Hail in North Carolina, May 18, 2010

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
218 PM EDT TUE MAY 18 2010

.SYNOPSIS...
HIGH PRESSURE WILL SLOWLY BUILD OVER THE CAROLINAS FROM THE
NORTHWEST ON WEDNESDAY AND THURSDAY...BEFORE SHIFTING EAST AND
MOVING OFF THE ATLANTIC COAST FRIDAY. A WARM FRONT WILL CROSS THE
AREA FRIDAY EVENING...AS LOW PRESSURE REMAINS TO OUR NORTHWEST THROUGH
THE WEEKEND.

&&

.NEAR TERM /THROUGH WEDNESDAY/...
A WEAK COLD FRONT WILL CROSS THE REGION FROM THE NW THIS EVENING.
THE RUC POOLS ENOUGH MOISTURE FOR CAPE VALUES TO INCREASE TO AROUND
1000 J/KG FOR A FEW HOURS...MAINLY ACROSS THE NRN UPSTATE AND SRN NC
FOOTHILLS AND PIEDMONT. SCT SHRA HAVE DEVELOPED OVER THE WRN PART OF
THE UPSTATE ALREADY. THEY SHOULD SLOWLY BECOME STRONGER AS THE AFTN
PROGRESSES AND A FEW OF THEM ARE LIKELY TO GROW INTO TSTMS. WITH THE
BROAD UPPER LOW PASSING TO OUR NORTH THIS EVENING...A BAND OF 50 KT
MID-TROPOSPHERIC WINDS WILL EXTEND ACROSS THE FA FOR SEVERAL MORE
HOURS. WITH THIS AMOUNT OF SHEAR AND INSTABILITY ONE OR TWO OF THE
STORMS COULD APPROACH SEVERE LIMITS. HOWEVER...LAPS SOUNDINGS
INDICATE THAT THE CAPE IS NOT DENSE IN THE BEST HAIL GROWTH ZONE
WHICH IS UP AROUND THE -10 TO -30 DEG C LEVEL. THE BNDRY LAYER IS
ALSO FAIRLY COOL...WHICH WILL LIMIT MICROBURST POTENTIAL.
THEREFORE...I WILL LEAVE OUT ANY MENTION OF SEVERE STORMS FROM THE
HWO FOR THE LATE AFTN AND EVENING HOURS.

LATER TONIGHT ANOTHER ROUND OF LOW CLOUDS IS LIKELY OVER THE NC
FOOTHILLS AND PIEDMONT. A DRIER WNW FLOW OVER THE UPSTATE SHOULD
KEEP THE LOW CLOUD COVER FROM MAKING IT THAT FAR SOUTH.

ON WED THE NAM POOLS MOISTURE ALONG THE NC/SC BORDER ALONG THE
PERSISTENT FRONTAL BNDRY...DEVELOPING A NARROW BAND OF FAIRLY HIGH
CAPE. HOWEVER...THE GFS IS MUCH DRIER WITH WEAKER CONVERGENCE. THE
SREF MEAN WIND...PRESSURE AND CAPE FIELDS ALSO IMPLY THAT THE NAM IS
OVERDONE. I HAVE ADDED SLIGHT CHANCE POPS TO THE I-77 CORRIDOR FOR
THE AFTN HOURS AS A FEW SHRA OR EVEN A TSTM CAN/T BE RULED OUT...BUT
I/M NOT LOOKING FOR ANYTHING STRONG OR WIDESPREAD.

&&

.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/...
AS OF 230 PM TUESDAY...WED NIGHT THROUGH THU NIGHT LOOK TO BE RATHER
QUIET AS HIGH PRESSURE TO THE NORTH NOSES INTO THE AREA AND THEN
GRADUALLY MOVES TO THE E. ANY SHOWERS DURING THIS TIME SHOULD BE
CONFINED TO THE UPSLOPE AREAS IN FAR WESTERN NC. MAX TEMPS ON THU
SHOULD BE NEAR OR JUST SLIGHTLY BELOW AVE. ON FRI....AN UPPER TROUGH
APPROACHES FROM THE WEST. LOOKS LIKE WITH SOME UPPER DIVERGENCE
DEVELOPING DURING THE DAY ALONG WITH A MOIST UPSLOPE
FLOW...SCATTERED SHOWERS AND THUNDERSTORMS SHOULD HAVE NO TROUBLE
DEVELOPING OVER THE MOUNTAINS AND THEN SPREADING INTO THE PIEDMONT
BY LATE IN THE DAY. STAYED CLOSE TO GMOS MAX TEMPS FOR FRI WHICH
WERE GENERALLY A COUPLE DEGREES BELOW AVERAGE...EXCEPT OVER THE FAR
EAST AND SOUTH WHERE MORE SUNSHINE WILL OCCUR.

&&

.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
AS OF 230 PM TUESDAY...GENERALLY FOLLOWED HPC GUIDANCE FOR THE
MEDIUM RANGE FORECAST WHICH FEATURED A A BLEND OF ECMWF/GFS ENSEMBLE
MEANS...BUT WEIGHTED TOWWARD THE ECM. UPPER AIR PATTERN WILL HAVE AN
UPPER LOW MOVING NORTH OF THE AREA FRI INTO SAT WITH AN UPPER LEVEL
RIDGE BUILDING TO THE WEST ON SUN WHICH EVENTUALLY BUILDS TO THE
NORTH OF THE AREA AS AN UPPER LOW MOVES SOUTH OF THE AREA BY TUE.

IN REGARD TO SENSIBLE WEATHER...IT LOOKS LIKE THIS PERIOD WILL BE
UNSETTLED AS AN UPPER LOW PASSES TO THE NW OF THE AREA FRI NIGHT
WITH AN ATTENDANT SURFACE FRONT MAKING A RUN AT THE MOUNTAINS BEFORE
DISSIPATING. UPPER DIVERGENCE...ALONG WITH A MOIST UPSLOPE FLOW
SHOULD PRODUCE NUMEROUS SHOWERS AND THUNDERSTORMS FRI NIGHT INTO
SAT. UPPER SUPPORT WANES BY SAT NIGHT WHICH SHOULD PRODUCE A LULL IN
SHOWER ACTIVITY SAT NIGHT INTO SUN MORNING. MODELS INDICATE THAT A
BACKDOOR COLD FRONT WILL REACH EASTERN AREAS SUN AFTERNOON AND MOVE
THROUGH THE ENTIRE AREA SUN NIGHT. CONVERGENCE ALONG THIS BOUNDARY
SHOULD TRIGGER SCATTERED SHOWERS/THUNDERSTORMS SUN AFTERNOON INTO
SUN NIGHT. BEHIND THE FRONT...A MOIST EASTERLY FETCH OFF THE
ATLANTIC WILL SET UP MON AND TUE. THIS SCENARIO FAVORS CONSIDERABLE
CLOUD COVER...ESPECIALLY IN THE MORNINGS WITH THE BEST CHANCE FOR
ANY SHOWERS IN MOUNTAINS DUE TO UPSLOPE FLOW. MAX TEMPS NEAR AVERAGE
SAT/SUN SHOULD BE A LITTLE BELOW AVERAGE MON/TUE

&&

.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
AT KCLT...THE IMMEDIATE CONCERN IS HOW QUICKLY THE MVFR CIGS WILL
BURN OFF. IT LOOKS TO BE ABOUT ANOTHER 1 TO 2 HOURS...WHICH IS WHAT
I HAVE IN THE TAF. LATER THIS EVENING A FEW SHRA/TSTMS MAY APPROACH
FROM THE WEST. I/M NOT CONFIDENT ENUF TO ADD CB YET...BUT THAT WILL
PROBABLY HAPPEN LATER IN THE AFTN. A WEAK COLD FRONT SHOULD TURN THE
WINDS OUT OF THE NW THIS EVENING...BUT THE WIND FIELD WILL BE
WEAK...SO I/M NOT HIGHLY CONFIDENT OF HOW THE WINDS WILL BEHAVE.
ANOTHER BOUT OF LIFR CIGS IS EXPECTED LATER TONIGHT AS A MOIST NE
FLOW DEVELOPS. AS THE WINDS WILL STAY OUT OF THE NE...THE CIGS MAY
TAKE LONGER TO MIX OUT THAN WHAT I CURRENTLY HAVE FOR WED.

ELSEWHERE...SCT SHRA HAVE STARTED TO DEVELOP WHERE THE LOW CLOUDS
HAVE BURNED OFF. I/VE ADDED CB/S AND VCSH TO THE UPSTATE SITES TO
ACCOUNT FOR THIS. A WIND SHIFT TO THE NW IS POSSIBLE LATER IN THE
EVENING...BUT WITH THE LIGHT WINDS...CONFIDENCE ON THE TIMING AND
THE EXACT DIRECTION OF THE WIND IS NOT HIGH. LIFR CIGS ARE EXPECTED
TO DEVELOP AGAIN AT KHKY AND KAVL. HOWEVER...THE GUIDANCE IMPLIES
THAT THEY WON/T MAKE IT TO THE UPSTATE WHERE THE LLVLS STAY DRIER.
THIS SEEMS REASONABLE AND I HAVE NOT ADDED LOW CIGS THERE.

OUTLOOK...SLOW DRYING EXPECTED THRU MID WEEK BUT MORNING TEMPO
RESTRICTIONS COULD LINGER...ESPECIALLY AT KAVL. NEXT WX SYSTEM
EXPECTED LATE WEEK THRU THE WEEKEND.

&&

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

&&

SYNOPSIS...JPT
NEAR TERM...MCAVOY
SHORT TERM...LG
LONG TERM...LG
AVIATION...MCAVOY

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
308 PM EDT TUE MAY 18 2010

GAZ010-017-018-026-028-029-NCZ033-035>037-048>053-056>059-062>065-
068>072-082-501>510-SCZ001>014-019-191915-
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-
308 PM EDT TUE MAY 18 2010

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

.DAY ONE...THIS AFTERNOON AND TONIGHT.

WIDELY SCATTERED THUNDERSTORMS THIS AFTERNOON WILL DISSIPATE THIS
EVENING.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY.

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...

NONE.

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
545 PM EDT TUE MAY 18 2010

NCZ068-508-510-182230-
CLEVELAND-EASTERN POLK-GREATER RUTHERFORD-
545 PM EDT TUE MAY 18 2010

...A STRONG THUNDERSTORM WILL AFFECT EASTERN POLK...SOUTHERN
RUTHERFORD AND SOUTHWESTERN CLEVELAND COUNTIES THROUGH 630 PM EDT...

AT 544 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM 4 MILES SOUTHWEST OF RUTHERFORDTON...MOVING EAST
AT 20 MPH.

* OTHER LOCATIONS AFFECTED INCLUDE BUT ARE NOT LIMITED TO BOSTIC...
  SPINDALE...RUTHERFORDTON...HARRIS...FOREST CITY...ELLENBORO...
  CLIFFSIDE...ALEXANDER MILLS...POLKVILLE...MOORESBORO...LATTIMORE...
  KINGSTOWN AND BOILING SPRINGS NC.

WIND GUSTS OF 30 TO 40 MPH...AND VERY HEAVY RAINFALL ARE EXPECTED
WITH THIS STORM.

LAT...LON 3543 8160 3518 8162 3524 8211 3542 8210

BSH

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
631 PM EDT TUE MAY 18 2010

NCZ068-508-SCZ008-182315-
CHEROKEE-CLEVELAND-GREATER RUTHERFORD-
631 PM EDT TUE MAY 18 2010

...A STRONG THUNDERSTORM WILL AFFECT NORTHEASTERN CHEROKEE...
SOUTHEASTERN RUTHERFORD AND SOUTHERN CLEVELAND COUNTIES THROUGH 715
PM EDT...

AT 626 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM 4 MILES NORTHWEST OF CLIFFSIDE...OR 10 MILES
SOUTHEAST OF RUTHERFORDTON...MOVING EAST AT 15 MPH.

PEOPLE IN NORTHEASTERN CHEROKEE...SOUTHEASTERN RUTHERFORD AND
SOUTHERN CLEVELAND COUNTIES...INCLUDING THE FOLLOWING LOCATIONS...

ELLENBORO...CLIFFSIDE...BOILING SPRINGS NC AND EARL...

SHOULD MONITOR THE WEATHER SITUATION CLOSELY. LISTEN FOR POSSIBLE
WARNINGS AND BE PREPARED TO TAKE APPROPRIATE ACTION SHOULD SEVERE
WEATHER THREATEN.

PEA SIZE HAIL...VERY HEAVY RAIN...AND WIND GUSTS OF 30 TO 40 MPH ARE
EXPECTED WITH THIS STORM.

LAT...LON 3531 8140 3507 8149 3521 8193 3539 8187

BSH