINE BY 12Z TUES.
HOWEVER...THE 4KM SPC WRF INDICATE THAT THE EASTERN EDGE OF
CONVECTION WILL LIKELY REMAIN WEST OF THE SOUTHERN APPALACHIANS. I
WILL FAVOR THE DRIER/SLOWER SOLUTION...BUT WILL INDICATE SCHC POPS
ACROSS THE WEST FACING SLOPES.

TUESDAY...A MID LEVEL TROF WITH A FEW WEAK EMBEDDED S/W IS EXPECTED
TO RIPPLE ACROSS THE REGION DURING THE DAYLIGHT HOURS. HOWEVER...THE
GFS MID LEVEL Q-VECTOR CONVERGENCE APPEARS VERY WEAK. IT APPEARS
THAT THE PRIMARY TRIGGER WILL BE THE SFC COLD FRONT...POSSIBLY
AUGMENTED BY A BAND OF WEAK JET DIVERGENCE. THE NAM INDICATES THAT
BROAD FIELD OF 500-1000 J/KG WITH WEAK CIN WILL EXIST ALONG AND
AHEAD OF THE COLD FRONT. SCT TO NUMEROUS SHRA SHOULD DEVELOP OR
TRACK ACROSS THE MTNS DURING THE MORNING. THE 12Z 4KM SPC-WRF
INDICATES THAT A BAND OF TSRA COULD DEVELOP IN THE LEE OF THE MTNS
DURING THE EARLY AFTERNOON...THEN TRACK EAST THROUGH THE MID/LATE
AFTERNOON. GIVEN WEAK SHEAR/LAPSE RATES...THESE STORMS WILL LIKELY
REMAIN ORDINARY. HOWEVER...COVERAGE SHOULD RANGE FROM NUMEROUS TO
WIDESPREAD ACROSS THE EASTERN FOOTHILLS AND PIEDMONT. I WILL
HANDCRAFT THE POP FORECAST TO FAVOR THE PLACEMENT AND TIMING OF THE
12Z 4KM SPC WRF. THIS APPROACH WILL INDICATE THE PASSAGE OF THE TSRA
LINE ACROSS CLT AROUND 21Z...WITH POPS FALLING BELOW SCHC BY EARLY
EVENING. THE LATE DAY FROPA MAY YIELD HIGHS IN THE L70S WITHIN THE
MTNS VALLEYS TO NEAR 80 EAST.

&&

.SHORT TERM /6 AM THIS MORNING THROUGH THURSDAY/...
AS OF 225 PM MONDAY...UPPER TROF MOVES EAST OF THE AREA TUE NITE AND
WED AS A SFC COLD FRONT MOVES EAST OF THE AREA TUE NITE AND HIGH
PRESSURE BUILDS IN FROM THE NORTH WED. ANY LINGERING PRECIP WITH THE
COLD FRONT SHOULD END QUICKLY TUE EVENING LEAVING A DRY FORECAST FOR
MOST OF THE NITE INTO WED. NORTH TO NW WINDS INCREASE TUE NITE IN
THE TIGHT PRESSURE GRADIENT BETWEEN THE DEPARTING COLD FRONT AND THE
APPROACHING HIGH. WIND GUSTS COULD REACH ADVISORY LEVEL ACROSS THE
RIDGES OF THE NRN MTNS AND BLUE RIDGE...BUT SHOULD REMAIN BELOW
CRITERION IN THE VALLEYS. GUSTY...BUT NOT AS STRONG...WINDS WILL
LINGER THRU THE DAY ON WED. A SEASONALLY COOL AIR MASS WILL MOVE IN
BEHIND THE FRONT WITH TEMPS TUE NITE AND WED NEAR TO SLIGHTLY BELOW
NORMAL.

UPPER RIDGING MOVES IN WED NITE AND THU AS THE CENTER OF SFC HIGH
PRESSURE CROSSES THE AREA AND MOVES OFF SHORE. FLOW BECOMES SLY ON
THU WITH A SLOW INCREASE IN MOISTURE. GOOD RADIATIONAL CONDITIONS
WILL LEAD TO LOWS NEAR TO A FEW DEGREES BELOW NORMAL WED NITE.
RISING THICKNESSES AND A MODERATING AIR MASS WILL HELP PUSH HIGHS
INTO THE NORMAL TO SLIGHTLY ABOVE NORMAL RANGE THU.

&&

.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
AS OF 230 PM EDT MONDAY...THE EXTENDED RANGE PERIOD INITIALIZES
THURSDAY EVENING UNDER SHORT WAVE RIDGING AND SURFACE HIGH
PRESSURE.  SOUTHERLY FLOW AT THE SURFACE WILL ALLOW FOR CONTINUED
WAA PATTERN AHEAD OF AN APPROACHING COLD FRONT.  A NORTHERN STREAM
UPPER TROF AND ITS ASSOCIATED SURFACE CYCLONE WILL BE CENTERED OVER
WESTERN GREAT LAKES WITH THE ABOVE MENTIONED COLD FRONT EXTENDING
SOUTHWARD THROUGH THE MISSISSIPPI RIVER VALLEY. THIS FRONT WILL PUSH
THROUGH NORTHEAST GA AND THE WESTERN CAROLINAS ON FRIDAY LEADING TO
INCREASING POPS FOR THE REGION.  INSTABILITY/SHEAR REMAIN SUFFICIENT
TO SUPPORT CONVECTION IN THE WARM SECTOR AHEAD OF AND ALONG THE
APPROACHING BOUNDARY AS THE ATMOSPHERE HEATS DIURNALLY INTO THE
AFTERNOON.  THE AREAS WITH THE HIGHEST THUNDERSTORM PROBABILITY WILL
BE THE FOOTHILLS/PIEDMONT REGIONS OF THE CAROLINAS ALONG WITH
PORTIONS OF NORTHEAST GA AND THE WESTERN UPSTATE.  SOME OF THESE
THUNDERSTORMS COULD REACH SEVERE LIMITS WITH THERMAL PROFILES
SUPPORTIVE OF LARGE HAIL AS THE PRIMARY THREAT.

THE FRONT WILL EJECT TO THE EAST OVERNIGHT INTO SATURDAY MORNING
WHILE A SECONDARY REINFORCING FRONT PASSES THROUGH SUNDAY MORNING.
THIS FRONT WILL BE MUCH DRIER...AND WILL BE ADVECTING INTO A DRIER
AIRMASS THAN THE PREVIOUS FROPA THEREFORE KEPT THE FORECAST DRY
THROUGH SUNDAY AFTERNOON WITH THE EXCEPTION OF SLIGHT CHANCE POPS
ALONG THE HIGHER TERRAIN DUE TO UPSLOPING EFFECTS.  BEYOND
THAT...MODEL UNCERTAINTY REIGNS REGARDING THE NEXT SYSTEM AND
POTENTIAL PRECIPITATION ON MONDAY EVENING THEREFORE LEANED HEAVILY
ON A ECMWF/GFS BLEND WHICH YIELDED INCREASING CHANCE LEVEL POPS INTO
TUESDAY.  TEMPERATURES THROUGH THE EXTENDED RANGE PERIOD WILL REMAIN
WELL ABOVE NORMAL FOR MOST OF CWFA THROUGH SATURDAY WITH SLIGHTLY
COOLER NEAR NORMAL TEMPERATURES BEHIND PASSAGE OF THE ABOVE
MENTIONED SECONDARY FRONT ON SUNDAY.

&&

.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
KCLT AND ELSEWHERE...LITTLE CHANGE IN THINKING FROM PREVIOUS TAFS.
INCREASING MID-HIGH CLOUDS THRU THE MORNING HOURS AHEAD OF AN
APPROACHING COLD FRONT. THE FRONT WILL CROSS THE AREA THIS
AFTN...WITH SCATTERED TO NUMEROUS SHWRS AND A FEW TSTMS. WILL
CONTINUE WITH PROB30 AND A PERIOD OF VCTS OR PREVAILING TSRA WHEN
EXPECT BEST CHC OF IMPACTS...MAINLY EARLY TO MID AFTN. ANY VSBY/CIG
RESTRICTIONS SHUD BE BRIEF WHERE PRECIP DIRECTLY AFFECTS THE
TERMINALS. DRY AIR AND CAA SHUD CUT OFF SHRA ACTIVITY AND SCOUR OUT
LOW VFR CLOUDS QUICKLY THIS EVENING...WITH NW WINDS LINGERING THRU
THE NIGHT. EXPECT STRONGEST WINDS AT KAVL WITH GUSTS IN THE 20-25 KT
RANGE OVERNIGHT.

OUTLOOK...DRY HIGH PRES RETURNS FOR WEDNESDAY/THURSDAY. ANOTHER COLD
FRONT WITH POTENTIAL FOR SHOWERS/TSTMS IS THEN EXPECTED TO CROSS THE
REGION FRIDAY.

CONFIDENCE TABLE...

            05-11Z        11-17Z        17-23Z        23-05Z
KCLT       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KGSP       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KAVL       HIGH 100%     HIGH 100%     HIGH  98%     HIGH 100%
KHKY       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KGMU       HIGH 100%     HIGH 100%     MED   78%     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_TABLES

&&

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

&&

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








000
FXUS62 KGSP 220237
AFDGSP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
1037 PM EDT MON APR 21 2014

.SYNOPSIS...
HIGH PRESSURE WILL WEAKEN AND SHIFT EAST BEFORE A COLD FRONT
CROSSES THE REGION ON TUESDAY. DRY HIGH PRESSURE WILL RETURN
WEDNESDAY AND THURSDAY...WITH ANOTHER COLD FRONT REACHING THE
CAROLINAS AND NORTHEAST GEORGIA FRIDAY.

&&

.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
AS OF 1025 PM...HIGH CLOUDS CONTINUE TO STREAM OVER THE AREA THIS
EVENING...AND WILL CONTINUE TO DO SO THROUGH THE OVERNIGHT. WE
CONTINUE TO SEE SPOTTY RETURNS ON REGIONAL RADAR IMAGERY...BUT HAVE
THUS FAR SEEN NO REPORTS OF CLOUDS BELOW 12 KFT...AND WITH THE
RELATIVELY DRY SUB-CLOUD LAYER...DOUBT WE/LL EVEN SEE SPRINKLES FROM
THESE RADAR ECHOES. THE LATEST MESOSCALE MODELS APPEAR TO HAVE
SLOWED THE TIMING OF PRE-FRONTAL SHOWERS INTO THE AREA EARLY
TUESDAY. HOWEVER...A GLANCE AT RADAR DATA FROM WAY UPSTREAM (I.E.
THE MISS VALLEY)...SUGGESTS CONVECTION MAY BE OUTPACING THESE MODEL
SOLUTIONS...SO WILL NOT MAKE SIGNIFICANT ADJUSTMENTS TO TIMING OF
POPS ATTM...WITH ISLD/SCT COVERAGE OF SHOWERS EXPECTED NEAR THE
ACROSS THE FAR WESTERN MTNS BY 12Z. OCCL HIGH CLOUDS AND LIGHT WIND
MAY LIMIT NOCTURNAL COOLING SOMEWHAT...ALTHOUGH PROBABLY NOT
SIGNIFICANTLY SO UNTIL MID-LEVEL CLOUDS ARRIVE PRIOR TO DAYBREAK.
TEMPS SHOULD COOL TO WITHIN A FEW DEGREES OF THE WARM SIDE OF
CLIMO.

AS OF 755 PM...WIDESPREAD HIGH CLOUDS CONTINUE OVER THE AREA THIS
EVENING. SOME LIGHT RETURNS ARE APPEARING ON REGIONAL RADARS...BUT
MUCH OF ANY (IF NOT ALL) PRECIP IS LIKELY EVAPORATING IN DRY
SUB-CLOUD AIR. OTHERWISE...SKIES WILL REMAIN MOSTLY/PARTLY CLOUDY
TONIGHT THROUGH THE EVENING...AND INDEED THE OVERNIGHT...WITH POPS
GRADUALLY RAMPING UP ACROSS THE MTNS TOWARD DAYBREAK IN ADVANCE OF
APPROACHING FRONTAL ZONE.

AS OF 245 PM...THROUGH TONIGHT...WEAK HIGH PRESSURE WILL GRADUALLY
ERODE AS A COLD FRONT SLIDES ACROSS THE MISSISSIPPI RIVER VALLEY.
MODEL FORECAST SOUNDINGS AND SATELLITE TRENDS INDICATE THAT MID TO
HIGH CLOUD COVER WILL LIKELY GRADUALLY INCREASE DAYBREAK. LIGHT SW
WINDS AND INCREASING SKY COVER SHOULD FAVOR LOW TEMPERATURES AROUND
5 DEGREES ABOVE NORMAL...OR FROM THE UPPER 40S ACROSS THE MTNS TO
MID 50S ALONG AND EAST OF I-85. BOTH THE NAM AND GFS INDICATE THAT
PRE-FRONTAL SHOWERS WILL REACH THE NC/TN LINE BY 12Z TUES.
HOWEVER...THE 4KM SPC WRF INDICATE THAT THE EASTERN EDGE OF
CONVECTION WILL LIKELY REMAIN WEST OF THE SOUTHERN APPALACHIANS. I
WILL FAVOR THE DRIER/SLOWER SOLUTION...BUT WILL INDICATE SCHC POPS
ACROSS THE WEST FACING SLOPES.

TUESDAY...A MID LEVEL TROF WITH A FEW WEAK EMBEDDED S/W IS EXPECTED
TO RIPPLE ACROSS THE REGION DURING THE DAYLIGHT HOURS. HOWEVER...THE
GFS MID LEVEL Q-VECTOR CONVERGENCE APPEARS VERY WEAK. IT APPEARS
THAT THE PRIMARY TRIGGER WILL BE THE SFC COLD FRONT...POSSIBLY
AUGMENTED BY A BAND OF WEAK JET DIVERGENCE. THE NAM INDICATES THAT
BROAD FIELD OF 500-1000 J/KG WITH WEAK CIN WILL EXIST ALONG AND
AHEAD OF THE COLD FRONT. SCT TO NUMEROUS SHRA SHOULD DEVELOP OR
TRACK ACROSS THE MTNS DURING THE MORNING. THE 12Z 4KM SPC-WRF
INDICATES THAT A BAND OF TSRA COULD DEVELOP IN THE LEE OF THE MTNS
DURING THE EARLY AFTERNOON...THEN TRACK EAST THROUGH THE MID/LATE
AFTERNOON. GIVEN WEAK SHEAR/LAPSE RATES...THESE STORMS WILL LIKELY
REMAIN ORDINARY. HOWEVER...COVERAGE SHOULD RANGE FROM NUMEROUS TO
WIDESPREAD ACROSS THE EASTERN FOOTHILLS AND PIEDMONT. I WILL
HANDCRAFT THE POP FORECAST TO FAVOR THE PLACEMENT AND TIMING OF THE
12Z 4KM SPC WRF. THIS APPROACH WILL INDICATE THE PASSAGE OF THE TSRA
LINE ACROSS CLT AROUND 21Z...WITH POPS FALLING BELOW SCHC BY EARLY
EVENING. THE LATE DAY FROPA MAY YIELD HIGHS IN THE L70S WITHIN THE
MTNS VALLEYS TO NEAR 80 EAST.

&&

.SHORT TERM /6 AM TUESDAY MORNING THROUGH THURSDAY/...
AS OF 225 PM MONDAY...UPPER TROF MOVES EAST OF THE AREA TUE NITE AND
WED AS A SFC COLD FRONT MOVES EAST OF THE AREA TUE NITE AND HIGH
PRESSURE BUILDS IN FROM THE NORTH WED. ANY LINGERING PRECIP WITH THE
COLD FRONT SHOULD END QUICKLY TUE EVENING LEAVING A DRY FORECAST FOR
MOST OF THE NITE INTO WED. NORTH TO NW WINDS INCREASE TUE NITE IN
THE TIGHT PRESSURE GRADIENT BETWEEN THE DEPARTING COLD FRONT AND THE
APPROACHING HIGH. WIND GUSTS COULD REACH ADVISORY LEVEL ACROSS THE
RIDGES OF THE NRN MTNS AND BLUE RIDGE...BUT SHOULD REMAIN BELOW
CRITERION IN THE VALLEYS. GUSTY...BUT NOT AS STRONG...WINDS WILL
LINGER THRU THE DAY ON WED. A SEASONALLY COOL AIR MASS WILL MOVE IN
BEHIND THE FRONT WITH TEMPS TUE NITE AND WED NEAR TO SLIGHTLY BELOW
NORMAL.

UPPER RIDGING MOVES IN WED NITE AND THU AS THE CENTER OF SFC HIGH
PRESSURE CROSSES THE AREA AND MOVES OFF SHORE. FLOW BECOMES SLY ON
THU WITH A SLOW INCREASE IN MOISTURE. GOOD RADIATIONAL CONDITIONS
WILL LEAD TO LOWS NEAR TO A FEW DEGREES BELOW NORMAL WED NITE.
RISING THICKNESSES AND A MODERATING AIR MASS WILL HELP PUSH HIGHS
INTO THE NORMAL TO SLIGHTLY ABOVE NORMAL RANGE THU.

&&

.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
AS OF 230 PM EDT MONDAY...THE EXTENDED RANGE PERIOD INITIALIZES
THURSDAY EVENING UNDER SHORT WAVE RIDGING AND SURFACE HIGH
PRESSURE.  SOUTHERLY FLOW AT THE SURFACE WILL ALLOW FOR CONTINUED
WAA PATTERN AHEAD OF AN APPROACHING COLD FRONT.  A NORTHERN STREAM
UPPER TROF AND ITS ASSOCIATED SURFACE CYCLONE WILL BE CENTERED OVER
WESTERN GREAT LAKES WITH THE ABOVE MENTIONED COLD FRONT EXTENDING
SOUTHWARD THROUGH THE MISSISSIPPI RIVER VALLEY. THIS FRONT WILL PUSH
THROUGH NORTHEAST GA AND THE WESTERN CAROLINAS ON FRIDAY LEADING TO
INCREASING POPS FOR THE REGION.  INSTABILITY/SHEAR REMAIN SUFFICIENT
TO SUPPORT CONVECTION IN THE WARM SECTOR AHEAD OF AND ALONG THE
APPROACHING BOUNDARY AS THE ATMOSPHERE HEATS DIURNALLY INTO THE
AFTERNOON.  THE AREAS WITH THE HIGHEST THUNDERSTORM PROBABILITY WILL
BE THE FOOTHILLS/PIEDMONT REGIONS OF THE CAROLINAS ALONG WITH
PORTIONS OF NORTHEAST GA AND THE WESTERN UPSTATE.  SOME OF THESE
THUNDERSTORMS COULD REACH SEVERE LIMITS WITH THERMAL PROFILES
SUPPORTIVE OF LARGE HAIL AS THE PRIMARY THREAT.

THE FRONT WILL EJECT TO THE EAST OVERNIGHT INTO SATURDAY MORNING
WHILE A SECONDARY REINFORCING FRONT PASSES THROUGH SUNDAY MORNING.
THIS FRONT WILL BE MUCH DRIER...AND WILL BE ADVECTING INTO A DRIER
AIRMASS THAN THE PREVIOUS FROPA THEREFORE KEPT THE FORECAST DRY
THROUGH SUNDAY AFTERNOON WITH THE EXCEPTION OF SLIGHT CHANCE POPS
ALONG THE HIGHER TERRAIN DUE TO UPSLOPING EFFECTS.  BEYOND
THAT...MODEL UNCERTAINTY REIGNS REGARDING THE NEXT SYSTEM AND
POTENTIAL PRECIPITATION ON MONDAY EVENING THEREFORE LEANED HEAVILY
ON A ECMWF/GFS BLEND WHICH YIELDED INCREASING CHANCE LEVEL POPS INTO
TUESDAY.  TEMPERATURES THROUGH THE EXTENDED RANGE PERIOD WILL REMAIN
WELL ABOVE NORMAL FOR MOST OF CWFA THROUGH SATURDAY WITH SLIGHTLY
COOLER NEAR NORMAL TEMPERATURES BEHIND PASSAGE OF THE ABOVE
MENTIONED SECONDARY FRONT ON SUNDAY.

&&

.AVIATION /03Z TUESDAY THROUGH SATURDAY/...
AT AND ELSEWHERE...VFR CONDITIONS EXPECTED DURING THE NEXT 12-18
HOURS...BUT THEN A COLD FRONT WILL BRING GOOD CHANCES FOR SHOWERS
AND THUNDERSTORMS BY TUE AFTERNOON. A PROB30 FOR TS WILL BE CARRIED
DURING EARLY AFTERNOON...WITH CATEGORICAL TSRA OR SHRA BY
MID-AFTERNOON UNTIL NEAR THE END OF THE PERIOD. BRIEF PERIODS OF
HEAVY RAIN COULD RESULT IN MVFR VISBY...POSSIBLY LOWER. OTHERWISE...
HIGH CIGS WILL GRADUALLY LOWER TO THE MID-LEVELS BY TUE AFTERNOON.
LIGHT SW WINDS WILL CONTINUE THROUGH THE OVERNIGHT...THEN INCREASE
TO AROUND 10 KTS BY LATE TUE MORNING.

OUTLOOK...DRY HIGH PRES RETURNS FOR WEDNESDAY/THURSDAY. ANOTHER COLD
FRONT WITH POTENTIAL FOR SHOWERS/TSTMS IS THEN EXPECTED TO CROSS THE
REGION FRIDAY.

CONFIDENCE TABLE...

            02-08Z        08-14Z        14-20Z        20-02Z
KCLT       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KGSP       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KAVL       HIGH 100%     HIGH 100%     HIGH  98%     HIGH 100%
KHKY       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KGMU       HIGH 100%     HIGH 100%     HIGH 100%     MED   69%
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_TABLES

&&

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

&&

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








000
FXUS62 KGSP 220004
AFDGSP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
804 PM EDT MON APR 21 2014

.SYNOPSIS...
HIGH PRESSURE WILL WEAKEN AND SHIFT EAST BEFORE A COLD FRONT
CROSSES THE REGION ON TUESDAY. DRY HIGH PRESSURE WILL RETURN
WEDNESDAY AND THURSDAY...WITH ANOTHER COLD FRONT REACHING THE
CAROLINAS AND NORTHEAST GEORGIA FRIDAY.

&&

.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
AS OF 755 PM...WIDESPREAD HIGH CLOUDS CONTINUE OVER THE AREA THIS
EVENING. SOME LIGHT RETURNS ARE APPEARING ON REGIONAL RADARS...BUT
MUCH OF ANY (IF NOT ALL) PRECIP IS LIKELY EVAPORATING IN DRY
SUB-CLOUD AIR. OTHERWISE...SKIES WILL REMAIN MOSTLY/PARTLY CLOUDY
TONIGHT THROUGH THE EVENING...AND INDEED THE OVERNIGHT...WITH POPS
GRADUALLY RAMPING UP ACROSS THE MTNS TOWARD DAYBREAK IN ADVANCE OF
APPROACHING FRONTAL ZONE.

AS OF 245 PM...THROUGH TONIGHT...WEAK HIGH PRESSURE WILL GRADUALLY
ERODE AS A COLD FRONT SLIDES ACROSS THE MISSISSIPPI RIVER VALLEY.
MODEL FORECAST SOUNDINGS AND SATELLITE TRENDS INDICATE THAT MID TO
HIGH CLOUD COVER WILL LIKELY GRADUALLY INCREASE DAYBREAK. LIGHT SW
WINDS AND INCREASING SKY COVER SHOULD FAVOR LOW TEMPERATURES AROUND
5 DEGREES ABOVE NORMAL...OR FROM THE UPPER 40S ACROSS THE MTNS TO
MID 50S ALONG AND EAST OF I-85. BOTH THE NAM AND GFS INDICATE THAT
PRE-FRONTAL SHOWERS WILL REACH THE NC/TN LINE BY 12Z TUES.
HOWEVER...THE 4KM SPC WRF INDICATE THAT THE EASTERN EDGE OF
CONVECTION WILL LIKELY REMAIN WEST OF THE SOUTHERN APPALACHIANS. I
WILL FAVOR THE DRIER/SLOWER SOLUTION...BUT WILL INDICATE SCHC POPS
ACROSS THE WEST FACING SLOPES.

TUESDAY...A MID LEVEL TROF WITH A FEW WEAK EMBEDDED S/W IS EXPECTED
TO RIPPLE ACROSS THE REGION DURING THE DAYLIGHT HOURS. HOWEVER...THE
GFS MID LEVEL Q-VECTOR CONVERGENCE APPEARS VERY WEAK. IT APPEARS
THAT THE PRIMARY TRIGGER WILL BE THE SFC COLD FRONT...POSSIBLY
AUGMENTED BY A BAND OF WEAK JET DIVERGENCE. THE NAM INDICATES THAT
BROAD FIELD OF 500-1000 J/KG WITH WEAK CIN WILL EXIST ALONG AND
AHEAD OF THE COLD FRONT. SCT TO NUMEROUS SHRA SHOULD DEVELOP OR
TRACK ACROSS THE MTNS DURING THE MORNING. THE 12Z 4KM SPC-WRF
INDICATES THAT A BAND OF TSRA COULD DEVELOP IN THE LEE OF THE MTNS
DURING THE EARLY AFTERNOON...THEN TRACK EAST THROUGH THE MID/LATE
AFTERNOON. GIVEN WEAK SHEAR/LAPSE RATES...THESE STORMS WILL LIKELY
REMAIN ORDINARY. HOWEVER...COVERAGE SHOULD RANGE FROM NUMEROUS TO
WIDESPREAD ACROSS THE EASTERN FOOTHILLS AND PIEDMONT. I WILL
HANDCRAFT THE POP FORECAST TO FAVOR THE PLACEMENT AND TIMING OF THE
12Z 4KM SPC WRF. THIS APPROACH WILL INDICATE THE PASSAGE OF THE TSRA
LINE ACROSS CLT AROUND 21Z...WITH POPS FALLING BELOW SCHC BY EARLY
EVENING. THE LATE DAY FROPA MAY YIELD HIGHS IN THE L70S WITHIN THE
MTNS VALLEYS TO NEAR 80 EAST.

&&

.SHORT TERM /6 AM TUESDAY MORNING THROUGH THURSDAY/...
AS OF 225 PM MONDAY...UPPER TROF MOVES EAST OF THE AREA TUE NITE AND
WED AS A SFC COLD FRONT MOVES EAST OF THE AREA TUE NITE AND HIGH
PRESSURE BUILDS IN FROM THE NORTH WED. ANY LINGERING PRECIP WITH THE
COLD FRONT SHOULD END QUICKLY TUE EVENING LEAVING A DRY FORECAST FOR
MOST OF THE NITE INTO WED. NORTH TO NW WINDS INCREASE TUE NITE IN
THE TIGHT PRESSURE GRADIENT BETWEEN THE DEPARTING COLD FRONT AND THE
APPROACHING HIGH. WIND GUSTS COULD REACH ADVISORY LEVEL ACROSS THE
RIDGES OF THE NRN MTNS AND BLUE RIDGE...BUT SHOULD REMAIN BELOW
CRITERION IN THE VALLEYS. GUSTY...BUT NOT AS STRONG...WINDS WILL
LINGER THRU THE DAY ON WED. A SEASONALLY COOL AIR MASS WILL MOVE IN
BEHIND THE FRONT WITH TEMPS TUE NITE AND WED NEAR TO SLIGHTLY BELOW
NORMAL.

UPPER RIDGING MOVES IN WED NITE AND THU AS THE CENTER OF SFC HIGH
PRESSURE CROSSES THE AREA AND MOVES OFF SHORE. FLOW BECOMES SLY ON
THU WITH A SLOW INCREASE IN MOISTURE. GOOD RADIATIONAL CONDITIONS
WILL LEAD TO LOWS NEAR TO A FEW DEGREES BELOW NORMAL WED NITE.
RISING THICKNESSES AND A MODERATING AIR MASS WILL HELP PUSH HIGHS
INTO THE NORMAL TO SLIGHTLY ABOVE NORMAL RANGE THU.

&&

.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
AS OF 230 PM EDT MONDAY...THE EXTENDED RANGE PERIOD INITIALIZES
THURSDAY EVENING UNDER SHORT WAVE RIDGING AND SURFACE HIGH
PRESSURE.  SOUTHERLY FLOW AT THE SURFACE WILL ALLOW FOR CONTINUED
WAA PATTERN AHEAD OF AN APPROACHING COLD FRONT.  A NORTHERN STREAM
UPPER TROF AND ITS ASSOCIATED SURFACE CYCLONE WILL BE CENTERED OVER
WESTERN GREAT LAKES WITH THE ABOVE MENTIONED COLD FRONT EXTENDING
SOUTHWARD THROUGH THE MISSISSIPPI RIVER VALLEY. THIS FRONT WILL PUSH
THROUGH NORTHEAST GA AND THE WESTERN CAROLINAS ON FRIDAY LEADING TO
INCREASING POPS FOR THE REGION.  INSTABILITY/SHEAR REMAIN SUFFICIENT
TO SUPPORT CONVECTION IN THE WARM SECTOR AHEAD OF AND ALONG THE
APPROACHING BOUNDARY AS THE ATMOSPHERE HEATS DIURNALLY INTO THE
AFTERNOON.  THE AREAS WITH THE HIGHEST THUNDERSTORM PROBABILITY WILL
BE THE FOOTHILLS/PIEDMONT REGIONS OF THE CAROLINAS ALONG WITH
PORTIONS OF NORTHEAST GA AND THE WESTERN UPSTATE.  SOME OF THESE
THUNDERSTORMS COULD REACH SEVERE LIMITS WITH THERMAL PROFILES
SUPPORTIVE OF LARGE HAIL AS THE PRIMARY THREAT.

THE FRONT WILL EJECT TO THE EAST OVERNIGHT INTO SATURDAY MORNING
WHILE A SECONDARY REINFORCING FRONT PASSES THROUGH SUNDAY MORNING.
THIS FRONT WILL BE MUCH DRIER...AND WILL BE ADVECTING INTO A DRIER
AIRMASS THAN THE PREVIOUS FROPA THEREFORE KEPT THE FORECAST DRY
THROUGH SUNDAY AFTERNOON WITH THE EXCEPTION OF SLIGHT CHANCE POPS
ALONG THE HIGHER TERRAIN DUE TO UPSLOPING EFFECTS.  BEYOND
THAT...MODEL UNCERTAINTY REIGNS REGARDING THE NEXT SYSTEM AND
POTENTIAL PRECIPITATION ON MONDAY EVENING THEREFORE LEANED HEAVILY
ON A ECMWF/GFS BLEND WHICH YIELDED INCREASING CHANCE LEVEL POPS INTO
TUESDAY.  TEMPERATURES THROUGH THE EXTENDED RANGE PERIOD WILL REMAIN
WELL ABOVE NORMAL FOR MOST OF CWFA THROUGH SATURDAY WITH SLIGHTLY
COOLER NEAR NORMAL TEMPERATURES BEHIND PASSAGE OF THE ABOVE
MENTIONED SECONDARY FRONT ON SUNDAY.

&&

.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
AT AND ELSEWHERE...VFR CONDITIONS EXPECTED DURING THE NEXT 12-18
HOURS...BUT THEN A COLD FRONT WILL BRING GOOD CHANCES FOR SHOWERS
AND THUNDERSTORMS BY TUE AFTERNOON. A PROB30 FOR TS WILL BE CARRIED
DURING EARLY AFTERNOON...WITH CATEGORICAL TSRA OR SHRA BY
MID-AFTERNOON UNTIL NEAR THE END OF THE PERIOD. BRIEF PERIODS OF
HEAVY RAIN COULD RESULT IN MVFR VISBY...POSSIBLY LOWER. OTHERWISE...
HIGH CIGS WILL GRADUALLY LOWER TO THE MID-LEVELS BY TUE AFTERNOON.
LIGHT SW WINDS WILL CONTINUE THROUGH THE OVERNIGHT...THEN INCREASE
TO AROUND 10 KTS BY LATE TUE MORNING.

OUTLOOK...DRY HIGH PRES RETURNS FOR WEDNESDAY/THURSDAY. ANOTHER COLD
FRONT WITH POTENTIAL FOR SHOWERS/TSTMS IS THEN EXPECTED TO CROSS THE
REGION FRIDAY.

CONFIDENCE TABLE...

            00-06Z        06-12Z        12-18Z        18-24Z
KCLT       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KGSP       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KAVL       HIGH 100%     HIGH 100%     HIGH  98%     HIGH  98%
KHKY       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KGMU       HIGH 100%     HIGH 100%     HIGH 100%     HIGH  81%
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_TABLES

&&

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

&&

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








000
FXUS62 KGSP 211845
AFDGSP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
245 PM EDT MON APR 21 2014

.SYNOPSIS...
HIGH PRESSURE WILL WEAKEN AND SHIFT EAST BEFORE A COLD FRONT
CROSSES THE REGION ON TUESDAY. DRY HIGH PRESSURE WILL RETURN
WEDNESDAY AND THURSDAY...WITH ANOTHER COLD FRONT REACHING THE
CAROLINAS AND NORTHEAST GEORGIA FRIDAY.

&&

.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
AS OF 245 PM...THROUGH TONIGHT...WEAK HIGH PRESSURE WILL GRADUALLY
ERODE AS A COLD FRONT SLIDES ACROSS THE MISSISSIPPI RIVER VALLEY.
MODEL FORECAST SOUNDINGS AND SATELLITE TRENDS INDICATE THAT MID TO
HIGH CLOUD COVER WILL LIKELY GRADUALLY INCREASE DAYBREAK. LIGHT SW
WINDS AND INCREASING SKY COVER SHOULD FAVOR LOW TEMPERATURES AROUND
5 DEGREES ABOVE NORMAL...OR FROM THE UPPER 40S ACROSS THE MTNS TO
MID 50S ALONG AND EAST OF I-85. BOTH THE NAM AND GFS INDICATE THAT
PRE-FRONTAL SHOWERS WILL REACH THE NC/TN LINE BY 12Z TUES.
HOWEVER...THE 4KM SPC WRF INDICATE THAT THE EASTERN EDGE OF
CONVECTION WILL LIKELY REMAIN WEST OF THE SOUTHERN APPALACHIANS. I
WILL FAVOR THE DRIER/SLOWER SOLUTION...BUT WILL INDICATE SCHC POPS
ACROSS THE WEST FACING SLOPES.

TUESDAY...A MID LEVEL TROF WITH A FEW WEAK EMBEDDED S/W IS EXPECTED
TO RIPPLE ACROSS THE REGION DURING THE DAYLIGHT HOURS. HOWEVER...THE
GFS MID LEVEL Q-VECTOR CONVERGENCE APPEARS VERY WEAK. IT APPEARS
THAT THE PRIMARY TRIGGER WILL BE THE SFC COLD FRONT...POSSIBLY
AUGMENTED BY A BAND OF WEAK JET DIVERGENCE. THE NAM INDICATES THAT
BROAD FIELD OF 500-1000 J/KG WITH WEAK CIN WILL EXIST ALONG AND
AHEAD OF THE COLD FRONT. SCT TO NUMEROUS SHRA SHOULD DEVELOP OR
TRACK ACROSS THE MTNS DURING THE MORNING. THE 12Z 4KM SPC-WRF
INDICATES THAT A BAND OF TSRA COULD DEVELOP IN THE LEE OF THE MTNS
DURING THE EARLY AFTERNOON...THEN TRACK EAST THROUGH THE MID/LATE
AFTERNOON. GIVEN WEAK SHEAR/LAPSE RATES...THESE STORMS WILL LIKELY
REMAIN ORDINARY. HOWEVER...COVERAGE SHOULD RANGE FROM NUMEROUS TO
WIDESPREAD ACROSS THE EASTERN FOOTHILLS AND PIEDMONT. I WILL
HANDCRAFT THE POP FORECAST TO FAVOR THE PLACEMENT AND TIMING OF THE
12Z 4KM SPC WRF. THIS APPROACH WILL INDICATE THE PASSAGE OF THE TSRA
LINE ACROSS CLT AROUND 21Z...WITH POPS FALLING BELOW SCHC BY EARLY
EVENING. THE LATE DAY FROPA MAY YIELD HIGHS IN THE L70S WITHIN THE
MTNS VALLEYS TO NEAR 80 EAST.

&&

.SHORT TERM /6 AM TUESDAY MORNING THROUGH THURSDAY/...
AS OF 225 PM MONDAY...UPPER TROF MOVES EAST OF THE AREA TUE NITE AND
WED AS A SFC COLD FRONT MOVES EAST OF THE AREA TUE NITE AND HIGH
PRESSURE BUILDS IN FROM THE NORTH WED. ANY LINGERING PRECIP WITH THE
COLD FRONT SHOULD END QUICKLY TUE EVENING LEAVING A DRY FORECAST FOR
MOST OF THE NITE INTO WED. NORTH TO NW WINDS INCREASE TUE NITE IN
THE TIGHT PRESSURE GRADIENT BETWEEN THE DEPARTING COLD FRONT AND THE
APPROACHING HIGH. WIND GUSTS COULD REACH ADVISORY LEVEL ACROSS THE
RIDGES OF THE NRN MTNS AND BLUE RIDGE...BUT SHOULD REMAIN BELOW
CRITERION IN THE VALLEYS. GUSTY...BUT NOT AS STRONG...WINDS WILL
LINGER THRU THE DAY ON WED. A SEASONALLY COOL AIR MASS WILL MOVE IN
BEHIND THE FRONT WITH TEMPS TUE NITE AND WED NEAR TO SLIGHTLY BELOW
NORMAL.

UPPER RIDGING MOVES IN WED NITE AND THU AS THE CENTER OF SFC HIGH
PRESSURE CROSSES THE AREA AND MOVES OFF SHORE. FLOW BECOMES SLY ON
THU WITH A SLOW INCREASE IN MOISTURE. GOOD RADIATIONAL CONDITIONS
WILL LEAD TO LOWS NEAR TO A FEW DEGREES BELOW NORMAL WED NITE.
RISING THICKNESSES AND A MODERATING AIR MASS WILL HELP PUSH HIGHS
INTO THE NORMAL TO SLIGHTLY ABOVE NORMAL RANGE THU.

&&

.LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/...
AS OF 230 PM EDT MONDAY...THE EXTENDED RANGE PERIOD INITIALIZES
THURSDAY EVENING UNDER SHORT WAVE RIDGING AND SURFACE HIGH
PRESSURE.  SOUTHERLY FLOW AT THE SURFACE WILL ALLOW FOR CONTINUED
WAA PATTERN AHEAD OF AN APPROACHING COLD FRONT.  A NORTHERN STREAM
UPPER TROF AND ITS ASSOCIATED SURFACE CYCLONE WILL BE CENTERED OVER
WESTERN GREAT LAKES WITH THE ABOVE MENTIONED COLD FRONT EXTENDING
SOUTHWARD THROUGH THE MISSISSIPPI RIVER VALLEY. THIS FRONT WILL PUSH
THROUGH NORTHEAST GA AND THE WESTERN CAROLINAS ON FRIDAY LEADING TO
INCREASING POPS FOR THE REGION.  INSTABILITY/SHEAR REMAIN SUFFICIENT
TO SUPPORT CONVECTION IN THE WARM SECTOR AHEAD OF AND ALONG THE
APPROACHING BOUNDARY AS THE ATMOSPHERE HEATS DIURNALLY INTO THE
AFTERNOON.  THE AREAS WITH THE HIGHEST THUNDERSTORM PROBABILITY WILL
BE THE FOOTHILLS/PIEDMONT REGIONS OF THE CAROLINAS ALONG WITH
PORTIONS OF NORTHEAST GA AND THE WESTERN UPSTATE.  SOME OF THESE
THUNDERSTORMS COULD REACH SEVERE LIMITS WITH THERMAL PROFILES
SUPPORTIVE OF LARGE HAIL AS THE PRIMARY THREAT.

THE FRONT WILL EJECT TO THE EAST OVERNIGHT INTO SATURDAY MORNING
WHILE A SECONDARY REINFORCING FRONT PASSES THROUGH SUNDAY MORNING.
THIS FRONT WILL BE MUCH DRIER...AND WILL BE ADVECTING INTO A DRIER
AIRMASS THAN THE PREVIOUS FROPA THEREFORE KEPT THE FORECAST DRY
THROUGH SUNDAY AFTERNOON WITH THE EXCEPTION OF SLIGHT CHANCE POPS
ALONG THE HIGHER TERRAIN DUE TO UPSLOPING EFFECTS.  BEYOND
THAT...MODEL UNCERTAINTY REIGNS REGARDING THE NEXT SYSTEM AND
POTENTIAL PRECIPITATION ON MONDAY EVENING THEREFORE LEANED HEAVILY
ON A ECMWF/GFS BLEND WHICH YIELDED INCREASING CHANCE LEVEL POPS INTO
TUESDAY.  TEMPERATURES THROUGH THE EXTENDED RANGE PERIOD WILL REMAIN
WELL ABOVE NORMAL FOR MOST OF CWFA THROUGH SATURDAY WITH SLIGHTLY
COOLER NEAR NORMAL TEMPERATURES BEHIND PASSAGE OF THE ABOVE
MENTIONED SECONDARY FRONT ON SUNDAY.

&&

.AVIATION /19Z MONDAY THROUGH SATURDAY/...
CLT...VFR. WEAK HIGH PRESSURE WILL GRADUALLY ERODE AS A COLD FRONT
APPROACHES FROM THE WEST. LIGHT SOUTHWEST WINDS WILL LIKELY PREVAIL
THROUGH THE TAF PERIOD. A BLEND OF THE MESOSCALE MODELS INDICATES
THAT THE COLD FRONT AND ASSOCIATED CONVECTION WILL PASS OVER THE
TERMINAL AFTER 18Z TUES. THE MOST LIKELY WINDOW FOR CONVECTION
SHOULD CENTER ON 21Z...PER CONVECTION ALLOWING MODELS. THE TAF WILL
FEATURE BKN070-080 WITH WEST-SOUTHWEST WINDS APPROACHING 10 KTS BY
MID DAY.

ELSEWHERE...SW WINDS AND VFR. KAVL FAVORING NW WINDS. MID LEVEL
TROUGH WITH EMBEDDED S/W WILL RIPPLE OVER THE SOUTHERN APPALACHIAN
REGION BY MID DAY. NAM INDICATES THAT A BROAD FIELD OF 500-1000 J/KG
OF CAPE WILL EXIST ALONG AND AHEAD OF THE COLD FRONT. CONVECTION
ALLOWING MODELS INDICATE THAT MTN SHRA/TSRA WILL DEVELOP DURING THE
MORNING...WITH A LINE OF TSRA DEVELOP IN THE LEE OF THE MTNS DURING
THE EARLY AFTERNOON. I WILL HIGHLIGHT WITH A PROB30 FOR MOST WESTERN
CAROLINA TERMINALS BETWEEN 16-18Z.

OUTLOOK...DRY HIGH PRES RETURNS FOR WEDNESDAY/THURSDAY. ANOTHER COLD
FRONT WITH POTENTIAL FOR SHOWERS/TSTMS IS THEN EXPECTED TO CROSS THE
REGION FRIDAY.

CONFIDENCE TABLE...

            18-24Z        00-06Z        06-12Z        12-18Z
KCLT       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KGSP       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KAVL       HIGH 100%     HIGH 100%     HIGH 100%     HIGH  87%
KHKY       HIGH 100%     HIGH 100%     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_TABLES

&&

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

&&

$$
SYNOPSIS...SBK
NEAR TERM...NED
SHORT TERM...RWH
LONG TERM...CDG
AVIATION...NED








000
FXUS62 KGSP 211814
AFDGSP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
214 PM EDT MON APR 21 2014

.SYNOPSIS...
HIGH PRESSURE WILL WEAKEN AND SHIFT EAST BEFORE A COLD FRONT
CROSSES THE REGION ON TUESDAY. DRY HIGH PRESSURE WILL RETURN
WEDNESDAY AND THURSDAY...WITH ANOTHER COLD FRONT REACHING THE
CAROLINAS AND NORTHEAST GEORGIA FRIDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 2 PM...FORECAST APPEARS ON TRACK. I WILL ISSUE A QUICK UPDATE
TO MAKE MINOR ADJUSTMENTS TO SKY...T/TD...AND WINDS.

AS OF 10 AM...A VERY PLEASANT DAY IN THE OFFING. LIGHT RETURN FLOW
AND SUNNY TO MOSTLY SUNNY CONDITIONS SHOULD PERSIST THROUGH THE
AFTERNOON. I WILL UPDATE TO MAKE ONLY MINOR UPDATES TO T/TD AND SKY.

AS OF 645 AM...UPDATED THE T/TD GRIDS WITH THE LATEST OBS...AND
TWEAKED AVIATION GRIDS FOR THE 12Z TAFS. OTHERWISE...FCST LOOKS ON
TRACK AND NO OTHER CHANGES NEEDED.

AS OF 205 AM...A QUIET NEAR TERM IS EXPECTED...AS SHARP UPR RIDGE
AXIS TRANSLATES EAST ACRS THE CWFA. AN INVERTED SFC RIDGE AXIS ALSO
REMAINS INVOF THE REGION...RESULTING IN LGT NE FLOW EAST OF THE MTNS
AND DRY CONDITIONS. THERE MAY BE SOME PATCHY FROST IN THE NORTHERN
MTNS...BUT NOTHING WIDESPREAD ACRS THE REST OF THE HIGH TERRAIN TO
WARRANT A FROST ADVISORY. TEMPS CURRENTLY LOOK ON TRACK.

TEMPS WILL CONTINUE TO REBOUND UNDER SUNNY SKIES AND LIGHT WINDS
TODAY. EXPECTING HIGHS TO BE ABOUT A CATEGORY ABOVE NORMAL...MAINLY
IN THE MID-UPR 70S ACRS THE AREA.

TONIGHT...MID AND UPR LVL HEIGHTS WILL FALL WITH AN APPROACHING
LATITUDINAL TROF AND ASSOCIATED COLD FRONT. THERE WILL BE AN
INCREASE IN MID-HIGH CLOUDS AND EVEN SOME STRATO-CU DEVELOPMENT IN
THE SW NC MTNS OVERNIGHT...KEEPING TEMPS ELEVATED ABOVE NORMAL IN
THE UPR 40S MTNS AN IN THE 50S PIEDMONT. GUIDANCE IN PRETTY GOOD
AGREEMENT ON SCATTERED SHOWERS ALONG/AHEAD OF THE FRONT CROSSING THE
OH/TN VALLEYS. A SLGT CHC TO LOW-END CHC POP WILL CREEP TO THE TN/NC
BORDER BEFORE DAYBREAK TUESDAY. OTHERWISE...IT SHUD BE DRY OVERNIGHT.

&&

.SHORT TERM /TUESDAY THROUGH THURSDAY/...
AS OF 205 AM EDT MONDAY...THE UPPER TROUGH THAT WILL CROSS THE ERN
U.S. ON TUE IS NOT PARTICULARLY AMPLIFIED OR COHERENT...BUT IT
SHOULD BE ACCOMPANIED BY SOME DEGREE OF UPPER LEVEL DIVERGENCE TUE
AFTN. THE WEAK UPPER FORCING AND LOW LEVEL CONVERGENCE ALONG THE
PASSING COLD FRONT SHOULD COMBINE WITH MODEST SFC BASED INSTABILITY
TO CREATE SCATTERED TO NUMEROUS COVERAGE OF SHOWERS AND TSTMS
THROUGH TUE AFTN. THE SEVERE TSTM THREAT LOOKS RATHER LIMITED BY THE
TALL SKINNY CAPE IN AREA MODEL PROFILES ALONG WITH MODEST 25 TO 30
KT SFC TO 3 KM SHEAR VALUES IN THE WESTERLY FLOW. HOWEVER...THE SPC
CALIBRATED SREF SEVERE TSTM PROBABILITIES CONTINUE TO POINT TO A NW
NC PIEDMONT MAXIMA...WHERE SFC INSTABILITY HAS JUST ENOUGH OVERLAP
WITH THE BEST WESTERLY SHEAR AND UPPER FORCING FOR A SLIGHTLY
GREATER SVR THREAT. THERE IS NOT ENOUGH CONFIDENCE FOR AN HWO
MENTION OF SEVERE TSTMS AT THIS POINT.

EXPECT BREEZY TO WINDY CONDITIONS POST FROPA TUE NIGHT INTO WED
MORNING. BROAD RIDGING WILL THEN RETURN WED THROUGH THU WITH DRY
CONDITIONS AND NEAR CLIMO MAXES AND MINS.

&&

.LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/...
AS OF 205 AM EDT MONDAY...A NRN TIER VORTEX CROSSING THE GREAT LAKES
ON FRI WILL NOT PROVIDE MUCH AMPLIFICATION TO THE TROUGH OVER THE
SRN TIER STATES. IN ADDITION...MOISTURE LOOKS SOMEWHAT LIMITED WITH
THE FRI SFC FRONT/TROUGH PASSAGE. HOWEVER...INSTABILITY IS RATHER
ROBUST ON BOTH THE GFS AND ECMWF SOLUTIONS ACROSS THE PIEDMONT FRI
AFTN AND ABOUT 40 KT OF DEEP LAYER SHEAR IS EVIDENT IN PROFILES.
LITTLE CHANGE WILL BE MADE TO THE LATE WEEK FORECAST...WITH CHC POPS
FOR TSRA THROUGHOUT THE REGION ON FRI.

BROAD TROUGHING WILL LIKELY LINGER INTO SAT OVER THE EAST...WITH A
SECONDARY COLD FRONT FEATURING A BETTER THERMAL CONTRAST APPROACHING
FROM THE N. THIS FRONT WILL LIKELY STALL IN OR NEAR THE FORECAST
AREA OVER THE WEEKEND. THE POSITION OF THE BOUNDARY WILL DETERMINE
WHERE INSTABILITY LINGERS/RETURNS AND THIS WILL BE DIFFICULT TO
PROJECT THAT FAR OUT IN THE FORECAST. WILL KEEP MAINLY ISOLD TO SCT
DIURNAL CONVECTIVE CHANCES GOING OVER THE WEEKEND FOR PRIMARY MTN
AND SW SECTIONS.

&&

.AVIATION /18Z MONDAY THROUGH SATURDAY/...
CLT...VFR. WEAK HIGH PRESSURE WILL GRADUALLY ERODE AS A COLD FRONT
APPROACHES FROM THE WEST. LIGHT SOUTHWEST WINDS WILL LIKELY PREVAIL
THROUGH THE TAF PERIOD. A BLEND OF THE MESOSCALE MODELS INDICATES
THAT THE COLD FRONT AND ASSOCIATED CONVECTION WILL PASS OVER THE
TERMINAL AFTER 18Z TUES. THE MOST LIKELY WINDOW FOR CONVECTION
SHOULD CENTER ON 21Z...PER CONVECTION ALLOWING MODELS. THE TAF WILL
FEATURE BKN070-080 WITH WEST-SOUTHWEST WINDS APPROACHING 10 KTS BY
MID DAY.

ELSEWHERE...SW WINDS AND VFR. KAVL FAVORING NW WINDS. MID LEVEL
TROUGH WITH EMBEDDED S/W WILL RIPPLE OVER THE SOUTHERN APPALACHIAN
REGION BY MID DAY. NAM INDICATES THAT A BROAD FIELD OF 500-1000 J/KG
OF CAPE WILL EXIST ALONG AND AHEAD OF THE COLD FRONT. CONVECTION
ALLOWING MODELS INDICATE THAT MTN SHRA/TSRA WILL DEVELOP DURING THE
MORNING...WITH A LINE OF TSRA DEVELOP IN THE LEE OF THE MTNS DURING
THE EARLY AFTERNOON. I WILL HIGHLIGHT WITH A PROB30 FOR MOST WESTERN
CAROLINA TERMINALS BETWEEN 16-18Z.

OUTLOOK...DRY HIGH PRES RETURNS FOR WEDNESDAY/THURSDAY. ANOTHER COLD
FRONT WITH POTENTIAL FOR SHOWERS/TSTMS IS THEN EXPECTED TO CROSS THE
REGION FRIDAY.

CONFIDENCE TABLE...

            18-24Z        00-06Z        06-12Z        12-18Z
KCLT       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KGSP       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KAVL       HIGH 100%     HIGH 100%     HIGH 100%     HIGH  87%
KHKY       HIGH 100%     HIGH 100%     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_TABLES

&&

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

&&

$$
SYNOPSIS...HG
NEAR TERM...ARK/NED
SHORT TERM...HG
LONG TERM...HG
AVIATION...NED








000
FXUS62 KGSP 211407
AFDGSP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
1007 AM EDT MON APR 21 2014

.SYNOPSIS...
HIGH PRESSURE WILL WEAKEN OVER THE REGION TODAY. A COLD FRONT WILL
CROSS THE AREA FROM THE WEST ON TUESDAY...WITH DRY HIGH PRESSURE
RETURNING WEDNESDAY THROUGH THURSDAY. ANOTHER COLD FRONT WILL REACH
THE REGION BY FRIDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 10 AM...A VERY PLEASANT DAY IN THE OFFING. LIGHT RETURN FLOW
AND SUNNY TO MOSTLY SUNNY CONDITIONS SHOULD PERSIST THROUGH THE
AFTERNOON. I WILL UPDATE TO MAKE ONLY MINOR UPDATES TO T/TD AND SKY.

AS OF 645 AM...UPDATED THE T/TD GRIDS WITH THE LATEST OBS...AND
TWEAKED AVIATION GRIDS FOR THE 12Z TAFS. OTHERWISE...FCST LOOKS ON
TRACK AND NO OTHER CHANGES NEEDED.

AS OF 205 AM...A QUIET NEAR TERM IS EXPECTED...AS SHARP UPR RIDGE
AXIS TRANSLATES EAST ACRS THE CWFA. AN INVERTED SFC RIDGE AXIS ALSO
REMAINS INVOF THE REGION...RESULTING IN LGT NE FLOW EAST OF THE MTNS
AND DRY CONDITIONS. THERE MAY BE SOME PATCHY FROST IN THE NORTHERN
MTNS...BUT NOTHING WIDESPREAD ACRS THE REST OF THE HIGH TERRAIN TO
WARRANT A FROST ADVISORY. TEMPS CURRENTLY LOOK ON TRACK.

TEMPS WILL CONTINUE TO REBOUND UNDER SUNNY SKIES AND LIGHT WINDS
TODAY. EXPECTING HIGHS TO BE ABOUT A CATEGORY ABOVE NORMAL...MAINLY
IN THE MID-UPR 70S ACRS THE AREA.

TONIGHT...MID AND UPR LVL HEIGHTS WILL FALL WITH AN APPROACHING
LATITUDINAL TROF AND ASSOCIATED COLD FRONT. THERE WILL BE AN
INCREASE IN MID-HIGH CLOUDS AND EVEN SOME STRATO-CU DEVELOPMENT IN
THE SW NC MTNS OVERNIGHT...KEEPING TEMPS ELEVATED ABOVE NORMAL IN
THE UPR 40S MTNS AN IN THE 50S PIEDMONT. GUIDANCE IN PRETTY GOOD
AGREEMENT ON SCATTERED SHOWERS ALONG/AHEAD OF THE FRONT CROSSING THE
OH/TN VALLEYS. A SLGT CHC TO LOW-END CHC POP WILL CREEP TO THE TN/NC
BORDER BEFORE DAYBREAK TUESDAY. OTHERWISE...IT SHUD BE DRY OVERNIGHT.

&&

.SHORT TERM /TUESDAY THROUGH THURSDAY/...
AS OF 205 AM EDT MONDAY...THE UPPER TROUGH THAT WILL CROSS THE ERN
U.S. ON TUE IS NOT PARTICULARLY AMPLIFIED OR COHERENT...BUT IT
SHOULD BE ACCOMPANIED BY SOME DEGREE OF UPPER LEVEL DIVERGENCE TUE
AFTN. THE WEAK UPPER FORCING AND LOW LEVEL CONVERGENCE ALONG THE
PASSING COLD FRONT SHOULD COMBINE WITH MODEST SFC BASED INSTABILITY
TO CREATE SCATTERED TO NUMEROUS COVERAGE OF SHOWERS AND TSTMS
THROUGH TUE AFTN. THE SEVERE TSTM THREAT LOOKS RATHER LIMITED BY THE
TALL SKINNY CAPE IN AREA MODEL PROFILES ALONG WITH MODEST 25 TO 30
KT SFC TO 3 KM SHEAR VALUES IN THE WESTERLY FLOW. HOWEVER...THE SPC
CALIBRATED SREF SEVERE TSTM PROBABILITIES CONTINUE TO POINT TO A NW
NC PIEDMONT MAXIMA...WHERE SFC INSTABILITY HAS JUST ENOUGH OVERLAP
WITH THE BEST WESTERLY SHEAR AND UPPER FORCING FOR A SLIGHTLY
GREATER SVR THREAT. THERE IS NOT ENOUGH CONFIDENCE FOR AN HWO
MENTION OF SEVERE TSTMS AT THIS POINT.

EXPECT BREEZY TO WINDY CONDITIONS POST FROPA TUE NIGHT INTO WED
MORNING. BROAD RIDGING WILL THEN RETURN WED THROUGH THU WITH DRY
CONDITIONS AND NEAR CLIMO MAXES AND MINS.

&&

.LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/...
AS OF 205 AM EDT MONDAY...A NRN TIER VORTEX CROSSING THE GREAT LAKES
ON FRI WILL NOT PROVIDE MUCH AMPLIFICATION TO THE TROUGH OVER THE
SRN TIER STATES. IN ADDITION...MOISTURE LOOKS SOMEWHAT LIMITED WITH
THE FRI SFC FRONT/TROUGH PASSAGE. HOWEVER...INSTABILITY IS RATHER
ROBUST ON BOTH THE GFS AND ECMWF SOLUTIONS ACROSS THE PIEDMONT FRI
AFTN AND ABOUT 40 KT OF DEEP LAYER SHEAR IS EVIDENT IN PROFILES.
LITTLE CHANGE WILL BE MADE TO THE LATE WEEK FORECAST...WITH CHC POPS
FOR TSRA THROUGHOUT THE REGION ON FRI.

BROAD TROUGHING WILL LIKELY LINGER INTO SAT OVER THE EAST...WITH A
SECONDARY COLD FRONT FEATURING A BETTER THERMAL CONTRAST APPROACHING
FROM THE N. THIS FRONT WILL LIKELY STALL IN OR NEAR THE FORECAST
AREA OVER THE WEEKEND. THE POSITION OF THE BOUNDARY WILL DETERMINE
WHERE INSTABILITY LINGERS/RETURNS AND THIS WILL BE DIFFICULT TO
PROJECT THAT FAR OUT IN THE FORECAST. WILL KEEP MAINLY ISOLD TO SCT
DIURNAL CONVECTIVE CHANCES GOING OVER THE WEEKEND FOR PRIMARY MTN
AND SW SECTIONS.

&&

.AVIATION /14Z MONDAY THROUGH FRIDAY/...
AT KCLT AND ELSEWHERE...VFR CONDITIONS EXPECTED FOR THE NEXT 24
HOURS AT ALL TAF SITES...AS SFC HIGH PRES AXIS TRANSLATES EAST ACRS
THE AREA. IT SHUD BE GENERALLY SKC OR FEW/SCT250 INTO EARLY
AFTN...THEN HIGH CLOUDS WILL BEGIN TO THICKEN/LOWER WITH APPROACH OF
AN UPR DISTURBANCE AND COLD FRONT. THE WINDS WILL BE LIGHT AND FAVOR
A N/NE DIRECTION UNTIL ABOUT NOON...THEN SHIFT TO FAVORING SW FOR
THE AFTN/EVE. MID CLOUDS OR HIGH-BASED STRATO-CU ARE EXPECTED TO
BEGIN DEVELOPING ACRS THE REGION TONIGHT...AS MOISTURE INCREASES
FROM THE WEST. SO NOT EXPECTING MUCH FOG POTENTIAL TONIGHT.
SCATTERED SHOWERS WITH THE FRONT WILL APPROACH THE NC MTNS...BUT NOT
EXPECTED TO REACH KAVL UNTIL AFTER 12Z TUESDAY.

OUTLOOK...A FAIRLY WET FRONTAL SYSTEM...WITH PIEDMONT
THUNDERSTORMS...IS EXPECTED ON TUE. DRY HIGH PRES RETURNS FOR
WEDNESDAY/THURSDAY. ANOTHER COLD FRONT WITH POTENTIAL FOR
SHOWERS/TSTMS IS THEN EXPECTED TO CROSS THE REGION FRIDAY.

CONFIDENCE TABLE...

            14-20Z        20-02Z        02-08Z        08-14Z
KCLT       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KGSP       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KAVL       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KHKY       HIGH 100%     HIGH 100%     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_TABLES

&&

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

&&

$$
SYNOPSIS...HG
NEAR TERM...ARK/NED
SHORT TERM...HG
LONG TERM...HG
AVIATION...ARK








000
FXUS62 KGSP 211044
AFDGSP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
644 AM EDT MON APR 21 2014

.SYNOPSIS...
HIGH PRESSURE WILL WEAKEN OVER THE REGION TODAY. A COLD FRONT WILL
CROSS THE AREA FROM THE WEST ON TUESDAY...WITH DRY HIGH PRESSURE
RETURNING WEDNESDAY THROUGH THURSDAY. ANOTHER COLD FRONT WILL REACH
THE REGION BY FRIDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 645 AM...UPDATED THE T/TD GRIDS WITH THE LATEST OBS...AND
TWEAKED AVIATION GRIDS FOR THE 12Z TAFS. OTHERWISE...FCST LOOKS ON
TRACK AND NO OTHER CHANGES NEEDED.

AS OF 205 AM...A QUIET NEAR TERM IS EXPECTED...AS SHARP UPR RIDGE
AXIS TRANSLATES EAST ACRS THE CWFA. AN INVERTED SFC RIDGE AXIS ALSO
REMAINS INVOF THE REGION...RESULTING IN LGT NE FLOW EAST OF THE MTNS
AND DRY CONDITIONS. THERE MAY BE SOME PATCHY FROST IN THE NORTHERN
MTNS...BUT NOTHING WIDESPREAD ACRS THE REST OF THE HIGH TERRAIN TO
WARRANT A FROST ADVISORY. TEMPS CURRENTLY LOOK ON TRACK.

TEMPS WILL CONTINUE TO REBOUND UNDER SUNNY SKIES AND LIGHT WINDS
TODAY. EXPECTING HIGHS TO BE ABOUT A CATEGORY ABOVE NORMAL...MAINLY
IN THE MID-UPR 70S ACRS THE AREA.

TONIGHT...MID AND UPR LVL HEIGHTS WILL FALL WITH AN APPROACHING
LATITUDINAL TROF AND ASSOCIATED COLD FRONT. THERE WILL BE AN
INCREASE IN MID-HIGH CLOUDS AND EVEN SOME STRATO-CU DEVELOPMENT IN
THE SW NC MTNS OVERNIGHT...KEEPING TEMPS ELEVATED ABOVE NORMAL IN
THE UPR 40S MTNS AN IN THE 50S PIEDMONT. GUIDANCE IN PRETTY GOOD
AGREEMENT ON SCATTERED SHOWERS ALONG/AHEAD OF THE FRONT CROSSING THE
OH/TN VALLEYS. A SLGT CHC TO LOW-END CHC POP WILL CREEP TO THE TN/NC
BORDER BEFORE DAYBREAK TUESDAY. OTHERWISE...IT SHUD BE DRY OVERNIGHT.

&&

.SHORT TERM /TUESDAY THROUGH THURSDAY/...
AS OF 205 AM EDT MONDAY...THE UPPER TROUGH THAT WILL CROSS THE ERN
U.S. ON TUE IS NOT PARTICULARLY AMPLIFIED OR COHERENT...BUT IT
SHOULD BE ACCOMPANIED BY SOME DEGREE OF UPPER LEVEL DIVERGENCE TUE
AFTN. THE WEAK UPPER FORCING AND LOW LEVEL CONVERGENCE ALONG THE
PASSING COLD FRONT SHOULD COMBINE WITH MODEST SFC BASED INSTABILITY
TO CREATE SCATTERED TO NUMEROUS COVERAGE OF SHOWERS AND TSTMS
THROUGH TUE AFTN. THE SEVERE TSTM THREAT LOOKS RATHER LIMITED BY THE
TALL SKINNY CAPE IN AREA MODEL PROFILES ALONG WITH MODEST 25 TO 30
KT SFC TO 3 KM SHEAR VALUES IN THE WESTERLY FLOW. HOWEVER...THE SPC
CALIBRATED SREF SEVERE TSTM PROBABILITIES CONTINUE TO POINT TO A NW
NC PIEDMONT MAXIMA...WHERE SFC INSTABILITY HAS JUST ENOUGH OVERLAP
WITH THE BEST WESTERLY SHEAR AND UPPER FORCING FOR A SLIGHTLY
GREATER SVR THREAT. THERE IS NOT ENOUGH CONFIDENCE FOR AN HWO
MENTION OF SEVERE TSTMS AT THIS POINT.

EXPECT BREEZY TO WINDY CONDITIONS POST FROPA TUE NIGHT INTO WED
MORNING. BROAD RIDGING WILL THEN RETURN WED THROUGH THU WITH DRY
CONDITIONS AND NEAR CLIMO MAXES AND MINS.

&&

.LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/...
AS OF 205 AM EDT MONDAY...A NRN TIER VORTEX CROSSING THE GREAT LAKES
ON FRI WILL NOT PROVIDE MUCH AMPLIFICATION TO THE TROUGH OVER THE
SRN TIER STATES. IN ADDITION...MOISTURE LOOKS SOMEWHAT LIMITED WITH
THE FRI SFC FRONT/TROUGH PASSAGE. HOWEVER...INSTABILITY IS RATHER
ROBUST ON BOTH THE GFS AND ECMWF SOLUTIONS ACROSS THE PIEDMONT FRI
AFTN AND ABOUT 40 KT OF DEEP LAYER SHEAR IS EVIDENT IN PROFILES.
LITTLE CHANGE WILL BE MADE TO THE LATE WEEK FORECAST...WITH CHC POPS
FOR TSRA THROUGHOUT THE REGION ON FRI.

BROAD TROUGHING WILL LIKELY LINGER INTO SAT OVER THE EAST...WITH A
SECONDARY COLD FRONT FEATURING A BETTER THERMAL CONTRAST APPROACHING
FROM THE N. THIS FRONT WILL LIKELY STALL IN OR NEAR THE FORECAST
AREA OVER THE WEEKEND. THE POSITION OF THE BOUNDARY WILL DETERMINE
WHERE INSTABILITY LINGERS/RETURNS AND THIS WILL BE DIFFICULT TO
PROJECT THAT FAR OUT IN THE FORECAST. WILL KEEP MAINLY ISOLD TO SCT
DIURNAL CONVECTIVE CHANCES GOING OVER THE WEEKEND FOR PRIMARY MTN
AND SW SECTIONS.

&&

.AVIATION /12Z MONDAY THROUGH FRIDAY/...
AT KCLT AND ELSEWHERE...VFR CONDITIONS EXPECTED FOR THE NEXT 24
HOURS AT ALL TAF SITES...AS SFC HIGH PRES AXIS TRANSLATES EAST ACRS
THE AREA. IT SHUD BE GENERALLY SKC OR FEW/SCT250 INTO EARLY
AFTN...THEN HIGH CLOUDS WILL BEGIN TO THICKEN/LOWER WITH APPROACH OF
AN UPR DISTURBANCE AND COLD FRONT. THE WINDS WILL BE LIGHT AND FAVOR
A N/NE DIRECTION UNTIL ABOUT NOON...THEN SHIFT TO FAVORING SW FOR
THE AFTN/EVE. MID CLOUDS OR HIGH-BASED STRATO-CU ARE EXPECTED TO
BEGIN DEVELOPING ACRS THE REGION TONIGHT...AS MOISTURE INCREASES
FROM THE WEST. SO NOT EXPECTING MUCH FOG POTENTIAL TONIGHT.
SCATTERED SHOWERS WITH THE FRONT WILL APPROACH THE NC MTNS...BUT NOT
EXPECTED TO REACH KAVL UNTIL AFTER 12Z TUESDAY.

OUTLOOK...A FAIRLY WET FRONTAL SYSTEM...WITH PIEDMONT
THUNDERSTORMS...IS EXPECTED ON TUE. DRY HIGH PRES RETURNS FOR
WEDNESDAY/THURSDAY. ANOTHER COLD FRONT WITH POTENTIAL FOR
SHOWERS/TSTMS IS THEN EXPECTED TO CROSS THE REGION FRIDAY.

CONFIDENCE TABLE...

            10-16Z        16-22Z        22-04Z        04-10Z
KCLT       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KGSP       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KAVL       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KHKY       HIGH 100%     HIGH 100%     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_TABLES

&&

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

&&

$$
SYNOPSIS...HG
NEAR TERM...ARK
SHORT TERM...HG
LONG TERM...HG
AVIATION...ARK








000
FXUS62 KGSP 210609
AFDGSP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
209 AM EDT MON APR 21 2014

.SYNOPSIS...
HIGH PRESSURE WILL WEAKEN OVER THE REGION TODAY. A COLD FRONT WILL
CROSS THE AREA FROM THE WEST ON TUESDAY...WITH DRY HIGH PRESSURE
RETURNING WEDNESDAY THROUGH THURSDAY. ANOTHER COLD FRONT WILL REACH
THE REGION BY FRIDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 205 AM...A QUIET NEAR TERM IS EXPECTED...AS SHARP UPR RIDGE
AXIS TRANSLATES EAST ACRS THE CWFA. AN INVERTED SFC RIDGE AXIS ALSO
REMAINS INVOF THE REGION...RESULTING IN LGT NE FLOW EAST OF THE MTNS
AND DRY CONDITIONS. THERE MAY BE SOME PATCHY FROST IN THE NORTHERN
MTNS...BUT NOTHING WIDESPREAD ACRS THE REST OF THE HIGH TERRAIN TO
WARRANT A FROST ADVISORY. TEMPS CURRENTLY LOOK ON TRACK.

TEMPS WILL CONTINUE TO REBOUND UNDER SUNNY SKIES AND LIGHT WINDS
TODAY. EXPECTING HIGHS TO BE ABOUT A CATEGORY ABOVE NORMAL...MAINLY
IN THE MID-UPR 70S ACRS THE AREA.

TONIGHT...MID AND UPR LVL HEIGHTS WILL FALL WITH AN APPROACHING
LATITUDINAL TROF AND ASSOCIATED COLD FRONT. THERE WILL BE AN
INCREASE IN MID-HIGH CLOUDS AND EVEN SOME STRATO-CU DEVELOPMENT IN
THE SW NC MTNS OVERNIGHT...KEEPING TEMPS ELEVATED ABOVE NORMAL IN
THE UPR 40S MTNS AN IN THE 50S PIEDMONT. GUIDANCE IN PRETTY GOOD
AGREEMENT ON SCATTERED SHOWERS ALONG/AHEAD OF THE FRONT CROSSING THE
OH/TN VALLEYS. A SLGT CHC TO LOW-END CHC POP WILL CREEP TO THE TN/NC
BORDER BEFORE DAYBREAK TUESDAY. OTHERWISE...IT SHUD BE DRY OVERNIGHT.

&&

.SHORT TERM /TUESDAY THROUGH THURSDAY/...
AS OF 205 AM EDT MONDAY...THE UPPER TROUGH THAT WILL CROSS THE ERN
U.S. ON TUE IS NOT PARTICULARLY AMPLIFIED OR COHERENT...BUT IT
SHOULD BE ACCOMPANIED BY SOME DEGREE OF UPPER LEVEL DIVERGENCE TUE
AFTN. THE WEAK UPPER FORCING AND LOW LEVEL CONVERGENCE ALONG THE
PASSING COLD FRONT SHOULD COMBINE WITH MODEST SFC BASED INSTABILITY
TO CREATE SCATTERED TO NUMEROUS COVERAGE OF SHOWERS AND TSTMS
THROUGH TUE AFTN. THE SEVERE TSTM THREAT LOOKS RATHER LIMITED BY THE
TALL SKINNY CAPE IN AREA MODEL PROFILES ALONG WITH MODEST 25 TO 30
KT SFC TO 3 KM SHEAR VALUES IN THE WESTERLY FLOW. HOWEVER...THE SPC
CALIBRATED SREF SEVERE TSTM PROBABILITIES CONTINUE TO POINT TO A NW
NC PIEDMONT MAXIMA...WHERE SFC INSTABILITY HAS JUST ENOUGH OVERLAP
WITH THE BEST WESTERLY SHEAR AND UPPER FORCING FOR A SLIGHTLY
GREATER SVR THREAT. THERE IS NOT ENOUGH CONFIDENCE FOR AN HWO
MENTION OF SEVERE TSTMS AT THIS POINT.

EXPECT BREEZY TO WINDY CONDITIONS POST FROPA TUE NIGHT INTO WED
MORNING. BROAD RIDGING WILL THEN RETURN WED THROUGH THU WITH DRY
CONDITIONS AND NEAR CLIMO MAXES AND MINS.

&&

.LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/...
AS OF 205 AM EDT MONDAY...A NRN TIER VORTEX CROSSING THE GREAT LAKES
ON FRI WILL NOT PROVIDE MUCH AMPLIFICATION TO THE TROUGH OVER THE
SRN TIER STATES. IN ADDITION...MOISTURE LOOKS SOMEWHAT LIMITED WITH
THE FRI SFC FRONT/TROUGH PASSAGE. HOWEVER...INSTABILITY IS RATHER
ROBUST ON BOTH THE GFS AND ECMWF SOLUTIONS ACROSS THE PIEDMONT FRI
AFTN AND ABOUT 40 KT OF DEEP LAYER SHEAR IS EVIDENT IN PROFILES.
LITTLE CHANGE WILL BE MADE TO THE LATE WEEK FORECAST...WITH CHC POPS
FOR TSRA THROUGHOUT THE REGION ON FRI.

BROAD TROUGHING WILL LIKELY LINGER INTO SAT OVER THE EAST...WITH A
SECONDARY COLD FRONT FEATURING A BETTER THERMAL CONTRAST APPROACHING
FROM THE N. THIS FRONT WILL LIKELY STALL IN OR NEAR THE FORECAST
AREA OVER THE WEEKEND. THE POSITION OF THE BOUNDARY WILL DETERMINE
WHERE INSTABILITY LINGERS/RETURNS AND THIS WILL BE DIFFICULT TO
PROJECT THAT FAR OUT IN THE FORECAST. WILL KEEP MAINLY ISOLD TO SCT
DIURNAL CONVECTIVE CHANCES GOING OVER THE WEEKEND FOR PRIMARY MTN
AND SW SECTIONS.

&&

.AVIATION /06Z MONDAY THROUGH FRIDAY/...
AT KCLT...A QUIET TAF PERIOD AS SFC HIGH PRES AXIS TRANSLATES ACRS
THE AREA...WITH GENERALLY SKC OR FEW/SCT250 THRU THE PERIOD. LGT
WINDS WILL FAVOR A NE DIRECTION UNTIL ABOUT NOON...THEN BECOME
VARIABLE DURING THE AFTN BEFORE SWITCHING TO SW.

ELSEWHERE...SIMILAR TO KCLT ABOVE...WITH LGT NE WINDS OR VARIABLE
THRU MID MORNING...THEN FAVORING SW BY EARLY AFTN. FCST SNDGS SHOW
POSSIBLE SOME HIGH-BASED CUMULUS DEVELOPING ACRS THE NC MTNS AND
INTO THE UPSTATE LATE AFTN/EARLY EVENING...BUT OTHERWISE CIRRUS ONLY
CLOUDS EXPECTED THRU THE PERIOD.

OUTLOOK...A FAIRLY WET FRONTAL SYSTEM...WITH PIEDMONT
THUNDERSTORMS...IS EXPECTED ON TUE...WITH DRYING RETURNING MID WEEK.

CONFIDENCE TABLE...

            06-12Z        12-18Z        18-24Z        00-06Z
KCLT       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KGSP       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KAVL       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KHKY       HIGH 100%     HIGH 100%     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_TABLES

&&

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

&&

$$
SYNOPSIS...HG
NEAR TERM...ARK
SHORT TERM...HG
LONG TERM...HG
AVIATION...ARK








    US Dept of Commerce
    National Oceanic and Atmospheric Administration
    National Weather Service
    1325 East West Highway
    Silver Spring, MD 20910
    Page Author: NWS Internet Services Team
Disclaimer
Information Quality
Credits
Glossary
Privacy Policy
Freedom of Information Act (FOIA)
About Us
Career Opportunities