Flash Flood and Hail in North Carolina, April 26, 2008

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
1259 PM EDT SAT APR 26 2008

.SYNOPSIS...
A WEAK COLD FRONT WILL PUSH INTO THE WESTERN CAROLINAS THIS
AFTERNOON AND WILL BECOME STATIONARY OVER THE REGION TONIGHT. THE
STATIONARY FRONT WILL LIKELY REMAIN OVER THE REGION UNTIL A STRONGER
COLD FRONT SWEEPS ACROSS THE REGION ON MONDAY. A LARGE CANADIAN
AIR MASS WILL SETTLE OVER THE SOUTHEAST MONDAY NIGHT...LINGERING
OVER THE REGION INTO THE MID WEEK.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
CONVECTION MOVING ACROSS CNTRL TN HAS WEAKENED CONSIDERABLY.
HOWEVER...WHEN BOUNDARY LAYER HEATS UP AND INSTABILITY DEVELOPS
EXPECT INCREASING CONVECTION AS IT MOVES IN...ESP OVER MTNS THIS
AFTN-EARLY EVE. BUOYANCY AND SHEAR NOT HIGH SO WIDESPREAD SEVERE WX
NOT EXPECTED BUT A FEW STORMS COULD PRODUCE LARGE HAIL. WITH FEWER
CLOUDS/SHOWERS THAN EXPECTED EARLIER TEMPS HAVE WARMED MORE QUICKLY
WITH DEW POINTS SLIGHTLY HIGHER AS WELL SO TWEAKED GRIDS ACCORDINGLY.

THE WEAK FRONT IS EXPECTED TO LAY DOWN ACROSS THE FORECAST AREA
OVERNIGHT ACCORDING TO THE MOST RECENT MODEL RUNS...AND SHOULD STALL
CLOSER TO THE SRN PART OF THE FORECAST AREA. WILL HOLD ONTO A CHANCE
POP ACROSS THE ENTIRE FCST AREA FOR THE EVENING HOURS AND THEN WILL
TAPER POPS FROM N TO S AFTER MIDNIGHT TO ACCOUNT FOR REMAINING WEAK
INSTABILITY AND CONVERGENCE ALONG THE SURFACE BOUNDARY.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY NIGHT/...
AS OF 225 AM SATURDAY...SHORT RANGE MODELS GENERALLY AGREE THAT THE
COLD FRONT WILL BECOME STATIONARY ACROSS THE CWA LATE TONIGHT. SFC
LOW PRESSURE WILL DEEPEN OVER THE MID MISSISSIPPI RIVER VALLEY SUN
MORNING AND WILL TRACK NE THROUGH THE DAY. AS THE LOW DEEPEN AND
APPROACHES THE OHIO RIVER VALLEY...FLOW ABOVE THE BL WILL STRENGTHEN
ACROSS THE FORECAST AREA. WEAK SFC RIDGE NORTH OF THE STATIONARY
FRONT MAY BECOME DAMMED DURING THE DAY...ESPECIALLY AS INCREASING
WIND FIELDS YIELDS WEAK ISENTROPIC LIFT AND UPSLOPE FLOW. IN
ADDITION...WAA MAY SUPPLY ENOUGH LLVL WARMING AND MOISTURE TO PUSH
CAPES INTO THE 200-500 J/KG RANGE. THE COMBINATION OF
ISENTROPIC/UPSLOPE LIFT...SFC BOUNDARY...AND INSTABILITY SHOULD
SUPPORT SCT TO NUMEROUS SHRA AND SCT TSRA BY SUN AFTERNOON. SUN/S
HIGH TEMPERATURES WILL REMAIN A CHALLENGE AS A WEAK IN-SITU WEDGE
ERODES DURING THE DAY. ONE OR TWO STORMS MAY BECOME STRONG TO
SEVERE...WITH GUSTY WINDS AND HAIL. WE WILL CONTINUE TO HIGHLIGHT IN
THE HWO. I WILL USE A BLEND OF THE COOLER MOS TEMPERATURE
GUIDANCE...FAVORING VALUES CLOSE TO CLIMATOLOGY.

SUN NIGHT...THE CENTER OF THE SFC LOW WILL RACE NORTHWARD...REACHING
THE CANADIAN BORDER BY 12Z MON. THE ASSOCIATED COLD FRONT WILL
LIKELY REMAIN WEST OF THE SPINE OF THE APPALACHIANS AT 12Z MON. THE
ENVIRONMENT AHEAD OF THE FRONT WILL REMAIN MOISTURE RICH...WITH
PCPBLE WATER EXPECTED TO RANGE FROM 1.2 TO 1.3 INCHES. ONGOING
UPSLOPE AND UPGLIDE...LINGERING INSTABILITY...AND SHALLOW SYNOPTIC
LIFT WILL ALLOW COVERAGE OF SHRA/TSRA TO REMAIN LIKELY TO MTN CATE
OVERNIGHT.

MONDAY...FRONTAL BAND OF SHRA/TSRA SHOULD BE CROSSING THE MTNS BY
SUNRISE. COVERAGE SHOULD BEGIN TO DECREASE FROM WEST TO EAST BY MID
TO LATE AFTERNOON. A FEW OF THESE STORMS MAY BECOME SEVERE...WE WILL
MENTION IN THE HWO. AFTER THE BAND PASSES...NW WINDS SHOULD
STRENGTHEN THROUGH THE REMAINDER OF THE DAY AND BECOME GUSTY. THE NW
WINDS WILL BRING CAA ACROSS THE REGION BY EARLY EVENING...KEEPING
HIGH TEMPS ABOUT 5 DEGREES SHORT OF NORMALS. RAINFALL FROM SUN INTO
MON SHOULD AVERAGE AN INCH ACROSS THE REGION.

&&

.LONG TERM /TUESDAY THROUGH SATURDAY/...
AS OF 240 AM SATURDAY...THE CENTER OF A COOL HIGH PRESSURE WILL PUSH
OVER THE MISSISSIPPI RIVER VALLEY BY 12Z TUES. LOW THICKNESSES AND
H85 TEMPS AROUND 0C REMAIN ACROSS THE WESTERN CWA. A BLEND OF
TEMPERATURE GUIDANCE INDICATES FREEZING TEMPS ABOVE 3 KFT AND MID
30S IN THE MTN VALLEYS. EAST OF THE MTNS...TEMPS MAY RANGE FROM THE
U30S TO L40S. I WILL ADD A MENTION OF FREEZE/FROST TEMPS IN THE MTN HWO
FOR TUESDAY MORNING.

TUESDAY NIGHT AND WEDNESDAY...THE CENTER OF HIGH PRESSURE WILL REACH
THE CWA BY SUNRISE AND WILL SHIFT EAST DURING THE DAY. WEAK
WAA SHOULD ALLOW H85 TEMPERATURES TO REMAIN IN THE SINGLE DIGITS
ABOVE 0C. MIN TEMPS ON WEDNESDAY SHOULD VERIFY A FEW DEGREES WARMER
THAN TUESDAY MORNING. HOWEVER...THE HIGHER ELEVATIONS COULD SEE
TEMPS FALL TO THE MID 30S FOR SEVERAL HOURS.

WEDNESDAY NIGHT THROUGH FRIDAY...HIGH PRESSURE WILL BECOME CENTERED
OVER THE WESTERN ATLANTIC WITH LOW PRESSURE DEVELOP IN THE LEE OF
THE ROCKIES. THIS SHOULD LEAVE THE CWA UNDER RETURN FLOW WITH A
STATIONARY FRONT WELL NORTH OF THE FORECAST AREA. I WILL KEEP POPS
LOW AND TEMPS NEAR NORMAL.

&&

.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
AS FRONT APPROACHES FROM THE W SCT CONVECTION WILL CONTINUE TO
DEVELOP AND SPREAD ACROSS THE CWA. HAVE VCTS AND CB CLOUDS ALL TAF
SITES AND WILL AMD WITH TEMPO TSRA IF/WHEN STORMS ARE EXPECTED TO
AFFECT A TERMINAL. THIS SHOULD TAPER OFF WITH COOLING BY EARLY EVE.
WENT WITH FCST GUIDANCE FOR MVFR CIG/VIS AROUND DAYBREAK...THEN VFR
LOW CLOUD CIGS AND INCREASING CONVECTION AGAIN TOWARD MID DAY SUN.

OUTLOOK...WITH FRONT STALLED JUST S OF AREA...UNSETTLED WEATHER
EXPECTED SUN AFTN-EVE AS BOUNDARY MOVES N...INCLUDING TSTMS AND
CIG/VSBY RESTRICTIONS. A STRONGER COLD FRONT WILL MOVE THROUGH THE
AREA MON...THEN DRYING. VFR CONDITIONS LIKELY TUE-WED.

&&

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

&&

SYNOPSIS...NED
NEAR TERM...PM/RB
SHORT TERM...NED
LONG TERM...NED
AVIATION...RB

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
420 AM EDT SAT APR 26 2008

GAZ010-017-NCZ033-048>053-058-059-062>065-501-503-505-507-509-
SCZ001>003-270830-
RABUN-HABERSHAM-AVERY-MADISON-YANCEY-MITCHELL-SWAIN-HAYWOOD-BUNCOMBE-
GRAHAM-NORTHERN JACKSON-MACON-SOUTHERN JACKSON-TRANSYLVANIA-
HENDERSON-CALDWELL MOUNTAINS-BURKE MOUNTAINS-MCDOWELL MOUNTAINS-
RUTHERFORD MOUNTAINS-POLK MOUNTAINS-OCONEE MOUNTAINS-
PICKENS MOUNTAINS-GREENVILLE MOUNTAINS-
420 AM EDT SAT APR 26 2008

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

.DAY ONE...TODAY AND TONIGHT

SHOWERS AND THUNDERSTORMS WILL DEVELOP ALONG AND AHEAD OF A COLD
FRONT TODAY. THE COVERAGE OF THE THUNDERSTORMS IS FORECAST TO PEAK
ACROSS THE MOUNTAINS THIS AFTERNOON AND EARLY EVENING. THESE
STORMS MAY PRODUCE FREQUENT CLOUD TO GROUND LIGHTNING...PERIODS OF
HEAVY DOWNPOURS...AND GUSTY WINDS. ONE OR TWO OF THESE STORMS
COULD PRODUCE PENNEY SIZED HAIL.

.DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY

ANOTHER ROUND OF THUNDERSTORMS IS FORECAST TO DEVELOP ACROSS THE
MOUNTAINS AND FOOTHILLS SUNDAY NIGHT AND MONDAY. A FEW OF THESE STORMS
COULD BECOME SEVERE...PRODUCING DAMAGING WINDS AND HAIL.

TEMPERATURES WILL FALL INTO THE LOW TO MID 30S ACROSS THE
MOUNTAINS AROUND SUNRISE TUESDAY. THESE TEMPERATURES MAY RESULT IN A
LIGHT FREEZE OR FROST...ESPECIALLY ABOVE 3000 FEET IN ELEVATION.

.SPOTTER INFORMATION STATEMENT...

SPOTTERS ARE ENCOURAGED TO REPORT SEVERE WEATHER TO THE NATIONAL
WEATHER SERVICE.

GAZ018-026-028-029-NCZ035>037-056-057-068>072-082-502-504-506-508-
510-SCZ004>014-019-270830-
STEPHENS-FRANKLIN-HART-ELBERT-ALEXANDER-IREDELL-DAVIE-CATAWBA-ROWAN-
CLEVELAND-LINCOLN-GASTON-MECKLENBURG-CABARRUS-UNION NC-
GREATER CALDWELL-GREATER BURKE-EASTERN MCDOWELL-GREATER RUTHERFORD-
EASTERN POLK-GREATER OCONEE-GREATER PICKENS-GREATER GREENVILLE-
SPARTANBURG-CHEROKEE-YORK-ANDERSON-ABBEVILLE-LAURENS-UNION SC-
CHESTER-GREENWOOD-
420 AM EDT SAT APR 26 2008

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

.DAY ONE...TODAY AND TONIGHT

SHOWERS AND THUNDERSTORMS WILL DEVELOP ALONG AND AHEAD OF A COLD
FRONT TODAY. THE COVERAGE OF THE THUNDERSTORMS IS FORECAST TO PEAK
ACROSS THE FOOTHILLS AND PIEDMONT THIS AFTERNOON AND EARLY EVENING. THESE
STORMS MAY PRODUCE FREQUENT CLOUD TO GROUND LIGHTNING...PERIODS OF
HEAVY DOWNPOURS...AND GUSTY WINDS. ONE OR TWO OF THESE STORMS
COULD PRODUCE PENNEY SIZED HAIL.

.DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY

ANOTHER ROUND OF THUNDERSTORMS IS FORECAST TO DEVELOP ACROSS THE
FOOTHILLS AND PIEDMONT SUNDAY NIGHT AND MONDAY. A FEW OF THESE STORMS
COULD BECOME SEVERE...PRODUCING DAMAGING WINDS AND HAIL.

.SPOTTER INFORMATION STATEMENT...

SPOTTERS ARE ENCOURAGED TO REPORT SEVERE WEATHER TO THE NATIONAL
WEATHER SERVICE.

NED

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
1225 PM EDT SAT APR 26 2008

NCZ065-509-510-261730-
EASTERN POLK-HENDERSON-POLK MOUNTAINS-
1225 PM EDT SAT APR 26 2008

...A STRONG THUNDERSTORM WILL AFFECT CENTRAL HENDERSON AND
NORTHWESTERN POLK COUNTIES THROUGH 130 PM EDT...

AT 1224 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM JUST WESR OF HENDERSONVILLE...MOVING EAST AT 17
MPH.

THIS STORM WILL BE NEAR...
  HENDERSONVILLE BY 1230 PM EDT.
  5 MILES NORTH OF COLUMBUS BY 115 PM EDT.
  LAKE ADGER BY 120 PM EDT.

PEA SIZE HAIL IS EXPECTED WITH THIS STORM.

LANE