000
FXUS62 KGSP 181231
AFDGSP
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
831 AM EDT SAT MAY 18 2013
.SYNOPSIS...
A MID LEVEL DISTURBANCE WILL DRIFT ACROSS THE REGION THIS WEEKEND. A
WARM AND MOIST AIRMASS WILL REMAIN OVER THE AREA NEXT WEEK. A COLD
FRONT WILL APPROACH THE WESTERN CAROLINAS FROM THE NORTH NEXT
WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 710 AM...LINE OF SHRA AND ISOLATED TSRA WILL MOVE ACROSS THE
AREA THIS MORNING WITH SHRA FILLING IN BEHIND. HAVE TRIED TO TIME
THIS WITH MORE TSRA DEVELOPING FOR THE AFTERNOON.
OPEN UPPER LOW SLIDES INTO THE CENTRAL APPALACHIANS TODAY AS THE
ATTENDANT TROF MOVES INTO THE SRN APPALACHIANS. SLY FLOW AHEAD OF
THIS SYSTEM IS SPREADING MOISTURE AND SHRA INTO NE GA ND THE WRN
CAROLINAS. AS THIS FLOW AND MOISTURE MOVE EASTWARD TODAY...THE
PRECIP WILL AS WELL. LOOKS LIKE INSTABILITY WILL REMAIN WEAK AS
CLOUDS RETARD HEATING...BUT LOW LEVEL MOISTURE WILL BE HIGH.
THEREFORE...EXPECT TSRA TO DEVELOP GIVEN THE FORCING EVEN WITH WEAK
INSTABILITY. THAT SAID...AS THE UPPER TROF MOVES INTO THE AREA...
ISOLATED STRONG TO POSSIBLY SEVERE STORMS COULD DEVELOP. CANNOT RULE
OUT ISOLATED HEAVY RAIN OVER THE MTNS AS WELL. HOWEVER...DOES NOT
APPEAR TO BE WIDESPREAD ENUF FOR A FLOOD WATCH ATTM. HIGHS WILL BE
AROUND 5 DEGREES BELOW THE READINGS FROM FRI.
THE LOW AND TROF SLIDE INTO THE PIEDMONT TONIGHT. THE SLY FLOW
SLIDES EASTWARD AS WELL. THIS WILL TAKE THE FOCUS OF THE CONVECTION
EAST AS WELL. BEST PRECIP CHC WILL BE OVER THE PIEDMONT DURING THE
NIGHT AND DIMINISH ELSEWHERE. EXPECT THE BEST QPF TO SLIDE EAST THRU
THE NITE AS WELL. WPC QPF FCST IS 1 INCH OR LESS TOTAL THRU THE END
OF THE NITE. THEREFORE...WHILE ISOLATED HEAVY RAINFALL IS
POSSIBLE...WIDESPREAD HEAVY RAINFALL IS NOT. ESPECIALLY AS IT LOOKS
LIKE THE MTNS WILL SEE THE HIGHEST RAINFALL DURING THE DAY AND THE
PIEDMONT DURING THE NITE. LOWS WILL BE 5 TO 10 DEGREES ABOVE NORMAL.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AT 300 AM EST SATURDAY...ON SUNDAY MORNING...THE REMAINS OF AN UPPER
LOW WILL BE SOMEWHERE OVER THE CENTRAL APPALACHIANS. A WEAK TROUGH
ASSOCIATED WITH THIS SYSTEM WILL CROSS THE WESTERN CAROLINAS AND NE
GA SUNDAY AND SUNDAY NIGHT. UPPER LEVEL RIDGING MOVES SLOWLY EAST
OVER THE SOUTHERN AND CENTRAL APPALACHIANS ON MONDAY AND MONDAY
NIGHT IN THE WAKE OF THE UPPER TROUGH.
MOISTURE ASSOCIATED WITH THE TROUGH WILL SUPPORT WIDESPREAD
PRECIPITATION ON SUNDAY. INSTABILITY WILL BE LIMITED BY CLOUD
COVER...BUT SHOULD STILL BE SUFFICIENT FOR CONVECTION. MODEL
SOUNDINGS SHOW A VERY MOIST PROFILE...WITH LITTLE DRY AIR ALOFT AND
LIMITED DRY AIR BENEATH THE CLOUD LAYER FOR EVAPORATIVE COOLING OR
DOWNDRAFT PRODUCTION. STEERING FLOW WILL BE ENOUGH TO KEEP CELLS
MOVING SLOWLY TO THE NE. A LIGHT SOUTHERLY SURFACE FLOW WILL PROVIDE
UPSLOPE FLOW ENHANCEMENT OF PRECIPITATION...MAINLY ALONG THE SOUTH
FACING BLUE RIDGE ESCARPMENT. SOME INSTABILITY WILL PERSIST THROUGH
SUNDAY NIGHT AS THE UPPER TROUGH PASSES...WITH STEERING FLOW
GRADUALLY VEERING TO THE EAST.
ON MONDAY SOME DRY IS INTRODUCED AT MID LEVELS AS THE UPPER TROUGH
DEPARTS. CLOUDS HEIGHTS RISE...WITH MORE DRY AIR AT THE SURFACE.
INSTABILITY INCREASES...SUPPORTING MORE OF A CONVECTIVE MODE TO
PRECIPITATION...THOUGH WITH DECREASING COVERAGE. MOISTURE WILL BE
SLOW TO DEPART TO THE EAST ON MONDAY NIGHT...BUT THE BEST MOISTURE
WILL BE NEAR THE COAST.
MAXIMUM TEMPERATURES WILL BE NEAR NORMAL...WITH MINIMUM TEMPERATURES
A COUPLE OF CATEGORIES ABOVE NORMAL. PRECIPITATION TOTALS COULD
EXCEED ONE INCH ALONG THE SOUTH FACING BLUE RIDGE ESCARPMENT OF
SW NC...WITH MOST OF THAT FALLING ON SUNDAY AND SUNDAY NIGHT.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AT 300 AM EST SATURDAY...AN UPPER RIDGE WILL MOVE SLOWLY ACROSS THE
CAROLINAS AND GA ON TUESDAY AND WEDNESDAY...WHILE AN UPPER TROUGH
ASSOCIATED WITH ANOTHER CLOSED LOW IN THE PLAINS MOVES TO THE MS
RIVER VALLEY. THE TROUGH DEAMPLIFIES AS IT CROSSES THE OH AND TN
VALLEYS ON THURSDAY...AND REACHES THE CENTRAL AND SOUTHERN
APPALACHIANS ON FRIDAY.
A WARM AND MOIST AIR MASS REMAINS OVER THE SOUTHEAST FROM TUESDAY
THROUGH FRIDAY. DIURNALLY MODULATED CONVECTION IS EXPECTED ON
TUESDAY AND WEDNESDAY. ON WEDNESDAY NIGHT BOTH THE GFS AND ECMWF
SHOW A CONVERGENCE OF ATLANTIC MOISTURE WITH MOISTURE LEFT OVER FROM
A DYING COLD FRONT THAT ARRIVES FROM THE WEST...JUST ABOUT OVER THE
SOUTHERN APPALACHIANS. THIS MOISTURE LINGER OVER OUR AREA INTO
THURSDAY...BEFORE STARTING TO MOVE OFF TO THE EAST ON FRIDAY. IF
THIS SCENARIO HOLD...PRECIPITATION WOULD BE MORE LIKELY TO PERSIST
OVERNIGHT...WITH GREATER COVERAGE AND ACCUMULATION. ON SATURDAY A
COLD CROSSES THE AREA FROM THE NORTH.
TEMPERATURES WILL BRIEFLY WARM ABOVE NORMAL AS THE UPPER RIDGE AXIS
ARRIVES...FALLING TO AROUND NORMAL AS HEIGHTS FALL WITH THE ADVANCE
OF THE UPPER TROUGH.
&&
.AVIATION /13Z SATURDAY THROUGH WEDNESDAY/...
AT KCLT/KHKY...LINE OF SHRA...WITH ISOLATED TSRA WILL MOVE TOWARD
THE AIRFIELDS THIS MORNING. VISBY HAS BEEN CONSISTENTLY LOWERING TO
IFR ACROSS FAR WESTERN NC AND UPSTATE SC AS THIS PRECIP PASSES
OVER...SO TEMPO FOR IFR CONDITIONS HAS BEEN INTRODUCED THIS MORNING.
MEANWHILE...TS HAVE BEEN VERY ISOLATED AND SHORT-LIVED SO FAR...SO
WE FEEL COMFORTABLE WITH OMITTING A TS MENTION FOR THIS MORNING.
THE PRECIP SHIELD SHOULD MOVE EAST OF THE TERMINALS DURING EARLY
AFTERNOON...BUT SHOWERS SHOULD DEVELOP/LINGER THROUGH THE
AFTERNOON...WITH SCATTERED TS EXPECTED TO DEVELOP AS WELL.
CONDITIONS DETERIORATE AFTER MIDNIGHT AS CIGS FALL THRU MVFR TO IFR
IN LINGERING SHRA. SLY WIND CONTINUE THRU THE PERIOD.
ELSEWHERE...PRECIP SHIELD PRODUCING WIDESPREAD/PERSISTENT IFR VISBY
WILL SHIFT EAST OF THE TERMINALS BETWEEN 14Z AND 15Z...WITH
IMPROVEMENT TO VFR EXPECTED FOR THE AFTERNOON. HOWEVER...SHOWERS
SHOULD DEVELOP/LINGER THROUGH THE AFTERNOON...WITH SCATTERED TS
EXPECTED TO DEVELOP AS WELL. CONDITIONS DETERIORATE AFTER MIDNIGHT
AS CIGS FALL THRU MVFR TO IFR IN LINGERING SHRA. SLY WIND CONTINUE
THRU THE PERIOD.
OUTLOOK...SHOWERS AND THUNDERSTORMS...AND ASSOCIATED RESTRICTIONS...
WILL PERSIST THROUGH MONDAY. FAIR WEATHER MAY RETURN BY TUESDAY.
CONFIDENCE TABLE...
12-18Z 18-24Z 00-06Z 06-12Z
KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 85%
KGSP HIGH 100% HIGH 100% HIGH 94% HIGH 91%
KAVL MED 69% MED 74% MED 69% HIGH 91%
KHKY HIGH 100% HIGH 100% HIGH 89% HIGH 93%
KGMU HIGH 89% HIGH 100% HIGH 92% HIGH 93%
KAND HIGH 96% HIGH 100% HIGH 100% MED 77%
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...JAT
NEAR TERM...RWH
SHORT TERM...JAT
LONG TERM...JAT
AVIATION...JDL/RWH
000
FXUS62 KGSP 180754
AFDGSP
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
354 AM EDT SAT MAY 18 2013
.SYNOPSIS...
A MID LEVEL DISTURBANCE WILL DRIFT ACROSS THE REGION THIS WEEKEND. A
WARM AND MOIST AIRMASS WILL REMAIN OVER THE AREA NEXT WEEK. A COLD
FRONT WILL APPROACH THE WESTERN CAROLINAS FROM THE NORTH NEXT
WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
OPEN UPPER LOW SLIDES INTO THE CENTRAL APPALACHIANS TODAY AS THE
ATTENDANT TROF MOVES INTO THE SRN APPALACHIANS. SLY FLOW AHEAD OF
THIS SYSTEM IS SPREADING MOISTURE AND SHRA INTO NE GA ND THE WRN
CAROLINAS. AS THIS FLOW AND MOISTURE MOVE EASTWARD TODAY...THE
PRECIP WILL AS WELL. LOOKS LIKE INSTABILITY WILL REMAIN WEAK AS
CLOUDS RETARD HEATING...BUT LOW LEVEL MOISTURE WILL BE HIGH.
THEREFORE...EXPECT TSRA TO DEVELOP GIVEN THE FORCING EVEN WITH WEAK
INSTABILITY. THAT SAID...AS THE UPPER TROF MOVES INTO THE MTNS...
ISOLATED STRONG TO POSSIBLY SEVERE STORMS COULD DEVELOP OVER THE
MTNS. CANNOT RULE OUT ISOLATED HEAVY RAIN OVER THE MTNS AS WELL.
HOWEVER...DOES NOT APPEAR TO BE WIDESPREAD ENUF FOR A FLOOD WATCH
ATTM. HIGHS WILL BE AROUND 5 DEGREES BELOW THE READINGS FROM FRI.
THE LOW AND TROF SLIDE INTO THE PIEDMONT TONIGHT. THE SLY FLOW
SLIDES EASTWARD AS WELL. THIS WILL TAKE THE FOCUS OF THE CONVECTION
EAST AS WELL. BEST PRECIP CHC WILL BE OVER THE PIEDMONT DURING THE
NIGHT AND DIMINISH ELSEWHERE. EXPECT THE BEST QPF TO SLIDE EAST THRU
THE NITE AS WELL. WPC QPF FCST IS 1 INCH OR LESS TOTAL THRU THE END
OF THE NITE. THEREFORE...WHILE ISOLATED HEAVY RAINFALL IS
POSSIBLE...WIDESPREAD HEAVY RAINFALL IS NOT. ESPECIALLY AS IT LOOKS
LIKE THE MTNS WILL SEE THE HIGHEST RAINFALL DURING THE DAY AND THE
PIEDMONT DURING THE NITE. LOWS WILL BE 5 TO 10 DEGREES ABOVE NORMAL.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AT 300 AM EST SATURDAY...ON SUNDAY MORNING...THE REMAINS OF AN UPPER
LOW WILL BE SOMEWHERE OVER THE CENTRAL APPALACHIANS. A WEAK TROUGH
ASSOCIATED WITH THIS SYSTEM WILL CROSS THE WESTERN CAROLINAS AND NE
GA SUNDAY AND SUNDAY NIGHT. UPPER LEVEL RIDGING MOVES SLOWLY EAST
OVER THE SOUTHERN AND CENTRAL APPALACHIANS ON MONDAY AND MONDAY
NIGHT IN THE WAKE OF THE UPPER TROUGH.
MOISTURE ASSOCIATED WITH THE TROUGH WILL SUPPORT WIDESPREAD
PRECIPITATION ON SUNDAY. INSTABILITY WILL BE LIMITED BY CLOUD
COVER...BUT SHOULD STILL BE SUFFICIENT FOR CONVECTION. MODEL
SOUNDINGS SHOW A VERY MOIST PROFILE...WITH LITTLE DRY AIR ALOFT AND
LIMITED DRY AIR BENEATH THE CLOUD LAYER FOR EVAPORATIVE COOLING OR
DOWNDRAFT PRODUCTION. STEERING FLOW WILL BE ENOUGH TO KEEP CELLS
MOVING SLOWLY TO THE NE. A LIGHT SOUTHERLY SURFACE FLOW WILL PROVIDE
UPSLOPE FLOW ENHANCEMENT OF PRECIPITATION...MAINLY ALONG THE SOUTH
FACING BLUE RIDGE ESCARPMENT. SOME INSTABILITY WILL PERSIST THROUGH
SUNDAY NIGHT AS THE UPPER TROUGH PASSES...WITH STEERING FLOW
GRADUALLY VEERING TO THE EAST.
ON MONDAY SOME DRY IS INTRODUCED AT MID LEVELS AS THE UPPER TROUGH
DEPARTS. CLOUDS HEIGHTS RISE...WITH MORE DRY AIR AT THE SURFACE.
INSTABILITY INCREASES...SUPPORTING MORE OF A CONVECTIVE MODE TO
PRECIPITATION...THOUGH WITH DECREASING COVERAGE. MOISTURE WILL BE
SLOW TO DEPART TO THE EAST ON MONDAY NIGHT...BUT THE BEST MOISTURE
WILL BE NEAR THE COAST.
MAXIMUM TEMPERATURES WILL BE NEAR NORMAL...WITH MINIMUM TEMPERATURES
A COUPLE OF CATEGORIES ABOVE NORMAL. PRECIPITATION TOTALS COULD
EXCEED ONE INCH ALONG THE SOUTH FACING BLUE RIDGE ESCARPMENT OF
SW NC...WITH MOST OF THAT FALLING ON SUNDAY AND SUNDAY NIGHT.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AT 300 AM EST SATURDAY...AN UPPER RIDGE WILL MOVE SLOWLY ACROSS THE
CAROLINAS AND GA ON TUESDAY AND WEDNESDAY...WHILE AN UPPER TROUGH
ASSOCIATED WITH ANOTHER CLOSED LOW IN THE PLAINS MOVES TO THE MS
RIVER VALLEY. THE TROUGH DEAMPLIFIES AS IT CROSSES THE OH AND TN
VALLEYS ON THURSDAY...AND REACHES THE CENTRAL AND SOUTHERN
APPALACHIANS ON FRIDAY.
A WARM AND MOIST AIR MASS REMAINS OVER THE SOUTHEAST FROM TUESDAY
THROUGH FRIDAY. DIURNALLY MODULATED CONVECTION IS EXPECTED ON
TUESDAY AND WEDNESDAY. ON WEDNESDAY NIGHT BOTH THE GFS AND ECMWF
SHOW A CONVERGENCE OF ATLANTIC MOISTURE WITH MOISTURE LEFT OVER FROM
A DYING COLD FRONT THAT ARRIVES FROM THE WEST...JUST ABOUT OVER THE
SOUTHERN APPALACHIANS. THIS MOISTURE LINGER OVER OUR AREA INTO
THURSDAY...BEFORE STARTING TO MOVE OFF TO THE EAST ON FRIDAY. IF
THIS SCENARIO HOLD...PRECIPITATION WOULD BE MORE LIKELY TO PERSIST
OVERNIGHT...WITH GREATER COVERAGE AND ACCUMULATION. ON SATURDAY A
COLD CROSSES THE AREA FROM THE NORTH.
TEMPERATURES WILL BRIEFLY WARM ABOVE NORMAL AS THE UPPER RIDGE AXIS
ARRIVES...FALLING TO AROUND NORMAL AS HEIGHTS FALL WITH THE ADVANCE
OF THE UPPER TROUGH.
&&
.AVIATION /08Z SATURDAY THROUGH WEDNESDAY/...
AT KCLT...A FEW CUMULUS CLOUDS AND INCREASING MID CLOUD WILL
CONTINUE ACROSS THE REGION THRU DAYBREAK. STARTING DURING THE
MORNING...AN AREA OF PCPN WILL BEGIN TO MOVE INTO THE REGION. IT
LOOS LIKE IT WILL ONLY SLOWLY MOVE INTO THE CLT AREA...HO HAVE HELD
OFF ON ANY PRECIP UNTIL AFTERNOON. THAT SAID...DID BRING LOWER VFR
CIGS IN DURING THE MORNING. CHC OF CONVECTION CONTINUE THRU THE
EVENING WITH LOW VFR CIGS CONTINUING. CALM WIND EARLY BECOMES SLY BY
MID MORNING AND CONTINUE THRU THE PERIOD.
ELSEWHERE...AN AREA OF SHOWERS WILL SLOWLY ACROSS NE GA AND INTO THE
WRN CAROLINAS THRU THE MORNING. KAVL WILL SEE PCPN FIRST...FOLLOWED
BY THE UPSTATE SITES AND KHKY. EXPECT CIGS AND VSBYS TO REMAIN LOW
VFR AS RAIN IS NOT THAT HEAVY. HOWEVER...MVFR DOES DEVELOP AT KAVL
AFTER DAYBREAK...BUT BECOMES VFR FOR THE AFTERNOON. EXPECT ANY
RESTRICTIONS ELSEWHERE WILL BE WITH HEAVIER SHRA OR TSRA. PRECIP CHC
AND ANY RESTRICTIONS CONTINUE THRU THE EVENING. LIGHT WIND BECOMES
S TO SW AFTER DAYBREAK AND CONTINUES THRU THE DAY INTO THE EVENING.
OUTLOOK...SHOWERS AND THUNDERSTORMS...AND ASSOCIATED RESTRICTIONS...
WILL PERSIST THROUGH MONDAY. FAIR WEATHER MAY RETURN BY TUESDAY.
CONFIDENCE TABLE...
08-14Z 14-20Z 20-02Z 02-08Z
KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 97%
KGSP HIGH 100% HIGH 98% HIGH 100% HIGH 100%
KAVL HIGH 95% HIGH 84% HIGH 97% HIGH 88%
KHKY HIGH 100% HIGH 100% HIGH 100% HIGH 93%
KGMU HIGH 100% HIGH 94% HIGH 100% HIGH 100%
KAND HIGH 97% HIGH 92% 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...JAT
NEAR TERM...RWH
SHORT TERM...JAT
LONG TERM...JAT
AVIATION...RWH
000
FXUS62 KGSP 180545
AFDGSP
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
145 AM EDT SAT MAY 18 2013
.SYNOPSIS...
A MID LEVEL DISTURBANCE WILL DRIFT ACROSS THE REGION THIS
WEEKEND... TRIGGEREING SHOWERS AND THUNDERSTORMS THROUGH THE
BEGINNING OF NEXT WEEK. SOUTHERLY FLOW WILL KEEP THE AIRMASS WARM
AND MOIST... AND THE PATTERN WILL REMAIN UNSETTLED UNTIL A FRONTAL
SYSTEM APPROACHES THE WESTERN CAROLINAS LATE NEXT WEEK.
&&
.NEAR TERM /THROUGH TODAY/...
AS OF 140 AM...SHRA HAVE MOVED INTO NE GA AND WILL MOVE INTO THE WRN
CAROLINAS BEFORE DAYBREAK. DO NOT EXPECT ANY TSRA UNTIL AFTER
DAYBREAK. UPDATED REST OF THE FIELDS WITH CURRENT CONDITIONS.
AS OF 1015 PM EDT FRIDAY...A BAND A LIGHT...MAINLY STRATIFORM PCPN
CONTINUES TO SLOWLY APPROACH THE SOUTHWEST MOUNTAINS FROM THE WEST.
THE PCPN IS A LITTLE AHEAD OF WHERE THE MODELS HAVE BEEN PLACING
IT...BUT IT/S ALSO WORKING THROUGH SOME DRY AIR AND IT WILL CONTINUE
TO APPROACH QUITE SLOWLY. I DID BUMP UP THE TIMING OF HIGHER POPS
ACROSS THE SOUTHWEST MOUNTAINS BY A FEW HOURS. HOWEVER...THERE ISN/T
A DROP OF PCPN IN THE FA AT THIS EXACT TIME...AND POPS FOR THE NEXT
COUPLE HOURS HAVE BEEN CUT TO BELOW THE SLIGHT CHANCE CATEGORY.
AS OF 745 PM EDT FRIDAY...SCATTERED STRONG THUNDERSTORMS HAVE
FINALLY LIFTED NORTH OF THE FORECAST AREA. THERE ISN/T MUCH FORCING
FOR PCPN UNTIL LATE TONIGHT WHEN AN MVC WILL SPREAD LIGHT STRATIFORM
PCPN AND A FEW HEAVIER SHRA/TSTMS INTO THE FA FROM THE SOUTHWEST.
UPSLOPE AND PROXIMITY TO THE POT VORT ANOMALY - AS SEEN ON THE 18
UTC GFS - WILL YIELD THE GREATEST COVERAGE OVER THE SOUTHWEST AND
CENTRAL MTNS AS WELL AS THE NE GA AND THE WRN UPSTATE. I/VE RAISED
POPS TO LIKELY IN THIS AREA...BUT NOT UNTIL AROUND 5 AM. EVERYTHING
ELSE LOOKS GOOD FOR THIS UPDATE.
AS OF 515 PM EDT FRIDAY...A FEW SHOWERS AND THUNDERSTORMS HAVE
DEVELOPED OVER THE WRN NC PIEDMONT...ESPECIALLY ACROSS ROWAN COUNTY.
THIS IS AN AREA OF WEAK MOISTURE AND SPEED CONVERGENCE. I/D EXPECT
CONVECTION TO CONTINUE ACROSS THIS AREA AND EXTENDING BACK INTO THE
SW NC FOOTHILLS FOR A FEW MORE HOURS. CONVECTION WILL ALSO PERSIST
OVER THE CENTRAL AND NRN MTNS. FARTHER SOUTH AND WEST LAPS ISN/T
SHOWING MUCH INSTABILITY AND MID AND HIGH LEVEL CLOUDS ARE SPREADING
IN WHICH SHOULD ALSO LIMIT CONVECTION. MUCH LATER
TONIGHT...HOWEVER...CONVECTION MAY SPREAD IN FROM THE SOUTHWEST AS
THE UPPER LOW APPROACHES. NOT SEEING A LOT OF ELEVATED INSTABILITY
BUT SHOWERS AND EVEN SOME STRATIFORM RAIN IS POSSIBLE. INTERESTINGLY
THERE IS SOME ELEVATED INSTABILITY OVER THE NC PIEDMONT. OUR
WORKSTATION WRF-ARW MODEL SHOWS CONVECTION DEVELOPING IN THAT AREA
AFTER MIDNIGHT. I WON/T BE THAT AGGRESSIVE...BUT IT/S SOMETHING TO
KEEP IN MIND.
AS OF 230 PM...LOOKING AT LATEST WV IMAGERY...WEAKENING UPPER
LEVEL TROF CONTINUES TO MOVE EASTWARD ACROSS THE TENNESSEE
VALLEY...THUS SPREADING MOISTURE THRU THE SOUTHEASTERN UNITED
STATES. WITH THIS...SOME SHOWER AND THUNDERSTORMS ACTIVITY IS
PRESENT ON RADAR ACROSS PORTIONS OF NORTHEAST MISSISSIPPI AND
NORTHWEST ALABAMA. LOCALLY...MID TO UPPER LEVEL CLOUD COVER
CONTINUES TO INCREASE ACROSS THE REGION AS A CONSEQUENCE OF DEEP
MOISTURE ADVECTION ALOFT. HEIGHTS WILL CONTINUE FALL ACROSS
NORTHEAST GEORGIA AND THE CAROLINAS THROUGH THE NEXT 24 HOURS AS
REMNANTS OF UPPER LEVEL TROF MOVE THROUGH. LATEST MESOANALYSIS
INDICATES A MODERATELY UNSTABLE AIRMASS ACROSS THE REGION THIS
AFTERNOON. STILL EXPECTING THE MAJORITY OF CONVECTIVE ACTIVITY TO
BE IN THE HIGHER TERRAINS AS UPSLOPE FLOW WILL PROVIDE ENOUGH LIFT
TO OVERCOME ANY CAPPING...THEREFORE KEPT LIKELY POPS ACROSS NORTHERN
MOST PORTIONS OF THE NC MOUNTAINS AND HIGHER END CHANCE POPS
ELSEWHERE IN THE HIGH TERRAIN. POPS DECREASE TO THE SOUTHEAST AS
LOCATIONS NEAR AND ALONG THE I85 CORRIDOR WILL HAVE THE MOST
DIFFICULT TIME OVERCOMING ANY INVERSION. THUS...WENT WITH SLIGHT
CHANCE POPS ACROSS THIS REGION.
TONIGHT AND TOMORROW...MODEL GUIDANCE REMAINS IN GOOD AGREEMENT WITH
REGARDS TO DECREASE IN CONVECTIVE ACTIVITY DURING THE OVERNIGHT
HOURS AS DAYTIME HEATING DISSIPATES. HOWEVER...AFTER SUNRISE
TOMORROW THE ABOVE MENTIONED UPPER LEVEL WAVE WILL BE CENTERED OVER
THE SOUTHERN APPALACHIANS. PRECIPITATION CHANCES WILL INCREASE ONCE
AGAIN DURING THE LATE MORNING HOURS ACROSS THE ENTIRE REGION. SOME
SHOWER AND THUNDERSTORM ACTIVITY COULD BE STRONG TOMORROW AFTERNOON
AND EVENING AS THERMAL PROFILES INDICATE SLIGHTLY DEEPER INSTABILITY
THAN PREVIOUS DAYS. LIKEWISE...SOME OF THESE SHOWERS AND
THUNDERSTORMS COULD PRODUCE LOCALLY HEAVY RAINFALL AS PRECIPITABLE
WATER VALUES EXCEED 1.5 INCHES THROUGHOUT THE PROFILE.
&&
.SHORT TERM /TONIGHT THROUGH MONDAY/...
AT 200 PM FRIDAY...A WEAKNESS WILL PERSIST IN THE UPPER HEIGHT FIELD
OVER THE SOUTHEAST THROUGH MUCH OF THE PERIOD...ALTHOUGH IT WILL
CONTINUE TO GRADUALLY FILL. MOISTURE WILL REMAIN DEEP AND ABUNDANT
ACROSS THE REGION THROUGH THE PERIOD...AS PWATS WILL RUN IN THE
NEIGHBORHOOD OF 1.5 INCHES THROUGH AT LEAST SUNDAY NIGHT. THIS
SHOULD PROMOTE DEVELOPMENT OF NUMEROUS SHOWERS AND THUNDERSTORMS
ACROSS THE AREA DURING THE AFTERNOONS AND EVENINGS. LOW LEVEL FOCI
FOR INITIATION SHOULD GENERALLY BE LIMITED TO DIFFERENTIAL
HEATING/TERRAIN EFFECTS AS WELL AS OUTFLOW BOUNDARIES. HOWEVER...IT
APPEARS A WEAK/QUASI-CAD BOUNDARY WILL BE DRAPED ACROSS THE
CAROLINAS DURING THIS TIME AS WELL. WITH RELATIVELY WEAK DEEP LAYER
FLOW EXPECTED TO PREDOMINATE...SLOW MOVING...TRAINING AND/OR
ANCHORING CELLS PRODUCING LOCALLY EXCESSIVE RAINFALL WILL BE THE
PRIMARY THREATS. ISOLATED PULSE SEVERE STORMS OR SMALL CLUSTERS WILL
BE POSSIBLE... BUT THE SEVERE WEATHER THREAT WILL HINGE LARGELY UPON
THE DEGREE OF INSTABILITY AND THEREFORE THE MAGNITUDE OF HEATING WE
SEE...WHICH WILL PROBABLY NOT AMOUNT TO MUCH CONSIDERING THE MOIST
ADIABATIC LAPSE RATES/PROBABLE WIDESPREAD AND PERSISTENT CLOUD
COVER. MIN TEMPS WILL AVERAGE WELL ABOVE NORMAL AND MAXES SLIGHTLY
BELOW CLIMO OWING TO THE VERY MOIST AIR MASS.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
AT 225 PM FRIDAY...AN UPPER LEVEL RIDGE WILL DOMINATE THE EASTERN
U.S INTO THE MIDDLE PART OF NEXT WEEK. AT THE SURFACE...THE WESTERN
EXTENSION OF THE BERMUDA HIGH WILL BE OVER THE SE STATES.
THEREFORE...EXPECT TEMPERATURES TO BE ABOVE CLIMO TUE AND WED.
DIURNALLY DRIVEN SCATTERED CONVECTION WILL OCCUR TUE AND WED WITH THE
GREATEST COVERAGE OVER THE MOUNTAINS. AN UPPER TROUGH WILL APPROACH
THE AREA FROM THE WEST LATE IN THE WEEK WITH THE ASSOCIATED COLD
FRONT MOVING THROUGH THE AREA LATE THU INTO FRI. THEREFORE...PRECIP
CHANCES WILL BE ON THE INCREASE THU...AND THEN DIMINISH ON FRI AS
THE FRONT MOVES TO THE EAST. TEMPERATURES WILL LOWER BACK TO
SEASONAL VALUES BY FRIDAY. STAYED CLOSE TO WPC GUIDANCE TEMPS/POPS.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
AT KCLT...A FEW CUMULUS CLOUDS AND INCREASING MID CLOUD WILL
CONTINUE ACROSS THE REGION THRU DAYBREAK. STARTING DURING THE
MORNING...AN AREA OF PCPN WILL BEGIN TO MOVE INTO THE REGION. IT
LOOS LIKE IT WILL ONLY SLOWLY MOVE INTO THE CLT AREA...HO HAVE HELD
OFF ON ANY PRECIP UNTIL AFTERNOON. THAT SAID...DID BRING LOWER VFR
CIGS IN DURING THE MORNING. CHC OF CONVECTION CONTINUE THRU THE
EVENING WITH LOW VFR CIGS CONTINUING. CALM WIND EARLY BECOMES SLY BY
MID MORNING AND CONTINUE THRU THE PERIOD.
ELSEWHERE...AN AREA OF SHOWERS WILL SLOWLY ACROSS NE GA AND INTO THE
WRN CAROLINAS THRU THE MORNING. KAVL WILL SEE PCPN FIRST...FOLLOWED
BY THE UPSTATE SITES AND KHKY. EXPECT CIGS AND VSBYS TO REMAIN LOW
VFR AS RAIN IS NOT THAT HEAVY. HOWEVER...MVFR DOES DEVELOP AT KAVL
AFTER DAYBREAK...BUT BECOMES VFR FOR THE AFTERNOON. EXPECT ANY
RESTRICTIONS ELSEWHERE WILL BE WITH HEAVIER SHRA OR TSRA. PRECIP CHC
AND ANY RESTRICTIONS CONTINUE THRU THE EVENING. LIGHT WIND BECOMES
S TO SW AFTER DAYBREAK AND CONTINUES THRU THE DAY INTO THE EVENING.
OUTLOOK...SHOWERS AND THUNDERSTORMS...AND ASSOCIATED RESTRICTIONS...
WILL PERSIST THROUGH MONDAY. FAIR WEATHER MAY RETURN BY TUESDAY.
CONFIDENCE TABLE...
05-11Z 11-17Z 17-23Z 23-05Z
KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGSP HIGH 100% HIGH 95% HIGH 100% HIGH 100%
KAVL HIGH 98% HIGH 85% HIGH 94% HIGH 93%
KHKY HIGH 100% HIGH 90% HIGH 99% HIGH 100%
KGMU HIGH 100% HIGH 93% HIGH 100% HIGH 100%
KAND HIGH 100% HIGH 98% HIGH 94% 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...LEV
NEAR TERM...CDG/MCAVOY/RWH
SHORT TERM...JDL
LONG TERM...LG
AVIATION...RWH
000
FXUS62 KGSP 180220
AFDGSP
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
1020 PM EDT FRI MAY 17 2013
.SYNOPSIS...
A MID LEVEL DISTURBANCE WILL DRIFT ACROSS THE REGION THIS
WEEKEND... TRIGGEREING SHOWERS AND THUNDERSTORMS THROUGH THE
BEGINNING OF NEXT WEEK. SOUTHERLY FLOW WILL KEEP THE AIRMASS WARM
AND MOIST... AND THE PATTERN WILL REMAIN UNSETTLED UNTIL A FRONTAL
SYSTEM APPROACHES THE WESTERN CAROLINAS LATE NEXT WEEK.
&&
.NEAR TERM /THROUGH SATURDAY/...
AS OF 1015 PM EDT FRIDAY...A BAND A LIGHT...MAINLY STRATIFORM PCPN
CONTINUES TO SLOWLY APPROACH THE SOUTHWEST MOUNTAINS FROM THE WEST.
THE PCPN IS A LITTLE AHEAD OF WHERE THE MODELS HAVE BEEN PLACING
IT...BUT IT/S ALSO WORKING THROUGH SOME DRY AIR AND IT WILL CONTINUE
TO APPROACH QUITE SLOWLY. I DID BUMP UP THE TIMING OF HIGHER POPS
ACROSS THE SOUTHWEST MOUNTAINS BY A FEW HOURS. HOWEVER...THERE ISN/T
A DROP OF PCPN IN THE FA AT THIS EXACT TIME...AND POPS FOR THE NEXT
COUPLE HOURS HAVE BEEN CUT TO BELOW THE SLIGHT CHANCE CATEGORY.
AS OF 745 PM EDT FRIDAY...SCATTERED STRONG THUNDERSTORMS HAVE
FINALLY LIFTED NORTH OF THE FORECAST AREA. THERE ISN/T MUCH FORCING
FOR PCPN UNTIL LATE TONIGHT WHEN AN MVC WILL SPREAD LIGHT STRATIFORM
PCPN AND A FEW HEAVIER SHRA/TSTMS INTO THE FA FROM THE SOUTHWEST.
UPSLOPE AND PROXIMITY TO THE POT VORT ANOMALY - AS SEEN ON THE 18
UTC GFS - WILL YIELD THE GREATEST COVERAGE OVER THE SOUTHWEST AND
CENTRAL MTNS AS WELL AS THE NE GA AND THE WRN UPSTATE. I/VE RAISED
POPS TO LIKELY IN THIS AREA...BUT NOT UNTIL AROUND 5 AM. EVERYTHING
ELSE LOOKS GOOD FOR THIS UPDATE.
AS OF 515 PM EDT FRIDAY...A FEW SHOWERS AND THUNDERSTORMS HAVE
DEVELOPED OVER THE WRN NC PIEDMONT...ESPECIALLY ACROSS ROWAN COUNTY.
THIS IS AN AREA OF WEAK MOISTURE AND SPEED CONVERGENCE. I/D EXPECT
CONVECTION TO CONTINUE ACROSS THIS AREA AND EXTENDING BACK INTO THE
SW NC FOOTHILLS FOR A FEW MORE HOURS. CONVECTION WILL ALSO PERSIST
OVER THE CENTRAL AND NRN MTNS. FARTHER SOUTH AND WEST LAPS ISN/T
SHOWING MUCH INSTABILITY AND MID AND HIGH LEVEL CLOUDS ARE SPREADING
IN WHICH SHOULD ALSO LIMIT CONVECTION. MUCH LATER
TONIGHT...HOWEVER...CONVECTION MAY SPREAD IN FROM THE SOUTHWEST AS
THE UPPER LOW APPROACHES. NOT SEEING A LOT OF ELEVATED INSTABILITY
BUT SHOWERS AND EVEN SOME STRATIFORM RAIN IS POSSIBLE. INTERESTINGLY
THERE IS SOME ELEVATED INSTABILITY OVER THE NC PIEDMONT. OUR
WORKSTATION WRF-ARW MODEL SHOWS CONVECTION DEVELOPING IN THAT AREA
AFTER MIDNIGHT. I WON/T BE THAT AGGRESSIVE...BUT IT/S SOMETHING TO
KEEP IN MIND.
AS OF 230 PM...LOOKING AT LATEST WV IMAGERY...WEAKENING UPPER
LEVEL TROF CONTINUES TO MOVE EASTWARD ACROSS THE TENNESSEE
VALLEY...THUS SPREADING MOISTURE THRU THE SOUTHEASTERN UNITED
STATES. WITH THIS...SOME SHOWER AND THUNDERSTORMS ACTIVITY IS
PRESENT ON RADAR ACROSS PORTIONS OF NORTHEAST MISSISSIPPI AND
NORTHWEST ALABAMA. LOCALLY...MID TO UPPER LEVEL CLOUD COVER
CONTINUES TO INCREASE ACROSS THE REGION AS A CONSEQUENCE OF DEEP
MOISTURE ADVECTION ALOFT. HEIGHTS WILL CONTINUE FALL ACROSS
NORTHEAST GEORGIA AND THE CAROLINAS THROUGH THE NEXT 24 HOURS AS
REMNANTS OF UPPER LEVEL TROF MOVE THROUGH. LATEST MESOANALYSIS
INDICATES A MODERATELY UNSTABLE AIRMASS ACROSS THE REGION THIS
AFTERNOON. STILL EXPECTING THE MAJORITY OF CONVECTIVE ACTIVITY TO
BE IN THE HIGHER TERRAINS AS UPSLOPE FLOW WILL PROVIDE ENOUGH LIFT
TO OVERCOME ANY CAPPING...THEREFORE KEPT LIKELY POPS ACROSS NORTHERN
MOST PORTIONS OF THE NC MOUNTAINS AND HIGHER END CHANCE POPS
ELSEWHERE IN THE HIGH TERRAIN. POPS DECREASE TO THE SOUTHEAST AS
LOCATIONS NEAR AND ALONG THE I85 CORRIDOR WILL HAVE THE MOST
DIFFICULT TIME OVERCOMING ANY INVERSION. THUS...WENT WITH SLIGHT
CHANCE POPS ACROSS THIS REGION.
TONIGHT AND TOMORROW...MODEL GUIDANCE REMAINS IN GOOD AGREEMENT WITH
REGARDS TO DECREASE IN CONVECTIVE ACTIVITY DURING THE OVERNIGHT
HOURS AS DAYTIME HEATING DISSIPATES. HOWEVER...AFTER SUNRISE
TOMORROW THE ABOVE MENTIONED UPPER LEVEL WAVE WILL BE CENTERED OVER
THE SOUTHERN APPALACHIANS. PRECIPITATION CHANCES WILL INCREASE ONCE
AGAIN DURING THE LATE MORNING HOURS ACROSS THE ENTIRE REGION. SOME
SHOWER AND THUNDERSTORM ACTIVITY COULD BE STRONG TOMORROW AFTERNOON
AND EVENING AS THERMAL PROFILES INDICATE SLIGHTLY DEEPER INSTABILITY
THAN PREVIOUS DAYS. LIKEWISE...SOME OF THESE SHOWERS AND
THUNDERSTORMS COULD PRODUCE LOCALLY HEAVY RAINFALL AS PRECIPITABLE
WATER VALUES EXCEED 1.5 INCHES THROUGHOUT THE PROFILE.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
AT 200 PM FRIDAY...A WEAKNESS WILL PERSIST IN THE UPPER HEIGHT FIELD
OVER THE SOUTHEAST THROUGH MUCH OF THE PERIOD...ALTHOUGH IT WILL
CONTINUE TO GRADUALLY FILL. MOISTURE WILL REMAIN DEEP AND ABUNDANT
ACROSS THE REGION THROUGH THE PERIOD...AS PWATS WILL RUN IN THE
NEIGHBORHOOD OF 1.5 INCHES THROUGH AT LEAST SUNDAY NIGHT. THIS
SHOULD PROMOTE DEVELOPMENT OF NUMEROUS SHOWERS AND THUNDERSTORMS
ACROSS THE AREA DURING THE AFTERNOONS AND EVENINGS. LOW LEVEL FOCI
FOR INITIATION SHOULD GENERALLY BE LIMITED TO DIFFERENTIAL
HEATING/TERRAIN EFFECTS AS WELL AS OUTFLOW BOUNDARIES. HOWEVER...IT
APPEARS A WEAK/QUASI-CAD BOUNDARY WILL BE DRAPED ACROSS THE
CAROLINAS DURING THIS TIME AS WELL. WITH RELATIVELY WEAK DEEP LAYER
FLOW EXPECTED TO PREDOMINATE...SLOW MOVING...TRAINING AND/OR
ANCHORING CELLS PRODUCING LOCALLY EXCESSIVE RAINFALL WILL BE THE
PRIMARY THREATS. ISOLATED PULSE SEVERE STORMS OR SMALL CLUSTERS WILL
BE POSSIBLE... BUT THE SEVERE WEATHER THREAT WILL HINGE LARGELY UPON
THE DEGREE OF INSTABILITY AND THEREFORE THE MAGNITUDE OF HEATING WE
SEE...WHICH WILL PROBABLY NOT AMOUNT TO MUCH CONSIDERING THE MOIST
ADIABATIC LAPSE RATES/PROBABLE WIDESPREAD AND PERSISTENT CLOUD
COVER. MIN TEMPS WILL AVERAGE WELL ABOVE NORMAL AND MAXES SLIGHTLY
BELOW CLIMO OWING TO THE VERY MOIST AIR MASS.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
AT 225 PM FRIDAY...AN UPPER LEVEL RIDGE WILL DOMINATE THE EASTERN
U.S INTO THE MIDDLE PART OF NEXT WEEK. AT THE SURFACE...THE WESTERN
EXTENSION OF THE BERMUDA HIGH WILL BE OVER THE SE STATES.
THEREFORE...EXPECT TEMPERATURES TO BE ABOVE CLIMO TUE AND WED.
DIURNALLY DRIVEN SCATTERED CONVECTION WILL OCCUR TUE AND WED WITH THE
GREATEST COVERAGE OVER THE MOUNTAINS. AN UPPER TROUGH WILL APPROACH
THE AREA FROM THE WEST LATE IN THE WEEK WITH THE ASSOCIATED COLD
FRONT MOVING THROUGH THE AREA LATE THU INTO FRI. THEREFORE...PRECIP
CHANCES WILL BE ON THE INCREASE THU...AND THEN DIMINISH ON FRI AS
THE FRONT MOVES TO THE EAST. TEMPERATURES WILL LOWER BACK TO
SEASONAL VALUES BY FRIDAY. STAYED CLOSE TO WPC GUIDANCE TEMPS/POPS.
&&
.AVIATION /02Z SATURDAY THROUGH WEDNESDAY/...
AT KCLT...A FEW CUMULUS CLOUDS WILL LINGER ACROSS THE REGION THROUGH
THE OVERNIGHT...THOUGH ANY CIGS SHOULD BE OF THE MID AND UPPER LEVEL
VARIETY. THE CIGS MAY LOWER TO AROUND 10KFT LATE TONIGHT AS AN UPPER
LOW APPROACHES FROM THE WEST. STARTING AT MID MORNING AN AREA OF
PCPN WILL BEGIN TO MOVE INTO THE REGION. IT/S REALLY QUESTIONABLE
HOW QUICKLY IT MOVES EAST. I SUSPECT WE WILL HAVE TO WAIT FOR AFTN
HEATING TO KICK IN BEFORE SHRA/TSTMS BEGIN IN EARNEST...WHICH IS
WHAT I/VE CARRIED IN THE TAF. WINDS WILL GENERALLY BE OUT OF THE S
TO SW THROUGH THE PERIOD.
ELSEWHERE...AN AREA OF SHOWERS...THUNDERSTORMS AND RAIN WILL SLOWLY
MOVE INTO THE WESTERN CAROLINAS LATE TONIGHT. KAVL WILL SEE PCPN
FIRST...FOLLOWED BY THE UPSTATE SITES AND KHKY. CIGS AND VSBYS WILL
FALL LATE TONIGHT...BUT THIS WILL PRIMARILY BE CONFINED TO THE
MOUNTAINS AND IMMEDIATE FOOTHILLS. WHILE THERE WON/T BE MUCH
HEATING...THERE SHOULD STILL BE A FAIR AMOUNT OF SHOWERY PCPN IN THE
AFTN ON SATURDAY...SOME OF WHICH WILL EVOLVE INTO TSTMS. THEREFORE
I/VE ADDED TEMPO THUNDER IN THE AFTN AT MOST SITES. NO WIND SHIFTS
THIS PERIOD WITH THE FLOW GENERALLY OUT OF THE S TO SW.
OUTLOOK...SHOWERS AND THUNDERSTORMS...AND ASSOCIATED RESTRICTIONS...
WILL PERSIST THROUGH MONDAY. FAIR WEATHER MAY RETURN BY TUESDAY.
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 93% HIGH 88% HIGH 89%
KHKY HIGH 100% HIGH 100% HIGH 98% HIGH 100%
KGMU HIGH 100% HIGH 98% HIGH 93% HIGH 100%
KAND HIGH 100% HIGH 100% HIGH 95% 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...LEV
NEAR TERM...CDG/MCAVOY
SHORT TERM...JDL
LONG TERM...LG
AVIATION...MCAVOY
000
FXUS62 KGSP 172355
AFDGSP
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
755 PM EDT FRI MAY 17 2013
.SYNOPSIS...
A MID LEVEL DISTURBANCE WILL DRIFT ACROSS THE REGION THIS
WEEKEND... TRIGGEREING SHOWERS AND THUNDERSTORMS THROUGH THE
BEGINNING OF NEXT WEEK. SOUTHERLY FLOW WILL KEEP THE AIRMASS WARM
AND MOIST... AND THE PATTERN WILL REMAIN UNSETTLED UNTIL A FRONTAL
SYSTEM APPROACHES THE WESTERN CAROLINAS LATE NEXT WEEK.
&&
.NEAR TERM /THROUGH SATURDAY/...
AS OF 745 PM EDT FRIDAY...SCATTERED STRONG THUNDERSTORMS HAVE
FINALLY LIFTED NORTH OF THE FORECAST AREA. THERE ISN/T MUCH FORCING
FOR PCPN UNTIL LATE TONIGHT WHEN AN MVC WILL SPREAD LIGHT STRATIFORM
PCPN AND A FEW HEAVIER SHRA/TSTMS INTO THE FA FROM THE SOUTHWEST.
UPSLOPE AND PROXIMITY TO THE POT VORT ANOMALY - AS SEEN ON THE 18
UTC GFS - WILL YIELD THE GREATEST COVERAGE OVER THE SOUTHWEST AND
CENTRAL MTNS AS WELL AS THE NE GA AND THE WRN UPSTATE. I/VE RAISED
POPS TO LIKELY IN THIS AREA...BUT NOT UNTIL AROUND 5 AM. EVERYTHING
ELSE LOOKS GOOD FOR THIS UPDATE.
AS OF 515 PM EDT FRIDAY...A FEW SHOWERS AND THUNDERSTORMS HAVE
DEVELOPED OVER THE WRN NC PIEDMONT...ESPECIALLY ACROSS ROWAN COUNTY.
THIS IS AN AREA OF WEAK MOISTURE AND SPEED CONVERGENCE. I/D EXPECT
CONVECTION TO CONTINUE ACROSS THIS AREA AND EXTENDING BACK INTO THE
SW NC FOOTHILLS FOR A FEW MORE HOURS. CONVECTION WILL ALSO PERSIST
OVER THE CENTRAL AND NRN MTNS. FARTHER SOUTH AND WEST LAPS ISN/T
SHOWING MUCH INSTABILITY AND MID AND HIGH LEVEL CLOUDS ARE SPREADING
IN WHICH SHOULD ALSO LIMIT CONVECTION. MUCH LATER
TONIGHT...HOWEVER...CONVECTION MAY SPREAD IN FROM THE SOUTHWEST AS
THE UPPER LOW APPROACHES. NOT SEEING A LOT OF ELEVATED INSTABILITY
BUT SHOWERS AND EVEN SOME STRATIFORM RAIN IS POSSIBLE. INTERESTINGLY
THERE IS SOME ELEVATED INSTABILITY OVER THE NC PIEDMONT. OUR
WORKSTATION WRF-ARW MODEL SHOWS CONVECTION DEVELOPING IN THAT AREA
AFTER MIDNIGHT. I WON/T BE THAT AGGRESSIVE...BUT IT/S SOMETHING TO
KEEP IN MIND.
AS OF 230 PM...LOOKING AT LATEST WV IMAGERY...WEAKENING UPPER
LEVEL TROF CONTINUES TO MOVE EASTWARD ACROSS THE TENNESSEE
VALLEY...THUS SPREADING MOISTURE THRU THE SOUTHEASTERN UNITED
STATES. WITH THIS...SOME SHOWER AND THUNDERSTORMS ACTIVITY IS
PRESENT ON RADAR ACROSS PORTIONS OF NORTHEAST MISSISSIPPI AND
NORTHWEST ALABAMA. LOCALLY...MID TO UPPER LEVEL CLOUD COVER
CONTINUES TO INCREASE ACROSS THE REGION AS A CONSEQUENCE OF DEEP
MOISTURE ADVECTION ALOFT. HEIGHTS WILL CONTINUE FALL ACROSS
NORTHEAST GEORGIA AND THE CAROLINAS THROUGH THE NEXT 24 HOURS AS
REMNANTS OF UPPER LEVEL TROF MOVE THROUGH. LATEST MESOANALYSIS
INDICATES A MODERATELY UNSTABLE AIRMASS ACROSS THE REGION THIS
AFTERNOON. STILL EXPECTING THE MAJORITY OF CONVECTIVE ACTIVITY TO
BE IN THE HIGHER TERRAINS AS UPSLOPE FLOW WILL PROVIDE ENOUGH LIFT
TO OVERCOME ANY CAPPING...THEREFORE KEPT LIKELY POPS ACROSS NORTHERN
MOST PORTIONS OF THE NC MOUNTAINS AND HIGHER END CHANCE POPS
ELSEWHERE IN THE HIGH TERRAIN. POPS DECREASE TO THE SOUTHEAST AS
LOCATIONS NEAR AND ALONG THE I85 CORRIDOR WILL HAVE THE MOST
DIFFICULT TIME OVERCOMING ANY INVERSION. THUS...WENT WITH SLIGHT
CHANCE POPS ACROSS THIS REGION.
TONIGHT AND TOMORROW...MODEL GUIDANCE REMAINS IN GOOD AGREEMENT WITH
REGARDS TO DECREASE IN CONVECTIVE ACTIVITY DURING THE OVERNIGHT
HOURS AS DAYTIME HEATING DISSIPATES. HOWEVER...AFTER SUNRISE
TOMORROW THE ABOVE MENTIONED UPPER LEVEL WAVE WILL BE CENTERED OVER
THE SOUTHERN APPALACHIANS. PRECIPITATION CHANCES WILL INCREASE ONCE
AGAIN DURING THE LATE MORNING HOURS ACROSS THE ENTIRE REGION. SOME
SHOWER AND THUNDERSTORM ACTIVITY COULD BE STRONG TOMORROW AFTERNOON
AND EVENING AS THERMAL PROFILES INDICATE SLIGHTLY DEEPER INSTABILITY
THAN PREVIOUS DAYS. LIKEWISE...SOME OF THESE SHOWERS AND
THUNDERSTORMS COULD PRODUCE LOCALLY HEAVY RAINFALL AS PRECIPITABLE
WATER VALUES EXCEED 1.5 INCHES THROUGHOUT THE PROFILE.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
AT 200 PM FRIDAY...A WEAKNESS WILL PERSIST IN THE UPPER HEIGHT FIELD
OVER THE SOUTHEAST THROUGH MUCH OF THE PERIOD...ALTHOUGH IT WILL
CONTINUE TO GRADUALLY FILL. MOISTURE WILL REMAIN DEEP AND ABUNDANT
ACROSS THE REGION THROUGH THE PERIOD...AS PWATS WILL RUN IN THE
NEIGHBORHOOD OF 1.5 INCHES THROUGH AT LEAST SUNDAY NIGHT. THIS
SHOULD PROMOTE DEVELOPMENT OF NUMEROUS SHOWERS AND THUNDERSTORMS
ACROSS THE AREA DURING THE AFTERNOONS AND EVENINGS. LOW LEVEL FOCI
FOR INITIATION SHOULD GENERALLY BE LIMITED TO DIFFERENTIAL
HEATING/TERRAIN EFFECTS AS WELL AS OUTFLOW BOUNDARIES. HOWEVER...IT
APPEARS A WEAK/QUASI-CAD BOUNDARY WILL BE DRAPED ACROSS THE
CAROLINAS DURING THIS TIME AS WELL. WITH RELATIVELY WEAK DEEP LAYER
FLOW EXPECTED TO PREDOMINATE...SLOW MOVING...TRAINING AND/OR
ANCHORING CELLS PRODUCING LOCALLY EXCESSIVE RAINFALL WILL BE THE
PRIMARY THREATS. ISOLATED PULSE SEVERE STORMS OR SMALL CLUSTERS WILL
BE POSSIBLE... BUT THE SEVERE WEATHER THREAT WILL HINGE LARGELY UPON
THE DEGREE OF INSTABILITY AND THEREFORE THE MAGNITUDE OF HEATING WE
SEE...WHICH WILL PROBABLY NOT AMOUNT TO MUCH CONSIDERING THE MOIST
ADIABATIC LAPSE RATES/PROBABLE WIDESPREAD AND PERSISTENT CLOUD
COVER. MIN TEMPS WILL AVERAGE WELL ABOVE NORMAL AND MAXES SLIGHTLY
BELOW CLIMO OWING TO THE VERY MOIST AIR MASS.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
AT 225 PM FRIDAY...AN UPPER LEVEL RIDGE WILL DOMINATE THE EASTERN
U.S INTO THE MIDDLE PART OF NEXT WEEK. AT THE SURFACE...THE WESTERN
EXTENSION OF THE BERMUDA HIGH WILL BE OVER THE SE STATES.
THEREFORE...EXPECT TEMPERATURES TO BE ABOVE CLIMO TUE AND WED.
DIURNALLY DRIVEN SCATTERED CONVECTION WILL OCCUR TUE AND WED WITH THE
GREATEST COVERAGE OVER THE MOUNTAINS. AN UPPER TROUGH WILL APPROACH
THE AREA FROM THE WEST LATE IN THE WEEK WITH THE ASSOCIATED COLD
FRONT MOVING THROUGH THE AREA LATE THU INTO FRI. THEREFORE...PRECIP
CHANCES WILL BE ON THE INCREASE THU...AND THEN DIMINISH ON FRI AS
THE FRONT MOVES TO THE EAST. TEMPERATURES WILL LOWER BACK TO
SEASONAL VALUES BY FRIDAY. STAYED CLOSE TO WPC GUIDANCE TEMPS/POPS.
&&
.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
AT KCLT...A FEW CUMULUS CLOUDS WILL LINGER ACROSS THE REGION THROUGH
THE OVERNIGHT...THOUGH ANY CIGS SHOULD BE OF THE MID AND UPPER LEVEL
VARIETY. THE CIGS MAY LOWER TO AROUND 10KFT LATE TONIGHT AS AN UPPER
LOW APPROACHES FROM THE WEST. STARTING AT MID MORNING AN AREA OF
PCPN WILL BEGIN TO MOVE INTO THE REGION. IT/S REALLY QUESTIONABLE
HOW QUICKLY IT MOVES EAST. I SUSPECT WE WILL HAVE TO WAIT FOR AFTN
HEATING TO KICK IN BEFORE SHRA/TSTMS BEGIN IN EARNEST...WHICH IS
WHAT I/VE CARRIED IN THE TAF. WINDS WILL GENERALLY BE OUT OF THE S
TO SW THROUGH THE PERIOD.
ELSEWHERE...AN AREA OF SHOWERS...THUNDERSTORMS AND RAIN WILL SLOWLY
MOVE INTO THE WESTERN CAROLINAS LATE TONIGHT. KAVL WILL SEE PCPN
FIRST...FOLLOWED BY THE UPSTATE SITES AND KHKY. CIGS AND VSBYS WILL
FALL LATE TONIGHT...BUT THIS WILL PRIMARILY BE CONFINED TO THE
MOUNTAINS AND IMMEDIATE FOOTHILLS. WHILE THERE WON/T BE MUCH
HEATING...THERE SHOULD STILL BE A FAIR AMOUNT OF SHOWERY PCPN IN THE
AFTN ON SATURDAY...SOME OF WHICH WILL EVOLVE INTO TSTMS. THEREFORE
I/VE ADDED TEMPO THUNDER IN THE AFTN AT MOST SITES. NO WIND SHIFTS
THIS PERIOD WITH THE FLOW GENERALLY OUT OF THE S TO SW.
OUTLOOK...SHOWERS AND THUNDERSTORMS...AND ASSOCIATED RESTRICTIONS...
WILL PERSIST THROUGH MONDAY. FAIR WEATHER MAY RETURN BY TUESDAY.
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 95% HIGH 87% HIGH 86%
KHKY HIGH 100% HIGH 100% HIGH 98% HIGH 94%
KGMU HIGH 100% HIGH 100% HIGH 91% HIGH 100%
KAND HIGH 100% HIGH 100% HIGH 95% 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...LEV
NEAR TERM...CDG/MCAVOY
SHORT TERM...JDL
LONG TERM...LG
AVIATION...MCAVOY
000
FXUS62 KGSP 172123
AFDGSP
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
523 PM EDT FRI MAY 17 2013
.SYNOPSIS...
A MID LEVEL DISTURBANCE WILL DRIFT ACROSS THE REGION THIS
WEEKEND... TRIGGEREING SHOWERS AND THUNDERSTORMS THROUGH THE
BEGINNING OF NEXT WEEK. SOUTHERLY FLOW WILL KEEP THE AIRMASS WARM
AND MOIST... AND THE PATTERN WILL REMAIN UNSETTLED UNTIL A FRONTAL
SYSTEM APPROACHES THE WESTERN CAROLINAS LATE NEXT WEEK.
&&
.NEAR TERM /THROUGH SATURDAY/...
AS OF 515 PM EDT FRIDAY...A FEW SHOWERS AND THUNDERSTORMS HAVE
DEVELOPED OVER THE WRN NC PIEDMONT...ESPECIALLY ACROSS ROWAN COUNTY.
THIS IS AN AREA OF WEAK MOISTURE AND SPEED CONVERGENCE. I/D EXPECT
CONVECTION TO CONTINUE ACROSS THIS AREA AND EXTENDING BACK INTO THE
SW NC FOOTHILLS FOR A FEW MORE HOURS. CONVECTION WILL ALSO PERSIST
OVER THE CENTRAL AND NRN MTNS. FARTHER SOUTH AND WEST LAPS ISN/T
SHOWING MUCH INSTABILITY AND MID AND HIGH LEVEL CLOUDS ARE SPREADING
IN WHICH SHOULD ALSO LIMIT CONVECTION. MUCH LATER
TONIGHT...HOWEVER...CONVECTION MAY SPREAD IN FROM THE SOUTHWEST AS
THE UPPER LOW APPROACHES. NOT SEEING A LOT OF ELEVATED INSTABILITY
BUT SHOWERS AND EVEN SOME STRATIFORM RAIN IS POSSIBLE. INTERESTINGLY
THERE IS SOME ELEVATED INSTABILITY OVER THE NC PIEDMONT. OUR
WORKSTATION WRF-ARW MODEL SHOWS CONVECTION DEVELOPING IN THAT AREA
AFTER MIDNIGHT. I WON/T BE THAT AGGRESSIVE...BUT IT/S SOMETHING TO
KEEP IN MIND.
AS OF 230 PM...LOOKING AT LATEST WV IMAGERY...WEAKENING UPPER
LEVEL TROF CONTINUES TO MOVE EASTWARD ACROSS THE TENNESSEE
VALLEY...THUS SPREADING MOISTURE THRU THE SOUTHEASTERN UNITED
STATES. WITH THIS...SOME SHOWER AND THUNDERSTORMS ACTIVITY IS
PRESENT ON RADAR ACROSS PORTIONS OF NORTHEAST MISSISSIPPI AND
NORTHWEST ALABAMA. LOCALLY...MID TO UPPER LEVEL CLOUD COVER
CONTINUES TO INCREASE ACROSS THE REGION AS A CONSEQUENCE OF DEEP
MOISTURE ADVECTION ALOFT. HEIGHTS WILL CONTINUE FALL ACROSS
NORTHEAST GEORGIA AND THE CAROLINAS THROUGH THE NEXT 24 HOURS AS
REMNANTS OF UPPER LEVEL TROF MOVE THROUGH. LATEST MESOANALYSIS
INDICATES A MODERATELY UNSTABLE AIRMASS ACROSS THE REGION THIS
AFTERNOON. STILL EXPECTING THE MAJORITY OF CONVECTIVE ACTIVITY TO
BE IN THE HIGHER TERRAINS AS UPSLOPE FLOW WILL PROVIDE ENOUGH LIFT
TO OVERCOME ANY CAPPING...THEREFORE KEPT LIKELY POPS ACROSS NORTHERN
MOST PORTIONS OF THE NC MOUNTAINS AND HIGHER END CHANCE POPS
ELSEWHERE IN THE HIGH TERRAIN. POPS DECREASE TO THE SOUTHEAST AS
LOCATIONS NEAR AND ALONG THE I85 CORRIDOR WILL HAVE THE MOST
DIFFICULT TIME OVERCOMING ANY INVERSION. THUS...WENT WITH SLIGHT
CHANCE POPS ACROSS THIS REGION.
TONIGHT AND TOMORROW...MODEL GUIDANCE REMAINS IN GOOD AGREEMENT WITH
REGARDS TO DECREASE IN CONVECTIVE ACTIVITY DURING THE OVERNIGHT
HOURS AS DAYTIME HEATING DISSIPATES. HOWEVER...AFTER SUNRISE
TOMORROW THE ABOVE MENTIONED UPPER LEVEL WAVE WILL BE CENTERED OVER
THE SOUTHERN APPALACHIANS. PRECIPITATION CHANCES WILL INCREASE ONCE
AGAIN DURING THE LATE MORNING HOURS ACROSS THE ENTIRE REGION. SOME
SHOWER AND THUNDERSTORM ACTIVITY COULD BE STRONG TOMORROW AFTERNOON
AND EVENING AS THERMAL PROFILES INDICATE SLIGHTLY DEEPER INSTABILITY
THAN PREVIOUS DAYS. LIKEWISE...SOME OF THESE SHOWERS AND
THUNDERSTORMS COULD PRODUCE LOCALLY HEAVY RAINFALL AS PRECIPITABLE
WATER VALUES EXCEED 1.5 INCHES THROUGHOUT THE PROFILE.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
AT 200 PM FRIDAY...A WEAKNESS WILL PERSIST IN THE UPPER HEIGHT FIELD
OVER THE SOUTHEAST THROUGH MUCH OF THE PERIOD...ALTHOUGH IT WILL
CONTINUE TO GRADUALLY FILL. MOISTURE WILL REMAIN DEEP AND ABUNDANT
ACROSS THE REGION THROUGH THE PERIOD...AS PWATS WILL RUN IN THE
NEIGHBORHOOD OF 1.5 INCHES THROUGH AT LEAST SUNDAY NIGHT. THIS
SHOULD PROMOTE DEVELOPMENT OF NUMEROUS SHOWERS AND THUNDERSTORMS
ACROSS THE AREA DURING THE AFTERNOONS AND EVENINGS. LOW LEVEL FOCI
FOR INITIATION SHOULD GENERALLY BE LIMITED TO DIFFERENTIAL
HEATING/TERRAIN EFFECTS AS WELL AS OUTFLOW BOUNDARIES. HOWEVER...IT
APPEARS A WEAK/QUASI-CAD BOUNDARY WILL BE DRAPED ACROSS THE
CAROLINAS DURING THIS TIME AS WELL. WITH RELATIVELY WEAK DEEP LAYER
FLOW EXPECTED TO PREDOMINATE...SLOW MOVING...TRAINING AND/OR
ANCHORING CELLS PRODUCING LOCALLY EXCESSIVE RAINFALL WILL BE THE
PRIMARY THREATS. ISOLATED PULSE SEVERE STORMS OR SMALL CLUSTERS WILL
BE POSSIBLE... BUT THE SEVERE WEATHER THREAT WILL HINGE LARGELY UPON
THE DEGREE OF INSTABILITY AND THEREFORE THE MAGNITUDE OF HEATING WE
SEE...WHICH WILL PROBABLY NOT AMOUNT TO MUCH CONSIDERING THE MOIST
ADIABATIC LAPSE RATES/PROBABLE WIDESPREAD AND PERSISTENT CLOUD
COVER. MIN TEMPS WILL AVERAGE WELL ABOVE NORMAL AND MAXES SLIGHTLY
BELOW CLIMO OWING TO THE VERY MOIST AIR MASS.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
AT 225 PM FRIDAY...AN UPPER LEVEL RIDGE WILL DOMINATE THE EASTERN
U.S INTO THE MIDDLE PART OF NEXT WEEK. AT THE SURFACE...THE WESTERN
EXTENSION OF THE BERMUDA HIGH WILL BE OVER THE SE STATES.
THEREFORE...EXPECT TEMPERATURES TO BE ABOVE CLIMO TUE AND WED.
DIURNALLY DRIVEN SCATTERED CONVECTION WILL OCCUR TUE AND WED WITH THE
GREATEST COVERAGE OVER THE MOUNTAINS. AN UPPER TROUGH WILL APPROACH
THE AREA FROM THE WEST LATE IN THE WEEK WITH THE ASSOCIATED COLD
FRONT MOVING THROUGH THE AREA LATE THU INTO FRI. THEREFORE...PRECIP
CHANCES WILL BE ON THE INCREASE THU...AND THEN DIMINISH ON FRI AS
THE FRONT MOVES TO THE EAST. TEMPERATURES WILL LOWER BACK TO
SEASONAL VALUES BY FRIDAY. STAYED CLOSE TO WPC GUIDANCE TEMPS/POPS.
&&
.AVIATION /21Z FRIDAY THROUGH WEDNESDAY/...
AT KCLT...VFR CONDITIONS WILL PREVAIL THROUGH THE FIRST HALF OF THE
TAF PERIOD. SOME AFTERNOON CONVECTION IS EXPECTED OVER THE NC
MOUNTAINS...HOWEVER THIS ACTIVITY SHOULD STAY TO THE WEST OF KCLT.
WINDS FOR THE REMAINDER OF THE DAY WILL STAY LIGHT AND SOUTHERLY.
OTHERWISE...EXPECTING CLOUD COVER TO INCREASE THIS EVENING AS
EASTWARD MOVING UPPER TROUGH CONTINUE TO APPROACH. THUS...CARRIED
LOW END VFR CIGS THROUGH THE MORNING...THEN LOWERED TO MVFR BY 13Z
AS SHOWER AND THUNDERSTORM ACTIVITY WILL BEING TO INCREASE ACROSS
THE REGION.
ELSEWHERE...EXPECTING CONDITIONS TO STAY AT VFR LEVELS THROUGH THE
EVENING WITH THE ONLY EXCEPTION BEING AT KHKY AS CIGS LOOK TO DROP
JUST AT OR BELOW 3K FEET. BY DAYBREAK SATURDAY...EXPECTING FLIGHT
CONDITIONS TO LOWER FURTHER AT THE REMAINING SITES TO MVFR LEVELS AS
OVERALL COVERAGE OF SHOWERS AND OR THUNDERSTORMS INCREASES.
OUTLOOK...SHOWER AND THUNDERSTORM COVERAGE...AND ASSOCIATED
RESTRICTIONS...WILL GRADUALLY INCREASE SATURDAY THROUGH MONDAY. FAIR
WEATHER MAY RETURN BY TUESDAY.
CONFIDENCE TABLE...
21-03Z 03-09Z 09-15Z 15-21Z
KCLT HIGH 100% HIGH 100% MED 63% HIGH 81%
KGSP HIGH 85% HIGH 100% HIGH 82% HIGH 85%
KAVL LOW 57% LOW 56% MED 63% MED 63%
KHKY HIGH 100% HIGH 100% MED 77% MED 72%
KGMU HIGH 92% HIGH 100% MED 78% MED 77%
KAND HIGH 100% HIGH 100% MED 78% MED 72%
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...LEV
NEAR TERM...CDG/MCAVOY
SHORT TERM...JDL
LONG TERM...LG
AVIATION...CDG
000
FXUS62 KGSP 171842
AFDGSP
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
242 PM EDT FRI MAY 17 2013
.SYNOPSIS...
A MID LEVEL DISTURBANCE WILL DRIFT ACROSS THE REGION THIS
WEEKEND... TRIGGERING SHOWERS AND THUNDERSTORMS THROUGH THE
BEGINNING OF NEXT WEEK. SOUTHERLY FLOW WILL KEEP THE AIRMASS WARM
AND MOIST... AND THE PATTERN WILL REMAIN UNSETTLED UNTIL A FRONTAL
SYSTEM APPROACHES THE WESTERN CAROLINAS LATE NEXT WEEK.
&&
.NEAR TERM /THROUGH SATURDAY/...
AS OF 230 PM...LOOKING AT LATEST WV IMAGERY...WEAKENING UPPER
LEVEL TROF CONTINUES TO MOVE EASTWARD ACROSS THE TENNESSEE
VALLEY...THUS SPREADING MOISTURE THRU THE SOUTHEASTERN UNITED
STATES. WITH THIS...SOME SHOWER AND THUNDERSTORMS ACTIVITY IS
PRESENT ON RADAR ACROSS PORTIONS OF NORTHEAST MISSISSIPPI AND
NORTHWEST ALABAMA. LOCALLY...MID TO UPPER LEVEL CLOUD COVER
CONTINUES TO INCREASE ACROSS THE REGION AS A CONSEQUENCE OF DEEP
MOISTURE ADVECTION ALOFT. HEIGHTS WILL CONTINUE FALL ACROSS
NORTHEAST GEORGIA AND THE CAROLINAS THROUGH THE NEXT 24 HOURS AS
REMNANTS OF UPPER LEVEL TROF MOVE THROUGH. LATEST MESOANALYSIS
INDICATES A MODERATELY UNSTABLE AIRMASS ACROSS THE REGION THIS
AFTERNOON. STILL EXPECTING THE MAJORITY OF CONVECTIVE ACTIVITY TO
BE IN THE HIGHER TERRAINS AS UPSLOPE FLOW WILL PROVIDE ENOUGH LIFT
TO OVERCOME ANY CAPPING...THEREFORE KEPT LIKELY POPS ACROSS NORTHERN
MOST PORTIONS OF THE NC MOUNTAINS AND HIGHER END CHANCE POPS
ELSEWHERE IN THE HIGH TERRAIN. POPS DECREASE TO THE SOUTHEAST AS
LOCATIONS NEAR AND ALONG THE I85 CORRIDOR WILL HAVE THE MOST
DIFFICULT TIME OVERCOMING ANY INVERSION. THUS...WENT WITH SLIGHT
CHANCE POPS ACROSS THIS REGION.
TONIGHT AND TOMORROW...MODEL GUIDANCE REMAINS IN GOOD AGREEMENT WITH
REGARDS TO DECREASE IN CONVECTIVE ACTIVITY DURING THE OVERNIGHT
HOURS AS DAYTIME HEATING DISSIPATES. HOWEVER...AFTER SUNRISE
TOMORROW THE ABOVE MENTIONED UPPER LEVEL WAVE WILL BE CENTERED OVER
THE SOUTHERN APPALACHIANS. PRECIPITATION CHANCES WILL INCREASE ONCE
AGAIN DURING THE LATE MORNING HOURS ACROSS THE ENTIRE REGION. SOME
SHOWER AND THUNDERSTORM ACTIVITY COULD BE STRONG TOMORROW AFTERNOON
AND EVENING AS THERMAL PROFILES INDICATE SLIGHTLY DEEPER INSTABILITY
THAN PREVIOUS DAYS. LIKEWISE...SOME OF THESE SHOWERS AND
THUNDERSTORMS COULD PRODUCE LOCALLY HEAVY RAINFALL AS PRECIPITABLE
WATER VALUES EXCEED 1.5 INCHES THROUGHOUT THE PROFILE.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
AT 200 PM FRIDAY...A WEAKNESS WILL PERSIST IN THE UPPER HEIGHT FIELD
OVER THE SOUTHEAST THROUGH MUCH OF THE PERIOD...ALTHOUGH IT WILL
CONTINUE TO GRADUALLY FILL. MOISTURE WILL REMAIN DEEP AND ABUNDANT
ACROSS THE REGION THROUGH THE PERIOD...AS PWATS WILL RUN IN THE
NEIGHBORHOOD OF 1.5 INCHES THROUGH AT LEAST SUNDAY NIGHT. THIS
SHOULD PROMOTE DEVELOPMENT OF NUMEROUS SHOWERS AND THUNDERSTORMS
ACROSS THE AREA DURING THE AFTERNOONS AND EVENINGS. LOW LEVEL FOCI
FOR INITIATION SHOULD GENERALLY BE LIMITED TO DIFFERENTIAL
HEATING/TERRAIN EFFECTS AS WELL AS OUTFLOW BOUNDARIES. HOWEVER...IT
APPEARS A WEAK/QUASI-CAD BOUNDARY WILL BE DRAPED ACROSS THE
CAROLINAS DURING THIS TIME AS WELL. WITH RELATIVELY WEAK DEEP LAYER
FLOW EXPECTED TO PREDOMINATE...SLOW MOVING...TRAINING AND/OR
ANCHORING CELLS PRODUCING LOCALLY EXCESSIVE RAINFALL WILL BE THE
PRIMARY THREATS. ISOLATED PULSE SEVERE STORMS OR SMALL CLUSTERS WILL
BE POSSIBLE... BUT THE SEVERE WEATHER THREAT WILL HINGE LARGELY UPON
THE DEGREE OF INSTABILITY AND THEREFORE THE MAGNITUDE OF HEATING WE
SEE...WHICH WILL PROBABLY NOT AMOUNT TO MUCH CONSIDERING THE MOIST
ADIABATIC LAPSE RATES/PROBABLE WIDESPREAD AND PERSISTENT CLOUD
COVER. MIN TEMPS WILL AVERAGE WELL ABOVE NORMAL AND MAXES SLIGHTLY
BELOW CLIMO OWING TO THE VERY MOIST AIR MASS.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
AT 225 PM FRIDAY...AN UPPER LEVEL RIDGE WILL DOMINATE THE EASTERN
U.S INTO THE MIDDLE PART OF NEXT WEEK. AT THE SURFACE...THE WESTERN
EXTENSION OF THE BERMUDA HIGH WILL BE OVER THE SE STATES.
THEREFORE...EXPECT TEMPERATURES TO BE ABOVE CLIMO TUE AND WED.
DIURNALLY DRIVEN SCATTERED CONVECTION WILL OCCUR TUE AND WED WITH THE
GREATEST COVERAGE OVER THE MOUNTAINS. AN UPPER TROUGH WILL APPROACH
THE AREA FROM THE WEST LATE IN THE WEEK WITH THE ASSOCIATED COLD
FRONT MOVING THROUGH THE AREA LATE THU INTO FRI. THEREFORE...PRECIP
CHANCES WILL BE ON THE INCREASE THU...AND THEN DIMINISH ON FRI AS
THE FRONT MOVES TO THE EAST. TEMPERATURES WILL LOWER BACK TO
SEASONAL VALUES BY FRIDAY. STAYED CLOSE TO WPC GUIDANCE TEMPS/POPS.
&&
.AVIATION /19Z FRIDAY THROUGH WEDNESDAY/...
AT KCLT...VFR CONDITIONS WILL PREVAIL THROUGH THE FIRST HALF OF THE
TAF PERIOD. SOME AFTERNOON CONVECTION IS EXPECTED OVER THE NC
MOUNTAINS...HOWEVER THIS ACTIVITY SHOULD STAY TO THE WEST OF KCLT.
WINDS FOR THE REMAINDER OF THE DAY WILL STAY LIGHT AND SOUTHERLY.
OTHERWISE...EXPECTING CLOUD COVER TO INCREASE THIS EVENING AS
EASTWARD MOVING UPPER TROUGH CONTINUE TO APPROACH. THUS...CARRIED
LOW END VFR CIGS THROUGH THE MORNING...THEN LOWERED TO MVFR BY 13Z
AS SHOWER AND THUNDERSTORM ACTIVITY WILL BEING TO INCREASE ACROSS
THE REGION.
ELSEWHERE...EXPECTING CONDITIONS TO STAY AT VFR LEVELS THROUGH THE
EVENING WITH THE ONLY EXCEPTION BEING AT KHKY AS CIGS LOOK TO DROP
JUST AT OR BELOW 3K FEET. BY DAYBREAK SATURDAY...EXPECTING FLIGHT
CONDITIONS TO LOWER FURTHER AT THE REMAINING SITES TO MVFR LEVELS AS
OVERALL COVERAGE OF SHOWERS AND OR THUNDERSTORMS INCREASES.
OUTLOOK...SHOWER AND THUNDERSTORM COVERAGE...AND ASSOCIATED
RESTRICTIONS...WILL GRADUALLY INCREASE SATURDAY THROUGH MONDAY. FAIR
WEATHER MAY RETURN BY TUESDAY.
CONFIDENCE TABLE...
18-24Z 00-06Z 06-12Z 12-18Z
KCLT HIGH 100% HIGH 100% HIGH 85% MED 66%
KGSP MED 63% HIGH 100% HIGH 94% MED 78%
KAVL LOW 56% LOW 57% LOW 55% MED 65%
KHKY HIGH 100% HIGH 100% HIGH 96% LOW 46%
KGMU MED 71% HIGH 100% HIGH 94% MED 65%
KAND HIGH 85% HIGH 100% HIGH 93% LOW 46%
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...LEV
NEAR TERM...CDG
SHORT TERM...JDL
LONG TERM...LG
AVIATION...CDG
000
FXUS62 KGSP 171804
AFDGSP
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
204 PM EDT FRI MAY 17 2013
.SYNOPSIS...
A MID LEVEL DISTURBANCE WILL DRIFT ACROSS THE REGION THIS
WEEKEND... TRIGGEREING SHOWERS AND THUNDERSTORMS THROUGH THE
BEGINNING OF NEXT WEEK. SOUTHERLY FLOW WILL KEEP THE AIRMASS WARM
AND MOIST... AND THE PATTERN WILL REMAIN UNSETTLED UNTIL A FRONTAL
SYSTEM APPROACHES THE WESTERN CAROLINAS LATE NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1005 AM...TEMPERATURES ACROSS THE REGION CONTINUE TO RISE AS A
THIN LAYER OF MID LEVEL CLOUDS ALLOWS FOR MODERATE RADIATIVE
HEATING. MOST SITES WERE REPORTING TEMPS IN THE UPPER 60S WITH A
FEW SITES BEING SLIGHTLY WARMER IN THE LOWER 70S. AFTER LOOKING AT
LATEST NEAR TERM MODEL GUIDANCE...LOOKS AS IF GREATEST THREAT FOR
ANY CONVECTIVE ACTIVITY TODAY CONTINUES TO BE ACROSS THE HIGH
TERRAIN OF THE CAROLINAS WERE UPSLOPE FLOW WILL PROVIDE ENOUGH LOW
LEVEL FORCING TO OVERCOME ANY CAPPING INVERSIONS. FURTHER SOUTH
ACROSS THE PIEDMONT OF SOUTH CAROLINA...FORECAST SOUNDINGS AND HIGH
RES MODEL GUIDANCE TEND TO KEEP CAP INTACT. THUS...DECIDED TO LOWER
TO SLIGHT CHANCE POPS NEAR AND ALONG THE I85 CORRIDOR. OTHERWISE...
FORECAST LOOKS TO BE ON TRACK AND NO OTHER CHANGES WERE MADE.
REMAINDER OF PREVIOUS DISCUSSION...
PREVIOUS DISCUSSION...A CLOSED LOW OVER THE MID-SOUTH OPENS UP AND
MOVES ALONG THE LOWER OH VALLEY TODAY. LOW LEVEL MOISTURE WILL BE ON
THE INCREASE ACROSS NC THRU THE DAY. THIS LEADS TO MODERATE
INSTABILITY ACROSS THE AREA BY AFTERNOON. HOWEVER...OVER NE GA AND
THE UPSTATE SOUTH OF I-85 A SIGNIFICANT AMOUNT OF CIN REMAINS IN
PLACE. THEREFORE...HAVE BEST PRECIP CHC OVER THE NC MTNS THEN
DECREASES SOUTH AND EAST. HIGHS SHUD BE 5 TO 10 DEGREES ABOVE
NORMAL.
THE NAM CONTINUES TO BE FARTHER SOUTH WITH THE UPPER LOW TONIGHT AS
IT MOVES SLOWLY EASTWARD. THE OTHER GUIDANCE KEEPS THE LOW CLOSER TO
THE OH VALLEY. EVEN WITH THE LOW POSITION...LOW LEVEL SLY FLOW
INCREASES AGAIN OVERNIGHT BRINGING AN INCREASE IN LOW LEVEL MOISTURE
AFTER MIDNIGHT. EXPECT CONVECTION TO EXHIBIT A SOMEWHAT NORMAL
DIURNAL TREND DURING THE EVENING. HOWEVER...PRECIP CHC INCREASES
FROM WEST TO EAST AFTER MIDNIGHT AS THE LOW LEVEL MOISTURE AND
FORCING INCREASE. TSRA WILL BE POSSIBLE AS WELL WITH THE FORCING AND
CONTINUED ELEVATED INSTABILITY. LOWS WILL BE AROUND 5 DEGREES ABOVE
NORMAL.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AT 300 AM EST FRIDAY...ON SATURDAY THE REMAINS OF AN UPPER LOW
TRACKS EAST OVER THE OH RIVER VALLEY IN THE GFS...AND OVER THE TN
RIVER VALLEY IN THE NAM. BOTH MODELS THEN MOVE THE SYSTEM SOUTHEAST
SATURDAY NIGHT...WITH THE GFS DISTURBANCE CROSSING THE CENTRAL
APPALACHIANS...AND THE NAM DISTURBANCE CROSSING NORTH GA. ON SUNDAY
THE GFS SYSTEM MOVES SLOWLY ACROSS THE CAROLINAS...WHILE THE NAM
SYSTEM MOVES EVEN SLOWER INTO THE UPPER SAVANNAH RIVER VALLEY. THE
GFS SYSTEM REACHES THE COAST ON SUNDAY NIGHT.
DEEP MOISTURE AND INSTABILITY WILL INCREASE AS THE REMAINS OF THE
UPPER LOW APPROACH...SUPPORTING INCREASING POPS...GENERALLY GREATER
DURING THE DAYTIME HOURS...BUT WITH OVERNIGHT ACTIVITY AS WELL.
CONVECTION WOULD APPEAR TO FINALLY WANE FROM THE WEST ON SUNDAY
NIGHT... ASSUMING THE GFS TIMING IS CORRECT. WITH A DEEP MOIST
LAYER...DRY AIR WILL NOT BE AVAILABLE FOR EVAPORATIVE COOLING...
LIMITING DOWNDRAFT PATERNAL. CONVECTIVE CELLS COULD PRODUCE HEAVY
RAINFALL...BUT WIND PROFILES SUGGEST CELLS WILL MOVE OFF TO THE
NORTHEAST ON MONDAY...AND MORE SLOWLY TO THE EAST ON SUNDAY...WITH A
WEAK SOUTHERLY UPSLOPE FLOW IN HTE LOWEST LEVELS. HIGH TEMPERATURES
WILL BE NEAR NORMAL...AND LOW TEMPERATURES A COUPLE OF CATEGORIES
ABOVE NORMAL.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
AT 300 AM EST FRIDAY...THE ECMWF AND GFS MOVE AN UPPER RIDGE SLOWLY
ACROSS THE SOUTHERN APPALACHIANS FROM MONDAY THROUGH WEDNESDAY...
ALTHOUGH THE GFS SHOWS A WEAKNESS IN THE RIDGE OVER THE CAROLINAS
THAT LINGERS INTO THURSDAY. AN UPPER TROUGH WILL MOVE FROM THE MS
RIVER VALLEY ON WEDNESDAY TO THE OH AND TN VALLEYS BY THURSDAY.
THE SOUTHEAST WILL REMAIN IN A WARM AND MOIST AIR MASS FROM MONDAY
THROUGH THURSDAY...WITH WEAK GULF INFLOW MAINLY TO THE WEST OF THE
APPALACHIANS. DIURNALLY MODULATED POPS WILL BE CARRIED...FAVORING
THE MOUNTAINS FOR THE HIGHEST POPS WITH OROGRAPHIC EFFECTS. MAXIMUM
TEMPERATURES WILL RUN NEAR NORMAL...WITH MINIMUMS A COUPLE OF
CATEGORIES ABOVE NORMAL.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
AT KCLT...VFR CONDITIONS WILL PREVAIL THROUGH THE FIRST HALF OF THE
TAF PERIOD. SOME AFTERNOON CONVECTION IS EXPECTED OVER THE NC
MOUNTAINS...HOWEVER THIS ACTIVITY SHOULD STAY TO THE WEST OF KCLT.
WINDS FOR THE REMAINDER OF THE DAY WILL STAY LIGHT AND SOUTHERLY.
OTHERWISE...EXPECTING CLOUD COVER TO INCREASE THIS EVENING AS
EASTWARD MOVING UPPER TROUGH CONTINUE TO APPROACH. THUS...CARRIED
LOW END VFR CIGS THROUGH THE MORNING...THEN LOWERED TO MVFR BY 13Z
AS SHOWER AND THUNDERSTORM ACTIVITY WILL BEING TO INCREASE ACROSS
THE REGION.
ELSEWHERE...EXPECTING CONDITIONS TO STAY AT VFR LEVELS THROUGH THE
EVENING WITH THE ONLY EXCEPTION BEING AT KHKY AS CIGS LOOK TO DROP
JUST AT OR BELOW 3K FEET. BY DAYBREAK SATURDAY...EXPECTING FLIGHT
CONDITIONS TO LOWER FURTHER AT THE REMAINING SITES TO MVFR LEVELS AS
OVERALL COVERAGE OF SHOWERS AND OR THUNDERSTORMS INCREASES.
OUTLOOK...SHOWER AND THUNDERSTORM COVERAGE...AND ASSOCIATED
RESTRICTIONS...WILL GRADUALLY INCREASE SATURDAY THROUGH MONDAY. FAIR
WEATHER MAY RETURN BY TUESDAY.
CONFIDENCE TABLE...
18-24Z 00-06Z 06-12Z 12-18Z
KCLT HIGH 100% HIGH 100% HIGH 85% MED 66%
KGSP MED 63% HIGH 100% HIGH 94% MED 78%
KAVL LOW 56% LOW 57% LOW 55% MED 65%
KHKY HIGH 100% HIGH 100% HIGH 96% LOW 46%
KGMU MED 71% HIGH 100% HIGH 94% MED 65%
KAND HIGH 85% HIGH 100% HIGH 93% LOW 46%
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...LEV
NEAR TERM...CDG/RWH
SHORT TERM...JAT
LONG TERM...JAT
AVIATION...CDG
000
FXUS62 KGSP 171409
AFDGSP
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
1009 AM EDT FRI MAY 17 2013
.SYNOPSIS...
A WARM AND INCREASINGLY MOIST AIR MASS WILL REMAIN OVER THE REGION
THROUGH THE REST OF THIS WEEK. A MID LEVEL DISTURBANCE WILL MOVE
ACROSS THE CAROLINAS THIS WEEKEND. WARM MOIST AIR WILL REMAIN OVER
THE AREA NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1005 AM...TEMPERATURES ACROSS THE REGION CONTINUE TO RISE AS A
THIN LAYER OF MID LEVEL CLOUDS ALLOWS FOR MODERATE RADIATIVE
HEATING. MOST SITES WERE REPORTING TEMPS IN THE UPPER 60S WITH A
FEW SITES BEING SLIGHTLY WARMER IN THE LOWER 70S. AFTER LOOKING AT
LATEST NEAR TERM MODEL GUIDANCE...LOOKS AS IF GREATEST THREAT FOR
ANY CONVECTIVE ACTIVITY TODAY CONTINUES TO BE ACROSS THE HIGH
TERRAIN OF THE CAROLINAS WERE UPSLOPE FLOW WILL PROVIDE ENOUGH LOW
LEVEL FORCING TO OVERCOME ANY CAPPING INVERSIONS. FURTHER SOUTH
ACROSS THE PIEDMONT OF SOUTH CAROLINA...FORECAST SOUNDINGS AND HIGH
RES MODEL GUIDANCE TEND TO KEEP CAP INTACT. THUS...DECIDED TO
LOWER TO SLIGHT CHANCE POPS NEAR AND ALONG THE I85 CORRIDOR.
OTHERWISE... FORECAST LOOKS TO BE ON TRACK AND NO OTHER CHANGES
WERE MADE.
REMAINDER OF PREVIOUS DISCUSSION...
PREVIOUS DISCUSSION...A CLOSED LOW OVER THE MID-SOUTH OPENS UP AND
MOVES ALONG THE LOWER OH VALLEY TODAY. LOW LEVEL MOISTURE WILL BE ON
THE INCREASE ACROSS NC THRU THE DAY. THIS LEADS TO MODERATE
INSTABILITY ACROSS THE AREA BY AFTERNOON. HOWEVER...OVER NE GA AND
THE UPSTATE SOUTH OF I-85 A SIGNIFICANT AMOUNT OF CIN REMAINS IN
PLACE. THEREFORE...HAVE BEST PRECIP CHC OVER THE NC MTNS THEN
DECREASES SOUTH AND EAST. HIGHS SHUD BE 5 TO 10 DEGREES ABOVE
NORMAL.
THE NAM CONTINUES TO BE FARTHER SOUTH WITH THE UPPER LOW TONIGHT AS
IT MOVES SLOWLY EASTWARD. THE OTHER GUIDANCE KEEPS THE LOW CLOSER TO
THE OH VALLEY. EVEN WITH THE LOW POSITION...LOW LEVEL SLY FLOW
INCREASES AGAIN OVERNIGHT BRINGING AN INCREASE IN LOW LEVEL MOISTURE
AFTER MIDNIGHT. EXPECT CONVECTION TO EXHIBIT A SOMEWHAT NORMAL
DIURNAL TREND DURING THE EVENING. HOWEVER...PRECIP CHC INCREASES
FROM WEST TO EAST AFTER MIDNIGHT AS THE LOW LEVEL MOISTURE AND
FORCING INCREASE. TSRA WILL BE POSSIBLE AS WELL WITH THE FORCING AND
CONTINUED ELEVATED INSTABILITY. LOWS WILL BE AROUND 5 DEGREES ABOVE
NORMAL.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AT 300 AM EST FRIDAY...ON SATURDAY THE REMAINS OF AN UPPER LOW
TRACKS EAST OVER THE OH RIVER VALLEY IN THE GFS...AND OVER THE TN
RIVER VALLEY IN THE NAM. BOTH MODELS THEN MOVE THE SYSTEM SOUTHEAST
SATURDAY NIGHT...WITH THE GFS DISTURBANCE CROSSING THE CENTRAL
APPALACHIANS...AND THE NAM DISTURBANCE CROSSING NORTH GA. ON SUNDAY
THE GFS SYSTEM MOVES SLOWLY ACROSS THE CAROLINAS...WHILE THE NAM
SYSTEM MOVES EVEN SLOWER INTO THE UPPER SAVANNAH RIVER VALLEY. THE
GFS SYSTEM REACHES THE COAST ON SUNDAY NIGHT.
DEEP MOISTURE AND INSTABILITY WILL INCREASE AS THE REMAINS OF THE
UPPER LOW APPROACH...SUPPORTING INCREASING POPS...GENERALLY GREATER
DURING THE DAYTIME HOURS...BUT WITH OVERNIGHT ACTIVITY AS WELL.
CONVECTION WOULD APPEAR TO FINALLY WANE FROM THE WEST ON SUNDAY
NIGHT... ASSUMING THE GFS TIMING IS CORRECT. WITH A DEEP MOIST
LAYER...DRY AIR WILL NOT BE AVAILABLE FOR EVAPORATIVE COOLING...
LIMITING DOWNDRAFT PATERNAL. CONVECTIVE CELLS COULD PRODUCE HEAVY
RAINFALL...BUT WIND PROFILES SUGGEST CELLS WILL MOVE OFF TO THE
NORTHEAST ON MONDAY...AND MORE SLOWLY TO THE EAST ON SUNDAY...WITH A
WEAK SOUTHERLY UPSLOPE FLOW IN HTE LOWEST LEVELS. HIGH TEMPERATURES
WILL BE NEAR NORMAL...AND LOW TEMPERATURES A COUPLE OF CATEGORIES
ABOVE NORMAL.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
AT 300 AM EST FRIDAY...THE ECMWF AND GFS MOVE AN UPPER RIDGE SLOWLY
ACROSS THE SOUTHERN APPALACHIANS FROM MONDAY THROUGH WEDNESDAY...
ALTHOUGH THE GFS SHOWS A WEAKNESS IN THE RIDGE OVER THE CAROLINAS
THAT LINGERS INTO THURSDAY. AN UPPER TROUGH WILL MOVE FROM THE MS
RIVER VALLEY ON WEDNESDAY TO THE OH AND TN VALLEYS BY THURSDAY.
THE SOUTHEAST WILL REMAIN IN A WARM AND MOIST AIR MASS FROM MONDAY
THROUGH THURSDAY...WITH WEAK GULF INFLOW MAINLY TO THE WEST OF THE
APPALACHIANS. DIURNALLY MODULATED POPS WILL BE CARRIED...FAVORING
THE MOUNTAINS FOR THE HIGHEST POPS WITH OROGRAPHIC EFFECTS. MAXIMUM
TEMPERATURES WILL RUN NEAR NORMAL...WITH MINIMUMS A COUPLE OF
CATEGORIES ABOVE NORMAL.
&&
.AVIATION /14Z FRIDAY THROUGH TUESDAY/...
AT KCLT AND ELSEWHERE...GENERALLY VFR CONDITIONS WILL CONTINUE
THROUGH THE TAF PERIOD. EXPECT INCREASING MID AND UPPER LEVEL CLOUDS
THRU THE MORNING. WITH SCT LOW VFR CLOUDS DEVELOPING BY NOON WITH
LOW VFR CIGS DEVELOPING DURING THE AFTERNOON. SHOULD SEE AN INCREASE
IN CONVECTIVE CHC TODAY...MAINLY ACROSS NC. THEREFORE...HAVE
INCLUDED PROB30 THERE BUT LEFT OUT OF SC WHERE INSTABILITY AND
MOISTURE ARE LOWER. SHUD SEE A DECREASE IN CONVECTION BY LATE
EVENING...BUT LOWER VFR CIGS CONTINUE. S TO SW WINDS INCREASE THRU
THE DAY THEN DIMINISH DURING THE EVENING. MVFR FOG MOST LIKELY BY
DAYBREAK SAT AT KAVL/KAND. COULD SEE FOG ELSEWHERE IF TSRA MOVE
OVER.
OUTLOOK...SHOWER AND THUNDERSTORM COVERAGE...AND ASSOCIATED
RESTRICTIONS...WILL GRADUALLY INCREASE SATURDAY THROUGH MONDAY. FAIR
WEATHER MAY RETURN BY TUESDAY.
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 98%
KAVL HIGH 100% HIGH 100% HIGH 100% HIGH 96%
KHKY HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGMU HIGH 100% HIGH 100% HIGH 100% HIGH 98%
KAND HIGH 100% HIGH 100% HIGH 100% HIGH 98%
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...JAT
NEAR TERM...CDG/RWH
SHORT TERM...JAT
LONG TERM...JAT
AVIATION...RWH
000
FXUS62 KGSP 171125
AFDGSP
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
725 AM EDT FRI MAY 17 2013
.SYNOPSIS...
A WARM AND INCREASINGLY MOIST AIR MASS WILL REMAIN OVER THE REGION
THROUGH THE REST OF THIS WEEK. A MID LEVEL DISTURBANCE WILL MOVE
ACROSS THE CAROLINAS THIS WEEKEND. WARM MOIST AIR WILL REMAIN OVER
THE AREA NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1045 AM...SKIES ONLY NOW BEGINNING TO BECOME BKN IN COVERAGE
OVER THE WRN CWFA...WITH OFF AND ON BKN CLOUDS ELSEWHERE. THIS HAS
ALLOWED TEMPS TO FALL A LITTLE BELOW EXPECTED VALUES. SHUD STILL SEE
A GOOD WARM UP WITH OFF AND ON SUNSHINE THRU MOST OF THE DAY AND
WARM SLY FLOW. STILL EXPECT BEST PRECIP CHC OVER THE MTNS AND NC
FOOTHILLS/PIEDMONT WITH ONLY ISOLATED CONVECTION S OF I-85. MAIN
CHANGES WERE FOR CURRENT CONDITIONS.
PREVIOUS DISCUSSION...A CLOSED LOW OVER THE MID-SOUTH OPENS UP AND
MOVES ALONG THE LOWER OH VALLEY TODAY. LOW LEVEL MOISTURE WILL BE ON
THE INCREASE ACROSS NC THRU THE DAY. THIS LEADS TO MODERATE
INSTABILITY ACROSS THE AREA BY AFTERNOON. HOWEVER...OVER NE GA AND
THE UPSTATE SOUTH OF I-85 A SIGNIFICANT AMOUNT OF CIN REMAINS IN
PLACE. THEREFORE...HAVE BEST PRECIP CHC OVER THE NC MTNS THEN
DECREASES SOUTH AND EAST TO SLIGHT CHC SOUTH OF I-85. HIGHS SHUD BE
5 TO 10 DEGREES ABOVE NORMAL.
THE NAM CONTINUES TO BE FARTHER SOUTH WITH THE UPPER LOW TONIGHT AS
IT MOVES SLOWLY EASTWARD. THE OTHER GUIDANCE KEEPS THE LOW CLOSER TO
THE OH VALLEY. EVEN WITH THE LOW POSITION...LOW LEVEL SLY FLOW
INCREASES AGAIN OVERNIGHT BRINGING AN INCREASE IN LOW LEVEL MOISTURE
AFTER MIDNIGHT. EXPECT CONVECTION TO EXHIBIT A SOMEWHAT NORMAL
DIURNAL TREND DURING THE EVENING. HOWEVER...PRECIP CHC INCREASES
FROM WEST TO EAST AFTER MIDNIGHT AS THE LOW LEVEL MOISTURE AND
FORCING INCREASE. TSRA WILL BE POSSIBLE AS WELL WITH THE FORCING AND
CONTINUED ELEVATED INSTABILITY. LOWS WILL BE AROUND 5 DEGREES ABOVE
NORMAL.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AT 300 AM EST FRIDAY...ON SATURDAY THE REMAINS OF AN UPPER LOW
TRACKS EAST OVER THE OH RIVER VALLEY IN THE GFS...AND OVER THE TN
RIVER VALLEY IN THE NAM. BOTH MODELS THEN MOVE THE SYSTEM SOUTHEAST
SATURDAY NIGHT...WITH THE GFS DISTURBANCE CROSSING THE CENTRAL
APPALACHIANS...AND THE NAM DISTURBANCE CROSSING NORTH GA. ON SUNDAY
THE GFS SYSTEM MOVES SLOWLY ACROSS THE CAROLINAS...WHILE THE NAM
SYSTEM MOVES EVEN SLOWER INTO THE UPPER SAVANNAH RIVER VALLEY. THE
GFS SYSTEM REACHES THE COAST ON SUNDAY NIGHT.
DEEP MOISTURE AND INSTABILITY WILL INCREASE AS THE REMAINS OF THE
UPPER LOW APPROACH...SUPPORTING INCREASING POPS...GENERALLY GREATER
DURING THE DAYTIME HOURS...BUT WITH OVERNIGHT ACTIVITY AS WELL.
CONVECTION WOULD APPEAR TO FINALLY WANE FROM THE WEST ON SUNDAY
NIGHT... ASSUMING THE GFS TIMING IS CORRECT. WITH A DEEP MOIST
LAYER...DRY AIR WILL NOT BE AVAILABLE FOR EVAPORATIVE COOLING...
LIMITING DOWNDRAFT PATERNAL. CONVECTIVE CELLS COULD PRODUCE HEAVY
RAINFALL...BUT WIND PROFILES SUGGEST CELLS WILL MOVE OFF TO THE
NORTHEAST ON MONDAY...AND MORE SLOWLY TO THE EAST ON SUNDAY...WITH A
WEAK SOUTHERLY UPSLOPE FLOW IN HTE LOWEST LEVELS. HIGH TEMPERATURES
WILL BE NEAR NORMAL...AND LOW TEMPERATURES A COUPLE OF CATEGORIES
ABOVE NORMAL.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
AT 300 AM EST FRIDAY...THE ECMWF AND GFS MOVE AN UPPER RIDGE SLOWLY
ACROSS THE SOUTHERN APPALACHIANS FROM MONDAY THROUGH WEDNESDAY...
ALTHOUGH THE GFS SHOWS A WEAKNESS IN THE RIDGE OVER THE CAROLINAS
THAT LINGERS INTO THURSDAY. AN UPPER TROUGH WILL MOVE FROM THE MS
RIVER VALLEY ON WEDNESDAY TO THE OH AND TN VALLEYS BY THURSDAY.
THE SOUTHEAST WILL REMAIN IN A WARM AND MOIST AIR MASS FROM MONDAY
THROUGH THURSDAY...WITH WEAK GULF INFLOW MAINLY TO THE WEST OF THE
APPALACHIANS. DIURNALLY MODULATED POPS WILL BE CARRIED...FAVORING
THE MOUNTAINS FOR THE HIGHEST POPS WITH OROGRAPHIC EFFECTS. MAXIMUM
TEMPERATURES WILL RUN NEAR NORMAL...WITH MINIMUMS A COUPLE OF
CATEGORIES ABOVE NORMAL.
&&
.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
AT KCLT AND ELSEWHERE...GENERALLY VFR CONDITIONS WILL CONTINUE
THROUGH THE TAF PERIOD. EXPECT INCREASING MID AND UPPER LEVEL CLOUDS
THRU THE MORNING. WITH SCT LOW VFR CLOUDS DEVELOPING BY NOON WITH
LOW VFR CIGS DEVELOPING DURING THE AFTERNOON. SHOULD SEE AN INCREASE
IN CONVECTIVE CHC TODAY...MAINLY ACROSS NC. THEREFORE...HAVE
INCLUDED PROB30 THERE BUT LEFT OUT OF SC WHERE INSTABILITY AND
MOISTURE ARE LOWER. SHUD SEE A DECREASE IN CONVECTION BY LATE
EVENING...BUT LOWER VFR CIGS CONTINUE. S TO SW WINDS INCREASE THRU
THE DAY THEN DIMINISH DURING THE EVENING. MVFR FOG MOST LIKELY BY
DAYBREAK SAT AT KAVL/KAND. COULD SEE FOG ELSEWHERE IF TSRA MOVE
OVER.
OUTLOOK...SHOWER AND THUNDERSTORM COVERAGE...AND ASSOCIATED
RESTRICTIONS...WILL GRADUALLY INCREASE SATURDAY THROUGH MONDAY. FAIR
WEATHER MAY RETURN BY TUESDAY.
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...JAT
NEAR TERM...RWH
SHORT TERM...JAT
LONG TERM...JAT
AVIATION...RWH
000
FXUS62 KGSP 170718
AFDGSP
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
318 AM EDT FRI MAY 17 2013
.SYNOPSIS...
A WARM AND INCREASINGLY MOIST AIR MASS WILL REMAIN OVER THE REGION
THROUGH THE REST OF THIS WEEK. A MID LEVEL DISTURBANCE WILL MOVE
ACROSS THE CAROLINAS THIS WEEKEND. WARM MOIST AIR WILL REMAIN OVER
THE AREA NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
A CLOSED LOW OVER THE MID-SOUTH OPENS UP AND MOVES ALONG THE LOWER
OH VALLEY TODAY. LOW LEVEL MOISTURE WILL BE ON THE INCREASE ACROSS
NC THRU THE DAY. THIS LEADS TO MODERATE INSTABILITY ACROSS THE AREA
BY AFTERNOON. HOWEVER...OVER NE GA AND THE UPSTATE SOUTH OF I-85 A
SIGNIFICANT AMOUNT OF CIN REMAINS IN PLACE. THEREFORE...HAVE BEST
PRECIP CHC OVER THE NC MTNS THEN DECREASES SOUTH AND EAST TO SLIGHT
CHC SOUTH OF I-85. HIGHS SHUD BE 5 TO 10 DEGREES ABOVE NORMAL.
THE NAM CONTINUES TO BE FARTHER SOUTH WITH THE UPPER LOW TONIGHT AS
IT MOVES SLOWLY EASTWARD. THE OTHER GUIDANCE KEEPS THE LOW CLOSER TO
THE OH VALLEY. EVEN WITH THE LOW POSITION...LOW LEVEL SLY FLOW
INCREASES AGAIN OVERNIGHT BRINGING AN INCREASE IN LOW LEVEL MOISTURE
AFTER MIDNIGHT. EXPECT CONVECTION TO EXHIBIT A SOMEWHAT NORMAL
DIURNAL TREND DURING THE EVENING. HOWEVER...PRECIP CHC INCREASES
FROM WEST TO EAST AFTER MIDNIGHT AS THE LOW LEVEL MOISTURE AND
FORCING INCREASE. TSRA WILL BE POSSIBLE AS WELL WITH THE FORCING AND
CONTINUED ELEVATED INSTABILITY. LOWS WILL BE AROUND 5 DEGREES ABOVE
NORMAL.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AT 300 AM EST FRIDAY...ON SATURDAY THE REMAINS OF AN UPPER LOW
TRACKS EAST OVER THE OH RIVER VALLEY IN THE GFS...AND OVER THE TN
RIVER VALLEY IN THE NAM. BOTH MODELS THEN MOVE THE SYSTEM SOUTHEAST
SATURDAY NIGHT...WITH THE GFS DISTURBANCE CROSSING THE CENTRAL
APPALACHIANS...AND THE NAM DISTURBANCE CROSSING NORTH GA. ON SUNDAY
THE GFS SYSTEM MOVES SLOWLY ACROSS THE CAROLINAS...WHILE THE NAM
SYSTEM MOVES EVEN SLOWER INTO THE UPPER SAVANNAH RIVER VALLEY. THE
GFS SYSTEM REACHES THE COAST ON SUNDAY NIGHT.
DEEP MOISTURE AND INSTABILITY WILL INCREASE AS THE REMAINS OF THE
UPPER LOW APPROACH...SUPPORTING INCREASING POPS...GENERALLY GREATER
DURING THE DAYTIME HOURS...BUT WITH OVERNIGHT ACTIVITY AS WELL.
CONVECTION WOULD APPEAR TO FINALLY WANE FROM THE WEST ON SUNDAY
NIGHT... ASSUMING THE GFS TIMING IS CORRECT. WITH A DEEP MOIST
LAYER...DRY AIR WILL NOT BE AVAILABLE FOR EVAPORATIVE COOLING...
LIMITING DOWNDRAFT PATERNAL. CONVECTIVE CELLS COULD PRODUCE HEAVY
RAINFALL...BUT WIND PROFILES SUGGEST CELLS WILL MOVE OFF TO THE
NORTHEAST ON MONDAY...AND MORE SLOWLY TO THE EAST ON SUNDAY...WITH A
WEAK SOUTHERLY UPSLOPE FLOW IN HTE LOWEST LEVELS. HIGH TEMPERATURES
WILL BE NEAR NORMAL...AND LOW TEMPERATURES A COUPLE OF CATEGORIES
ABOVE NORMAL.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
AT 300 AM EST FRIDAY...THE ECMWF AND GFS MOVE AN UPPER RIDGE SLOWLY
ACROSS THE SOUTHERN APPALACHIANS FROM MONDAY THROUGH WEDNESDAY...
ALTHOUGH THE GFS SHOWS A WEAKNESS IN THE RIDGE OVER THE CAROLINAS
THAT LINGERS INTO THURSDAY. AN UPPER TROUGH WILL MOVE FROM THE MS
RIVER VALLEY ON WEDNESDAY TO THE OH AND TN VALLEYS BY THURSDAY.
THE SOUTHEAST WILL REMAIN IN A WARM AND MOIST AIR MASS FROM MONDAY
THROUGH THURSDAY...WITH WEAK GULF INFLOW MAINLY TO THE WEST OF THE
APPALACHIANS. DIURNALLY MODULATED POPS WILL BE CARRIED...FAVORING
THE MOUNTAINS FOR THE HIGHEST POPS WITH OROGRAPHIC EFFECTS. MAXIMUM
TEMPERATURES WILL RUN NEAR NORMAL...WITH MINIMUMS A COUPLE OF
CATEGORIES ABOVE NORMAL.
&&
.AVIATION /07Z FRIDAY THROUGH TUESDAY/...
AT KCLT AND ELSEWHERE...VFR CONDITIONS WILL CONTINUE THROUGH THE TAF
PERIOD. THAT SAID...KAVL COULD SEE MVFR FOG AROUND DAYBREAK. EXPECT
INCREASING MID AND UPPER LEVEL CLOUDS THRU DAYBREAK INTO THE
MORNING. SHOULD SEE AN INCREASE IN CONVECTIVE CHC TODAY...MAINLY
ACROSS NC. THEREFORE...HAVE INCLUDED PROB30 THERE BUT LEFT OUT OF SC
WHERE INSTABILITY AND MOISTURE ARE LOWER. SHUD SEE A DECREASE IN
CONVECTION BY LATE EVENING...BUT LOWER VFR CIGS CONTINUE. S TO SW
WINDS INCREASE THRU THE DAY THEN DIMINISH DURING THE EVENING.
OUTLOOK...SHOWER AND THUNDERSTORM COVERAGE...AND ASSOCIATED
RESTRICTIONS...WILL GRADUALLY INCREASE SATURDAY THROUGH MONDAY. FAIR
WEATHER MAY RETURN BY TUESDAY.
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 97% 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...JAT
NEAR TERM...RWH
SHORT TERM...JAT
LONG TERM...JAT
AVIATION...RWH
000
FXUS62 KGSP 170545
AFDGSP
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
145 AM EDT FRI MAY 17 2013
.SYNOPSIS...
A WARM AND INCREASINGLY MOIST AIR MASS WILL REMAIN OVER THE REGION
THROUGH THE REST OF THIS WEEK. A MID LEVEL DISTURBANCE WILL MOVE
ACROSS THE CAROLINAS THIS WEEKEND... TRIGGERING A MORE UNSETTLED
PATTERN WITH SHOWERS AND THUNDERSTORMS FOLLOWING A MAINLY DIURNAL
TREND THROUGH EARLY NEXT WEEK. A COLD FRONT WILL APPROACH THE
AREA DURING THE MIDDLE PART OF NEXT WEEK.
&&
.NEAR TERM /THROUGH TODAY/...
AS OF 145 AM...HAVE SEEN BREAK IN THE CLOUDS ACROSS THE AREA...BUT
MID AND HIGH CLOUDS SHUD RETURN BY DAYBREAK...AT LEAST ACROSS THE
WEST. THIS MAY LEAD TO A LITTLE BETTER COOLING EARLY...SO LOWS MAY
BE A DEGREE OR TWO BELOW PREV FCST.
AS OF 1030 PM EDT...ANY REMAINING POPS HAVE BEEN YANKED AS THE BNDRY
LAYER HAS CONTINUED TO COOL. I TRIMMED SKY COVER BACK A BIT. AS
CLOUDS ARE WARMING AND DISSIPATING UPSTREAM THAT WILL PROBABLY BE A
TREND THROUGH THE REST OF THE NIGHT.
AS OF 745 PM EDT...STILL NO SHOWERS OR THUNDERSTORMS OVER THE FA.
THE CONVECTION UPSTREAM OF THE REGION ISN/T ORGANIZED AND IS SHOWING
LITTLE EASTWARD MOVEMENT. WITH WEAK SHEAR AND LIMITED
INSTABILITY...POPS HAVE BEEN REMOVED FOR THE OVERNIGHT HOURS WITH
THE EXCEPTION OF A SLIGHT CHANCE RIGHT ALONG THE TN LINE.
AS OF 545 PM EDT...A SHORT WAVE IS MOVING ACROSS THE FOOTHILLS AT
THIS TIME. CONVECTION NEVER DID FIRE AHEAD OF THE WAVE...AND NVA
BEHIND IT SHOULD SUPPRESS CONVECTION FOR A FEW MORE HOURS. THEREFORE
I/VE REMOVED POPS FOR A WHILE...THOUGH I DO HAVE A PERIOD OF SLIGHT
CHANCE POPS LATER IN THE EVENING AS CONVECTION DEVELOPING OVER THE
CUMBERLAND PLATEAU MAY WORK INTO THE MTNS BY THAT TIME.
AS OF 230 PM EDT...BROAD UPPER LEVEL CLOSED LOW LOCATED OVER THE
OZARKS CONTINUES TO SLOWLY MOVE TO THE EAST...THUS SPREADING MID TO
UPPER LEVEL MOISTURE ACROSS THE SOUTHEASTERN UNITED STATES.
MEANWHILE ON A MORE LOCAL SCALE...LARGE CLOUD SHIELD CONTINUES TO
SPREAD ACROSS NORTHEAST GEORGIA AND THE CAROLINAS...THUS STUNTING
DAYTIME HEATING TRENDS SOMEWHAT. HOWEVER...MODEL GUIDANCE STILL
INDICATES SBCAPE VALUES HAVE TOPPED THE 1000J/KG MARK ACROSS
PORTIONS OF NORTHEAST GEORGIA...THE NORTHERN PIEDMONT OF SOUTH
CAROLINA...AND THE SOUTHERN MOUNTAIN REGIONS OF NORTH CAROLINA.
STILL EXPECTING SOME CONVECTIVE INITIATION ACROSS THE HIGH TERRAINS
LATER THIS AFTERNOON AS THE CAP WEAKENS...THEREFORE KEPT CHANCE POPS
FOR THIS REGION.
OTHERWISE...EXPECTING CONVECTIVE PROBABILITIES TO DROP DURING THE
OVERNIGHT HOURS DUE TO DIURNAL COOLING EFFECTS. LOW TEMPS OVERNIGHT
WILL BE SLIGHTLY WARMER THAN LAST NIGHT AS MID TO HIGH CLOUD DECK
WILL REMAIN OVER THE AREA. FOR FRIDAY...MODEL GUIDANCE INDICATES
THE ABOVE MENTIONED UPPER LOW WILL PASS BY TO THE NORTH THUS
PROVIDING AT LEAST SOME BROAD SCALE LIFTING ACROSS THE AREA. THIS
COMBINED WITH DIURNAL HEATING IN THE AFTERNOON PROMPTED INCREASES TO
LIKELY POPS ACROSS THE NORTH CAROLINA MOUNTAINS...AND CHANCE POPS
ELSEWHERE.
&&
.SHORT TERM /TONIGHT THROUGH SUNDAY/...
SHORT TERM PERIOD CHARACTERIZED BY STEADY AND SUMMER-LIKE SOUTHERLY
FLOW ON WESTERN PERIPHERY OF BERMUDA HIGH...WITH UPPER TROUGH RIDING
OVER SE CONUS RIDGE PROVIDING SOME WEAK FORCING FROM DPVA BUT
ENHANCING LLVL WINDS AND MIDLEVEL LAPSE RATES. FRI NIGHT THE COMBINED
LIFTING EFFECTS OF THE TROUGH AND SOUTHERLY FLOW ARE SUFFICIENT TO
THINK THAT SOME OF THE ELEVATED INSTABILITY SHOWN ON NAM FCST
SOUNDINGS COULD BE REALIZED...SO THOUGH POPS WILL DIMINISH AS
CONVECTION WANES FOLLOWING DIURNAL MAX FRI AFTN IT IS PRUDENT TO
MAINTAIN AT LEAST A SCHC MOST PLACES OVERNIGHT. THE INCREASING LLVL
WINDS FRI NIGHT MAY ENHANCE LLVL LIFT ESPECIALLY NEAR THE BLUE RIDGE
ESCARPMENT TOWARD SAT MORNING ALLOWING FOR INCREASING PRECIP CHANCES.
THE WINDS WILL ALSO MAINTAIN FAIRLY MIXED CONDITIONS JUST ABOVE THE
SFC SO ONCE DIURNAL HEATING BEGINS SATURDAY CONVECTION SHOULD EASILY
BEGIN TO FIRE BY LATE MORNING. CAPE VALUES OF AT LEAST SEVERAL
HUNDRED JOULES FCST BY GFS/NAM CONSENSUS...WITH HIGHEST VALUES OVER
THE PIEDMONT WHERE IT APPEARS SKIES WILL BE CLEARER DUE TO LATER
CONVECTIVE INITIATION ALLOWING FOR BETTER HEATING. SHEAR TOO WEAK TO
SUGGEST A THREAT OF ORGANIZED TSTMS AND DEEP MOISTURE SUFFICIENTLY
HIGH TO LIMIT DOWNBURST THREAT.
SIMILAR STORY FOR SATURDAY NIGHT INTO SUNDAY WITH SOME ELEVATED
CONVECTION POSSIBLY CONTINUING OVERNIGHT AND A FAIRLY EARLY DIURNAL
RISE IN ACTIVITY SUN MORNING UNDER LARGELY THE SAME SYNOPTIC SETUP.
ONE DIFFERENCE IS THAT THE UPPER TROUGH SHOULD BE OVERHEAD
SUNDAY...PERHAPS LIMITING CONVECTION SOMEWHAT DUE TO MORE HIGH
CLOUDINESS...THOUGH ALSO ENHANCING INSTABILITY THROUGH BETTER UPPER
LAPSE RATES. MOISTURE INCREASES THROUGH THE COLUMN BUT ESPECIALLY IN
THE LOW LEVELS WHERE CONDENSATION PRESSURE DEFICITS DECREASE AND MAKE
UP FOR THE CONVECTIVE LIMITATIONS POSED BY THE EXPECTED CLOUD COVER.
HAVE KEPT POPS IN HIGH CHANCE RANGE SUNDAY. THE INCREASED MOISTURE IS
ALSO REFLECTED IN HIGHER PWAT VALUES AT THIS TIME...THE HIGHEST OF
THE PERIOD...SUPPORTING HEFTIER QPF VALUES THOUGH STILL NOT OF GREAT
CONCERN.
LOW TEMPS WILL BE A BIT ABOVE NORMAL ON ACCOUNT OF CLOUD COVER. HIGH
TEMPS WILL BE HELD NEAR NORMAL VALUES WITH THE SOUTHERLY FLOW
OFFSETTING THE LIMITED HEATING BY CLOUD COVER DURING THE PERIOD.
FAVORED COOL SIDE OF GUIDANCE IN THE HIGHER TERRAIN WHERE CLOUD COVER
EXPECTED TO SEE DIURNAL INCREASES EARLIER IN THE DAY.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
AS OF 102 PM THURSDAY...FOR MONDAY AND TUESDAY...WE ARE STILL
EXPECTING TO BE TRANSITIONING TO S/WV RIDGING ALOFT...LEE TROUGHING
AND MEAN SOUTHERLY LLVL FLOW AROUND BERMUDA HIPRES. BASED ON THIS...
DAILY PCPN CHANCES WILL GRADUALLY LOWER TO JUST TOKEN CLIMO...MAINLY
DIURNAL POPS FOR DEEP CONVECTION BY TUESDAY. MAX TEMPERATURES EACH
DAY ARE SLATED TO BE A FEW DEG F ABOVE CLIMO. UPPER HEIGHTS ATOP THE
SE CONUS LOOK TO STEADILY LOWER THROUGH THE LATTER HALF OF THE
PERIOD WITH UPPER WAVE PROGGED TO DIG FROM THE MIDWEST TO THE OHIO
VALLEY. THE ATTENDANT FRONTAL ZONE MAY ALSO BE IMPINGING UPON OUR
AREA BY DAY 7. WITH THIS POTENTIAL INCREASE IN FORCING...MOISTURE AND
FLOW...DAILY THUNDERSTORM CHANCES...AND PERHAPS INTENSITY...WILL
INCREASE.
&&
.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
AT KCLT AND ELSEWHERE...VFR CONDITIONS WILL CONTINUE THROUGH THE TAF
PERIOD. THAT SAID...KAVL COULD SEE MVFR FOG AROUND DAYBREAK. EXPECT
INCREASING MID AND UPPER LEVEL CLOUDS THRU DAYBREAK INTO THE
MORNING. SHOULD SEE AN INCREASE IN CONVECTIVE CHC TODAY...MAINLY
ACROSS NC. THEREFORE...HAVE INCLUDED PROB30 THERE BUT LEFT OUT OF SC
WHERE INSTABILITY AND MOISTURE ARE LOWER. SHUD SEE A DECREASE IN
CONVECTION BY LATE EVENING...BUT LOWER VFR CIGS CONTINUE. S TO SW
WINDS INCREASE THRU THE DAY THEN DIMINISH DURING THE EVENING.
OUTLOOK...SHOWER AND THUNDERSTORM COVERAGE...AND ASSOCIATED
RESTRICTIONS...WILL GRADUALLY INCREASE SATURDAY THROUGH MONDAY. FAIR
WEATHER MAY RETURN BY TUESDAY.
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 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...LEV
NEAR TERM...MCAVOY/RWH
SHORT TERM...WIMBERLEY
LONG TERM...CSH
AVIATION...RWH
000
FXUS62 KGSP 170234
AFDGSP
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
1034 PM EDT THU MAY 16 2013
.SYNOPSIS...
A WARM AND INCREASINGLY MOIST AIR MASS WILL REMAIN OVER THE REGION
THROUGH THE REST OF THIS WEEK. A MID LEVEL DISTURBANCE WILL MOVE
ACROSS THE CAROLINAS THIS WEEKEND... TRIGGERING A MORE UNSETTLED
PATTERN WITH SHOWERS AND THUNDERSTORMS FOLLOWING A MAINLY DIURNAL
TREND THROUGH EARLY NEXT WEEK. A COLD FRONT WILL APPROACH THE
AREA DURING THE MIDDLE PART OF NEXT WEEK.
&&
.NEAR TERM /THROUGH FRIDAY/...
AS OF 1030 PM EDT...ANY REMAINING POPS HAVE BEEN YANKED AS THE BNDRY
LAYER HAS CONTINUED TO COOL. I TRIMMED SKY COVER BACK A BIT. AS
CLOUDS ARE WARMING AND DISSIPATING UPSTREAM THAT WILL PROBABLY BE A
TREND THROUGH THE REST OF THE NIGHT.
AS OF 745 PM EDT...STILL NO SHOWERS OR THUNDERSTORMS OVER THE FA.
THE CONVECTION UPSTREAM OF THE REGION ISN/T ORGANIZED AND IS SHOWING
LITTLE EASTWARD MOVEMENT. WITH WEAK SHEAR AND LIMITED
INSTABILITY...POPS HAVE BEEN REMOVED FOR THE OVERNIGHT HOURS WITH
THE EXCEPTION OF A SLIGHT CHANCE RIGHT ALONG THE TN LINE.
AS OF 545 PM EDT...A SHORT WAVE IS MOVING ACROSS THE FOOTHILLS AT
THIS TIME. CONVECTION NEVER DID FIRE AHEAD OF THE WAVE...AND NVA
BEHIND IT SHOULD SUPPRESS CONVECTION FOR A FEW MORE HOURS. THEREFORE
I/VE REMOVED POPS FOR A WHILE...THOUGH I DO HAVE A PERIOD OF SLIGHT
CHANCE POPS LATER IN THE EVENING AS CONVECTION DEVELOPING OVER THE
CUMBERLAND PLATEAU MAY WORK INTO THE MTNS BY THAT TIME.
AS OF 230 PM EDT...BROAD UPPER LEVEL CLOSED LOW LOCATED OVER THE
OZARKS CONTINUES TO SLOWLY MOVE TO THE EAST...THUS SPREADING MID TO
UPPER LEVEL MOISTURE ACROSS THE SOUTHEASTERN UNITED STATES.
MEANWHILE ON A MORE LOCAL SCALE...LARGE CLOUD SHIELD CONTINUES TO
SPREAD ACROSS NORTHEAST GEORGIA AND THE CAROLINAS...THUS STUNTING
DAYTIME HEATING TRENDS SOMEWHAT. HOWEVER...MODEL GUIDANCE STILL
INDICATES SBCAPE VALUES HAVE TOPPED THE 1000J/KG MARK ACROSS
PORTIONS OF NORTHEAST GEORGIA...THE NORTHERN PIEDMONT OF SOUTH
CAROLINA...AND THE SOUTHERN MOUNTAIN REGIONS OF NORTH CAROLINA.
STILL EXPECTING SOME CONVECTIVE INITIATION ACROSS THE HIGH TERRAINS
LATER THIS AFTERNOON AS THE CAP WEAKENS...THEREFORE KEPT CHANCE POPS
FOR THIS REGION.
OTHERWISE...EXPECTING CONVECTIVE PROBABILITIES TO DROP DURING THE
OVERNIGHT HOURS DUE TO DIURNAL COOLING EFFECTS. LOW TEMPS OVERNIGHT
WILL BE SLIGHTLY WARMER THAN LAST NIGHT AS MID TO HIGH CLOUD DECK
WILL REMAIN OVER THE AREA. FOR FRIDAY...MODEL GUIDANCE INDICATES
THE ABOVE MENTIONED UPPER LOW WILL PASS BY TO THE NORTH THUS
PROVIDING AT LEAST SOME BROAD SCALE LIFTING ACROSS THE AREA. THIS
COMBINED WITH DIURNAL HEATING IN THE AFTERNOON PROMPTED INCREASES TO
LIKELY POPS ACROSS THE NORTH CAROLINA MOUNTAINS...AND CHANCE POPS
ELSEWHERE.
&&
.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY/...
SHORT TERM PERIOD CHARACTERIZED BY STEADY AND SUMMER-LIKE SOUTHERLY
FLOW ON WESTERN PERIPHERY OF BERMUDA HIGH...WITH UPPER TROUGH RIDING
OVER SE CONUS RIDGE PROVIDING SOME WEAK FORCING FROM DPVA BUT
ENHANCING LLVL WINDS AND MIDLEVEL LAPSE RATES. FRI NIGHT THE COMBINED
LIFTING EFFECTS OF THE TROUGH AND SOUTHERLY FLOW ARE SUFFICIENT TO
THINK THAT SOME OF THE ELEVATED INSTABILITY SHOWN ON NAM FCST
SOUNDINGS COULD BE REALIZED...SO THOUGH POPS WILL DIMINISH AS
CONVECTION WANES FOLLOWING DIURNAL MAX FRI AFTN IT IS PRUDENT TO
MAINTAIN AT LEAST A SCHC MOST PLACES OVERNIGHT. THE INCREASING LLVL
WINDS FRI NIGHT MAY ENHANCE LLVL LIFT ESPECIALLY NEAR THE BLUE RIDGE
ESCARPMENT TOWARD SAT MORNING ALLOWING FOR INCREASING PRECIP CHANCES.
THE WINDS WILL ALSO MAINTAIN FAIRLY MIXED CONDITIONS JUST ABOVE THE
SFC SO ONCE DIURNAL HEATING BEGINS SATURDAY CONVECTION SHOULD EASILY
BEGIN TO FIRE BY LATE MORNING. CAPE VALUES OF AT LEAST SEVERAL
HUNDRED JOULES FCST BY GFS/NAM CONSENSUS...WITH HIGHEST VALUES OVER
THE PIEDMONT WHERE IT APPEARS SKIES WILL BE CLEARER DUE TO LATER
CONVECTIVE INITIATION ALLOWING FOR BETTER HEATING. SHEAR TOO WEAK TO
SUGGEST A THREAT OF ORGANIZED TSTMS AND DEEP MOISTURE SUFFICIENTLY
HIGH TO LIMIT DOWNBURST THREAT.
SIMILAR STORY FOR SATURDAY NIGHT INTO SUNDAY WITH SOME ELEVATED
CONVECTION POSSIBLY CONTINUING OVERNIGHT AND A FAIRLY EARLY DIURNAL
RISE IN ACTIVITY SUN MORNING UNDER LARGELY THE SAME SYNOPTIC SETUP.
ONE DIFFERENCE IS THAT THE UPPER TROUGH SHOULD BE OVERHEAD
SUNDAY...PERHAPS LIMITING CONVECTION SOMEWHAT DUE TO MORE HIGH
CLOUDINESS...THOUGH ALSO ENHANCING INSTABILITY THROUGH BETTER UPPER
LAPSE RATES. MOISTURE INCREASES THROUGH THE COLUMN BUT ESPECIALLY IN
THE LOW LEVELS WHERE CONDENSATION PRESSURE DEFICITS DECREASE AND MAKE
UP FOR THE CONVECTIVE LIMITATIONS POSED BY THE EXPECTED CLOUD COVER.
HAVE KEPT POPS IN HIGH CHANCE RANGE SUNDAY. THE INCREASED MOISTURE IS
ALSO REFLECTED IN HIGHER PWAT VALUES AT THIS TIME...THE HIGHEST OF
THE PERIOD...SUPPORTING HEFTIER QPF VALUES THOUGH STILL NOT OF GREAT
CONCERN.
LOW TEMPS WILL BE A BIT ABOVE NORMAL ON ACCOUNT OF CLOUD COVER. HIGH
TEMPS WILL BE HELD NEAR NORMAL VALUES WITH THE SOUTHERLY FLOW
OFFSETTING THE LIMITED HEATING BY CLOUD COVER DURING THE PERIOD.
FAVORED COOL SIDE OF GUIDANCE IN THE HIGHER TERRAIN WHERE CLOUD COVER
EXPECTED TO SEE DIURNAL INCREASES EARLIER IN THE DAY.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
AS OF 102 PM THURSDAY...FOR MONDAY AND TUESDAY...WE ARE STILL
EXPECTING TO BE TRANSITIONING TO S/WV RIDGING ALOFT...LEE TROUGHING
AND MEAN SOUTHERLY LLVL FLOW AROUND BERMUDA HIPRES. BASED ON THIS...
DAILY PCPN CHANCES WILL GRADUALLY LOWER TO JUST TOKEN CLIMO...MAINLY
DIURNAL POPS FOR DEEP CONVECTION BY TUESDAY. MAX TEMPERATURES EACH
DAY ARE SLATED TO BE A FEW DEG F ABOVE CLIMO. UPPER HEIGHTS ATOP THE
SE CONUS LOOK TO STEADILY LOWER THROUGH THE LATTER HALF OF THE
PERIOD WITH UPPER WAVE PROGGED TO DIG FROM THE MIDWEST TO THE OHIO
VALLEY. THE ATTENDANT FRONTAL ZONE MAY ALSO BE IMPINGING UPON OUR
AREA BY DAY 7. WITH THIS POTENTIAL INCREASE IN FORCING...MOISTURE AND
FLOW...DAILY THUNDERSTORM CHANCES...AND PERHAPS INTENSITY...WILL
INCREASE.
&&
.AVIATION /03Z FRIDAY THROUGH TUESDAY/...
AT KCLT AND ELSEWHERE...VFR CONDITIONS WILL CONTINUE THROUGH THE
ENTIRE TAF PERIOD. MID AND UPPER LEVEL CLOUDS CUT DOWN ON THE
INSTABILITY EARLIER IN THE DAY AND NO SHRA/TSTMS HAVE DEVELOPED OVER
THE REGION. AS WE ARE APPROACHING SUNSET...WE SHOULD BE SHOWER FREE
THE REST OF THE NIGHT. EXPECTING A LITTLE MORE SUN ON FRIDAY...WHICH
SHOULD YIELD ISOLATED TO SCT SHRA/TSTMS OVER THE WRN CAROLINAS.
ADDED PROB30 TO A FEW TAF SITES. THE BEST CHANCES LOOK TO BE OVER
THE MTNS AND FOOTHILLS...AND IN A WEAK CONVERGENCE AXIS OVER THE WRN
NC PIEDMONT...INCLUDING KCLT.
OUTLOOK...SHOWER AND THUNDERSTORM COVERAGE...AND ASSOCIATED
RESTRICTIONS...WILL GRADUALLY INCREASE FRIDAY THROUGH MONDAY. FAIR
WEATHER MAY RETURN BY TUESDAY.
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 89% 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...LEV
NEAR TERM...MCAVOY
SHORT TERM...WIMBERLEY
LONG TERM...CSH
AVIATION...MCAVOY
000
FXUS62 KGSP 162349
AFDGSP
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
749 PM EDT THU MAY 16 2013
.SYNOPSIS...
A WARM AND INCREASINGLY MOIST AIR MASS WILL REMAIN OVER THE REGION
THROUGH THE REST OF THIS WEEK. A MID LEVEL DISTURBANCE WILL MOVE
ACROSS THE CAROLINAS THIS WEEKEND... TRIGGERING A MORE UNSETTLED
PATTERN WITH SHOWERS AND THUNDERSTORMS FOLLOWING A MAINLY DIURNAL
TREND THROUGH EARLY NEXT WEEK. A COLD FRONT WILL APPROACH THE
AREA DURING THE MIDDLE PART OF NEXT WEEK.
&&
.NEAR TERM /THROUGH FRIDAY/...
AS OF 745 PM EDT...STILL NO SHOWERS OR THUNDERSTORMS OVER THE FA.
THE CONVECTION UPSTREAM OF THE REGION ISN/T ORGANIZED AND IS SHOWING
LITTLE EASTWARD MOVEMENT. WITH WEAK SHEAR AND LIMITED
INSTABILITY...POPS HAVE BEEN REMOVED FOR THE OVERNIGHT HOURS WITH
THE EXCEPTION OF A SLIGHT CHANCE RIGHT ALONG THE TN LINE.
AS OF 545 PM EDT...A SHORT WAVE IS MOVING ACROSS THE FOOTHILLS AT
THIS TIME. CONVECTION NEVER DID FIRE AHEAD OF THE WAVE...AND NVA
BEHIND IT SHOULD SUPPRESS CONVECTION FOR A FEW MORE HOURS. THEREFORE
I/VE REMOVED POPS FOR A WHILE...THOUGH I DO HAVE A PERIOD OF SLIGHT
CHANCE POPS LATER IN THE EVENING AS CONVECTION DEVELOPING OVER THE
CUMBERLAND PLATEAU MAY WORK INTO THE MTNS BY THAT TIME.
AS OF 230 PM EDT...BROAD UPPER LEVEL CLOSED LOW LOCATED OVER THE
OZARKS CONTINUES TO SLOWLY MOVE TO THE EAST...THUS SPREADING MID TO
UPPER LEVEL MOISTURE ACROSS THE SOUTHEASTERN UNITED STATES.
MEANWHILE ON A MORE LOCAL SCALE...LARGE CLOUD SHIELD CONTINUES TO
SPREAD ACROSS NORTHEAST GEORGIA AND THE CAROLINAS...THUS STUNTING
DAYTIME HEATING TRENDS SOMEWHAT. HOWEVER...MODEL GUIDANCE STILL
INDICATES SBCAPE VALUES HAVE TOPPED THE 1000J/KG MARK ACROSS
PORTIONS OF NORTHEAST GEORGIA...THE NORTHERN PIEDMONT OF SOUTH
CAROLINA...AND THE SOUTHERN MOUNTAIN REGIONS OF NORTH CAROLINA.
STILL EXPECTING SOME CONVECTIVE INITIATION ACROSS THE HIGH TERRAINS
LATER THIS AFTERNOON AS THE CAP WEAKENS...THEREFORE KEPT CHANCE POPS
FOR THIS REGION.
OTHERWISE...EXPECTING CONVECTIVE PROBABILITIES TO DROP DURING THE
OVERNIGHT HOURS DUE TO DIURNAL COOLING EFFECTS. LOW TEMPS OVERNIGHT
WILL BE SLIGHTLY WARMER THAN LAST NIGHT AS MID TO HIGH CLOUD DECK
WILL REMAIN OVER THE AREA. FOR FRIDAY...MODEL GUIDANCE INDICATES
THE ABOVE MENTIONED UPPER LOW WILL PASS BY TO THE NORTH THUS
PROVIDING AT LEAST SOME BROAD SCALE LIFTING ACROSS THE AREA. THIS
COMBINED WITH DIURNAL HEATING IN THE AFTERNOON PROMPTED INCREASES TO
LIKELY POPS ACROSS THE NORTH CAROLINA MOUNTAINS...AND CHANCE POPS
ELSEWHERE.
&&
.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY/...
SHORT TERM PERIOD CHARACTERIZED BY STEADY AND SUMMER-LIKE SOUTHERLY
FLOW ON WESTERN PERIPHERY OF BERMUDA HIGH...WITH UPPER TROUGH RIDING
OVER SE CONUS RIDGE PROVIDING SOME WEAK FORCING FROM DPVA BUT
ENHANCING LLVL WINDS AND MIDLEVEL LAPSE RATES. FRI NIGHT THE COMBINED
LIFTING EFFECTS OF THE TROUGH AND SOUTHERLY FLOW ARE SUFFICIENT TO
THINK THAT SOME OF THE ELEVATED INSTABILITY SHOWN ON NAM FCST
SOUNDINGS COULD BE REALIZED...SO THOUGH POPS WILL DIMINISH AS
CONVECTION WANES FOLLOWING DIURNAL MAX FRI AFTN IT IS PRUDENT TO
MAINTAIN AT LEAST A SCHC MOST PLACES OVERNIGHT. THE INCREASING LLVL
WINDS FRI NIGHT MAY ENHANCE LLVL LIFT ESPECIALLY NEAR THE BLUE RIDGE
ESCARPMENT TOWARD SAT MORNING ALLOWING FOR INCREASING PRECIP CHANCES.
THE WINDS WILL ALSO MAINTAIN FAIRLY MIXED CONDITIONS JUST ABOVE THE
SFC SO ONCE DIURNAL HEATING BEGINS SATURDAY CONVECTION SHOULD EASILY
BEGIN TO FIRE BY LATE MORNING. CAPE VALUES OF AT LEAST SEVERAL
HUNDRED JOULES FCST BY GFS/NAM CONSENSUS...WITH HIGHEST VALUES OVER
THE PIEDMONT WHERE IT APPEARS SKIES WILL BE CLEARER DUE TO LATER
CONVECTIVE INITIATION ALLOWING FOR BETTER HEATING. SHEAR TOO WEAK TO
SUGGEST A THREAT OF ORGANIZED TSTMS AND DEEP MOISTURE SUFFICIENTLY
HIGH TO LIMIT DOWNBURST THREAT.
SIMILAR STORY FOR SATURDAY NIGHT INTO SUNDAY WITH SOME ELEVATED
CONVECTION POSSIBLY CONTINUING OVERNIGHT AND A FAIRLY EARLY DIURNAL
RISE IN ACTIVITY SUN MORNING UNDER LARGELY THE SAME SYNOPTIC SETUP.
ONE DIFFERENCE IS THAT THE UPPER TROUGH SHOULD BE OVERHEAD
SUNDAY...PERHAPS LIMITING CONVECTION SOMEWHAT DUE TO MORE HIGH
CLOUDINESS...THOUGH ALSO ENHANCING INSTABILITY THROUGH BETTER UPPER
LAPSE RATES. MOISTURE INCREASES THROUGH THE COLUMN BUT ESPECIALLY IN
THE LOW LEVELS WHERE CONDENSATION PRESSURE DEFICITS DECREASE AND MAKE
UP FOR THE CONVECTIVE LIMITATIONS POSED BY THE EXPECTED CLOUD COVER.
HAVE KEPT POPS IN HIGH CHANCE RANGE SUNDAY. THE INCREASED MOISTURE IS
ALSO REFLECTED IN HIGHER PWAT VALUES AT THIS TIME...THE HIGHEST OF
THE PERIOD...SUPPORTING HEFTIER QPF VALUES THOUGH STILL NOT OF GREAT
CONCERN.
LOW TEMPS WILL BE A BIT ABOVE NORMAL ON ACCOUNT OF CLOUD COVER. HIGH
TEMPS WILL BE HELD NEAR NORMAL VALUES WITH THE SOUTHERLY FLOW
OFFSETTING THE LIMITED HEATING BY CLOUD COVER DURING THE PERIOD.
FAVORED COOL SIDE OF GUIDANCE IN THE HIGHER TERRAIN WHERE CLOUD COVER
EXPECTED TO SEE DIURNAL INCREASES EARLIER IN THE DAY.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
AS OF 102 PM THURSDAY...FOR MONDAY AND TUESDAY...WE ARE STILL
EXPECTING TO BE TRANSITIONING TO S/WV RIDGING ALOFT...LEE TROUGHING
AND MEAN SOUTHERLY LLVL FLOW AROUND BERMUDA HIPRES. BASED ON THIS...
DAILY PCPN CHANCES WILL GRADUALLY LOWER TO JUST TOKEN CLIMO...MAINLY
DIURNAL POPS FOR DEEP CONVECTION BY TUESDAY. MAX TEMPERATURES EACH
DAY ARE SLATED TO BE A FEW DEG F ABOVE CLIMO. UPPER HEIGHTS ATOP THE
SE CONUS LOOK TO STEADILY LOWER THROUGH THE LATTER HALF OF THE
PERIOD WITH UPPER WAVE PROGGED TO DIG FROM THE MIDWEST TO THE OHIO
VALLEY. THE ATTENDANT FRONTAL ZONE MAY ALSO BE IMPINGING UPON OUR
AREA BY DAY 7. WITH THIS POTENTIAL INCREASE IN FORCING...MOISTURE AND
FLOW...DAILY THUNDERSTORM CHANCES...AND PERHAPS INTENSITY...WILL
INCREASE.
&&
.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
AT KCLT AND ELSEWHERE...VFR CONDITIONS WILL CONTINUE THROUGH THE
ENTIRE TAF PERIOD. MID AND UPPER LEVEL CLOUDS CUT DOWN ON THE
INSTABILITY EARLIER IN THE DAY AND NO SHRA/TSTMS HAVE DEVELOPED OVER
THE REGION. AS WE ARE APPROACHING SUNSET...WE SHOULD BE SHOWER FREE
THE REST OF THE NIGHT. EXPECTING A LITTLE MORE SUN ON FRIDAY...WHICH
SHOULD YIELD ISOLATED TO SCT SHRA/TSTMS OVER THE WRN CAROLINAS.
ADDED PROB30 TO A FEW TAF SITES. THE BEST CHANCES LOOK TO BE OVER
THE MTNS AND FOOTHILLS...AND IN A WEAK CONVERGENCE AXIS OVER THE WRN
NC PIEDMONT...INCLUDING KCLT.
OUTLOOK...SHOWER AND THUNDERSTORM COVERAGE...AND ASSOCIATED
RESTRICTIONS...WILL GRADUALLY INCREASE FRIDAY THROUGH MONDAY. FAIR
WEATHER MAY RETURN BY TUESDAY.
CONFIDENCE TABLE...
23-05Z 05-11Z 11-17Z 17-23Z
KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAVL HIGH 100% HIGH 100% HIGH 86% MED 60%
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...LEV
NEAR TERM...MCAVOY
SHORT TERM...WIMBERLEY
LONG TERM...CSH
AVIATION...CDG
000
FXUS62 KGSP 162147
AFDGSP
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
547 PM EDT THU MAY 16 2013
.SYNOPSIS...
A WARM AND INCREASINGLY MOIST AIR MASS WILL REMAIN OVER THE REGION
THROUGH THE REST OF THIS WEEK. A MID LEVEL DISTURBANCE WILL MOVE
ACROSS THE CAROLINAS THIS WEEKEND... TRIGGERING A MORE UNSETTLED
PATTERN WITH SHOWERS AND THUNDERSTORMS FOLLOWING A MAINLY DIURNAL
TREND THROUGH EARLY NEXT WEEK. A COLD FRONT WILL APPROACH THE
AREA DURING THE MIDDLE PART OF NEXT WEEK.
&&
.NEAR TERM /THROUGH FRIDAY/...
AS OF 545 PM EDT...A SHORT WAVE IS MOVING ACROSS THE FOOTHILLS AT
THIS TIME. CONVECTION NEVER DID FIRE AHEAD OF THE WAVE...AND NVA
BEHIND IT SHOULD SUPPRESS CONVECTION FOR A FEW MORE HOURS. THEREFORE
I/VE REMOVED POPS FOR A WHILE...THOUGH I DO HAVE A PERIOD OF SLIGHT
CHANCE POPS LATER IN THE EVENING AS CONVECTION DEVELOPING OVER THE
CUMBERLAND PLATEAU MAY WORK INTO THE MTNS BY THAT TIME.
AS OF 230 PM EDT...BROAD UPPER LEVEL CLOSED LOW LOCATED OVER THE
OZARKS CONTINUES TO SLOWLY MOVE TO THE EAST...THUS SPREADING MID TO
UPPER LEVEL MOISTURE ACROSS THE SOUTHEASTERN UNITED STATES.
MEANWHILE ON A MORE LOCAL SCALE...LARGE CLOUD SHIELD CONTINUES TO
SPREAD ACROSS NORTHEAST GEORGIA AND THE CAROLINAS...THUS STUNTING
DAYTIME HEATING TRENDS SOMEWHAT. HOWEVER...MODEL GUIDANCE STILL
INDICATES SBCAPE VALUES HAVE TOPPED THE 1000J/KG MARK ACROSS
PORTIONS OF NORTHEAST GEORGIA...THE NORTHERN PIEDMONT OF SOUTH
CAROLINA...AND THE SOUTHERN MOUNTAIN REGIONS OF NORTH CAROLINA.
STILL EXPECTING SOME CONVECTIVE INITIATION ACROSS THE HIGH TERRAINS
LATER THIS AFTERNOON AS THE CAP WEAKENS...THEREFORE KEPT CHANCE POPS
FOR THIS REGION.
OTHERWISE...EXPECTING CONVECTIVE PROBABILITIES TO DROP DURING THE
OVERNIGHT HOURS DUE TO DIURNAL COOLING EFFECTS. LOW TEMPS OVERNIGHT
WILL BE SLIGHTLY WARMER THAN LAST NIGHT AS MID TO HIGH CLOUD DECK
WILL REMAIN OVER THE AREA. FOR FRIDAY...MODEL GUIDANCE INDICATES
THE ABOVE MENTIONED UPPER LOW WILL PASS BY TO THE NORTH THUS
PROVIDING AT LEAST SOME BROAD SCALE LIFTING ACROSS THE AREA. THIS
COMBINED WITH DIURNAL HEATING IN THE AFTERNOON PROMPTED INCREASES TO
LIKELY POPS ACROSS THE NORTH CAROLINA MOUNTAINS...AND CHANCE POPS
ELSEWHERE.
&&
.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY/...
SHORT TERM PERIOD CHARACTERIZED BY STEADY AND SUMMER-LIKE SOUTHERLY
FLOW ON WESTERN PERIPHERY OF BERMUDA HIGH...WITH UPPER TROUGH RIDING
OVER SE CONUS RIDGE PROVIDING SOME WEAK FORCING FROM DPVA BUT
ENHANCING LLVL WINDS AND MIDLEVEL LAPSE RATES. FRI NIGHT THE COMBINED
LIFTING EFFECTS OF THE TROUGH AND SOUTHERLY FLOW ARE SUFFICIENT TO
THINK THAT SOME OF THE ELEVATED INSTABILITY SHOWN ON NAM FCST
SOUNDINGS COULD BE REALIZED...SO THOUGH POPS WILL DIMINISH AS
CONVECTION WANES FOLLOWING DIURNAL MAX FRI AFTN IT IS PRUDENT TO
MAINTAIN AT LEAST A SCHC MOST PLACES OVERNIGHT. THE INCREASING LLVL
WINDS FRI NIGHT MAY ENHANCE LLVL LIFT ESPECIALLY NEAR THE BLUE RIDGE
ESCARPMENT TOWARD SAT MORNING ALLOWING FOR INCREASING PRECIP CHANCES.
THE WINDS WILL ALSO MAINTAIN FAIRLY MIXED CONDITIONS JUST ABOVE THE
SFC SO ONCE DIURNAL HEATING BEGINS SATURDAY CONVECTION SHOULD EASILY
BEGIN TO FIRE BY LATE MORNING. CAPE VALUES OF AT LEAST SEVERAL
HUNDRED JOULES FCST BY GFS/NAM CONSENSUS...WITH HIGHEST VALUES OVER
THE PIEDMONT WHERE IT APPEARS SKIES WILL BE CLEARER DUE TO LATER
CONVECTIVE INITIATION ALLOWING FOR BETTER HEATING. SHEAR TOO WEAK TO
SUGGEST A THREAT OF ORGANIZED TSTMS AND DEEP MOISTURE SUFFICIENTLY
HIGH TO LIMIT DOWNBURST THREAT.
SIMILAR STORY FOR SATURDAY NIGHT INTO SUNDAY WITH SOME ELEVATED
CONVECTION POSSIBLY CONTINUING OVERNIGHT AND A FAIRLY EARLY DIURNAL
RISE IN ACTIVITY SUN MORNING UNDER LARGELY THE SAME SYNOPTIC SETUP.
ONE DIFFERENCE IS THAT THE UPPER TROUGH SHOULD BE OVERHEAD
SUNDAY...PERHAPS LIMITING CONVECTION SOMEWHAT DUE TO MORE HIGH
CLOUDINESS...THOUGH ALSO ENHANCING INSTABILITY THROUGH BETTER UPPER
LAPSE RATES. MOISTURE INCREASES THROUGH THE COLUMN BUT ESPECIALLY IN
THE LOW LEVELS WHERE CONDENSATION PRESSURE DEFICITS DECREASE AND MAKE
UP FOR THE CONVECTIVE LIMITATIONS POSED BY THE EXPECTED CLOUD COVER.
HAVE KEPT POPS IN HIGH CHANCE RANGE SUNDAY. THE INCREASED MOISTURE IS
ALSO REFLECTED IN HIGHER PWAT VALUES AT THIS TIME...THE HIGHEST OF
THE PERIOD...SUPPORTING HEFTIER QPF VALUES THOUGH STILL NOT OF GREAT
CONCERN.
LOW TEMPS WILL BE A BIT ABOVE NORMAL ON ACCOUNT OF CLOUD COVER. HIGH
TEMPS WILL BE HELD NEAR NORMAL VALUES WITH THE SOUTHERLY FLOW
OFFSETTING THE LIMITED HEATING BY CLOUD COVER DURING THE PERIOD.
FAVORED COOL SIDE OF GUIDANCE IN THE HIGHER TERRAIN WHERE CLOUD COVER
EXPECTED TO SEE DIURNAL INCREASES EARLIER IN THE DAY.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
AS OF 102 PM THURSDAY...FOR MONDAY AND TUESDAY...WE ARE STILL
EXPECTING TO BE TRANSITIONING TO S/WV RIDGING ALOFT...LEE TROUGHING
AND MEAN SOUTHERLY LLVL FLOW AROUND BERMUDA HIPRES. BASED ON THIS...
DAILY PCPN CHANCES WILL GRADUALLY LOWER TO JUST TOKEN CLIMO...MAINLY
DIURNAL POPS FOR DEEP CONVECTION BY TUESDAY. MAX TEMPERATURES EACH
DAY ARE SLATED TO BE A FEW DEG F ABOVE CLIMO. UPPER HEIGHTS ATOP THE
SE CONUS LOOK TO STEADILY LOWER THROUGH THE LATTER HALF OF THE
PERIOD WITH UPPER WAVE PROGGED TO DIG FROM THE MIDWEST TO THE OHIO
VALLEY. THE ATTENDANT FRONTAL ZONE MAY ALSO BE IMPINGING UPON OUR
AREA BY DAY 7. WITH THIS POTENTIAL INCREASE IN FORCING...MOISTURE AND
FLOW...DAILY THUNDERSTORM CHANCES...AND PERHAPS INTENSITY...WILL
INCREASE.
&&
.AVIATION /22Z THURSDAY THROUGH TUESDAY/...
AT KCLT AND ELSEWHERE...VFR CONDITIONS WILL CONTINUE THROUGH THE
ENTIRE TAF PERIOD. MID TO HIGH LEVEL CLOUDS WILL REMAIN DOMINATE AS
MOISTURE CONTINUES TO ADVECT IN ON THE EAST SIDE OF AN UPPER LOW
LOCATED OVER THE MIDSOUTH REGION. CONTINUES TO LOOK AS IF ALL TAF
SITES WILL REMAIN DRY WITH THE ONLY EXCEPTIONS BEING NEAR KAVL WHERE
SCATTERED AFTERNOON CONVECTION WILL TAKE PLACE. THUS...ADDED
MENTION OF VCTS AT 21Z WITH CBS AT 6K FT. OTHERWISE...WINDS WILL
REMAIN GENERALLY LIGHT AND OUT OF THE SOUTH SOUTHWEST THROUGH
MORNING BEFORE BACKING TO A MORE SOUTHERLY COMPONENT BY MID TO LATE
MORNING ON FRIDAY.
OUTLOOK...SHOWER AND THUNDERSTORM COVERAGE...AND ASSOCIATED
RESTRICTIONS...WILL GRADUALLY INCREASE FRIDAY THROUGH MONDAY.
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% MED 60%
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...LEV
NEAR TERM...MCAVOY
SHORT TERM...WIMBERLEY
LONG TERM...CSH
AVIATION...CDG
000
FXUS62 KGSP 161844
AFDGSP
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
244 PM EDT THU MAY 16 2013
.SYNOPSIS...
A WARM AND INCREASINGLY MOIST AIR MASS WILL REMAIN OVER THE REGION
THROUGH THE REST OF THIS WEEK. A MID LEVEL DISTURBANCE WILL MOVE
ACROSS THE CAROLINAS THIS WEEKEND... TRIGGERING A MORE UNSETTLED
PATTERN WITH SHOWERS AND THUNDERSTORMS FOLLOWING A MAINLY DIURNAL
TREND THROUGH EARLY NEXT WEEK. A COLD FRONT WILL APPROACH THE
AREA DURING THE MIDDLE PART OF NEXT WEEK.
&&
.NEAR TERM /THROUGH FRIDAY/...
AS OF 230 PM EDT...BROAD UPPER LEVEL CLOSED LOW LOCATED OVER THE
OZARKS CONTINUES TO SLOWLY MOVE TO THE EAST...THUS SPREADING MID TO
UPPER LEVEL MOISTURE ACROSS THE SOUTHEASTERN UNITED STATES.
MEANWHILE ON A MORE LOCAL SCALE...LARGE CLOUD SHIELD CONTINUES TO
SPREAD ACROSS NORTHEAST GEORGIA AND THE CAROLINAS...THUS STUNTING
DAYTIME HEATING TRENDS SOMEWHAT. HOWEVER...MODEL GUIDANCE STILL
INDICATES SBCAPE VALUES HAVE TOPPED THE 1000J/KG MARK ACROSS
PORTIONS OF NORTHEAST GEORGIA...THE NORTHERN PIEDMONT OF SOUTH
CAROLINA...AND THE SOUTHERN MOUNTAIN REGIONS OF NORTH CAROLINA.
STILL EXPECTING SOME CONVECTIVE INITIATION ACROSS THE HIGH TERRAINS
LATER THIS AFTERNOON AS THE CAP WEAKENS...THEREFORE KEPT CHANCE POPS
FOR THIS REGION.
OTHERWISE...EXPECTING CONVECTIVE PROBABILITIES TO DROP DURING THE
OVERNIGHT HOURS DUE TO DIURNAL COOLING EFFECTS. LOW TEMPS OVERNIGHT
WILL BE SLIGHTLY WARMER THAN LAST NIGHT AS MID TO HIGH CLOUD DECK
WILL REMAIN OVER THE AREA. FOR FRIDAY...MODEL GUIDANCE INDICATES
THE ABOVE MENTIONED UPPER LOW WILL PASS BY TO THE NORTH THUS
PROVIDING AT LEAST SOME BROAD SCALE LIFTING ACROSS THE AREA. THIS
COMBINED WITH DIURNAL HEATING IN THE AFTERNOON PROMPTED INCREASES TO
LIKELY POPS ACROSS THE NORTH CAROLINA MOUNTAINS...AND CHANCE POPS
ELSEWHERE.
&&
.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY/...
SHORT TERM PERIOD CHARACTERIZED BY STEADY AND SUMMER-LIKE SOUTHERLY
FLOW ON WESTERN PERIPHERY OF BERMUDA HIGH...WITH UPPER TROUGH RIDING
OVER SE CONUS RIDGE PROVIDING SOME WEAK FORCING FROM DPVA BUT
ENHANCING LLVL WINDS AND MIDLEVEL LAPSE RATES. FRI NIGHT THE COMBINED
LIFTING EFFECTS OF THE TROUGH AND SOUTHERLY FLOW ARE SUFFICIENT TO
THINK THAT SOME OF THE ELEVATED INSTABILITY SHOWN ON NAM FCST
SOUNDINGS COULD BE REALIZED...SO THOUGH POPS WILL DIMINISH AS
CONVECTION WANES FOLLOWING DIURNAL MAX FRI AFTN IT IS PRUDENT TO
MAINTAIN AT LEAST A SCHC MOST PLACES OVERNIGHT. THE INCREASING LLVL
WINDS FRI NIGHT MAY ENHANCE LLVL LIFT ESPECIALLY NEAR THE BLUE RIDGE
ESCARPMENT TOWARD SAT MORNING ALLOWING FOR INCREASING PRECIP CHANCES.
THE WINDS WILL ALSO MAINTAIN FAIRLY MIXED CONDITIONS JUST ABOVE THE
SFC SO ONCE DIURNAL HEATING BEGINS SATURDAY CONVECTION SHOULD EASILY
BEGIN TO FIRE BY LATE MORNING. CAPE VALUES OF AT LEAST SEVERAL
HUNDRED JOULES FCST BY GFS/NAM CONSENSUS...WITH HIGHEST VALUES OVER
THE PIEDMONT WHERE IT APPEARS SKIES WILL BE CLEARER DUE TO LATER
CONVECTIVE INITIATION ALLOWING FOR BETTER HEATING. SHEAR TOO WEAK TO
SUGGEST A THREAT OF ORGANIZED TSTMS AND DEEP MOISTURE SUFFICIENTLY
HIGH TO LIMIT DOWNBURST THREAT.
SIMILAR STORY FOR SATURDAY NIGHT INTO SUNDAY WITH SOME ELEVATED
CONVECTION POSSIBLY CONTINUING OVERNIGHT AND A FAIRLY EARLY DIURNAL
RISE IN ACTIVITY SUN MORNING UNDER LARGELY THE SAME SYNOPTIC SETUP.
ONE DIFFERENCE IS THAT THE UPPER TROUGH SHOULD BE OVERHEAD
SUNDAY...PERHAPS LIMITING CONVECTION SOMEWHAT DUE TO MORE HIGH
CLOUDINESS...THOUGH ALSO ENHANCING INSTABILITY THROUGH BETTER UPPER
LAPSE RATES. MOISTURE INCREASES THROUGH THE COLUMN BUT ESPECIALLY IN
THE LOW LEVELS WHERE CONDENSATION PRESSURE DEFICITS DECREASE AND MAKE
UP FOR THE CONVECTIVE LIMITATIONS POSED BY THE EXPECTED CLOUD COVER.
HAVE KEPT POPS IN HIGH CHANCE RANGE SUNDAY. THE INCREASED MOISTURE IS
ALSO REFLECTED IN HIGHER PWAT VALUES AT THIS TIME...THE HIGHEST OF
THE PERIOD...SUPPORTING HEFTIER QPF VALUES THOUGH STILL NOT OF GREAT
CONCERN.
LOW TEMPS WILL BE A BIT ABOVE NORMAL ON ACCOUNT OF CLOUD COVER. HIGH
TEMPS WILL BE HELD NEAR NORMAL VALUES WITH THE SOUTHERLY FLOW
OFFSETTING THE LIMITED HEATING BY CLOUD COVER DURING THE PERIOD.
FAVORED COOL SIDE OF GUIDANCE IN THE HIGHER TERRAIN WHERE CLOUD COVER
EXPECTED TO SEE DIURNAL INCREASES EARLIER IN THE DAY.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
AS OF 102 PM THURSDAY...FOR MONDAY AND TUESDAY...WE ARE STILL
EXPECTING TO BE TRANSITIONING TO S/WV RIDGING ALOFT...LEE TROUGHING
AND MEAN SOUTHERLY LLVL FLOW AROUND BERMUDA HIPRES. BASED ON THIS...
DAILY PCPN CHANCES WILL GRADUALLY LOWER TO JUST TOKEN CLIMO...MAINLY
DIURNAL POPS FOR DEEP CONVECTION BY TUESDAY. MAX TEMPERATURES EACH
DAY ARE SLATED TO BE A FEW DEG F ABOVE CLIMO. UPPER HEIGHTS ATOP THE
SE CONUS LOOK TO STEADILY LOWER THROUGH THE LATTER HALF OF THE
PERIOD WITH UPPER WAVE PROGGED TO DIG FROM THE MIDWEST TO THE OHIO
VALLEY. THE ATTENDANT FRONTAL ZONE MAY ALSO BE IMPINGING UPON OUR
AREA BY DAY 7. WITH THIS POTENTIAL INCREASE IN FORCING...MOISTURE AND
FLOW...DAILY THUNDERSTORM CHANCES...AND PERHAPS INTENSITY...WILL
INCREASE.
&&
.AVIATION /19Z THURSDAY THROUGH TUESDAY/...
AT KCLT AND ELSEWHERE...VFR CONDITIONS WILL CONTINUE THROUGH THE
ENTIRE TAF PERIOD. MID TO HIGH LEVEL CLOUDS WILL REMAIN DOMINATE AS
MOISTURE CONTINUES TO ADVECT IN ON THE EAST SIDE OF AN UPPER LOW
LOCATED OVER THE MIDSOUTH REGION. CONTINUES TO LOOK AS IF ALL TAF
SITES WILL REMAIN DRY WITH THE ONLY EXCEPTIONS BEING NEAR KAVL WHERE
SCATTERED AFTERNOON CONVECTION WILL TAKE PLACE. THUS...ADDED
MENTION OF VCTS AT 21Z WITH CBS AT 6K FT. OTHERWISE...WINDS WILL
REMAIN GENERALLY LIGHT AND OUT OF THE SOUTH SOUTHWEST THROUGH
MORNING BEFORE BACKING TO A MORE SOUTHERLY COMPONENT BY MID TO LATE
MORNING ON FRIDAY.
OUTLOOK...SHOWER AND THUNDERSTORM COVERAGE...AND ASSOCIATED
RESTRICTIONS...WILL GRADUALLY INCREASE FRIDAY THROUGH MONDAY.
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 91% MED 79%
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...LEV
NEAR TERM...CDG
SHORT TERM...WIMBERLEY
LONG TERM...CSH
AVIATION...CDG
000
FXUS62 KGSP 161757
AFDGSP
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
157 PM EDT THU MAY 16 2013
.SYNOPSIS...
A WARM AND INCREASINGLY MOIST AIR MASS WILL REMAIN OVER THE REGION
THROUGH THE REST OF THIS WEEK. A MID LEVEL DISTURBANCE WILL MOVE
ACROSS THE CAROLINAS THIS WEEKEND... TRIGGERING A MORE UNSETTLED
PATTERN WITH SHOWERS AND THUNDERSTORMS FOLLOWING A MAINLY DIURNAL
TREND THROUGH EARLY NEXT WEEK. A COLD FRONT WILL APPROACH THE
AREA DURING THE MIDDLE PART OF NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1020 AM EDT...MID TO UPPER LEVEL MOISTURE CONTINUES TO ADVECT
INTO THE REGION AS EVIDENT BY WATER VAPOR IMAGERY. LARGE CLOUD
SHIELD LOCATED OVER MUCH OF NORTHEAST GEORGIA WILL CONTINUE TO MARCH
TO THE EAST. THUS...EXPECTING OVERALL CLOUD COVER TO CONTINUE TO
INCREASE IN THE MID TO UPPER LEVELS. TEMPERATURES ACROSS THE REGION
CONTINUE TO RISE AS MOST SITES ARE REPORTING TEMPS IN THE MID TO
UPPER 70S WITH SOUTH SOUTHWEST WINDS IN THE 6-10KTS RANGE. PREVIOUS
POP FORECAST LOOKS TO BE ON TRACK WITH POTENTIAL CONVECTION LATER IN
THE AFTERNOON ACROSS THE NORTH CAROLINA MOUNTAINS...AND THEN
SPREADING INTO THE PEIDMONTS..THEREFORE NO CHANGES WERE MADE.
PREVIOUS DISCUSSION...
OTHERWISE...WATER VAPOR IMAGERY SHOWS A 500 MB LOW CENTER MEANDERING
EAST INTO AR THIS MORNING. THIS FEATURE WILL GRADUALLY OPEN UP AND
CONTINUE EAST...STEADILY BREAKING DOWN THE RIDGE OVER THE
APPALACHIANS AND THICKENING MID AND HIGH LEVEL CLOUDS OVER THE
FORECAST AREA. SCATTERED CONVECTION SHOULD DEVELOP FIRST TODAY OVER
THE SW MTNS OF NC WHERE A LOW LEVEL SW UPSLOPE FLOW AND WEAK VORT
MAXIMA ALOFT WILL PROVIDE TRIGGERING. SOME CONVECTIVE INHIBITION
REMAINS IN MODEL PROFILES TODAY...BUT THIS SHOULD BE OVERCOME IN THE
MTNS WITH THE WEAK FORCING...WITH A FEW STRONG TSTMS THEN POSSIBLE
IN THE FAIRLY STEEP LAPSE RATES ALOFT. WESTERLY STEERING FLOW WILL
CARRY SCATTERED MTN CONVECTION INTO THE FOOTHILLS THIS
AFTERNOON...AND ISOLD COVERAGE MAY SURVIVE EAST INTO THE PIEDMONT
LATE IN THE DAY. DESPITE THE INCREASING CLOUDS...EXPECT MAXES 5
DEGREES OR MORE ABOVE NORMAL.
ALTHOUGH THE CONVECTION WILL WANE WITH THE LOSS OF DAYTIME HEATING
TONIGHT...ISOLATED SHOWERS COULD LINGER OVERNIGHT OVER THE NC MTNS
AS WEAK ENERGY AHEAD OF THE OPENING UPPER LOW PUSHES INTO THE
APPALACHIANS. EXPECT WARM MINS UNDER THE CLOUD COVER...WITH MAINLY
50S MTNS AND LOWER 60S PIEDMONT.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY/...
AS OF 235 AM THURSDAY...ON FRIDAY...THE MID LEVEL HEIGHTS WILL
FEATURE SLIGHT RIDGING ACROSS THE CWA AS A BROAD LOW TRACKS OVER THE
LOWER OHIO RIVER VALLEY. AT H7...RIDGING IS SLIGHTLY BETTER
DEFINED...WITH THE CENTER OF THE H7 HIGH OFF THE COAST OF SC. AT THE
SFC...A STATIONARY FRONT WILL TRACK GENERALLY WEST TO EAST ACROSS
THE VIRGINIAS DURING THE AFTERNOON. FORECAST SOUNDINGS INDICATE THAT
MOISTURE WILL INCREASE AHEAD OF THE MID LEVEL TROF...PW VALUES
RANGING ACROSS THE CWA FROM 1.25 TO 1.5 INCHES. TEMPERATURES BELOW
H5 WILL REMAIN VERY MILD...LIMITING CAPE VALUES LESS THAN 1000 J/KG.
THE INCREASE IN LLVL MOISTURE SHOULD KEEP CIN FAIRLY WEAK AND
SHALLOW DURING THE AFTERNOON. GIVEN THE APPROACH OF THE MID LEVEL
TROF...BROAD FIELD OF INSTABILITY...AND DEEP MOISTURE...I WILL
FORECAST LIKELY POPS ACROSS THE MTNS AND CHC EAST FOR SHRA/TSRA. MOS
CONSENSUS SUPPORTS HIGHS FROM AROUND 80 AT KAVL TO MID TO UPPER 80S
EAST OF THE MTNS.
SATURDAY...THE FORCING ASSOCIATED WITH THE MID LEVEL TROF WILL FAVOR
A TRACK NE ALONG THE OHIO RIVER VALLEY. DEEP CONVECTION ACROSS THE
FORECAST AREA SHOULD GRADUALLY ASHE OUT EARLY SATURDAY
MORNING...WITH MIN POP EXPECTED AROUND 20 PERCENT. BY SATURDAY
AFTERNOON...THE MAIN WEATHER FEATURES WILL REMAIN COMPARABLE TO
FRIDAY. FORECAST SOUNDINGS ACROSS THE CWA INDICATE
INSTABILITY/STABILITY VALUES VERY CLOSE TO FRIDAY. GIVEN THE
SIMILARITY TO FRI...I WILL USE PERSISTENCE FOR THE PEAK POP DURING
THE MID AFTERNOON PERIOD. HIGH TEMPERATURE MAY VERIFY 2 TO 3 DEGREES
COOLER THAN FRIDAY...WITH DEWPOINTS 2 TO 4 DEGREES HIGHER.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
AS OF 102 PM THURSDAY...FOR MONDAY AND TUESDAY...WE ARE STILL
EXPECTING TO BE TRANSITIONING TO S/WV RIDGING ALOFT...LEE TROUGHING
AND MEAN SOUTHERLY LLVL FLOW AROUND BERMUDA HIPRES. BASED ON THIS...
DAILY PCPN CHANCES WILL GRADUALLY LOWER TO JUST TOKEN CLIMO...MAINLY
DIURNAL POPS FOR DEEP CONVECTION BY TUESDAY. MAX TEMPERATURES EACH
DAY ARE SLATED TO BE A FEW DEG F ABOVE CLIMO. UPPER HEIGHTS ATOP THE
SE CONUS LOOK TO STEADILY LOWER THROUGH THE LATTER HALF OF THE
PERIOD WITH UPPER WAVE PROGGED TO DIG FROM THE MIDWEST TO THE OHIO
VALLEY. THE ATTENDANT FRONTAL ZONE MAY ALSO BE IMPINGING UPON OUR
AREA BY DAY 7. WITH THIS POTENTIAL INCREASE IN FORCING...MOISTURE AND
FLOW...DAILY THUNDERSTORM CHANCES...AND PERHAPS INTENSITY...WILL
INCREASE.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
AT KCLT AND ELSEWHERE...VFR CONDITIONS WILL CONTINUE THROUGH THE
ENTIRE TAF PERIOD. MID TO HIGH LEVEL CLOUDS WILL REMAIN DOMINATE AS
MOISTURE CONTINUES TO ADVECT IN ON THE EAST SIDE OF AN UPPER LOW
LOCATED OVER THE MIDSOUTH REGION. CONTINUES TO LOOK AS IF ALL TAF
SITES WILL REMAIN DRY WITH THE ONLY EXCEPTIONS BEING NEAR KAVL WHERE
SCATTERED AFTERNOON CONVECTION WILL TAKE PLACE. THUS...ADDED
MENTION OF VCTS AT 21Z WITH CBS AT 6K FT. OTHERWISE...WINDS WILL
REMAIN GENERALLY LIGHT AND OUT OF THE SOUTH SOUTHWEST THROUGH
MORNING BEFORE BACKING TO A MORE SOUTHERLY COMPONENT BY MID TO LATE
MORNING ON FRIDAY.
OUTLOOK...SHOWER AND THUNDERSTORM COVERAGE...AND ASSOCIATED
RESTRICTIONS...WILL GRADUALLY INCREASE FRIDAY THROUGH MONDAY.
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 91% MED 79%
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...LEV
NEAR TERM...CDG/HG
SHORT TERM...NED
LONG TERM...CSH
AVIATION...CDG
000
FXUS62 KGSP 161424
AFDGSP
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
1024 AM EDT THU MAY 16 2013
.SYNOPSIS...
A WARM AIR MASS WILL REMAIN OVER THE REGION THROUGH THE REST OF THIS
WEEK. CONDITIONS WILL BECOME MORE UNSETTLED AS A MID LEVEL
DISTURBANCE RIPPLES ACROSS THE CAROLINAS LATE THIS WEEKEND. A COLD
FRONT WILL SLOWLY APPROACH THE SOUTHERN APPALACHIANS DURING THE
MIDDLE PART OF NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1020 AM EDT...MID TO UPPER LEVEL MOISTURE CONTINUES TO ADVECT
INTO THE REGION AS EVIDENT BY WATER VAPOR IMAGERY. LARGE CLOUD
SHIELD LOCATED OVER MUCH OF NORTHEAST GEORGIA WILL CONTINUE TO MARCH
TO THE EAST. THUS...EXPECTING OVERALL CLOUD COVER TO CONTINUE TO
INCREASE IN THE MID TO UPPER LEVELS. TEMPERATURES ACROSS THE REGION
CONTINUE TO RISE AS MOST SITES ARE REPORTING TEMPS IN THE MID TO
UPPER 70S WITH SOUTH SOUTHWEST WINDS IN THE 6-10KTS RANGE. PREVIOUS
POP FORECAST LOOKS TO BE ON TRACK WITH POTENTIAL CONVECTION LATER IN
THE AFTERNOON ACROSS THE NORTH CAROLINA MOUNTAINS...AND THEN
SPREADING INTO THE PIEDMONTS..THEREFORE NO CHANGES WERE MADE.
PREVIOUS DISCUSSION...
OTHERWISE...WATER VAPOR IMAGERY SHOWS A 500 MB LOW CENTER MEANDERING
EAST INTO AR THIS MORNING. THIS FEATURE WILL GRADUALLY OPEN UP AND
CONTINUE EAST...STEADILY BREAKING DOWN THE RIDGE OVER THE
APPALACHIANS AND THICKENING MID AND HIGH LEVEL CLOUDS OVER THE
FORECAST AREA. SCATTERED CONVECTION SHOULD DEVELOP FIRST TODAY OVER
THE SW MTNS OF NC WHERE A LOW LEVEL SW UPSLOPE FLOW AND WEAK VORT
MAXIMA ALOFT WILL PROVIDE TRIGGERING. SOME CONVECTIVE INHIBITION
REMAINS IN MODEL PROFILES TODAY...BUT THIS SHOULD BE OVERCOME IN THE
MTNS WITH THE WEAK FORCING...WITH A FEW STRONG TSTMS THEN POSSIBLE
IN THE FAIRLY STEEP LAPSE RATES ALOFT. WESTERLY STEERING FLOW WILL
CARRY SCATTERED MTN CONVECTION INTO THE FOOTHILLS THIS
AFTERNOON...AND ISOLD COVERAGE MAY SURVIVE EAST INTO THE PIEDMONT
LATE IN THE DAY. DESPITE THE INCREASING CLOUDS...EXPECT MAXES 5
DEGREES OR MORE ABOVE NORMAL.
ALTHOUGH THE CONVECTION WILL WANE WITH THE LOSS OF DAYTIME HEATING
TONIGHT...ISOLATED SHOWERS COULD LINGER OVERNIGHT OVER THE NC MTNS
AS WEAK ENERGY AHEAD OF THE OPENING UPPER LOW PUSHES INTO THE
APPALACHIANS. EXPECT WARM MINS UNDER THE CLOUD COVER...WITH MAINLY
50S MTNS AND LOWER 60S PIEDMONT.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY/...
AS OF 235 AM THURSDAY...ON FRIDAY...THE MID LEVEL HEIGHTS WILL
FEATURE SLIGHT RIDGING ACROSS THE CWA AS A BROAD LOW TRACKS OVER THE
LOWER OHIO RIVER VALLEY. AT H7...RIDGING IS SLIGHTLY BETTER
DEFINED...WITH THE CENTER OF THE H7 HIGH OFF THE COAST OF SC. AT THE
SFC...A STATIONARY FRONT WILL TRACK GENERALLY WEST TO EAST ACROSS
THE VIRGINIAS DURING THE AFTERNOON. FORECAST SOUNDINGS INDICATE THAT
MOISTURE WILL INCREASE AHEAD OF THE MID LEVEL TROF...PW VALUES
RANGING ACROSS THE CWA FROM 1.25 TO 1.5 INCHES. TEMPERATURES BELOW
H5 WILL REMAIN VERY MILD...LIMITING CAPE VALUES LESS THAN 1000 J/KG.
THE INCREASE IN LLVL MOISTURE SHOULD KEEP CIN FAIRLY WEAK AND
SHALLOW DURING THE AFTERNOON. GIVEN THE APPROACH OF THE MID LEVEL
TROF...BROAD FIELD OF INSTABILITY...AND DEEP MOISTURE...I WILL
FORECAST LIKELY POPS ACROSS THE MTNS AND CHC EAST FOR SHRA/TSRA. MOS
CONSENSUS SUPPORTS HIGHS FROM AROUND 80 AT KAVL TO MID TO UPPER 80S
EAST OF THE MTNS.
SATURDAY...THE FORCING ASSOCIATED WITH THE MID LEVEL TROF WILL FAVOR
A TRACK NE ALONG THE OHIO RIVER VALLEY. DEEP CONVECTION ACROSS THE
FORECAST AREA SHOULD GRADUALLY ASHE OUT EARLY SATURDAY
MORNING...WITH MIN POP EXPECTED AROUND 20 PERCENT. BY SATURDAY
AFTERNOON...THE MAIN WEATHER FEATURES WILL REMAIN COMPARABLE TO
FRIDAY. FORECAST SOUNDINGS ACROSS THE CWA INDICATE
INSTABILITY/STABILITY VALUES VERY CLOSE TO FRIDAY. GIVEN THE
SIMILARITY TO FRI...I WILL USE PERSISTENCE FOR THE PEAK POP DURING
THE MID AFTERNOON PERIOD. HIGH TEMPERATURE MAY VERIFY 2 TO 3 DEGREES
COOLER THAN FRIDAY...WITH DEWPOINTS 2 TO 4 DEGREES HIGHER.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
AS OF 300 AM THURSDAY...I WILL USE A BLEND OF THE GFS AND ECMWF
THROUGH THE MEDIUM RANGE. SUNDAY APPEARS TO BE THE DAY OF PEAK
COVERAGE OF SHRA AND TSRA ACROSS THE FORECAST AREA. BY SUNDAY
AFTERNOON INTO THE EARLY EVENING...GUIDANCE INDICATES THAT THE BOUNDARY
THAT LINGERED OVER THE VIRGINAS EARLIER IN THE WEEKEND WILL PUSH
INTO THE I-40 CORRIDOR. ALOFT...H7 TO H5 TROF AXIS AND VORT MAX WILL
RIPPLE OVER THE SOUTHERN APPALACHIANS...COOLING MID TROPOSPHERE
TEMPERATURES A DEGREE OR TWO. IN ADDITION...PW VALUES ACROSS THE CWA
WILL RANGE GENERALLY ABOVE 1.5 INCHES. THE COMBINATION PASSING
VORT...STEEPING LAPSE RATES...INCREASING MOISTURE SHOULD SUPPORT
LIKELY MTN POPS WITH HIGH CHC TO SOLID CHC EAST OF THE MTNS. HIGH
TEMPERATURES MAY RANGE WITHIN A COUPLE OF DEGREES OF NORMAL.
MON THROUGH WED...THE ENVIRONMENT ACROSS THE CWA WILL SEE A GRADUAL
REDUCTION IN PW VALUES AS S/W RIDGING BUILDS EAST ACROSS THE
APPALACHIANS. THE FORECAST AREA IS EXPECTED TO REMAIN ON THE WESTERN
EDGE OF A BERMUDA HIGH. ON WED...A COLD FRONT WILL APPROACH THE
REGION FROM THE WEST...BUT IS NOT EXPECTED TO ARRIVE OVER THE REGION
UNTIL WED NIGHT/EARLY THURSDAY. THIS PATTERN SHOULD BE VERY
FAVORABLE TO DIURNAL AIR MASS SHRA/TSRA. I WILL FORECAST A PEAK OF
CHC POPS DURING THE HEAT OF THE AFTERNOON...FADING TO SCHC OR LESS
DURING THE EARLY MORNING HOURS. TEMPERATURES WILL RANGE FROM NORMAL
TO 2 TO 3 DEGREES ABOVE.
&&
.AVIATION /15Z THURSDAY THROUGH MONDAY/...
AT KCLT...MID AND HIGH CLOUDS WILL INCREASE AND THICKEN THROUGH THE
PERIOD AS AN UPPER LEVEL LOW PRESSURE SYSTEM BREAKS DOWN THE RIDGE
FROM THE WEST. SCATTERED MOUNTAIN CONVECTION TODAY COULD MAKE A RUN
EASTWARD IN THE WESTERLY STEERING FLOW...BUT THERE IS ONLY A SLIGHT
CHANCE OF IT SURVIVING EAST TO KCLT LATE DAY. IF IT DOES...IT WOULD
PROBABLY IMPACT THE AIRFIELD MAINLY 22Z TO 00Z. SW WINDS WILL
INCREASE WITH MIXING TODAY BUT REMAIN GENERALLY 10 KT OR LESS WITH
ONLY LIMITED GUSTS.
ELSEWHERE...MID AND HIGH CLOUD CEILINGS WILL DEVELOP AND PERSIST
THROUGH THE PERIOD AS A 500 MB LOW CENTER OPENS UP TO THE W.
SCATTERED CONVECTION SHOULD DEVELOP OVER THE SW NC MTNS BY MIDDAY
AND STEER E...WITH THE BEST CHANCE OF THUNDER AT KAVL. SCT ACTIVITY
WILL LIKELY SPILL OUT INTO THE FOOTHILLS DURING THE AFTN...WITH
PROB30 FEATURED FOR TSRA FROM KGMU TO KGSP TO KHKY 21Z TO 00Z.
ANTICIPATE STEADY SW FLOW THROUGH THE PERIOD AT MAINLY 5 TO 10
KT...WITH ISOLATED LOW END GUSTS POSSIBLE DURING AFTERNOON MIXING.
KAVL WILL BE THE EXCEPTION...WITH MORE NW FLOW THROUGH THE PERIOD.
OUTLOOK...SHOWER AND THUNDERSTORM COVERAGE...AND ASSOCIATED
RESTRICTIONS...WILL GRADUALLY INCREASE FRIDAY THROUGH MONDAY.
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...NED
NEAR TERM...CDG/HG
SHORT TERM...NED
LONG TERM...NED
AVIATION...HG
000
FXUS62 KGSP 161048
AFDGSP
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
648 AM EDT THU MAY 16 2013
.SYNOPSIS...
A WARM AIR MASS WILL REMAIN OVER THE REGION THROUGH THE REST OF THIS
WEEK. CONDITIONS WILL BECOME MORE UNSETTLED AS A MID LEVEL
DISTURBANCE RIPPLES ACROSS THE CAROLINAS LATE THIS WEEKEND. A COLD
FRONT WILL SLOWLY APPROACH THE SOUTHERN APPALACHIANS DURING THE
MIDDLE PART OF NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 645 AM EDT...THE INCREASE IN MID AND HIGH CLOUDS HAS BEEN
HASTENED A BIT WITH THE LATEST UPDATE...AS CIRRUS IS LOOKING MORE
OPAQUE.
OTHERWISE...WATER VAPOR IMAGERY SHOWS A 500 MB LOW CENTER MEANDERING
EAST INTO AR THIS MORNING. THIS FEATURE WILL GRADUALLY OPEN UP AND
CONTINUE EAST...STEADILY BREAKING DOWN THE RIDGE OVER THE
APPALACHIANS AND THICKENING MID AND HIGH LEVEL CLOUDS OVER THE
FORECAST AREA. SCATTERED CONVECTION SHOULD DEVELOP FIRST TODAY OVER
THE SW MTNS OF NC WHERE A LOW LEVEL SW UPSLOPE FLOW AND WEAK VORT
MAXIMA ALOFT WILL PROVIDE TRIGGERING. SOME CONVECTIVE INHIBITION
REMAINS IN MODEL PROFILES TODAY...BUT THIS SHOULD BE OVERCOME IN THE
MTNS WITH THE WEAK FORCING...WITH A FEW STRONG TSTMS THEN POSSIBLE
IN THE FAIRLY STEEP LAPSE RATES ALOFT. WESTERLY STEERING FLOW WILL
CARRY SCATTERED MTN CONVECTION INTO THE FOOTHILLS THIS
AFTERNOON...AND ISOLD COVERAGE MAY SURVIVE EAST INTO THE PIEDMONT
LATE IN THE DAY. DESPITE THE INCREASING CLOUDS...EXPECT MAXES 5
DEGREES OR MORE ABOVE NORMAL.
ALTHOUGH THE CONVECTION WILL WANE WITH THE LOSS OF DAYTIME HEATING
TONIGHT...ISOLATED SHOWERS COULD LINGER OVERNIGHT OVER THE NC MTNS
AS WEAK ENERGY AHEAD OF THE OPENING UPPER LOW PUSHES INTO THE
APPALACHIANS. EXPECT WARM MINS UNDER THE CLOUD COVER...WITH MAINLY
50S MTNS AND LOWER 60S PIEDMONT.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY/...
AS OF 235 AM THURSDAY...ON FRIDAY...THE MID LEVEL HEIGHTS WILL
FEATURE SLIGHT RIDGING ACROSS THE CWA AS A BROAD LOW TRACKS OVER THE
LOWER OHIO RIVER VALLEY. AT H7...RIDGING IS SLIGHTLY BETTER
DEFINED...WITH THE CENTER OF THE H7 HIGH OFF THE COAST OF SC. AT THE
SFC...A STATIONARY FRONT WILL TRACK GENERALLY WEST TO EAST ACROSS
THE VIRGINIAS DURING THE AFTERNOON. FORECAST SOUNDINGS INDICATE THAT
MOISTURE WILL INCREASE AHEAD OF THE MID LEVEL TROF...PW VALUES
RANGING ACROSS THE CWA FROM 1.25 TO 1.5 INCHES. TEMPERATURES BELOW
H5 WILL REMAIN VERY MILD...LIMITING CAPE VALUES LESS THAN 1000 J/KG.
THE INCREASE IN LLVL MOISTURE SHOULD KEEP CIN FAIRLY WEAK AND
SHALLOW DURING THE AFTERNOON. GIVEN THE APPROACH OF THE MID LEVEL
TROF...BROAD FIELD OF INSTABILITY...AND DEEP MOISTURE...I WILL
FORECAST LIKELY POPS ACROSS THE MTNS AND CHC EAST FOR SHRA/TSRA. MOS
CONSENSUS SUPPORTS HIGHS FROM AROUND 80 AT KAVL TO MID TO UPPER 80S
EAST OF THE MTNS.
SATURDAY...THE FORCING ASSOCIATED WITH THE MID LEVEL TROF WILL FAVOR
A TRACK NE ALONG THE OHIO RIVER VALLEY. DEEP CONVECTION ACROSS THE
FORECAST AREA SHOULD GRADUALLY ASHE OUT EARLY SATURDAY
MORNING...WITH MIN POP EXPECTED AROUND 20 PERCENT. BY SATURDAY
AFTERNOON...THE MAIN WEATHER FEATURES WILL REMAIN COMPARABLE TO
FRIDAY. FORECAST SOUNDINGS ACROSS THE CWA INDICATE
INSTABILITY/STABILITY VALUES VERY CLOSE TO FRIDAY. GIVEN THE
SIMILARITY TO FRI...I WILL USE PERSISTENCE FOR THE PEAK POP DURING
THE MID AFTERNOON PERIOD. HIGH TEMPERATURE MAY VERIFY 2 TO 3 DEGREES
COOLER THAN FRIDAY...WITH DEWPOINTS 2 TO 4 DEGREES HIGHER.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
AS OF 300 AM THURSDAY...I WILL USE A BLEND OF THE GFS AND ECMWF
THROUGH THE MEDIUM RANGE. SUNDAY APPEARS TO BE THE DAY OF PEAK
COVERAGE OF SHRA AND TSRA ACROSS THE FORECAST AREA. BY SUNDAY
AFTERNOON INTO THE EARLY EVENING...GUIDANCE INDICATES THAT THE BOUNDARY
THAT LINGERED OVER THE VIRGINAS EARLIER IN THE WEEKEND WILL PUSH
INTO THE I-40 CORRIDOR. ALOFT...H7 TO H5 TROF AXIS AND VORT MAX WILL
RIPPLE OVER THE SOUTHERN APPALACHIANS...COOLING MID TROPOSPHERE
TEMPERATURES A DEGREE OR TWO. IN ADDITION...PW VALUES ACROSS THE CWA
WILL RANGE GENERALLY ABOVE 1.5 INCHES. THE COMBINATION PASSING
VORT...STEEPING LAPSE RATES...INCREASING MOISTURE SHOULD SUPPORT
LIKELY MTN POPS WITH HIGH CHC TO SOLID CHC EAST OF THE MTNS. HIGH
TEMPERATURES MAY RANGE WITHIN A COUPLE OF DEGREES OF NORMAL.
MON THROUGH WED...THE ENVIRONMENT ACROSS THE CWA WILL SEE A GRADUAL
REDUCTION IN PW VALUES AS S/W RIDGING BUILDS EAST ACROSS THE
APPALACHIANS. THE FORECAST AREA IS EXPECTED TO REMAIN ON THE WESTERN
EDGE OF A BERMUDA HIGH. ON WED...A COLD FRONT WILL APPROACH THE
REGION FROM THE WEST...BUT IS NOT EXPECTED TO ARRIVE OVER THE REGION
UNTIL WED NIGHT/EARLY THURSDAY. THIS PATTERN SHOULD BE VERY
FAVORABLE TO DIURNAL AIR MASS SHRA/TSRA. I WILL FORECAST A PEAK OF
CHC POPS DURING THE HEAT OF THE AFTERNOON...FADING TO SCHC OR LESS
DURING THE EARLY MORNING HOURS. TEMPERATURES WILL RANGE FROM NORMAL
TO 2 TO 3 DEGREES ABOVE.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
AT KCLT...MID AND HIGH CLOUDS WILL INCREASE AND THICKEN THROUGH THE
PERIOD AS AN UPPER LEVEL LOW PRESSURE SYSTEM BREAKS DOWN THE RIDGE
FROM THE WEST. SCATTERED MOUNTAIN CONVECTION TODAY COULD MAKE A RUN
EASTWARD IN THE WESTERLY STEERING FLOW...BUT THERE IS ONLY A SLIGHT
CHANCE OF IT SURVIVING EAST TO KCLT LATE DAY. IF IT DOES...IT WOULD
PROBABLY IMPACT THE AIRFIELD MAINLY 22Z TO 00Z. SW WINDS WILL
INCREASE WITH MIXING TODAY BUT REMAIN GENERALLY 10 KT OR LESS WITH
ONLY LIMITED GUSTS.
ELSEWHERE...MID AND HIGH CLOUD CEILINGS WILL DEVELOP AND PERSIST
THROUGH THE PERIOD AS A 500 MB LOW CENTER OPENS UP TO THE W.
SCATTERED CONVECTION SHOULD DEVELOP OVER THE SW NC MTNS BY MIDDAY
AND STEER E...WITH THE BEST CHANCE OF THUNDER AT KAVL. SCT ACTIVITY
WILL LIKELY SPILL OUT INTO THE FOOTHILLS DURING THE AFTN...WITH
PROB30 FEATURED FOR TSRA FROM KGMU TO KGSP TO KHKY 21Z TO 00Z.
ANTICIPATE STEADY SW FLOW THROUGH THE PERIOD AT MAINLY 5 TO 10
KT...WITH ISOLATED LOW END GUSTS POSSIBLE DURING AFTERNOON MIXING.
KAVL WILL BE THE EXCEPTION...WITH MORE NW FLOW THROUGH THE PERIOD.
OUTLOOK...SHOWER AND THUNDERSTORM COVERAGE...AND ASSOCIATED
RESTRICTIONS...WILL GRADUALLY INCREASE FRIDAY THROUGH MONDAY.
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...NED
NEAR TERM...HG
SHORT TERM...NED
LONG TERM...NED
AVIATION...HG
000
FXUS62 KGSP 160849
AFDGSP
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
449 AM EDT THU MAY 16 2013
.SYNOPSIS...
A WARM AIR MASS WILL REMAIN OVER THE REGION THROUGH THE REST OF THIS
WEEK. CONDITIONS WILL BECOME MORE UNSETTLED AS A MID LEVEL
DISTURBANCE RIPPLES ACROSS THE CAROLINAS LATE THIS WEEKEND. A COLD
FRONT WILL SLOWLY APPROACH THE SOUTHERN APPALACHIANS DURING THE
MIDDLE PART OF NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 445 AM EDT...THE MAIN ADJUSTMENT TO THE FORECAST IS TO ADD
MORE HIGH LEVEL CLOUDS AS CIRRUS HAS THICKENED UP ACROSS THE
FORECAST AREA. OTHERWISE...WATER VAPOR IMAGERY SHOWS A 500 MB LOW
CENTER MEANDERING EAST INTO AR THIS MORNING. THIS FEATURE WILL
GRADUALLY OPEN UP AND CONTINUE EAST...STEADILY BREAKING DOWN THE
RIDGE OVER THE APPALACHIANS AND SPREADING ADDITIONAL MID AND HIGH
LEVEL CLOUDS INTO THE FORECAST AREA. SCATTERED CONVECTION SHOULD
DEVELOP FIRST TODAY OVER THE SW MTNS OF NC WHERE A LOW LEVEL SW
UPSLOPE FLOW AND WEAK VORT MAXIMA ALOFT WILL PROVIDE TRIGGERING.
SOME CONVECTIVE INHIBITION REMAINS IN MODEL PROFILES TODAY...BUT
THIS SHOULD BE OVERCOME IN THE MTNS WITH THE WEAK FORCING...WITH A
FEW STRONG TSTMS THEN POSSIBLE IN THE FAIRLY STEEP LAPSE RATES
ALOFT. WESTERLY STEERING FLOW WILL CARRY SCATTERED MTN CONVECTION
INTO THE FOOTHILLS THIS AFTERNOON...AND ISOLD COVERAGE MAY SURVIVE
EAST INTO THE PIEDMONT LATE IN THE DAY. DESPITE THE INCREASING
CLOUDS...EXPECT MAXES 5 DEGREES OR MORE ABOVE NORMAL.
ALTHOUGH THE CONVECTION WILL WANE WITH THE LOSS OF DAYTIME HEATING
TONIGHT...ISOLATED SHOWERS COULD LINGER OVERNIGHT OVER THE NC MTNS
AS WEAK ENERGY AHEAD OF THE OPENING UPPER LOW PUSHES INTO THE
APPALACHIANS. EXPECT WARM MINS UNDER THE CLOUD COVER...WITH MAINLY
50S MTNS AND LOWER 60S PIEDMONT.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY/...
AS OF 235 AM THURSDAY...ON FRIDAY...THE MID LEVEL HEIGHTS WILL
FEATURE SLIGHT RIDGING ACROSS THE CWA AS A BROAD LOW TRACKS OVER THE
LOWER OHIO RIVER VALLEY. AT H7...RIDGING IS SLIGHTLY BETTER
DEFINED...WITH THE CENTER OF THE H7 HIGH OFF THE COAST OF SC. AT THE
SFC...A STATIONARY FRONT WILL TRACK GENERALLY WEST TO EAST ACROSS
THE VIRGINIAS DURING THE AFTERNOON. FORECAST SOUNDINGS INDICATE THAT
MOISTURE WILL INCREASE AHEAD OF THE MID LEVEL TROF...PW VALUES
RANGING ACROSS THE CWA FROM 1.25 TO 1.5 INCHES. TEMPERATURES BELOW
H5 WILL REMAIN VERY MILD...LIMITING CAPE VALUES LESS THAN 1000 J/KG.
THE INCREASE IN LLVL MOISTURE SHOULD KEEP CIN FAIRLY WEAK AND
SHALLOW DURING THE AFTERNOON. GIVEN THE APPROACH OF THE MID LEVEL
TROF...BROAD FIELD OF INSTABILITY...AND DEEP MOISTURE...I WILL
FORECAST LIKELY POPS ACROSS THE MTNS AND CHC EAST FOR SHRA/TSRA. MOS
CONSENSUS SUPPORTS HIGHS FROM AROUND 80 AT KAVL TO MID TO UPPER 80S
EAST OF THE MTNS.
SATURDAY...THE FORCING ASSOCIATED WITH THE MID LEVEL TROF WILL FAVOR
A TRACK NE ALONG THE OHIO RIVER VALLEY. DEEP CONVECTION ACROSS THE
FORECAST AREA SHOULD GRADUALLY ASHE OUT EARLY SATURDAY
MORNING...WITH MIN POP EXPECTED AROUND 20 PERCENT. BY SATURDAY
AFTERNOON...THE MAIN WEATHER FEATURES WILL REMAIN COMPARABLE TO
FRIDAY. FORECAST SOUNDINGS ACROSS THE CWA INDICATE
INSTABILITY/STABILITY VALUES VERY CLOSE TO FRIDAY. GIVEN THE
SIMILARITY TO FRI...I WILL USE PERSISTENCE FOR THE PEAK POP DURING
THE MID AFTERNOON PERIOD. HIGH TEMPERATURE MAY VERIFY 2 TO 3 DEGREES
COOLER THAN FRIDAY...WITH DEWPOINTS 2 TO 4 DEGREES HIGHER.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
AS OF 300 AM THURSDAY...I WILL USE A BLEND OF THE GFS AND ECMWF
THROUGH THE MEDIUM RANGE. SUNDAY APPEARS TO BE THE DAY OF PEAK
COVERAGE OF SHRA AND TSRA ACROSS THE FORECAST AREA. BY SUNDAY
AFTERNOON INTO THE EARLY EVENING...GUIDANCE INDICATES THAT THE BOUNDARY
THAT LINGERED OVER THE VIRGINAS EARLIER IN THE WEEKEND WILL PUSH
INTO THE I-40 CORRIDOR. ALOFT...H7 TO H5 TROF AXIS AND VORT MAX WILL
RIPPLE OVER THE SOUTHERN APPALACHIANS...COOLING MID TROPOSPHERE
TEMPERATURES A DEGREE OR TWO. IN ADDITION...PW VALUES ACROSS THE CWA
WILL RANGE GENERALLY ABOVE 1.5 INCHES. THE COMBINATION PASSING
VORT...STEEPING LAPSE RATES...INCREASING MOISTURE SHOULD SUPPORT
LIKELY MTN POPS WITH HIGH CHC TO SOLID CHC EAST OF THE MTNS. HIGH
TEMPERATURES MAY RANGE WITHIN A COUPLE OF DEGREES OF NORMAL.
MON THROUGH WED...THE ENVIRONMENT ACROSS THE CWA WILL SEE A GRADUAL
REDUCTION IN PW VALUES AS S/W RIDGING BUILDS EAST ACROSS THE
APPALACHIANS. THE FORECAST AREA IS EXPECTED TO REMAIN ON THE WESTERN
EDGE OF A BERMUDA HIGH. ON WED...A COLD FRONT WILL APPROACH THE
REGION FROM THE WEST...BUT IS NOT EXPECTED TO ARRIVE OVER THE REGION
UNTIL WED NIGHT/EARLY THURSDAY. THIS PATTERN SHOULD BE VERY
FAVORABLE TO DIURNAL AIR MASS SHRA/TSRA. I WILL FORECAST A PEAK OF
CHC POPS DURING THE HEAT OF THE AFTERNOON...FADING TO SCHC OR LESS
DURING THE EARLY MORNING HOURS. TEMPERATURES WILL RANGE FROM NORMAL
TO 2 TO 3 DEGREES ABOVE.
&&
.AVIATION /09Z THURSDAY THROUGH MONDAY/...
AT KCLT...MID AND HIGH CLOUDS WILL INCREASE THROUGH THE PERIOD AS AN
UPPER LEVEL LOW PRESSURE SYSTEM BREAKS DOWN THE RIDGE FROM THE WEST.
SCATTERED MOUNTAIN CONVECTION TODAY COULD MAKE A RUN EASTWARD IN THE
WESTERLY STEERING FLOW...BUT THERE IS ONLY A SLIGHT CHANCE OF IT
SURVIVING EAST TO KCLT LATE DAY. IF IT DID...IT WOULD PROBABLY
IMPACT THE AIRFIELD 22Z TO 00Z. SW WINDS WILL INCREASE WITH MIXING
TODAY BUT REMAIN GENERALLY 10 KT OR LESS WITH ONLY LIMITED GUSTS.
ELSEWHERE...MID AND HIGH CLOUD CEILINGS WILL DEVELOP AND PERSIST
THROUGH THE PERIOD AS A 500 MB LOW CENTER OPENS UP TO THE W.
SCATTERED CONVECTION SHOULD DEVELOP OVER THE SW NC MTNS BY MIDDAY
AND STEER E...WITH THE BEST CHANCE OF THUNDER AT KAVL. SCT ACTIVITY
WILL LIKELY SPILL OUT INTO THE FOOTHILLS DURING THE AFTN...WITH
PROB30 FEATURED FOR TSRA FROM KGMU TO KGSP...AND MAINLY VCSH NEAR
KHKY. ANTICIPATE STEADY SW FLOW THROUGH THE PERIOD AT MAINLY 5 TO 10
KT...WITH ISOLATED LOW END GUSTS POSSIBLE DURING AFTERNOON MIXING.
OUTLOOK...SHOWER AND THUNDERSTORM COVERAGE...AND ASSOCIATED
RESTRICTIONS...WILL GRADUALLY INCREASE FRIDAY THROUGH MONDAY.
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 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...NED
NEAR TERM...HG
SHORT TERM...NED
LONG TERM...NED
AVIATION...HG
000
FXUS62 KGSP 160719
AFDGSP
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
319 AM EDT THU MAY 16 2013
.SYNOPSIS...
A WARM AIR MASS WILL REMAIN OVER THE REGION THROUGH THE REST OF THIS
WEEK. CONDITIONS WILL BECOME MORE UNSETTLED AS A MID LEVEL
DISTURBANCE RIPPLES ACROSS THE CAROLINAS LATE THIS WEEKEND. A COLD
FRONT WILL SLOWLY APPROACH THE SOUTHERN APPALACHIANS DURING THE
MIDDLE PART OF NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 230 AM EDT...WATER VAPOR IMAGERY SHOWS A 500 MB LOW CENTER
MEANDERING EAST ACROSS ERN OK EARLY THIS MORNING. THIS FEATURE WILL
GRADUALLY OPEN UP AND CONTINUE MOVING EAST...STEADILY BREAKING DOWN
THE RIDGE OVER THE APPALACHIANS AND SPREADING MID AND HIGH LEVEL
CLOUDS INTO THE FORECAST AREA. SCATTERED CONVECTION SHOULD DEVELOP
FIRST TODAY OVER THE SW MTNS OF NC WHERE A LOW LEVEL SW UPSLOPE FLOW
AND WEAK VORT MAXIMA ALOFT WILL PROVIDE TRIGGERING. SOME CONVECTIVE
INHIBITION REMAINS IN MODEL PROFILES TODAY...BUT THIS SHOULD BE
OVERCOME IN THE MTNS WITH THE WEAK FORCING...WITH A FEW STRONG TSTMS
THEN POSSIBLE IN THE FAIRLY STEEP LAPSE RATES ALOFT. WESTERLY
STEERING FLOW WILL CARRY SCATTERED MTN CONVECTION INTO THE FOOTHILLS
THIS AFTERNOON...AND ISOLD COVERAGE MAY SURVIVE EAST INTO THE
PIEDMONT LATE IN THE DAY. DESPITE THE INCREASING CLOUDS...EXPECT
MAXES 5 DEGREES OR MORE ABOVE NORMAL.
ALTHOUGH THE CONVECTION WILL WANE WITH THE LOSS OF DAYTIME HEATING
TONIGHT...ISOLATED SHOWERS COULD LINGER OVERNIGHT OVER THE NC MTNS
AS WEAK ENERGY AHEAD OF THE OPENING UPPER LOW PUSHES INTO THE
APPALACHIANS. EXPECT WARM MINS UNDER THE CLOUD COVER...WITH MAINLY
50S MTNS AND LOWER 60S PIEDMONT.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY/...
AS OF 235 AM THURSDAY...ON FRIDAY...THE MID LEVEL HEIGHTS WILL
FEATURE SLIGHT RIDGING ACROSS THE CWA AS A BROAD LOW TRACKS OVER THE
LOWER OHIO RIVER VALLEY. AT H7...RIDGING IS SLIGHTLY BETTER
DEFINED...WITH THE CENTER OF THE H7 HIGH OFF THE COAST OF SC. AT THE
SFC...A STATIONARY FRONT WILL TRACK GENERALLY WEST TO EAST ACROSS
THE VIRGINIAS DURING THE AFTERNOON. FORECAST SOUNDINGS INDICATE THAT
MOISTURE WILL INCREASE AHEAD OF THE MID LEVEL TROF...PW VALUES
RANGING ACROSS THE CWA FROM 1.25 TO 1.5 INCHES. TEMPERATURES BELOW
H5 WILL REMAIN VERY MILD...LIMITING CAPE VALUES LESS THAN 1000 J/KG.
THE INCREASE IN LLVL MOISTURE SHOULD KEEP CIN FAIRLY WEAK AND
SHALLOW DURING THE AFTERNOON. GIVEN THE APPROACH OF THE MID LEVEL
TROF...BROAD FIELD OF INSTABILITY...AND DEEP MOISTURE...I WILL
FORECAST LIKELY POPS ACROSS THE MTNS AND CHC EAST FOR SHRA/TSRA. MOS
CONSENSUS SUPPORTS HIGHS FROM AROUND 80 AT KAVL TO MID TO UPPER 80S
EAST OF THE MTNS.
SATURDAY...THE FORCING ASSOCIATED WITH THE MID LEVEL TROF WILL FAVOR
A TRACK NE ALONG THE OHIO RIVER VALLEY. DEEP CONVECTION ACROSS THE
FORECAST AREA SHOULD GRADUALLY ASHE OUT EARLY SATURDAY
MORNING...WITH MIN POP EXPECTED AROUND 20 PERCENT. BY SATURDAY
AFTERNOON...THE MAIN WEATHER FEATURES WILL REMAIN COMPARABLE TO
FRIDAY. FORECAST SOUNDINGS ACROSS THE CWA INDICATE
INSTABILITY/STABILITY VALUES VERY CLOSE TO FRIDAY. GIVEN THE
SIMILARITY TO FRI...I WILL USE PERSISTENCE FOR THE PEAK POP DURING
THE MID AFTERNOON PERIOD. HIGH TEMPERATURE MAY VERIFY 2 TO 3 DEGREES
COOLER THAN FRIDAY...WITH DEWPOINTS 2 TO 4 DEGREES HIGHER.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
AS OF 300 AM THURSDAY...I WILL USE A BLEND OF THE GFS AND ECMWF
THROUGH THE MEDIUM RANGE. SUNDAY APPEARS TO BE THE DAY OF PEAK
COVERAGE OF SHRA AND TSRA ACROSS THE FORECAST AREA. BY SUNDAY
AFTERNOON INTO THE EARLY EVENING...GUIDANCE INDICATES THAT THE BOUNDARY
THAT LINGERED OVER THE VIRGINAS EARLIER IN THE WEEKEND WILL PUSH
INTO THE I-40 CORRIDOR. ALOFT...H7 TO H5 TROF AXIS AND VORT MAX WILL
RIPPLE OVER THE SOUTHERN APPALACHIANS...COOLING MID TROPOSPHERE
TEMPERATURES A DEGREE OR TWO. IN ADDITION...PW VALUES ACROSS THE CWA
WILL RANGE GENERALLY ABOVE 1.5 INCHES. THE COMBINATION PASSING
VORT...STEEPING LAPSE RATES...INCREASING MOISTURE SHOULD SUPPORT
LIKELY MTN POPS WITH HIGH CHC TO SOLID CHC EAST OF THE MTNS. HIGH
TEMPERATURES MAY RANGE WITHIN A COUPLE OF DEGREES OF NORMAL.
MON THROUGH WED...THE ENVIRONMENT ACROSS THE CWA WILL SEE A GRADUAL
REDUCTION IN PW VALUES AS S/W RIDGING BUILDS EAST ACROSS THE
APPALACHIANS. THE FORECAST AREA IS EXPECTED TO REMAIN ON THE WESTERN
EDGE OF A BERMUDA HIGH. ON WED...A COLD FRONT WILL APPROACH THE
REGION FROM THE WEST...BUT IS NOT EXPECTED TO ARRIVE OVER THE REGION
UNTIL WED NIGHT/EARLY THURSDAY. THIS PATTERN SHOULD BE VERY
FAVORABLE TO DIURNAL AIR MASS SHRA/TSRA. I WILL FORECAST A PEAK OF
CHC POPS DURING THE HEAT OF THE AFTERNOON...FADING TO SCHC OR LESS
DURING THE EARLY MORNING HOURS. TEMPERATURES WILL RANGE FROM NORMAL
TO 2 TO 3 DEGREES ABOVE.
&&
.AVIATION /07Z THURSDAY THROUGH MONDAY/...
AT KCLT...MID AND HIGH CLOUDS WILL INCREASE THROUGH THE PERIOD AS AN
UPPER LEVEL LOW PRESSURE SYSTEM BREAKS DOWN THE RIDGE FROM THE WEST.
SCATTERED MOUNTAIN CONVECTION TODAY COULD MAKE A RUN EASTWARD IN THE
WESTERLY STEERING FLOW...BUT THERE IS ONLY A SLIGHT CHANCE OF IT
SURVIVING EAST TO KCLT LATE DAY. IF IT DID...IT WOULD PROBABLY
IMPACT THE AIRFIELD 22Z TO 00Z. SW WINDS WILL INCREASE WITH MIXING
TODAY BUT REMAIN GENERALLY 10 KT OR LESS WITH ONLY LIMITED GUSTS.
ELSEWHERE...MID AND HIGH CLOUD CEILINGS WILL DEVELOP AND PERSIST
THROUGH THE PERIOD AS A 500 MB LOW CENTER OPENS UP TO THE W.
SCATTERED CONVECTION SHOULD DEVELOP OVER THE SW NC MTNS BY MIDDAY
AND STEER E...WITH THE BEST CHANCE OF THUNDER AT KAVL. SCT ACTIVITY
WILL LIKELY SPILL OUT INTO THE FOOTHILLS DURING THE AFTN...WITH
PROB30 FEATURED FOR TSRA FROM KGMU TO KGSP...AND MAINLY VCSH NEAR
KHKY. ANTICIPATE STEADY SW FLOW THROUGH THE PERIOD AT MAINLY 5 TO 10
KT...WITH ISOLATED LOW END GUSTS POSSIBLE DURING AFTERNOON MIXING.
OUTLOOK...SHOWER AND THUNDERSTORM COVERAGE...AND ASSOCIATED
RESTRICTIONS...WILL GRADUALLY INCREASE FRIDAY THROUGH MONDAY.
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 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...NED
NEAR TERM...HG
SHORT TERM...NED
LONG TERM...NED
AVIATION...HG
000
FXUS62 KGSP 160601
AFDGSP
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
201 AM EDT THU MAY 16 2013
.SYNOPSIS...
HIGH PRESSURE SITUATED OFF THE CAROLINA COAST WILL DRIVE
SOUTHWESTERLY FLOW FOR THE WESTERN CAROLINAS AND NORTHEAST
GEORGIA...MAINTAINING A WARM AND MOIST AIRMASS THROUGHOUT THE
PERIOD. AN UPPER LEVEL DISTURBANCE WILL APPROACH ON THURSDAY AND
KEEP THE PATTERN UNSETTLED THROUGH EARLY NEXT WEEK...WITH A COLD
FRONT EXPECTED TO CROSS THE REGION BY LATE TUESDAY OR EARLY
WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 130 AM EDT...WATER VAPOR IMAGERY SHOWS A 500 MB LOW CENTER
MEANDERING E ACROSS OK EARLY THIS MORNING. THIS FEATURE WILL
GRADUALLY OPEN UP AND CONTINUE MOVING EAST...STEADILY BREAKING DOWN
THE RIDGE OVER THE APPALACHIANS AND SPREADING MID AND HIGH LEVEL
CLOUD INTO THE FORECAST AREA. SCATTERED CONVECTION SHOULD DEVELOP
FIRST TODAY OVER THE SW MTNS OF NC WHERE A LOW LEVEL SW UPSLOPE FLOW
AND WEAK VORT MAXIMA ALOFT WILL PROVIDE SOME TRIGGERING. SOME
CONVECTIVE INHIBITION WILL REMAIN IN MODEL PROFILES TODAY...BUT THIS
SHOULD BE OVERCOME IN THE MTNS WITH THE WEAK FORCING...WITH A FEW
STRONG TSTMS THEN POSSIBLE IN THE FAIRLY STEEP LAPSE RATES ALOFT.
WESTERLY STEERING FLOW WILL CARRY SCATTERED MTN CONVECTION INTO THE
FOOTHILLS THIS AFTERNOON...AND ISOLD COVERAGE MAY SURVIVE EAST INTO
THE PIEDMONT LATE IN THE DAY. DESPITE THE INCREASING CLOUDS...EXPECT
MAXES 5 DEGREES OR MORE ABOVE NORMAL.
ALTHOUGH THE CONVECTION WILL WANE WITH THE LOSS OF DAYTIME HEATING
TONIGHT...ISOLATED SHOWERS COULD LINGER OVERNIGHT OVER THE NC MTNS
AS WEAK ENERGY AHEAD OF THE OPENING UPPER LOW PUSHES INTO THE
APPALACHIANS. EXPECT WARM MINS UNDER THE CLOUD COVER...WITH MAINLY
50S MTNS AND LOWER 60S PIEDMONT.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY/...
AS OF 215 PM WEDNESDAY...THE SHORT TERM WILL FEATURE DIURNALLY
DRIVEN CONVECTION ALONG WITH A WEAK ZONAL UPPER FLOW THROUGH SAT.
THE MODELS FORECAST A COUPLE WEAK IMPULSES MOVING ACROSS THE AREA AS
WELL. PARTLY CLOUDY CONDITIONS SHOULD PREVAIL THROUGH
FRIDAY...WITH SCATTERED SHOWERS/THUDNERSTORMS DEVELOPING OVER THE
MOUNTAINS BY EARLY AFTERNOON...AND IN THE FOOTHILLS AND PIEDMONT
AREAS DURING THE MID TO LATE AFTERNOON HOURS. CONVECTION SHOULD
WANE AGAIN FRI NIGHT...THEN SCATTERED SHOWERS/STORMS SHOULD FIRE
BACK UP SAT AFTERNOON ACROSS THE FORECAST AREA. WARM LOW LEVEL
THICKNESS VALUES WILL SUPPORT ABOVE AVERAGE TEMPS ON FRI AND SAT.
USED A BLEND OF GUIDANCE SOURCES TO GENERATE TEMP FIELDS.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
AS OF 140 PM WEDNESDAY...WPC FAVORED A BLEND OF THE 06Z GFS/00Z ECM
ENSEMBLES FOR THE MEDIUM RANGE. THE EXPECTATION IS FOR AN AMPLIFYING
UPPER RIDGE TO DEVELOP OVER THE EASTERN U.S. THE FIRST PART OF NEXT
WEEK AS A SIGNIFICANT UPPER TROUGH DEVELOPS OVER THE CENTRAL PART OF
THE COUNTRY. THE WEEKEND LOOKS LIKE IT WILL BE QUITE UNSETTLED AS A
REMNANT VORT MAX MOVES ACROSS THE AREA SAT NIGHT INTO SUNDAY...AND A
BACKDOOR COLD FRONT APPROACHES. THE LATEST GUIDANCE DOES KEEP THE
FRONT JUST TO THE NE OF THE AREA SAT NIGHT INTO SUN. HENCE...WILL
HAVE FAIRLY ROBUST POPS IN THE SAT NIGHT/SUN TIMEFRAME WITH THE
HIGHEST VALUES OVER THE NORTHERN REACHES OF THE FORECAST AREA. AS
THE UPPER RIDGE BUILDS NEXT WEEK...THE PRECIP SHOULD BECOME MORE
DIURNAL IN NATURE WITH THE HIGHEST COVERAGE OF SHOWERS/STORMS OVER
THE CLIMATOLOGICAL FAVORED MOUNTAINS. WITH MORE IN THE WAY OF
CLOUDINESS EXPECTED...MAX TEMPS SHOULD AVERAGE NEAR NORMAL SUN AND
MON...BUT RISE TO ABOUT A CATEGORY ABOVE AVERAGE FOR TUE AND WED.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
AT KCLT...MID AND HIGH CLOUDS WILL INCREASE THROUGH THE PERIOD AS AN
UPPER LEVEL LOW PRESSURE SYSTEM BREAKS DOWN THE RIDGE FROM THE WEST.
SCATTERED MOUNTAIN CONVECTION TODAY COULD MAKE A RUN EASTWARD IN THE
WESTERLY STEERING FLOW...BUT THERE IS ONLY A SLIGHT CHANCE OF IT
SURVIVING EAST TO KCLT LATE DAY. IF IT DID...IT WOULD PROBABLY
IMPACT THE AIRFIELD 22Z TO 00Z. SW WINDS WILL INCREASE WITH MIXING
TODAY BUT REMAIN GENERALLY 10 KT OR LESS WITH ONLY LIMITED GUSTS.
ELSEWHERE...MID AND HIGH CLOUD CEILINGS WILL DEVELOP AND PERSIST
THROUGH THE PERIOD AS A 500 MB LOW CENTER OPENS UP TO THE W.
SCATTERED CONVECTION SHOULD DEVELOP OVER THE SW NC MTNS BY MIDDAY
AND STEER E...WITH THE BEST CHANCE OF THUNDER AT KAVL. SCT ACTIVITY
WILL LIKELY SPILL OUT INTO THE FOOTHILLS DURING THE AFTN...WITH
PROB30 FEATURED FOR TSRA FROM KGMU TO KGSP...AND MAINLY VCSH NEAR
KHKY. ANTICIPATE STEADY SW FLOW THROUGH THE PERIOD AT MAINLY 5 TO 10
KT...WITH ISOLATED LOW END GUSTS POSSIBLE DURING AFTERNOON MIXING.
OUTLOOK...SHOWER AND THUNDERSTORM COVERAGE...AND ASSOCIATED
RESTRICTIONS...WILL GRADUALLY INCREASE FRIDAY THROUGH MONDAY.
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...LEV
NEAR TERM...HG
SHORT TERM...LG
LONG TERM...LG
AVIATION...HG
000
FXUS62 KGSP 160248
AFDGSP
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
1048 PM EDT WED MAY 15 2013
.SYNOPSIS...
HIGH PRESSURE SITUATED OFF THE CAROLINA COAST WILL DRIVE
SOUTHWESTERLY FLOW FOR THE WESTERN CAROLINAS AND NORTHEAST
GEORGIA... MAINTAINING A WARM AND MOIST AIRMASS THROUGHOUT THE
PERIOD. AN UPPER LEVEL DISTURBANCE WILL APPROACH ON THURSDAY AND
KEEP THE PATTERN UNSETTLED THROUGH EARLY NEXT WEEK... WITH A COLD
FRONT EXPECTED TO CROSS THE REGION BY LATE TUESDAY OR EARLY
WEDNESDAY.
&&
.NEAR TERM /THROUGH THURSDAY/...
AS OF 1045 PM EDT...THE CURRENT GRIDS ARE IN GOOD SHAPE AND ONLY
MINOR TWEAKS WERE MADE.
AS OF 735 PM EDT...ISOLATED SHRA/TSTMS HAVE DEVELOPED OVER THE WRN
NC FOOTHILLS AND PIEDMONT IN A WEAK SFC CONVERGENCE AXIS. THE CELLS
MAY CONTINUE TO FIRE FOR ANOTHER HOUR OR TWO...BUT THEY SHOULD DIE
OUT AFTER THAT CONSIDERING THE WEAK SYNOPTIC SCALE FORCING.
AS OF 230 PM EDT...PLEASANT WEATHER CONDITIONS CONTINUE TO PREVAIL
ACROSS THE WESTERN CAROLINAS AND NORTHEAST GEORGIA. AMPLE SUNSHINE
AND SOUTH TO SOUTHWESTERLY FLOW AT THE SFC HAS PROPELLED
TEMPERATURES WELL INTO THE LOWER TO MID 80S WITH SOME SITES
REPORTING IN THE UPPER 80S.
OTHERWISE...UPPER LEVEL RIDGE CONTINUES TO DOMINATE THE WEATHER
ACROSS THE ENTIRE SOUTHEASTERN UNITED STATES. A RATHER LOW
AMPLITUDE LONG WAVE TROUGH...AND AN ASSOCIATED CUTOFF 570MB LOW WERE
LOCATED OVER WESTERN OKLAHOMA AND PORTIONS OF WEST TEXAS. WATER
VAPOR IMAGERY SHOWS A PLUME OF MOISTURE SPILLING IN ON THE EAST SIDE
OF THIS FEATURE ACROSS THE MIDSOUTH ALLOWING FOR SOME THUNDERSTORM
DEVELOPMENT. LOCALLY...THE ABOVE MENTIONED RIDGE LOOKS TO BREAK
DOWN OVER THE NEXT 24 HOURS AS THE WHOLE PATTERN SHIFTS EASTWARD.
LOOKING AT MODEL GUIDANCE...BOTH THE NAM AND THE GFS SHOW A
DEVELOPING MCS FEATURE OVER PORTIONS OF THE OHIO VALLEY DURING THE
MID TO LATE MORNING HOURS ON THURSDAY. AS THIS FEATURE CONTINUES TO
MOVE DOWNSTREAM IN THE NORTHWEST FLOW ALOFT...THE ATMOSPHERE WILL
CONTINUE TO DESTABILIZE OVER THE NORTH CAROLINA MOUNTAINS AND BOTH
THE SOUTH AND NORTH CAROLINA FOOTHILLS. AS THE MCS...OR ITS
REMNANTS APPROACH THE MOUNTAINS BY EARLY AFTERNOON...CONVECTION WILL
LIKELY INCREASE IN COVERAGE. FURTHERMORE...BY MID TO LATE
AFTERNOON...THERE IS A CHANCE THAT SHOWERS AND THUNDERSTORMS WILL
DEVELOP OVER THE PIEDMONT REGIONS OF NORTH AND SOUTH CAROLINA AS
THESE PROCESSES PROGRESS TO THE SOUTHEAST.
&&
.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/...
AS OF 215 PM WEDNESDAY...THE SHORT TERM WILL FEATURE DIURNALLY
DRIVEN CONVECTION ALONG WITH A WEAK ZONAL UPPER FLOW THROUGH SAT.
THE MODELS FORECAST A COUPLE WEAK IMPULSES MOVING ACROSS THE AREA AS
WELL. ANY REMNANT CONVECTION THU EVENING SHOULD DISSIPATE BEFORE
MIDNIGHT WITH PARTLY CLOUDY AND MILD CONDITIONS PREVAILING FOR THE
OVERNIGHT. PARTLY CLOUDY CONDITIONS SHOULD THEN PREVAIL THROUGH
FRIDAY...WITH SCATTERED SHOWERS/THUDNERSTORMS DEVELOPING OVER THE
MOUNTAINS BY EARLY AFTERNOON...AND IN THE FOOTHILLS AND PIEDMONT
AREAS DURING THE MID TO LATE AFTERNOON HOURS. CONVECTION SHOULD WANE
AGAIN FRI NIGHT...THEN SCATTERED SHOWERS/STORMS SHOULD FIRE BACK UP
SAT AFTERNOON ACROSS THE FORECAST AREA. WARM LOW LEVEL THICKNESS
VALUES WILL SUPPORT ABOVE AVERAGE TEMPS ON FRI AND SAT. USED A BLEND
OF GUIDANCE SOURCES TO GENERATE TEMP FIELDS.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
AS OF 140 PM WEDNESDAY...WPC FAVORED A BLEND OF THE 06Z GFS/00Z ECM
ENSEMBLES FOR THE MEDIUM RANGE. THE EXPECTATION IS FOR AN AMPLIFYING
UPPER RIDGE TO DEVELOP OVER THE EASTERN U.S. THE FIRST PART OF NEXT
WEEK AS A SIGNIFICANT UPPER TROUGH DEVELOPS OVER THE CENTRAL PART OF
THE COUNTRY. THE WEEKEND LOOKS LIKE IT WILL BE QUITE UNSETTLED AS A
REMNANT VORT MAX MOVES ACROSS THE AREA SAT NIGHT INTO SUNDAY...AND A
BACKDOOR COLD FRONT APPROACHES. THE LATEST GUIDANCE DOES KEEP THE
FRONT JUST TO THE NE OF THE AREA SAT NIGHT INTO SUN. HENCE...WILL
HAVE FAIRLY ROBUST POPS IN THE SAT NIGHT/SUN TIMEFRAME WITH THE
HIGHEST VALUES OVER THE NORTHERN REACHES OF THE FORECAST AREA. AS
THE UPPER RIDGE BUILDS NEXT WEEK...THE PRECIP SHOULD BECOME MORE
DIURNAL IN NATURE WITH THE HIGHEST COVERAGE OF SHOWERS/STORMS OVER
THE CLIMATOLOGICAL FAVORED MOUNTAINS. WITH MORE IN THE WAY OF
CLOUDINESS EXPECTED...MAX TEMPS SHOULD AVERAGE NEAR NORMAL SUN AND
MON...BUT RISE TO ABOUT A CATEGORY ABOVE AVERAGE FOR TUE AND WED.
&&
.AVIATION /03Z THURSDAY THROUGH MONDAY/...
AT KCLT AND ELSEWHERE...VFR CONDITIONS WILL CONTINUE TO PREVAIL
THROUGH THE ENTIRE TAF PERIOD. SOUTHWEST WINDS WILL DECREASE IN
MAGNITUDE DURING THE OVERNIGHT HOURS TONIGHT...BEFORE INCREASING YET
AGAIN BY LATE MORNING ON THURSDAY. MODEL GUIDANCE CONTINUES TO
INDICATE SOME INSTABILITY ACROSS THE ENTIRE REGION...MAINLY AFTER
18Z THURSDAY. KCLT APPEARS TO HAVE THE LOWEST CHANCE OF CONVECTION
TOMORROW AFTERNOON...AND THUNDER HAS NOT BEEN CARRIED AT THAT
AIRFIELD. ADDED VCSH AND CB/S AT THE OTHER AIRFIELDS EXCEPT KAND FOR
TOMORROW AFTERNOON.
OUTLOOK...VFR CONDITIONS ARE GENERALLY EXPECTED THROUGH THE REST OF
THE WEEK. HOWEVER...SCATTERED MAINLY AFTN AND EVENING THUNDERSTORMS
WILL BE POSSIBLE EACH AFTERNOON THROUGH THE WEEKEND.
CONFIDENCE TABLE...
02-08Z 08-14Z 14-20Z 20-02Z
KCLT HIGH 100% HIGH 100% HIGH 100% N/A
KGSP HIGH 100% HIGH 100% HIGH 100% N/A
KAVL HIGH 100% HIGH 100% HIGH 100% N/A
KHKY HIGH 100% HIGH 100% HIGH 100% N/A
KGMU HIGH 100% HIGH 100% HIGH 100% N/A
KAND HIGH 100% HIGH 100% HIGH 100% N/A
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...LEV
NEAR TERM...MCAVOY
SHORT TERM...LG
LONG TERM...LG
AVIATION...MCAVOY
000
FXUS62 KGSP 152341
AFDGSP
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
741 PM EDT WED MAY 15 2013
.SYNOPSIS...
HIGH PRESSURE SITUATED OFF THE CAROLINA COAST WILL DRIVE
SOUTHWESTERLY FLOW FOR THE WESTERN CAROLINAS AND NORTHEAST
GEORGIA... MAINTAINING A WARM AND MOIST AIRMASS THROUGHOUT THE
PERIOD. AN UPPER LEVEL DISTURBANCE WILL APPROACH ON THURSDAY AND
KEEP THE PATTERN UNSETTLED THROUGH EARLY NEXT WEEK... WITH A COLD
FRONT EXPECTED TO CROSS THE REGION BY LATE TUESDAY OR EARLY
WEDNESDAY.
&&
.NEAR TERM /THROUGH THURSDAY/...
AS OF 735 PM EDT...ISOLATED SHRA/TSTMS HAVE DEVELOPED OVER THE WRN
NC FOOTHILLS AND PIEDMONT IN A WEAK SFC CONVERGENCE AXIS. THE CELLS
MAY CONTINUE TO FIRE FOR ANOTHER HOUR OR TWO...BUT THEY SHOULD DIE
OUT AFTER THAT CONSIDERING THE WEAK SYNOPTIC SCALE FORCING.
AS OF 230 PM EDT...PLEASANT WEATHER CONDITIONS CONTINUE TO PREVAIL
ACROSS THE WESTERN CAROLINAS AND NORTHEAST GEORGIA. AMPLE SUNSHINE
AND SOUTH TO SOUTHWESTERLY FLOW AT THE SFC HAS PROPELLED
TEMPERATURES WELL INTO THE LOWER TO MID 80S WITH SOME SITES
REPORTING IN THE UPPER 80S.
OTHERWISE...UPPER LEVEL RIDGE CONTINUES TO DOMINATE THE WEATHER
ACROSS THE ENTIRE SOUTHEASTERN UNITED STATES. A RATHER LOW
AMPLITUDE LONG WAVE TROUGH...AND AN ASSOCIATED CUTOFF 570MB LOW WERE
LOCATED OVER WESTERN OKLAHOMA AND PORTIONS OF WEST TEXAS. WATER
VAPOR IMAGERY SHOWS A PLUME OF MOISTURE SPILLING IN ON THE EAST SIDE
OF THIS FEATURE ACROSS THE MIDSOUTH ALLOWING FOR SOME THUDNERSTORM
DEVELOPMENT. LOCALLY...THE ABOVE MENTIONED RIDGE LOOKS TO BREAK
DOWN OVER THE NEXT 24 HOURS AS THE WHOLE PATTERN SHIFTS EASTWARD.
LOOKING AT MODEL GUIDANCE...BOTH THE NAM AND THE GFS SHOW A
DEVELOPING MCS FEATURE OVER PORTIONS OF THE OHIO VALLEY DURING THE
MID TO LATE MORNING HOURS ON THURSDAY. AS THIS FEATURE CONTINUES TO
MOVE DOWNSTREAM IN THE NORTHWEST FLOW ALOFT...THE ATMOSPHERE WILL
CONTINUE TO DESTABILIZE OVER THE NORTH CAROLINA MOUNTAINS AND BOTH
THE SOUTH AND NORTH CAROLINA FOOTHILLS. AS THE MCS...OR ITS
REMNANTS APPROACH THE MOUNTAINS BY EARLY AFTERNOON...CONVECTION WILL
LIKELY INCREASE IN COVERAGE. FURTHERMORE...BY MID TO LATE
AFTERNOON...THERE IS A CHANCE THAT SHOWERS AND THUNDERSTORMS WILL
DEVELOP OVER THE PIEDMONT REGIONS OF NORTH AND SOUTH CAROLINA AS
THESE PROCESSES PROGRESS TO THE SOUTHEAST.
&&
.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/...
AS OF 215 PM WEDNESDAY...THE SHORT TERM WILL FEATURE DIURNALLY
DRIVEN CONVECTION ALONG WITH A WEAK ZONAL UPPER FLOW THROUGH SAT.
THE MODELS FORECAST A COUPLE WEAK IMPULSES MOVING ACROSS THE AREA AS
WELL. ANY REMNANT CONVECTION THU EVENING SHOULD DISSIPATE BEFORE
MIDNIGHT WITH PARTLY CLOUDY AND MILD CONDITIONS PREVAILING FOR THE
OVERNIGHT. PARTLY CLOUDY CONDITIONS SHOULD THEN PREVAIL THROUGH
FRIDAY...WITH SCATTERED SHOWERS/THUDNERSTORMS DEVELOPING OVER THE
MOUNTAINS BY EARLY AFTERNOON...AND IN THE FOOTHILLS AND PIEDMONT
AREAS DURING THE MID TO LATE AFTERNOON HOURS. CONVECTION SHOULD WANE
AGAIN FRI NIGHT...THEN SCATTERED SHOWERS/STORMS SHOULD FIRE BACK UP
SAT AFTERNOON ACROSS THE FORECAST AREA. WARM LOW LEVEL THICKNESS
VALUES WILL SUPPORT ABOVE AVERAGE TEMPS ON FRI AND SAT. USED A BLEND
OF GUIDANCE SOURCES TO GENERATE TEMP FIELDS.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
AS OF 140 PM WEDNESDAY...WPC FAVORED A BLEND OF THE 06Z GFS/00Z ECM
ENSEMBLES FOR THE MEDIUM RANGE. THE EXPECTATION IS FOR AN AMPLIFYING
UPPER RIDGE TO DEVELOP OVER THE EASTERN U.S. THE FIRST PART OF NEXT
WEEK AS A SIGNIFICANT UPPER TROUGH DEVELOPS OVER THE CENTRAL PART OF
THE COUNTRY. THE WEEKEND LOOKS LIKE IT WILL BE QUITE UNSETTLED AS A
REMNANT VORT MAX MOVES ACROSS THE AREA SAT NIGHT INTO SUNDAY...AND A
BACKDOOR COLD FRONT APPROACHES. THE LATEST GUIDANCE DOES KEEP THE
FRONT JUST TO THE NE OF THE AREA SAT NIGHT INTO SUN. HENCE...WILL
HAVE FAIRLY ROBUST POPS IN THE SAT NIGHT/SUN TIMEFRAME WITH THE
HIGHEST VALUES OVER THE NORTHERN REACHES OF THE FORECAST AREA. AS
THE UPPER RIDGE BUILDS NEXT WEEK...THE PRECIP SHOULD BECOME MORE
DIURNAL IN NATURE WITH THE HIGHEST COVERAGE OF SHOWERS/STORMS OVER
THE CLIMATOLOGICAL FAVORED MOUNTAINS. WITH MORE IN THE WAY OF
CLOUDINESS EXPECTED...MAX TEMPS SHOULD AVERAGE NEAR NORMAL SUN AND
MON...BUT RISE TO ABOUT A CATEGORY ABOVE AVERAGE FOR TUE AND WED.
&&
.AVIATION /00Z THURSDAY THROUGH MONDAY/...
AT KCLT AND ELSEWHERE...VFR CONDITIONS WILL CONTINUE TO PREVAIL
THROUGH THE ENTIRE TAF PERIOD. SOUTHWEST WINDS WILL DECREASE IN
MAGNITUDE DURING THE OVERNIGHT HOURS TONIGHT...BEFORE INCREASING YET
AGAIN BY LATE MORNING ON THURSDAY. MODEL GUIDANCE CONTINUES TO
INDICATE SOME INSTABILITY ACROSS THE ENTIRE REGION...MAINLY AFTER
18Z THURSDAY. KCLT APPEARS TO HAVE THE LOWEST CHANCE OF CONVECTION
TOMORROW AFTERNOON...AND THUNDER HAS NOT BEEN CARRIED AT THAT
AIRFIELD. ADDED VCSH AND CB/S AT THE OTHER AIRFIELDS EXCEPT KAND FOR
TOMORROW AFTERNOON.
OUTLOOK...VFR CONDITIONS ARE GENERALLY EXPECTED THROUGH THE REST OF
THE WEEK. HOWEVER...SCATTERED MAINLY AFTN AND EVENING THUNDERSTORMS
WILL BE POSSIBLE EACH AFTERNOON THROUGH THE WEEKEND.
CONFIDENCE TABLE...
23-05Z 05-11Z 11-17Z 17-23Z
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...LEV
NEAR TERM...MCAVOY
SHORT TERM...LG
LONG TERM...LG
AVIATION...MCAVOY
000
FXUS62 KGSP 151845
AFDGSP
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
245 PM EDT WED MAY 15 2013
.SYNOPSIS...
HIGH PRESSURE SITUATED OFF THE CAROLINA COAST WILL DRIVE
SOUTHWESTERLY FLOW FOR THE WESTERN CAROLINAS AND NORTHEAST
GEORGIA... MAINTAINING A WARM AND MOIST AIRMASS THROUGHOUT THE
PERIOD. AN UPPER LEVEL DISTURBANCE WILL APPROACH ON THURSDAY AND
KEEP THE PATTERN UNSETTLED THROUGH EARLY NEXT WEEK... WITH A COLD
FRONT EXPECTED TO CROSS THE REGION BY LATE TUESDAY OR EARLY
WEDNESDAY.
&&
.NEAR TERM /THROUGH THURSDAY/...
AS OF 230 PM EDT...PLEASANT WEATHER CONDITIONS CONTINUE TO PREVAIL
ACROSS THE WESTERN CAROLINAS AND NORTHEAST GEORGIA. AMPLE SUNSHINE
AND SOUTH TO SOUTHWESTERLY FLOW AT THE SFC HAS PROPELLED
TEMPERATURES WELL INTO THE LOWER TO MID 80S WITH SOME SITES
REPORTING IN THE UPPER 80S.
OTHERWISE...UPPER LEVEL RIDGE CONTINUES TO DOMINATE THE WEATHER
ACROSS THE ENTIRE SOUTHEASTERN UNITED STATES. A RATHER LOW
AMPLITUDE LONG WAVE TROUGH...AND AN ASSOCIATED CUTOFF 570MB LOW WERE
LOCATED OVER WESTERN OKLAHOMA AND PORTIONS OF WEST TEXAS. WATER
VAPOR IMAGERY SHOWS A PLUME OF MOISTURE SPILLING IN ON THE EAST SIDE
OF THIS FEATURE ACROSS THE MIDSOUTH ALLOWING FOR SOME THUNDERSTORM
DEVELOPMENT. LOCALLY...THE ABOVE MENTIONED RIDGE LOOKS TO BREAK
DOWN OVER THE NEXT 24 HOURS AS THE WHOLE PATTERN SHIFTS EASTWARD.
LOOKING AT MODEL GUIDANCE...BOTH THE NAM AND THE GFS SHOW A
DEVELOPING MCS FEATURE OVER PORTIONS OF THE OHIO VALLEY DURING THE
MID TO LATE MORNING HOURS ON THURSDAY. AS THIS FEATURE CONTINUES TO
MOVE DOWNSTREAM IN THE NORTHWEST FLOW ALOFT...THE ATMOSPHERE WILL
CONTINUE TO DESTABILIZE OVER THE NORTH CAROLINA MOUNTAINS AND BOTH
THE SOUTH AND NORTH CAROLINA FOOTHILLS. AS THE MCS...OR ITS
REMNANTS APPROACH THE MOUNTAINS BY EARLY AFTERNOON...CONVECTION WILL
LIKELY INCREASE IN COVERAGE. FURTHERMORE...BY MID TO LATE
AFTERNOON...THERE IS A CHANCE THAT SHOWERS AND THUNDERSTORMS WILL
DEVELOP OVER THE PIEDMONT REGIONS OF NORTH AND SOUTH CAROLINA AS
THESE PROCESSES PROGRESS TO THE SOUTHEAST.
&&
.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/...
AS OF 215 PM WEDNESDAY...THE SHORT TERM WILL FEATURE DIURNALLY
DRIVEN CONVECTION ALONG WITH A WEAK ZONAL UPPER FLOW THROUGH SAT.
THE MODELS FORECAST A COUPLE WEAK IMPULSES MOVING ACROSS THE AREA AS
WELL. ANY REMNANT CONVECTION THU EVENING SHOULD DISSIPATE BEFORE
MIDNIGHT WITH PARTLY CLOUDY AND MILD CONDITIONS PREVAILING FOR THE
OVERNIGHT. PARTLY CLOUDY CONDITIONS SHOULD THEN PREVAIL THROUGH
FRIDAY...WITH SCATTERED SHOWERS/THUNDERSTORMS DEVELOPING OVER THE
MOUNTAINS BY EARLY AFTERNOON...AND IN THE FOOTHILLS AND PIEDMONT
AREAS DURING THE MID TO LATE AFTERNOON HOURS. CONVECTION SHOULD WANE
AGAIN FRI NIGHT...THEN SCATTERED SHOWERS/STORMS SHOULD FIRE BACK UP
SAT AFTERNOON ACROSS THE FORECAST AREA. WARM LOW LEVEL THICKNESS
VALUES WILL SUPPORT ABOVE AVERAGE TEMPS ON FRI AND SAT. USED A BLEND
OF GUIDANCE SOURCES TO GENERATE TEMP FIELDS.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
AS OF 140 PM WEDNESDAY...WPC FAVORED A BLEND OF THE 06Z GFS/00Z ECM
ENSEMBLES FOR THE MEDIUM RANGE. THE EXPECTATION IS FOR AN AMPLIFYING
UPPER RIDGE TO DEVELOP OVER THE EASTERN U.S. THE FIRST PART OF NEXT
WEEK AS A SIGNIFICANT UPPER TROUGH DEVELOPS OVER THE CENTRAL PART OF
THE COUNTRY. THE WEEKEND LOOKS LIKE IT WILL BE QUITE UNSETTLED AS A
REMNANT VORT MAX MOVES ACROSS THE AREA SAT NIGHT INTO SUNDAY...AND A
BACKDOOR COLD FRONT APPROACHES. THE LATEST GUIDANCE DOES KEEP THE
FRONT JUST TO THE NE OF THE AREA SAT NIGHT INTO SUN. HENCE...WILL
HAVE FAIRLY ROBUST POPS IN THE SAT NIGHT/SUN TIMEFRAME WITH THE
HIGHEST VALUES OVER THE NORTHERN REACHES OF THE FORECAST AREA. AS
THE UPPER RIDGE BUILDS NEXT WEEK...THE PRECIP SHOULD BECOME MORE
DIURNAL IN NATURE WITH THE HIGHEST COVERAGE OF SHOWERS/STORMS OVER
THE CLIMATOLOGICAL FAVORED MOUNTAINS. WITH MORE IN THE WAY OF
CLOUDINESS EXPECTED...MAX TEMPS SHOULD AVERAGE NEAR NORMAL SUN AND
MON...BUT RISE TO ABOUT A CATEGORY ABOVE AVERAGE FOR TUE AND WED.
&&
.AVIATION /19Z WEDNESDAY THROUGH MONDAY/...
AT KCLT AND ELSEWHERE...VFR CONDITIONS WILL CONTINUE TO PREVAIL
THROUGH THE ENTIRE TAF PERIOD. SOUTHWEST WINDS WILL DECREASE IN
MAGNITUDE DURING THE OVERNIGHT HOURS TONIGHT...BEFORE INCREASING YET
AGAIN BY LATE MORNING ON THURSDAY. MODEL GUIDANCE CONTINUES TO
INDICATE SOME INSTABILITY ACROSS THE ENTIRE REGION...MAINLY AFTER
18Z THURSDAY SO THUNDERSTORMS ARE NOT EXPECTED BEFORE THE END OF THE
TAF PERIOD.
OUTLOOK...VFR CONDITIONS ARE GENERALLY EXPECTED THROUGH THE REST OF
THE WEEK. HOWEVER...SCATTERED AFTN AND EVENING THUNDERSTORMS WILL BE
POSSIBLE FROM THURSDAY AFTERNOON THROUGH THE WEEKEND.
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...LEV
NEAR TERM...CDG/PM
SHORT TERM...LG
LONG TERM...LG
AVIATION...CDG/PM
000
FXUS62 KGSP 151757
AFDGSP
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
157 PM EDT WED MAY 15 2013
.SYNOPSIS...
HIGH PRESSURE SITUATED OFF THE CAROLINA COAST WILL DRIVE
SOUTHWESTERLY FLOW FOR THE WESTERN CAROLINAS AND NORTHEAST
GEORGIA... MAINTAINING A WARM AND MOIST AIRMASS THROUGHOUT THE
PERIOD. AN UPPER LEVEL DISTURBANCE WILL APPROACH ON THURSDAY AND
KEEP THE PATTERN UNSETTLED THROUGH EARLY NEXT WEEK... WITH A COLD
FRONT EXPECTED TO CROSS THE REGION BY LATE TUESDAY OR EARLY
WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 145 PM EDT...TEMPERATURES ACROSS THE REGION HAVE STRECTHED
INTO THE LOWER TO MID 80S WITH MOSTLY CLEAR SKIES. SOUTHWEST
WINDS IN THE 8-10KTS RANGE PREVAILED ACROSS MOST OF THE
REGION...WITH ASHEVILLE SEEING SOME GUSTING UP THE FRENCH BROAD
VALLEY.
REMAINDER OF PREVIOUS DISCUSSION...
THE H5 LOW WILL MEANDER INTO THE MID MS RIVER VALLEY TONIGHT...WITH
ALL ATTENDANT SHORTWAVE ENERGY STAYING W OF THE FORECAST AREA
THROUGH THE PERIOD. EXPECT MAINLY AN INCREASE IN HIGH CLOUDS FROM
THE W OVERNIGHT...WITH MIN TEMPERATURES 1 TO 2 CATEGORIES ABOVE
NORMAL.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY/...
AS OF 225 AM WEDNESDAY...BROAD MID LEVEL RIDGING WILL REMAIN OVER
THE FORECAST AREA BY SUNRISE THURSDAY. DURING THE AFTERNOON AND
EVENING...THE H5 TROUGH WILL RIPPLE ACROSS THE SOUTHERN MISSISSIPPI
RIVER VALLEY...RESULTING IN FALLING HEIGHTS ACROSS THE SOUTHERN
APPALACHIANS. AT THE SFC...A WEST TO EAST FRONT WILL BECOMING
STATIONARY ACROSS THE MID APPALACHIANS AND MID ATLANTIC STATES...WITH
HIGH PRESSURE ACROSS THE SOUTHEAST. FORECAST SOUNDINGS INDICATE
FAIRLY MILD TEMPERATURES BELOW H5 WITH DEEP WEST WINDS. A CONSENSUS
OF MOS GUIDANCE SUPPORTS HIGHS WITHIN THE MTN VALLEYS IN THE LOW 80S
WITH MID TO UPPER 80S EAST...DEWPOINTS IN THE LOW TO MID 50S.
FORECAST SOUNDINGS ALSO INDICATES CIN VALUES BETWEEN 50-100 J/KG
EAST OF THE MTNS. I WILL FORECAST CHC POPS ACROSS THE MTNS FOR
SHRA/TSRA...FAVORING THE TN LINE FOR THE GREATEST COVERAGE. EAST OF
THE MTNS...INHIBITION SHOULD KEEP DEEP CONVECTION LIMITED TO ISO
COVERAGE. CONVECTION IS FORECAST TO SLOWLY ASHE OUT DURING THE
EVENING HOURS. CLOUD COVER AND MILE LLVL THICKNESSES WILL FAVOR MIN
TEMPERATURES AROUND 3 TO 5 DEGREES ABOVE NORMAL.
FRIDAY...THE H5 TROF OR CLOSED LOW IS EXPECTED TO SLIDE OVER THE
FORECAST AREA DURING THE AFTERNOON. SHORT RANGE MODELS SHOW VERY
LITTLE CHANGE IN THE SFC FEATURES FROM THURSDAY.
HOWEVER...INCREASING MOISTURE AND GRADUALLY RISING DEWPOINTS SHOULD
PROVIDE SLIGHT INCREASE IN CONDITIONAL INSTABILITY WITH SHALLOW CIN
LAYER. I WILL FORECAST CHC POPS ACROSS THE NC AND MTN ZONES...SCHC
ELSEWHERE. HIGH TEMPERATURES WILL LIKELY RANGE VERY CLOSE TO
THURSDAY VALUES.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
AS OF 140 PM WEDNESDAY...WPC FAVORED A BLEND OF THE 06Z GFS/00Z ECM
ENSEMBLES FOR THE MEDIUM RANGE. THE EXPECTATION IS FOR AN AMPLIFYING
UPPER RIDGE TO DEVELOP OVER THE EASTERN U.S. THE FIRST PART OF NEXT
WEEK AS A SIGNIFICANT UPPER TROUGH DEVELOPS OVER THE CENTRAL PART OF
THE COUNTRY. THE WEEKEND LOOKS LIKE IT WILL BE QUITE UNSETTLED AS A
REMNANT VORT MAX MOVES ACROSS THE AREA SAT NIGHT INTO SUNDAY...AND A
BACKDOOR COLD FRONT APPROACHES. THE LATEST GUIDANCE DOES KEEP THE
FRONT JUST TO THE NE OF THE AREA SAT NIGHT INTO SUN. HENCE...WILL
HAVE FAIRLY ROBUST POPS IN THE SAT NIGHT/SUN TIMEFRAME WITH THE
HIGHEST VALUES OVER THE NORTHERN REACHES OF THE FORECAST AREA. AS
THE UPPER RIDGE BUILDS NEXT WEEK...THE PRECIP SHOULD BECOME MORE
DIURNAL IN NATURE WITH THE HIGHEST COVERAGE OF SHOWERS/STORMS OVER
THE CLIMATOLOGICAL FAVORED MOUNTAINS. WITH MORE IN THE WAY OF
CLOUDINESS EXPECTED...MAX TEMPS SHOULD AVERAGE NEAR NORMAL SUN AND
MON...BUT RISE TO ABOUT A CATEGORY ABOVE AVERAGE FOR TUE AND WED.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
AT KCLT AND ELSEWHERE...VFR CONDITIONS WILL CONTINUE TO PREVAIL
THROUGH THE ENTIRE TAF PERIOD. SOUTHWEST WINDS WILL DECREASE IN
MAGNITUDE DURING THE OVERNIGHT HOURS TONIGHT...BEFORE INCREASING YET
AGAIN BY LATE MORNING ON THURSDAY. MODEL GUIDANCE CONTINUES TO
INDICATE SOME INSTABILITY ACROSS THE ENTIRE REGION...MAINLY AFTER
18Z THURSDAY SO THUNDERSTORMS ARE NOT EXPECTED BEFORE THE END OF THE
TAF PERIOD.
OUTLOOK...VFR CONDITIONS ARE GENERALLY EXPECTED THROUGH THE REST OF
THE WEEK. HOWEVER...SCATTERED AFTN AND EVENING THUNDERSTORMS WILL BE
POSSIBLE FROM THURSDAY AFTERNOON THROUGH THE WEEKEND.
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...LEV
NEAR TERM...CDG/PM
SHORT TERM...NED
LONG TERM...LG
AVIATION...CDG/PM
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