Special Weather Statement, NWS Greenville-Spartanburg, SC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
753 PM EDT FRI MAR 30 2012

.SYNOPSIS...
AN UPPER LEVEL DISTURBANCE WILL MOVE FROM THE GULF STATES TO THE
CAROLINA COAST BY LATE SATURDAY. DRIER AIR WILL MOVE IN SATURDAY
NIGHT THROUGH MONDAY ASSOCIATED WITH AN UPPER LEVEL RIDGE. EXPECT
ANOTHER NORTHERN GULF WEATHER DISTURBANCE TO MOVE TOWARD THE REGION
BY THE MIDDLE OF NEXT WEEK.

&&

.NEAR TERM /THROUGH SATURDAY/...
AS OF 745 PM...WIDESPREAD GENERALLY LIGHT RETURNS ON RADAR ACRS THE
AREA...AS DEEP RH AND MCV ENCROACHES ON THE CWFA FROM THE WEST THIS
EVENING. HAVE TWEAKED POPS BASED ON TRENDS. LIKELY POPS LOOKS GOOD
WITH ONLY ISOLD-SCT TSTM MENTION GIVEN LACK OF INSTBY.
OTHERWISE...ONLY MINOR TWEAKS TO THE FCST THRU SATURDAY FOR 00Z TAFS.

PREVIOUS DISCUSSION...
AT 230 PM EDT FRIDAY...THE REMNANTS OF A SOUTHERN STREAM UPPER LOW
WILL APPROACH OUR AREA FROM THE WSW LATE TODAY...CROSSING THE AREA
TONIGHT. ACTIVITY NOW IN AL IS EXPECTED OT REACH OUR AREA BY EARLY
EVENING...TAKING MOST OF THE NIGHT TO PASS THROUGH. INSTABILITY IS
EXPECTED TO BE LIMITED. MODEL GUIDANCE SUPPORTS FOG DEVELOPMENT LATE
TONIGHT IN THE RAIN SOAKED AIR...BUT SUPPORT FOR DENSE FOG IS
MARGINAL AND SPOTTY AT THIS POINT. MINIMUM TEMPERATURES WILL BE NEAR
MID MAY NORMALS UNDER CLOUD COVER WITH A LIGHT SW WIND.

A SHORTWAVE WILL DIVE SOUTHEAST TOWARD OUR AREA FROM THE NORTHERN
PLAINS TONIGHT...AND AN ASSOCIATED COLD FRONT WILL REACH OUR AREA
SATURDAY MORNING...CROSSING THE AREA BY MID AFTERNOON. THIS BOUNDARY
WILL HAVE A BETTER CHANCE OF PRODUCING THUNDERSTORMS WITH DAYTIME
HEATING...ALTHOUGH CAPE VALUES APPEAR TO REMAIN BELOW 700 J/KG...AND
SHEAR IS SOMEWHAT LIMITED. SCATTERED NW FLOW RAIN SHOWERS WILL
PERSIST ALONG THE TN BORDER THROUGH THE AFTERNOON. MAXIMUM
TEMPERATURES WILL BE NEAR MID MAY NORMALS AS A DOWNSLOPE FLOW
FOLLOWS THE FRONTAL PASSAGE.

&&

.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
AS OF 230 PM FRIDAY...A WEAK COLD FRONT WILL CONTINUE TO MOVE SOUTH
OF THE AREA SAT NIGHT WITH SURFACE HIGH PRESSURE RIDGING ACROSS THE
WESTERN CAROLINAS/NE GA BY 12Z SUNDAY. ANY LEFT OVER MOUNTAIN
CONVECTION SAT EVENING IS EXPECTED TO DISSIPATE RAPIDLY AROUND 00Z.
UPPER HEIGHTS ARE FORECAST TO RISE THROUGH THE FIRST OF THE WEEK AS
AN UPPER RIDGE DEVELOPS OVER THE CNETRAL U.S. AND MOVES EASTWARD.
HENCE...GENERALLY DRY WEATHER WITH MUCH ABOVE AVERAGE TEMPS ARE IN
THE OFFING FOR THE PERIOD. THE EXCEPTION TO THE DRY FORECAST WILL BE
MONDAY AFTERNOON OVER THE MOUNTAINS WHERE SCATTERED LATE DAY
CONVECTION MAY DEVELOP AS INSTABILITY INCREASES. OUTSIDE THE
MOUNTAINS...MAX TEMPS SUNDAY ARE EXPECTED TO TOP OUT MAINLY IN THE
UPPER 70S TO LOWER 80S...AND THEN WARM INTO THE MID TO UPPER 80S ON
MONDAY. IN THE MOUNTAIN VALLEYS...HIGHS WILL BE IN THE MID TO UPPER
70S SUNDAY...WARMING TO AROUND 80 ON MONDAY.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
AS OF 200 PM FRIDAY...GFS AND ECM IN GENERAL AGREEMENT THAT UPPER
RIDGE OVER THE SE U.S. AT THE VERY BEGINNING OF THE PERIOD WILL
QUICKLY DISSIPATE AS A STRONG TROUGH DEVELOPS IN NEW ENGLAND BY
MIDWEEK WHICH WILL LOWER HEIGHTS ALL ALONG THE EAST COAST. AT THE
SAME TIME...IT APPEARS THAT THE CLOSED LOW OVER TX WILL TEND TO BE
SHUNTED SE DUE TO THE DEVELOPING TROUGH ALONG THE EAST COAST. MODELS
INDICATE THAT A BACKDOOR COLD FRONT WILL MAKE A RUN AT THE AREA MON
NIGHT...BUT EXPECT THAT IT WILL WASH OUT ON TUE AS A SUBTROPICAL
HIGH  HOLDS SWAY OVER THE AREA. AS EAST COAST UPPER TROUGH DEVELOPS
EXPECT A SURFACE COLD FRONT TO APPROACH TUE NIGHT AND PASS THROUGH
THE AREA SOMETIME ON WED. IN REGARD TO POPS...WILL DISREGARD ANY
PRECIP RESPONSE BY MODELS WITH BACKDOOR FRONT MON NIGHT AND ONLY
INDICATE SCATTERED DIURNAL CONVECTION IN THE MOUNTAINS TUE
AFTERNOON. WILL THEN RAMP UP POPS ALL AREAS LATE TUE NIGHT AND WED
WITH EXPECTED FRONTAL PASSAGE...AND THEN DRY THINGS OUT FOR THU AND
FRI. HPC GUIDANCE HINTS AT A POTENTIAL WAVE ALONG THE FRONT FOR THU
WHICH COULD COMPLICATE THE FORECAST...SO HAVE LEFT SOME LOW END
CHANCE POPS ACROSS THE SOUTHERN UPSTATE ON THU. FOR NOW WILL
ANTICIPATE CANADIAN HIGH PRESSURE ESSENTIALLY BUILDING SOUTH OVER
THE AREA ON THU WHICH WILL CONTINUE TO DOMINATE THE WEATHER FOR FRI.
STAYED CLOSE TO HPC TEMP GUIDANCE WHICH IS MUCH ABOVE AVERAGE FOR
TUE...THEN GRADUALLY COOLING TO NEAR AVERAGE VALUES BY FRI.

&&

.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
AT KCLT...AT TIME OF 00Z TAF ISSUANCE...NUMEROUS SHOWERS ACRS THE
AREA...WITH ONLY A COUPLE OF EMBEDDED TSTMS ACRS GA. THERE IS JUST
ENUF INSTBY THAT A COUPLE OF THE SHWRS INVOF THE UPSTATE AND KCLT
TERMINALS COULD PRODUCE LIGHTNING. WILL KEEP CB MENTION FOR NEXT
NEXT FEW HOURS...BUT MAY BE REMOVED WITH AMENDMENTS LATER THIS
EVENING. AS FOR RESTRICTIONS...A BELOW AVERAGE CONFIDENCE FCST...AS
GUIDANCE SEEMS TO BE HITTING LOW CIGS AND VSBY HARD CONSIDERING THE
LOW DEWPTS AND COPIOUS MID-HIGH CLOUD COVER. I TRIED NOT TO STRAY
TOO FAR FROM PREVIOUS TAFS...TAKING A BLEND OF GUIDANCE. WITH THAT
SAID...AS WIDESPREAD SHWRS OVERSPREAD THE AREA LATER THIS
EVENING...PROBABLY WILL BE AT LEAST MVFR CIGS/VSBY AT TIMES THRU
DAYBREAK SAT (AND SOME IFR IN SPOTS). WINDS SHIFT TO NW AND DRY AIR
QUICKLY SHUD HELP IMPROVE CONDITIONS TO VFR LATE MORNING. SOME
CONVECTION MAY DEVELOP NEAR THE UPSTATE AND CLT SITES SAT AFTN...BUT
COVERAGE IS EXPECTED TO BE FAIRLY LOW. SO NO MENTION WITH THESE TAFS.

OUTLOOK...FOG MAY DEVELOP SUNDAY MORNING BEHIND THE FRONT...WITH
DRIER CONDITIONS EXPECTED LATER SUNDAY AND MONDAY. ANOTHER SYSTEM
APPROACHES TUESDAY...BUT RESTRICTIONS SHOULD HOLD OFF UNTIL
WEDNESDAY.

AN EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLE SHOWING THE
PERCENTAGE OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED ISSUANCE
CATEGORY IS AVAILABLE AT FOLLOWING LINK (USE LOWER CASE)...

WWW.WEATHER.GOV/GSP/AVIATION/TABLES.HTM

&&

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

&&

SYNOPSIS...DEO
NEAR TERM...ARK/JAT
SHORT TERM...LG
LONG TERM...LG
AVIATION...ARK

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
311 PM EDT FRI MAR 30 2012

GAZ010-017-018-026-028-029-NCZ033-035>037-048>053-056>059-062>065-
068>072-082-501>510-SCZ001>014-019-311915-
RABUN-HABERSHAM-STEPHENS-FRANKLIN-HART-ELBERT-AVERY-ALEXANDER-
IREDELL-DAVIE-MADISON-YANCEY-MITCHELL-SWAIN-HAYWOOD-BUNCOMBE-CATAWBA-
ROWAN-GRAHAM-NORTHERN JACKSON-MACON-SOUTHERN JACKSON-TRANSYLVANIA-
HENDERSON-CLEVELAND-LINCOLN-GASTON-MECKLENBURG-CABARRUS-UNION NC-
CALDWELL MOUNTAINS-GREATER CALDWELL-BURKE MOUNTAINS-GREATER BURKE-
MCDOWELL MOUNTAINS-EASTERN MCDOWELL-RUTHERFORD MOUNTAINS-
GREATER RUTHERFORD-POLK MOUNTAINS-EASTERN POLK-OCONEE MOUNTAINS-
PICKENS MOUNTAINS-GREENVILLE MOUNTAINS-GREATER OCONEE-
GREATER PICKENS-GREATER GREENVILLE-SPARTANBURG-CHEROKEE-YORK-
ANDERSON-ABBEVILLE-LAURENS-UNION SC-CHESTER-GREENWOOD-
311 PM EDT FRI MAR 30 2012

THIS HAZARDOUS WEATHER OUTLOOK IS FOR NORTHEAST GEORGIA...PIEDMONT
NORTH CAROLINA...WESTERN NORTH CAROLINA AND UPSTATE SOUTH CAROLINA.

.DAY ONE...THIS AFTERNOON AND TONIGHT.

NUMEROUS SHOWERS AND SCATTERED THUNDERSTORMS WILL DEVELOP OVER THE
REGION THIS EVENING AND CONTINUE INTO THE NIGHT. THE MAIN THREAT FROM
THE THUNDERSTORMS THROUGH TONIGHT WILL BE BRIEF HEAVY RAIN AND
CLOUD TO GROUND LIGHTNING.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY.

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...

NONE.

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
813 PM EDT FRI MAR 30 2012

NCZ057-071-072-310045-
CABARRUS-MECKLENBURG-ROWAN-
813 PM EDT FRI MAR 30 2012

...STRONG THUNDERSTORMS WILL AFFECT CABARRUS...EASTERN MECKLENBURG
AND SOUTHERN ROWAN COUNTIES THROUGH 845 PM EDT...

AT 812 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
STRONG THUNDERSTORMS ALONG A LINE EXTENDING FROM 6 MILES EAST OF
HUNTERSVILLE TO 5 MILES SOUTH OF HARRISBURG...MOVING NORTHEAST AT 25
MPH.

THESE STORMS WILL BE NEAR...
  CHARLOTTE MOTOR SPEEDWAY...
  KANNAPOLIS...
  LANDIS...
  MOUNT PLEASANT...

WIND GUSTS OF 30 TO 40 MPH ARE EXPECTED WITH THESE STORMS.

LAT...LON 3534 8039 3533 8041 3525 8045 3521 8066
      3545 8080 3564 8046 3541 8035

RB