Severe Thunderstorm Warning 73, NWS Greenville-Spartanburg, SC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
734 PM EDT SUN MAY 3 2009

.SYNOPSIS...
A SLOW MOVING COLD FRONT WILL CROSS TENNESSEE TONIGHT AND MONDAY
WITH LOW PRESSURES MOVING ALONG THE FRONT.  FRONTS WILL CONTINUE TO
WOBBLE ABOUT OVER THE SOUTHEAST INTO NEXT WEEKEND.  HIGH PRESSURE
FROM THE PLAINS STATES MAY PUSH NEXT WEEKENDS FRONT SOUTH OF OUR
AREA BY SUNDAY.

&&

.NEAR TERM /THROUGH MONDAY/...
WEAKENING LINEAR CONVECTIVE SYSTEM CONTINUES ITS MARCH TOWARD
EXTREME NE GA AND WRN SC. WILL TAKE THIS OPPORTUNITY TO BUMP UP THE
POP ACCORDINGLY. HARD TO SAY HOW MUCH WIND ENERGY THE LINE WILL HAVE
AS IT IS EXPECTED TO DIE AS IT MOVES IN...BUT PRESENCE OF SURFACE
BASED INSTABILITY SUGGESTS THAT IT WILL AT LEAST HAVE SOME
CAPABILITY FOR PRODUCING WIND DAMAGE. UPDATE WILL BE MADE FOR NEW
SEVERE THUNDERSTORM WATCH ACCORDINGLY.

REMAINDER OF OLD NEAR TERM DISCUSSION FOLLOWS...
ACTIVE WEATHER PATTERN WILL CONTINUE IN THE NEAR TERM AS SOUTHERN
STREAM TROUGH CONTINUES TO TRACK NE FROM THE LOWER MS VALLEY.
ATTENDANT SURFACE LOW WILL TRACK NE ALONG STALLED FRONTAL BOUNDARY
DRAPED ACROSS THE TN VALLEY. COPIUS GULF MOISTURE CONTINUES TO POOLE
ALONG AND S OF THE BOUNDARY AND TSTM COMPLEXES CONTINUE TO DEVELOP
IN THE MOIST/UNSTABLE AIRMASS. FOR THE OVERNIGHT...AS MAIN SHORT
WAVE TRACKS NE AND UPPER DIVERGENCE INCREASES OVER THE FORECAST
AREA...SEE NO REASON WHY A MCS WILL NOT CLIP AT LEAST THE WESTERN
HALF OF THE FORECAST AREA OVERNIGHT...SO WILL SHOW HIGH POPS AGAIN
WEST TONIGHT TAPERING DOWN TO THE E...WITH A BREAK LIKELY AGAIN LATE
TONIGHT AS MCS MOVES OFF TO THE NE. WITH PWATS UP TO 1.5 AND THE
POTENTIAL FOR OROGRAPHIC ENHANCEMENT SOME LOCALLY HEAVY RAIN IS
POSSIBLE OVERNIGHT IN THE MOUNTAINS. HPC HAS SLIGHT RISK OF
EXCESSIVE RAINFALL NOW TO THE WEST OF THE MOUNTAINS.
HOWEVER...GENERALLY 1-2 STILL LOOKS GOOD TONIGHT IN THE MOUNTAINS.
BUT WITH RATHER HIGH FLOOD GUIDANCE DO NOT BELIEVE THERE WILL BE
ANY FLOOD ISSUES.

AS SURFACE LOW MOVES TO THE N OF THE AREA ON MONDAY...THE FRONT WILL
MOVE SE IN ITS WAKE...AND LOOKS TO BECOME STATIONARY SOMEWHERE IN
THE PIEDMONT MONDAY AFTERNOON. THIS WILL SERVE AS A FOCAL POINT FOR
WHAT LOOKS TO BE WIDESPREAD/SHOWERS THUNDERSTORMS ACROSS THE
SOUTHERN PORTION OF THE FORECAST AREA MONDAY AFTERNOON. WILL SHOW
POPS LOWERING ACROSS THE MOUTNAINS MONDAY AFTERNOON BEGIND THE
FRONT. USED A MOS BLEND FOR MIN/MAX TEMPS.

&&

.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/...
AS OF 245 PM SUNDAY...GOOD CONVECTIVE COVERAGE IS EXPECTED OVER THE
EASTERN PART OF THE FA MON EVENING AS THERE IS GOOD MODEL AGREEMENT
THAT A SHORT WAVE WILL MOVE ACROSS THE REGION. SURFACE CONVERGENCE
IS GOOD AND UPPER DIFFLUENCE LOOKS FAVORABLE FOR LIFT AS WELL. I
HAVE LIKELY POPS EAST AND CHANCE POPS WEST...WITH PCPN TAPERING OFF
AFTER MIDNIGHT. WITH THE WET AIRMASS AND RELATIVELY WEAK MID LEVEL
FLOW...SEVERE STORMS DO NOT APPEAR LIKELY.

TUE IS ANOTHER LOW CONFIDENCE FORECAST. THE GFS HAS A SHORT WAVE
RIDGE OVER THE REGION...AS DOES THE OLD EC. THE LATEST NAM BRINGS A
SHORT WAVE ACROSS THE REGION...AS DOES THE UKMET. THE SREF FAVORS
THE GFS AND AFTER COLLABORATION WITH THE NEIGHBORS I/VE GONE WITH
EITHER SLIGHT CHANCE POPS OR LOW END CHANCE POPS FOR THE DAY.
STILL...I WOULDN/T BANK ON A DRY FORECAST. THE SAME APPLIES FOR WED
AS THERE ARE TIMING DIFFERENCES WITH MINOR WAVES MOVING ACROSS THE
REGION. TAKING A BLEND OF THE FASTER GFS AND THE LIKELY SLIGHTLY
OVER AMPLIFIED ECMWF...A WAVE WILL PROBABLY CROSS THE REGION LATE
WED OR WED NIGHT. THEREFORE I HAVE HIGHER POPS IN THE FORECAST WED
AFTN AND OVERNIGHT.

I DON/T SEE ANYTHING THAT ADVERTISES PARTICULARLY HEAVY RAIN OR A
SIGNIFICANT SEVERE WEATHER THREAT EITHER DAY...BUT WITH AN ACTIVE
PATTERN IN MAY...EITHER OR BOTH THREATS COULD MATERIALIZE.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
AS OF 230 PM SUNDAY...THE LATEST ECMWF AND GFS CONTINUE TO INCREASE
THE AMPLITUDE OF THE RIDGE OVER SW STATES FOR THE END OF THE WEEK.
IT/S STILL NOT A VERY HIGH AMPLITUDE FEATURE...BUT IT/S STRONG
ENOUGH TO KEEP A BROAD TROUGH OVER THE EASTERN STATES. BY THU THIS
RESULTS IN A WEST NORTHWESTERLY FLOW ACROSS THE REGION. OVERALL IT
LOOKS LIKE A DRY DAY...THOUGH UPSTREAM CAPE VALUES ARE HIGHT ON BOTH
MODELS...AND AN MCS COULD AFFECT THE MTNS SOMETIME DURING THE THU
PERIOD...THOUGH I COULDN/T BEGIN TO GUESS WHEN. I/LL KEEP CHANCE
POPS IN THE MTNS AND SLGT CHANCE ELSEWHERE TO ACCOUNT FOR THIS.

BY FRI THE GFS GOES A LITTLE OVERBOARD WITH THE AMPLITUDE OF THE ERN
CONUS TROUGH...DRIVING A COLD FRONT THROUGH THE FA EARLY IN THE DAY
AND BRINING IN A DRY AND A LITTLE COOLER AIRMASS THROUGH THE
WEEKEND. THE ECMWF IS SLOWER AND NOT AS DEEP WITH THE TROUGH...SO
IT/S FRONT DOESN/T COME THROUGH UNTIL SAT MORNING AND IT/S WEAKER
WHEN IT DOES. THE CANADIAN IS EVEN FARTHER WEST. THE EC SEEMS LIKE A
GOOD COMPROMISE. HPC WENT WITH A SIMILAR SOLUTION...SO I HAVE CHANCE
POPS OVER MOST OF THE AREA FRI AHEAD OF THE FRONT. I HOLD ON TO LOW
CHANCE POPS ON SAT OVER THE MTNS...BUT IF CURRENT TRENDS HOLD IT
MIGHT BE DRY. AND I HAVE A DRY FORECAST FOR SUN. WITH THE DRIER
PATTERN...TEMPERATURES SHOULD MAKE IT INTO THE LOW 80S THU-SUN
OUTSIDE THE MTNS.

&&

.AVIATION /00Z MONDAY THROUGH FRIDAY/...
MAIN CONCERN FOR THE NEAR TERM IS THE DYING SQUALL LINE PUSHING EAST
ACROSS N GA. IT APPEARS LIKE IT WILL SURVIVE TO AT LEAST REACH KAND
AND PERHAPS KGMU/KGSP. THIS WILL BE TIMED BASED ON RECENT MOVEMENT.
THOSE TAF SITES CAN EXPECT GUSTY SW WINDS AS THE LINE PASSES...AND
BRIEF VISIBILITY RESTRICTIONS. WHAT IS LEFT OF THE LINE WILL DIE AS
IT MOVES EAST. WILL HANDLE THIS WITH TEMPO GROUPS FOR SHOWERS
FARTHER N AT KAVL/KHKY AND TAKE A WAIT AND SEE APPROACH FOR KCLT.

AS FOR KCLT...LOOKS LIKE VFR CONDITIONS ARE A SAFE BET AT LEAST
UNTIL AFTER EVENING TRAFFIC LESSENS...WITH WIND SOME COMPONENT OF
SOUTH. ANOTHER PERIOD OF LOW STRATOCU IS EXPECTED TO DEVELOP DURING
THE PRE-DAWN HOURS. IFR IS POSSIBLE BUT FOR NOW THIS IS LIMITED TO
THE LOW END OF MVFR BECAUSE OF THE POSSIBILITY OF CONVECTIVE DEBRIS
KEEPING IT STIRRED UP ENOUGH. CEILING WILL GRADUALLY LIFT ABOVE 3K
FEET DURING MIDDAY. AT ANY TIME A SHOWER OR THUNDERSTORM COULD
DEVELOP WITH HEATING ON MONDAY...SO FOR NOW THIS IS HANDLED WITH
VCSH.

ALL OTHER TAF SITES SHOULD BEHAVE SIMILARLY. ALTHO GUIDANCE DOES NOT
INDICATE LOW CLOUD CEILINGS LATE TONIGHT...ALL GET A PERIOD OF AT
LEAST MVFR STRATOCU THAT SHOULD GRADUALLY LIFT AFTER SUNRISE. THE
DAY SHOULD NOT BE A WASHOUT...BUT CONVECTIVE PRECIP COULD DEVELOP AT
ANY TIME FROM MID MORNING ONWARD.

OUTLOOK...MORNING FOG/STRATUS WILL BE POSSIBLE IN THE EARLY MORNINGS
INTO MID WEEK. A BREAK FROM THE SHOWERS IS ANTICIPATED ON TUE WITH A
CHANCE FOR MORE SHOWERS/THUNDERSTORMS ON WED.

&&

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

&&

SYNOPSIS...MCAVOY
NEAR TERM...LG/PM
SHORT TERM...MCAVOY
LONG TERM...MCAVOY
AVIATION...PM

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
422 PM EDT SUN MAY 3 2009

GAZ010-017-018-026-028-029-SCZ001-002-004-005-010-011-019-042030-
RABUN-HABERSHAM-STEPHENS-FRANKLIN-HART-ELBERT-OCONEE MOUNTAINS-
PICKENS MOUNTAINS-GREATER OCONEE-GREATER PICKENS-ANDERSON-ABBEVILLE-
GREENWOOD-
422 PM EDT SUN MAY 3 2009

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

.DAY ONE...THIS AFTERNOON AND TONIGHT.

A LINE OF STRONG TO SEVERE THUNDERSTORMS WILL MOVE ACROSS
NORTHERN GEORGIA DURING THE LATE AFTERNOON HOURS. IF THE STORMS
HOLD TOGETHER THEY WILL MOVE INTO NORTHEAST GEORGIA...THE
MOUNTAINS OF SOUTHWEST NORTH CAROLINA...AND WESTERN UPSTATE SOUTH
CAROLINA...BEGINNING AROUND 7 PM. THESE STORMS HAVE HAD A HISTORY
OF PRODUCING DAMAGING WINDS.

MONITOR PRODUCTS ISSUED BY THIS OFFICE FOR INFORMATION ON THIS
DEVELOPING SEVERE WEATHER THREAT.

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

SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS WILL AFFECT THE
WESTERN CAROLINAS AND NORTHEAST GEORGIA MONDAY AND MONDAY NIGHT.
A FEW OF THESE STORMS COULD BECOME SEVERE...PRODUCING LARGE HAIL
AND DAMAGING WINDS.

.SPOTTER INFORMATION STATEMENT...

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

NCZ035>037-056-057-068>072-082-502-504-506>510-SCZ003-006>009-
012>014-042030-
ALEXANDER-IREDELL-DAVIE-CATAWBA-ROWAN-CLEVELAND-LINCOLN-GASTON-
MECKLENBURG-CABARRUS-UNION NC-GREATER CALDWELL-GREATER BURKE-
EASTERN MCDOWELL-RUTHERFORD MOUNTAINS-GREATER RUTHERFORD-
POLK MOUNTAINS-EASTERN POLK-GREENVILLE MOUNTAINS-GREATER GREENVILLE-
SPARTANBURG-CHEROKEE-YORK-LAURENS-UNION SC-CHESTER-
422 PM EDT SUN MAY 3 2009

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

.DAY ONE...THIS AFTERNOON AND TONIGHT.

A LINE OF THUNDERSTORMS COULD MOVE ACROSS THE NORTHEASTERN UPSTATE
LATER THIS EVENING...INCLUDING THE GREENVILLE AND SPARTANBURG
METRO AREAS. THE LINE WILL BE WEAKENING BY THE TIME IT MOVES INTO
THE REGION...BUT A FEW DAMAGING WIND GUSTS WILL BE POSSIBLE.

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

SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS WILL AFFECT THE
WESTERN CAROLINAS MONDAY AND MONDAY NIGHT. A FEW OF THESE STORMS
COULD BECOME SEVERE...PRODUCING LARGE HAIL AND DAMAGING WINDS.

.SPOTTER INFORMATION STATEMENT...

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

NCZ033-048>053-058-059-062>065-501-503-505-042030-
AVERY-MADISON-YANCEY-MITCHELL-SWAIN-HAYWOOD-BUNCOMBE-GRAHAM-
NORTHERN JACKSON-MACON-SOUTHERN JACKSON-TRANSYLVANIA-HENDERSON-
CALDWELL MOUNTAINS-BURKE MOUNTAINS-MCDOWELL MOUNTAINS-
422 PM EDT SUN MAY 3 2009

THIS HAZARDOUS WEATHER OUTLOOK IS FOR WESTERN NORTH CAROLINA.

.DAY ONE...THIS AFTERNOON AND TONIGHT.

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

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

SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS WILL AFFECT THE
MOUNTAINS AND FOOTHILLS OF THE WESTERN NORTH CAROLINA MONDAY AND
MONDAY NIGHT. A FEW OF THESE STORMS COULD BECOME SEVERE...
PRODUCING LARGE HAIL AND DAMAGING WINDS.

.SPOTTER INFORMATION STATEMENT...

NONE.

MCAVOY

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
221 PM EDT SUN MAY 03 2009

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0500 PM     TSTM WND DMG     6 ENE EARL              35.24N 81.45W
05/02/2009                   CLEVELAND          NC   TRAINED SPOTTER

            TREE AND LARGE LIMBS DOWN BETWEEN SHELBY AND KINGS
            MOUNTAIN.

&&

TBENTHAL

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
719 PM EDT SUN MAY 3 2009

GAZ010-NCZ059-062>064-040015-
MACON-NORTHERN JACKSON-RABUN-SOUTHERN JACKSON-TRANSYLVANIA-
719 PM EDT SUN MAY 3 2009

...A STRONG THUNDERSTORM WILL AFFECT EASTERN MACON...JACKSON...RABUN
AND SOUTHWESTERN TRANSYLVANIA COUNTIES THROUGH 815 PM EDT...

AT 717 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM 5 MILES NORTHEAST OF LAKE BURTON...OR 7 MILES
WEST OF CLAYTON...MOVING NORTHEAST AT 35 MPH.

* OTHER LOCATIONS AFFECTED INCLUDE BUT ARE NOT LIMITED TO LAKE
  BURTON...LAKE THORPE...TIGER...SKY VALLEY...PINE MOUNTAIN...
  MOUNTAIN CITY...MOCCASIN CREEK STATE PARK...DILLARD...CLAYTON...
  WOLF MOUNTAIN...WEBSTER...TUCKASEGEE...SCALY...SAPPHIRE...ROSMAN...
  OTTO...LAKE TOXAWAY...HIGHLANDS...GAY...FRANKLIN...CULLOWHEE...
  CASHIERS AND BALSAM GROVE.

HEAVY RAINFALL...SMALL HAIL...AND WIND GUSTS UP TO 40 MPH ARE
EXPECTED WITH THIS STORM.

07