Areal Flood Advisory 21, NWS Greenville-Spartanburg, SC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
608 AM EDT SAT APR 16 2011

.SYNOPSIS...
A COLD FRONT WILL TRACK ACROSS THE FORECAST AREA TODAY...THEN MOVE
OFF THE COAST THIS EVENING. A SURFACE RIDGE WILL BUILD OVER THE
REGION SUNDAY AND REMAIN INTO MID WEEK. ANOTHER COLD FRONT IS
EXPECTED TO AFFECT THE AREA FOR THE LAST PART OF THE WEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
AT 6 AM...A QUICK UPDATE TO INCLUDE TORNADO WATCH 149 FOR MOST OF
NORTHEAST GA...THE UPSTATE OF SC...AND THE CORRIDOR FROM AVL EAST TO
CLT.

LATEST WV IMAGES INDICATED A MID LEVEL LOW OVER THE CENTRAL CONUS
WITH A PLUME OF MOISTURE FROM THE FL PANHANDLE NORTH ACROSS THE
APPALACHIANS. DRY AIR WRAPPING ON THE SOUTHERN SIDE OF THE LOW
SHOULD BEGIN TO MOVE EAST ACROSS THE SOUTHERN APPALACHIANS DURING
THE PRE DAWN HOURS...PUSHING ACROSS THE REMAINDER OF THE CWA THROUGH
THE AFTERNOON. RECENT RADAR IMAGES SHOW A SHARP LINE OF WEAK
REFLECTIVITY ASSOCIATED WITH THE SFC COLD FRONT/DRY AIR NEAR THE
AL/GA/TN LINE. AREAS OF MODERATE SHRA AND ISO EMBEDDED TSRA EXTENDED
FROM THE VICINITY OF THE COLD FRONT EAST ACROSS THE PIEDMONT OF THE
CAROLINAS. CAPE ACROSS THE REGION REMAINS VERY LIMITED TO NEAR ZERO.
HOWEVER...0 TO 1 KM HELICITY VALUES RANGE FROM 300 TO 400 M2/S2
AHEAD OF THE FRONT. IN ADDITION...QG FORCING ASSOCIATED WITH THE
CENTRAL CONUS LOW WILL PEAK ACROSS THE CWA BETWEEN 12 TO 18Z. IT
APPEARS THAT THE SHRA CLUSTERS WILL CONTINUE ACROSS THE CWA AHEAD OF
THE COLD FRONT. THE COLD FRONT IS FORECAST TO MOVE ACROSS THE UPPER
SAVANNAH RIVER VALLEY AROUND 15Z...AND REACHING THE CLT METRO AREA
AROUND 21Z. POPS WILL REMAIN NEAR 100 PERCENT AHEAD OF THE
FRONT...BUT WILL FALL SHARPLY AS THE BOUNDARY BEGINS TO MOVE WEST TO
EAST ACROSS THE FORECAST AREA. SVR TSRA POTENTIAL APPEARS VERY
LIMITED THIS MORNING. INSTABILITY IS EXPECTED TO INCREASE RAPIDLY
AFTER SUNRISE...ESPECIALLY ALONG AND EAST OF THE I-77 CORRIDOR. 4KM
WRF INDICATES THAT A LINE OF ORGANIZED TSRA WILL DEVELOP ALONG THE
FRONT OVER THE NC PIEDMONT THIS AFTERNOON. BASED ON THE TIMING OF
THE FRONT I WOULD ANTICIPATE THAT THE LINE WILL INITIATE EAST OF
I-77 DURING THE MID TO LATE AFTERNOON. THE STORMS THAT DEVELOP
WITHIN THE CWA WILL HAVE THE POTENTIAL FOR DAMAGING WINDS/HAIL AND
BRIEF TORNADOES...WILL HIGHLIGHT IN THE HWO.

OBSERVED RAINFALL ACROSS THE EAST FACING SLOPES OF THE WESTERN NC
MTNS RANGED FROM NEAR 3 INCHES TO 1 INCH. AREA RIVERS AND STREAMS
HAVE STARTED TO RISE...POSSIBLE YIELDING NEAR BANKFULL LEVELS WITHIN
THE HEADWATERS LATER TODAY. AN ADDITIONAL 1 TO 1.5 INCHES MAY FALL
OVER THE REGION BEFORE RAINFALL ENDS.

FORECAST SOUNDINGS INDICATE THAT POST FRONTAL MIXING HEIGHTS WILL
INCREASE TO 6 TO 8 KFT THIS AFTERNOON. WINDS WITHIN THE MIXED LAYER
WILL GENERALLY RANGE FROM 30 TO 40 KTS...WITH SFC GUSTS REACHING
NEAR 30 KTS. BASED ON THE CURRENT WIND OBS AND EXPECTED MIXING WINDS
TODAY...I WILL ISSUE A LAKE WIND ADVISORY FOR THE ENTIRE
CWA...KEEPING THE MORNING WIND ADVISORY FOR THE TN BORDER COUNTIES.

TEMPERATURES WILL PEAK NEAR NORMAL THIS AFTERNOON.
TONIGHT...CLEARING CONDITIONS WILL CAA SHOULD RESULT IN MIN TEMPS 3
TO 5 DEGREES BELOW NORMAL. TEMPERATURES ACROSS THE MTNS WILL RANGE
IN THE MID TO UPPER 30S...WITH BREEZY NORTHWEST WINDS.

&&

.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 330 AM SATURDAY...FRONT MOVES WELL E OF CWA SAT NIGHT WITH NW
FLOW SHWRS LINGERING OVER TN BORDER MTNS AND A PERIOD OF LGT SNOW
MIXING IN WITH RAIN AT THE HIGHER ELEVATIONS BEFORE PRECIP ENDS
AROUND DAYBREAK. LOWS WILL BE WITHIN A DEG OR TWO OF AVG SAT
NIGHT...THEN A DEG OR TWO ABOVE AVG SUN AS A RIDGE BUILDS INTO THE
AREA UNDER MSUNNY SKIES. RIDGE AXIS MOVES OFFSHORE MON WITH S FLOW
DEVELOPING ACROSS THE REGION. TEMPS SHOULD BE A COUPLE CATEGORIES
ABOVE AVG.

&&

.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 330 AM SATURDAY...A WEAK UPPER RIDGE BUILDS OVER THE AREA MON
NIGHT INTO TUE WITH A SFC HIGH OFF THE SE COAST RIDGING UP INTO THE
AREA. EXPECT PCLOUDY SKIES WITH ABOVE AVG TEMPS FOR THE FIRST PART
OF THE WEEK. A SERIES OF WEAK UPPER WAVES MOVE ACROSS THE REGION
WED-THU WITH A COLD FRONT EXPECTED TO APPROACH THE CWA FROM THE NW
WED NIGHT-THU. THIS WILL BRING A CHC OF SHWRS AND TSTMS TO THE
AREA...ESP TO THE MTNS. THE ECMWF PUSHES THE FRONT THRU THE CWA THU
AND WASHES IT OUT TO THE S WHILE THE GFS STALLS THE FRONT ALONG THE
S CWA AND MAINTAINS HIGHER CHC POPS THRU FRI. USED A BLEND FOR
SLIGHT CHC TO CHC POPS...ESP OVER THE MTNS...WED AFTN-FRI. TEMPS ARE
EXPECTED TO REMAIN ABOVE AVG.

&&

.AVIATION /10Z SATURDAY THROUGH WEDNESDAY/...
AT KCLT...GUSTY SOUTHEAST WINDS WILL CONTINUE ACROSS THE TERMINAL
THROUGH THE PRE DAWN HOURS...THEN VEERING SOUTH AROUND SUNRISE. SHRA
WILL BRING TEMPO REDUCTIONS TO VIS THIS MORNING...HOWEVER...VIS
SHOULD FAVOR VFR THROUGH SUNRISE. MOS AND FORECAST SOUNDINGS
INDICATE THAT CEILINGS WILL LOWER TO IFR THIS MORNING...WITH A
GRADUAL IMPROVEMENT TO MVFR BY MID DAY. WINDS WILL CONTINUE TO VEER
THROUGH THE DAYLIGHT HOURS...ESPECIALLY AS A COLD FRONT CROSSES THE
TERMINAL DURING THE MID AFTERNOON. CB SHOULD HOLD OFF UNTIL MID
MORNING AND REMAIN UNTIL THE PASSAGE OF THE COLD FRONT. BY THIS
EVENING...EXPECTING CLEARING CONDITIONS WITH WINDS FAVORING A
WEST DIRECTION WITH SPEEDS BETWEEN 9 TO 13 KTS.

ELSEWHERE ACRS THE FA...PERIODS OF MODERATE SHRA WILL CONTINUE
ACROSS THE TERMINALS THIS MORNING...LOWERING VIS TEMPO TO MVFR/IFR
WITH HEAVIER RAINFALL. MOS AND FORECAST SOUNDINGS INDICATE THAT
CEILINGS WILL LOWER TO IFR THIS MORNING WITH GUSTY SOUTHEAST WINDS.
A GRADUAL IMPROVEMENT TO MVFR IS EXPECTED BY MID DAY...GUSTY WINDS
VEERING TO SOUTHWEST. CLEARING SKY COVER WILL ADVANCE SOUTHWEST TO
NORTHEAST ACROSS THE TERMINALS THIS AFTERNOON IN THE WAKE OF A COLD
FRONT. CB SHOULD HOLD OFF UNTIL MID MORNING AND REMAIN UNTIL THE
PASSAGE OF THE COLD FRONT. BY THIS EVENING...EXPECTING CLEAR
CONDITIONS WITH WINDS FAVORING A WEST DIRECTION WITH SPEEDS BETWEEN
9 TO 13 KTS.

OUTLOOK...DRY HIGH PRESSURE WILL BUILD OVER THE REGION ON SUNDAY AND
REMAIN THROUGH TUESDAY. ANOTHER COLD FRONT MAY SWEEP ACROSS THE
REGION WEDNESDAY AND WEDNESDAY NIGHT.

&&

.GSP WATCHES/WARNINGS/ADVISORIES...
GA...LAKE WIND ADVISORY UNTIL 8 PM EDT THIS EVENING FOR GAZ010-017-
     018-026-028-029.
NC...LAKE WIND ADVISORY UNTIL 8 PM EDT THIS EVENING FOR NCZ035>037-
     053-056-057-059-062>065-068>072-082-501>510.
     WIND ADVISORY UNTIL 8 AM EDT THIS MORNING FOR NCZ033-048>052-
     058.
SC...LAKE WIND ADVISORY UNTIL 8 PM EDT THIS EVENING FOR SCZ001>014-
     019.

&&

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

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
427 AM EDT SAT APR 16 2011

GAZ010-017-018-026-028-029-NCZ035>037-053-056-057-059-062>065-
068>072-082-501>510-SCZ001>014-019-170830-
RABUN-HABERSHAM-STEPHENS-FRANKLIN-HART-ELBERT-ALEXANDER-IREDELL-
DAVIE-BUNCOMBE-CATAWBA-ROWAN-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-
427 AM EDT SAT APR 16 2011

...LAKE WIND ADVISORY IN EFFECT UNTIL 8 PM EDT THIS EVENING...

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

.DAY ONE...TODAY AND TONIGHT.

PLEASE LISTEN TO NOAA WEATHER RADIO OR GO TO WEATHER.GOV ON THE
INTERNET FOR MORE INFORMATION ABOUT THE FOLLOWING HAZARDS.

   LAKE WIND ADVISORY.

WIDESPREAD SHOWERS AND SCATTERED THUNDERSTORMS WILL MOVE EAST
ACROSS THE AREA TODAY. DAMAGING STRAIGHT LINE WINDS AND ISOLATED
TORNADOES WILL BE POSSIBLE...MAINLY ACROSS THE PIEDMONT. RAINFALL
TOTALS OF 2 TO 3 INCHES ARE EXPECTED ACROSS THE MOUNTAINS AND
ADJACENT FOOTHILLS BY THE TIME THE RAIN ENDS LATER TODAY. SOME
URBAN AND SMALL STREAM FLOODING CAN BE EXPECTED.

.DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY.

.SPOTTER INFORMATION STATEMENT...

NONE.

NCZ033-048>052-058-170830-
AVERY-MADISON-YANCEY-MITCHELL-SWAIN-HAYWOOD-GRAHAM-
427 AM EDT SAT APR 16 2011

...WIND ADVISORY IN EFFECT UNTIL 8 AM EDT THIS MORNING...

THIS HAZARDOUS WEATHER OUTLOOK IS FOR WESTERN NORTH CAROLINA.

.DAY ONE...TODAY AND TONIGHT.

PLEASE LISTEN TO NOAA WEATHER RADIO OR GO TO WEATHER.GOV ON THE
INTERNET FOR MORE INFORMATION ABOUT THE FOLLOWING HAZARDS.

   WIND ADVISORY.

WIDESPREAD SHOWERS AND SCATTERED THUNDERSTORMS WILL MOVE EAST
ACROSS THE AREA TODAY. DAMAGING STRAIGHT LINE WINDS AND ISOLATED
TORNADOES WILL BE POSSIBLE...MAINLY ACROSS THE PIEDMONT. RAINFALL
TOTALS OF 2 TO 3 INCHES ARE EXPECTED ACROSS THE MOUNTAINS AND
ADJACENT FOOTHILLS BY THE TIME THE RAIN ENDS LATER TODAY. SOME
URBAN AND SMALL STREAM FLOODING ARE POSSIBLE.

.DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY.

.SPOTTER INFORMATION STATEMENT...

NONE.

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
542 AM EDT SAT APR 16 2011

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

0520 AM     FLASH FLOOD      LITTLE RIVER            35.24N 82.63W
04/16/2011                   TRANSYLVANIA       NC   OFFICIAL NWS OBS

            THE STAGE OF THE LITTLE RIVER WAS 9.06 FT. FLOOD STAGE IS
            9 FT.

0525 AM     FLASH FLOOD      HENDERSONVILLE          35.32N 82.46W
04/16/2011                   HENDERSON          NC   OFFICIAL NWS OBS

            THE STAGE ON MUD CREEK WAS 7.52 FT. FLOOD STAGE IS 7.5
            FT.

&&

NED

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
611 AM EDT SAT APR 16 2011

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

0545 AM     FLASH FLOOD      HENDERSONVILLE          35.32N 82.46W
04/16/2011                   HENDERSON          NC   OFFICIAL NWS OBS

            THE STAGE ON BAT FORK CREEK WAS 7.18 FT. FLOOD STAGE IS 7
            FT.

&&

NED