Lightning Strike in North Carolina, September 18, 2009

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
347 AM EDT FRI SEP 18 2009

.SYNOPSIS...
WEAK SURFACE HIGH PRESSURE WILL CONTINUE TO RIDGE IN FROM THE
NORTHEAST THROUGH THE WEEKEND...WHILE ABUNDANT MOISTURE REMAINS OVER
THE REGION. LITTLE CHANGE IS EXPECTED IN THE SYNOPTIC PATTERN UNTIL A
COLD FRONT APPROACHES THE AREA FROM THE WEST LATE NEXT WEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
A QUICK UPDATE TO ADDRESS SHORT TERM RADAR TRENDS...MAINLY TO RAISE
POP TO CATEGORICAL ACROSS THE EASTERN PIEDMONT OF SC. NEW NEAR TERM
DISCUSSION WILL BE SENT BY 08Z.

THE CWFA TO REMAIN WITHIN PLUME OF HIGH PWAT AIR...NEARLY 2 INCHES
AS PER 00 UTC KFFC SNDG...UNDER SW FLOW ALOFT DOWNSTREAM OF CYCLONE
SPINNING NEAR THE NW GULF OF MEXICO. VEERING AND INCREASING 85H FLOW
ATOP OF LINGERING SFC NE WINDS...SHOULD ADVECT HIGHER LLVL DWPTS
NORTHWARD INTO THE REGION OVERNIGHT. THE EXPECTED INCREASE IN THIS
MOIST LLVL UPGLIDE FLOW SHOULD ALLOW FOR SHOWER CVRG TO EXPAND/
DEVELOP ACRS THE BALANCE OF THE REGION...ALTHOUGH CONTINUED
REDEVELOPMENT OF DEEP CONVECTION JUST OFF TO OUR SOUTH AND SOUTHWEST
HAS THE POTENTIAL OF LIMITING EXPECTED PCPN AMTS AND EVEN THE
EXPECTED SHOWER CVRG. THE INCOMING 00 UTC NAM CONTINUES TO ADVERTISE
THIS SCENARIO FRIDAY MORNING...WRINGING OUT DEEP CONVECTIVE RAINFALL
OFF TO OUR SOUTH/SOUTHWEST...BUT SUSPECT CONTINUED UPGLIDE WILL
RESULT IN NUMEROUS SHOWERS...ESPECIALLY ACRS THE SW HALF OF THE
CWFA. A WEAKENING OF THE WAA FLOW IS EXPECTED FRIDAY AFTERNOON AS
LOW CIGS LIFT AND PERHAPS SKIES BRIGHTEN AS A WEAKLY UNSTABLE
AIRMASS DEVELOPS.

&&

.SHORT TERM /SATURDAY THROUGH MONDAY/...
AS OF 3 AM FRIDAY...THE SHORT TERM FCST PICKS UP AT 12Z ON SAT WITH
THE UPPER RIDGE BUILDING IN FROM THE NORTHEAST AND A SFC HIGH
BECOMING STRONGER AT THE SFC AND TURNING THE FLOW EASTERLY. TOWARDS
THE END OF THE PERIOD THE SFC HIGH WILL GRADUALLY SLIDE EASTWARD AND
OUT OVER THE ATLANTIC WHILE THE UPPER TROUGH DEEPENS OVER THE
CENTRAL CONUS. STILL EXPECT HIGH END CHANCE TO LIKELY POPS THROUGH
THE PERIOD AS AMPLE MOISTURE IN THE LOW AND MID LVLS WILL PREVAIL
WITH THE EASTERLY FLOW. THIS COUPLED WITH FAVORABLE ISENTROPIC LIFT
AND UPSLOPE ENHANCEMENT SHOULD PRODUCE PRECIP. BEST POPS AND QPF
WERE GENERALLY KEPT IN THE WESTERN ZONES AND ALONG THE ESCARPMENT
ALTHOUGH QPE COULD WIND UP BEING FAIRLY HOMOGENEOUS THRU MONDAY.
AMPLE CLOUD COVER SHOULD KEEP MAX TEMPS A BIT BELOW AVG AND MIN
TEMPS SLIGHTLY ABOVE AVG ON SAT...SUN...AND MON.

&&

.LONG TERM /MONDAY NIGHT THROUGH THURSDAY/...
AS OF 320 AM FRIDAY...THE MEDIUM RANGE FCST BEGINS 00Z TUES WITH
THE SFC HIGH REMAINING OVER THE NE CONUS WITH THE WEDGE REMAINING
LARGELY INTACT THRU WED. THE SFC LOW AND ITS ASSOCIATED COLD FRONT
WERE EXPECTED TO APPROACH THE REGION BY MID WEEK...HOWEVER THE
LATEST LONG RANGE MODEL RUNS APPEAR TO WASH OUT THE FRONT BEFORE IT
REACHES THE CAROLINAS AS WE MAINTAIN WEAK SFC HIGH PRESSURE THRU DAY
7. WE WILL SEE IF THIS PATTERN HOLDS UP OVER THE NEXT FEW MODEL
CYCLES. I KEPT THE SENSIBLE FCST MOSTLY UNCHANGED WITH CHC POPS OVER
THE CWA THRU DAY 7. WITH MCLOUDY SKIES HIGH TEMPS SHOULD REMAIN
BELOW AVG THRU WED AND LOWS ABOVE AVG. INCREASING SOUTHERLY FLOW
WELL AHEAD OF THE FRONT WILL PUSH HIGHS A FEW DEGREES WARMER AT THE
END OF THE PERIOD.

&&

.AVIATION /08Z FRIDAY THROUGH TUESDAY/...
AT KCLT...LIGHT NE WIND TO CONTINUE OVERNIGHT...AND THROUGH THE
BETTER PART OF FRIDAY. MVFR CEILING SHOULD DROP INTO IFR CATEGORY NO
LATER THAN 08Z AS PRECIP MOVES UP FROM THE SOUTH. HAVE INCLUDED A
PERIOD OF MVFR VISIBILITY IN SHOWERS BASED ON RADAR TRENDS AT
ISSUANCE TIME. ONCE THE FLIGHT CATEGORY DROPS TO IFR IT WILL
PROBABLY STAY THERE THROUGH MOST OF FRIDAY MORNING...UNTIL BOUNDARY
LAYER WARMING LIFTS IT BACK UP TO MVFR. ANYTHING BETTER THAN MVFR
LOOKS DOUBTFUL BEFORE THE END OF THE PERIOD.

ELSEWHERE...DEEP MOISTURE AND UPSLOPE/UPGLIDE WILL MAINTAIN
EXTENSIVE LOW CLOUDINESS ACROSS THE REGION THROUGH THE PERIOD. IN
THIS REGIME...A SHOWER COULD REALLY POP UP AT ANY TIME AT ANY TAF
SITE. RATHER THAN KEEP A VCSH THROUGH THE ENTIRE PERIOD...WILL
UPDATE TAFS TO REFLECT RADAR TRENDS OVER THE NEXT SEVERAL HOURS. AT
THIS POINT...IT APPEARS THAT MOST OF THE HEAVIER PRECIP WILL SLIDE
ACROSS THE AREA NEAR KCLT THROUGH THE EARLY MORNING. CEILINGS SHOULD
DROP TO IFR AROUND 08Z AS UPGLIDE INCREASES...AND ONCE FORMED...THIS
IFR CEILING WILL STAY UNTIL ABOUT MIDDAY. BOUNDARY LAYER WARMING
SHOULD LIFT THE CEILING UP INTO MVFR RANGE BY 16Z OR SO...WHERE IT
SHOULD REMAIN THROUGH THE END OF THE PERIOD. THE EXCEPTION WILL BE
KAVL...WHERE SUN COULD BREAK OUT IN THE LATE AFTERNOON. EXPECT LIGHT
NE WINDS.

OUTLOOK...LOW PRESSURE NEAR THE GULF COAST AND WEAK HIGH PRESSURE
OVER THE WESTERN CAROLINAS WILL FAVOR VERY MOIST LOW LEVEL
CONDITIONS THROUGH THE WEEKEND. EXPECT PERIODS OF RAIN AND
RESTRICTIONS...MAINLY MVFR...WITH IFR POSSIBLE AROUND DAWN.

&&

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

&&

SYNOPSIS...JPT
NEAR TERM...PM
SHORT TERM...JPT
LONG TERM...JPT
AVIATION...PM

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
513 AM EDT FRI SEP 18 2009

GAZ010-017-018-026-028-029-NCZ033-035>037-048>053-056>059-062>065-
068>072-082-501>510-SCZ001>014-019-190915-
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-
513 AM EDT FRI SEP 18 2009

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

.DAY ONE...TODAY AND TONIGHT.

WIDESPREAD SHOWERS AND POSSIBLY A LIGHTNING STRIKE OR TWO WILL
CONTINUE ACROSS THE AREA TODAY.

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

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...

NONE.

JPT