Severe Thunderstorm Warning 293, NWS Greenville-Spartanburg, SC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
1100 AM EDT SUN JUL 18 2010

.SYNOPSIS...
WITH THE BERMUDA HIGH TO OUR EAST...MOIST SOUTHERLY FLOW WILL
PERSIST THROUGH THE EARLY PART OF THE WEEK...AND THE CHANCE OF
AFTERNOON SHOWERS AND THUNDERSTORMS WILL CONTINUE. EXPECT HOT
WEATHER WITH LOWERING CHANCES OF THUNDERSTORMS TO RETURN BY THE
MIDDLE OF NEXT WEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
THE WEAK UPPER LEVEL TROUGH WILL REMAIN IN PLACE THROUGH THE
AFTERNOON. NO SIGNIFICANT WAVES ARE INDICATED IN THE NEAR TERM
MODELS THIS AFTN...BUT MOIST PROFILES WITH PRECIPITABLE WATER VALUES
NEAR TWO INCHES SHOULD ALLOW VERY SOLID SCATTERED COVERAGE OF
SHOWERS/TSTMS TO DEVELOP. THE MOIST PROFILES SHOULD ALSO KEEP
HEATING DOWN...LIMIT CAPE...AND MAKE ANY SEVERE WIND THREAT
MARGINAL. ONCE AGAIN...ANY HYDRO THREAT SHOULD BE LIMITED TO AREAS
OF TRAINING CELLS.

ANY LINGERING CONVECTION SHOULD STEADILY WEAKEN TONIGHT...BUT COULD
SEE WRN MTN COVERAGE INCREASE AGAIN OVERNIGHT AS AN UPSTREAM
SHORTWAVE APPROACHES THE MTNS.

&&

.SHORT TERM /MONDAY THROUGH TUESDAY/...
AS OF 245 PM SUNDAY...TONIGHT SHOULD ACTUALLY BE RATHER SIMILAR TO
SATURDAY NIGHT. ALTHOUGH THERE WILL BE A GENERAL ABSENCE OF
ORGANIZED FORCING FOR UVV...PLENTIFUL MOISTURE/LINGERING INSTABILITY
WILL LIKELY RESULT IN AT LEAST ISLD SHOWERS/STORMS FOR MUCH OF THE
OVERNIGHT. OTHERWISE...HIGH MOISTURE CONTENT AND CLOUD COVER SHOULD
RESULT IN ANOTHER NIGHT WITH ABOVE NORMAL MIN TEMPS.

ANOTHER WEAK SW TROUGH IS EXPECTED TO APPROACH THE REGION BY MONDAY
AFTERNOON. THIS SHOULD ACT ON A MODERATELY UNSTABLE YET VERY MOIST
ATMOSPHERE TO PRODUCE SCT/NUMEROUS COVERAGE OF CONVECTION DURING THE
AFTERNOON. WE HAVE OPTED TO KEEP POPS IN THE CHANCE RANGE FOR NOW...
BUT WOULD NOT BE SURPRISED IF LIKELY POPS BECOME NECESSARY...ESP
OVER THE HIGHER TERRAIN.

FOR TUESDAY...THERE WILL NOT BE AS MUCH IN THE WAY OF UPPER
SUPPORT...BUT WITH THE REGION STILL POISED UNDER THE SOUTHERN EXTENT
OF THE WESTERLIES...LAYER RH VALUES OF AROUND 70 PERCENT...AND
MODERATE INSTABILITY...ANOTHER ROUND OF SCT DIURNAL CONVECTION CAN
BE EXPECTED TUE AFTERNOON. PERSISTENT JUICY/SOMEWHAT CLOUDY AIR MASS
WILL ENSURE NEAR-NORMAL MAX TEMPS AND ABOVE NORMAL LOWS THROUGH THE
PERIOD.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
AS OF 255 AM SUNDAY...THE MAIN FEATURE OF THE EXTENDED WILL BE A
BUILDING UPPER RIDGE...WHICH WILL LEAD TO VERY WARM TEMPS AND LESS
IN THE WAY OF CONVECTIVE COVERAGE. HOWEVER...THE SIGNAL IN THE
GLOBAL MODELS IS THAT MOISTURE WILL REMAIN IN RELATIVE ABUNDANCE...
PARTICULARLY NEAR THE SURFACE. THEREFORE...CONVECTIVE CHANCES ARE
NOT EXPECTED TO DISAPPEAR COMPLETELY DURING THE MIDDLE/LATTER PART
OF NEXT WEEK.

&&

.AVIATION /15Z SUNDAY THROUGH THURSDAY/...
AT KCLT...EXCEPT SW FLOW AT LESS THAN 10 KT THROUGH THE DAY...WITH
GENERALLY ALTOCUMULUS MID LEVEL CEILINGS. SOME CU EARLY AND THEN CB
LATER THIS AFTN WILL LIKELY DEVELOP...BUT CONFIDENCE REMAINS LOW ON
TIMING THE ACTIVITY. WILL FEATURE VCSH AFTER 17Z FOR NOW. DIURNAL
CONVECTION WILL END THIS EVENING WITH A RETURN TO HIGH CLOUDS AND
CONTINUED LIGHT SW FLOW OVERNIGHT.

ELSEWHERE...MID AND HIGH CLOUDS WILL GIVE WAY TO CB CIGS THROUGH THE
AFTN WITH HEATING. NO SIGNIFICANT SOURCES OF LIFT ARE EXPECTED...BUT
SHOWER AND TSTM COVERAGE WILL STEADILY INCREASE IN THE VERY MOIST
AIRMASS. VCSH ARE ALREADY NEEDED FROM KAND TO KGSP...AND WILL BE
LIKELY THROUGHOUT THIS AFTN/EVENING. ANY RESTRICTIONS SHOULD ONLY BE
ASSOCIATED WITH TSTMS AND THESE ARE TOO UNCERTAIN TO INCLUDE IN TAF
AT PRESENT. A RETURN TO MVFR VSBY IS EXPECTED OVERNIGHT AT KAVL AND
KHKY.

OUTLOOK...TYPICAL SUMMER PATTERN WILL SET UP FOR THE WEEK WITH AREAS
OF MRNG FOG AND SCT AFTN-EVE TSTMS EACH DAY.

&&

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

&&

SYNOPSIS...BSH
NEAR TERM...HG
SHORT TERM...JDL
LONG TERM...JDL
AVIATION...HG

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
614 AM EDT SUN JUL 18 2010

GAZ010-017-018-026-028-029-NCZ033-035>037-048>053-056>059-062>065-
068>072-082-501>510-SCZ001>014-019-191015-
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-
614 AM EDT SUN JUL 18 2010

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

.DAY ONE...TODAY AND TONIGHT.

SCATTERED SHOWERS AND THUNDERSTORMS WILL DEVELOP ONCE AGAIN THIS
AFTERNOON. THE MAIN THREAT WITH THESE STORMS WILL BE FROM LOCALLY
HEAVY RAINFALL AND CLOUD TO GROUND LIGHTNING. HOWEVER...AN ISOLATED
SEVERE STORM OR TWO MAY PRODUCE LOCALLY DAMAGING WINDS. IN
ADDITION...THERE IS A THREAT FOR ISOLATED AREAS OF EXCESSIVE
RAINFALL AND FLASH FLOODING...PARTICULARLY IN URBAN LOCATIONS AND
OTHER FLOOD PRONE AREAS.

.DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY.

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...

SKYWARN SPOTTERS ARE REQUESTED TO FORWARD ANY REPORTS OF LARGE
HAIL...DAMAGING WINDS...TORNADOES OR FLASH FLOODING TO OUR OFFICE.

LANE

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
1200 PM EDT SUN JUL 18 2010

NCZ501-502-181645-
CALDWELL MOUNTAINS-GREATER CALDWELL-
1200 PM EDT SUN JUL 18 2010

...A STRONG THUNDERSTORM WILL AFFECT NORTHERN CALDWELL COUNTY THROUGH
1245 PM EDT...

AT 1158 AM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM NEAR GLOBE...OR 6 MILES SOUTH OF BLOWING ROCK...
MOVING EAST AT 10 MPH.

THIS STORM WILL AFFECT MAINLY LOCATIONS FROM UPTON TO NEAR
PATTERSON. PEA SIZE HAIL...WIND GUSTS OF 30 TO 40 MPH...AND
TORRENTIAL RAINFALL ARE EXPECTED WITH THIS STORM. THE HEAVY RAIN MAY
FLOOD LOW LYING AREAS SUCH AS DITCHES AND UNDERPASSES...AND PRODUCE
RAPID RISES ON STREAMS AND CREEK.S

LAT...LON 3610 8152 3609 8146 3606 8140 3602 8135
      3590 8136 3596 8178 3599 8178 3605 8173
      3608 8178 3611 8177 3612 8155

HG