Flash Flood Warning 1, NWS Greenville-Spartanburg, SC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
255 AM EST MON MAR 20 2000

COMPLEX AMPLIFIED UPPER PATTERN WILL GROW MORE COMPLICATED OVER THE
NEXT 36 HOURS. IMPRESSIVE CLOSED LOW OVER THE MID MS VALLEY THIS
MORNING WILL CONTINUE TO GRADUALLY LIFT OUT TO THE EAST UP THE OH
VALLEY TODAY AS AXIS OF NEGATIVELY TILTED MID/UPPER TROF SWINGS
ACROSS THE SOUTHEAST AND CAROLINAS...UNTIL A MID/UPPER HIGH CLOSES
OFF ACROSS NEW ENGLAND AND THE CANADIAN MARITIMES THIS EVENING. THIS
UPPER HIGH WILL BLOCK THE EXIT OF THE CLOSED LOW AND FORCE IT TO
MEANDER TO THE EAST AND SOUTHEAST ACROSS THE CENTRAL APPALACHIANS
AND MID ATLANTIC TONIGHT AND TUESDAY. THIS COMPLICATING FACTOR WILL
MOST LIKELY CAUSE TROUBLE FOR TUESDAY BY KEEPING A GRADIENT OF
MOISTURE AND FORCING NEARBY.

FOR THE SHORT TERM...KGSP RADAR CONTINUES TO SHOW VERY STRONG WINDS
OF 50 KNOTS OR BETTER IN THE LOWEST FEW THOUSAND FEET ALONG THE
LEADING EDGE OF THE HEAVIER PRECIP...WHICH WAS MOVING OVER THE
WESTERN PART OF THE FCST AREA AT 07Z. THE RUC SHOWS WINDS SUBSIDING
QUICKLY AFTER THE PASSAGE OF THE MAIN PRECIP BAND. TIMING THE
MOVEMENT OF THE BACK EDGE OF THE HEAVIER PRECIP PUTS IT THROUGH
AVL/GSP/GRD AROUND 11Z OR SO. MAY HAVE TO KEEP THE WIND WARNING/
ADVISORY GOING PAST ZONE ISSUANCE TIME AND WILL FURTHER EVALUATE
THIS JUST BEFORE ZONE ISSUANCE. ALTHO THE BACK EDGE OF THE HEAVIER
PRECIP WILL ALREADY BE MOVING IN ACROSS THE AREA AT 09Z...PLAN ON
KEEPING THE FLASH FLOOD WATCH FOR THIS PACKAGE INITIALLY.

THE SCENARIO I ENVISIONED YESTERDAY STILL SEEMS PLAUSIBLE FOR TODAY.
THE MODELS SHOW THE FORCING FOR THE PRECIP BAND SWEEPING ACROSS THE
FORECAST AREA IN THE 12Z TO 18Z TIME FRAME...WHICH MAKES SENSE GIVEN
THE RADAR TRENDS. WILL KEEP THE IDEA OF PRECIP TAPERING OFF IN THE
MORNING ACROSS THE WESTERN HALF AND IN THE AFTERNOON OVER THE
EASTERN PART. WILL SPLIT THE ZONES ACCORDING TO THE BACK EDGE OF THE
MAIN PRECIP BAND AND KEEP CATEGORICAL PRECIP CHANCE E AND CHANCE W.

AFTER THE MAIN PRECIP BAND MOVES PAST...A THREAT FOR ADDITIONAL
PRECIP WILL REMAIN. SATELLITE IMAGERY SHOWS SOME BREAKS IN THE
CLOUDINESS OVER AL MOVING INTO WRN GA. EXPECT WE WILL SEE SOME
PARTIAL CLEARING BY LATE MORNING OVER NE GA/SC PIEDMONT WHICH WILL
ALLOW FOR SOME DESTABILIZATION. LAPSE RATES WILL STEEPEN AS A MID
LEVEL COLD POOL MOVES OVERHEAD DURING MIDDAY. THE ETA SHOWS SBCAPE
OF AROUND 1000 J/KG AT 18Z WITH SOME RESIDUAL SHEAR. THE MAIN
PROBLEM IS...OF COURSE...WE STILL HAVE THIS WEDGED-IN AIR MASS
ACROSS THE AREA. INDICATIONS ARE THAT THE WEDGE IS BEING SCOURED OUT
ACROSS UPSTATE SC. THE RUC SHOWS A TRIPLE-POINT SURFACE LOW MOVING
ACROSS THE UPSTATE THIS MORNING. THUS...THE BEST CHANCE FOR TSTM
REDEVELOPMENT SHOULD BE GENERALLY S OF I-85. SPC HAS A SLGT RISK
ALONG THE SE FRINGE OF THE FORECAST AREA...WHICH SEEMS REASONABLE.
PLAN ON ADDRESSING THIS POTENTIAL IN A SEVERE WEATHER OUTLOOK.

DIVERGING MODEL SOLUTIONS WITH REGARD TO THE TRACK OF THE TRIPLE
POINT LOW MAKES THE FORECAST FOR TONITE AND TUESDAY PROBLEMATIC. THE
NGM KEEPS THE LOW FARTHER SW ALONG THE SC COAST WHICH WRAPS MORE
PRECIP BACK OVER THE FORECAST AREA TONITE AND TUESDAY. THE AVN IS A
BIT FARTHER N THAN THE ETA BUT HAS SOME PRECIP WRAPPING BACK OVER
THE NRN FOOTHILLS/NW PIEDMONT. AM INCLINED TO FOLLOW CLOSER TO THE
ETA/AVN POSITION OF THE SURFACE LOW...AND THINK IT WOULD BE BEST TO
KEEP A PRECIP CHANCE OVER THE NORTHERN FRINGE THRU THE PERIOD
SIMILAR TO THE AVN PRECIP FIELD. DOWNSLOPE E OF THE MOUNTAINS SHOULD
KEEP  THE PRECIP AWAY FROM UPSTATE SC/NE GA. THE END RESULT WILL BE
A SIGNIFICANT NE/SW GRADIENT IN CLOUDS/PRECIP/TEMPS ACROSS THE
REGION ON TUESDAY.

...PRELIM NUMBERS...
AVL 53/39/59 632
CLT 56/44/62 943
GSP 59/43/66 821

.GSP...HIGH WIND WARNING UNTIL 12Z MONDAY ALL NC MTN ZONES.
       WIND ADVISORY UNTIL 12Z MONDAY GA/SC MTN ZONES.
       FLASH FLOOD WATCH MONDAY MORNING NCZ062>067-GAZ010-017-
          SCZ001>003.

MOORE

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREENVILLE SPARTANBURG SC
1138 PM EST SUN MAR 19 2000

TIME (EST) .....CITY LOCATION....... ST   ...EVENT/REMARKS...
           .....COUNTY LOCATION.....

1100 PM    MACON                     NC   NON TSTM WINDS
03/19/00   MACON                          COUNTY REPORTS ABOUT A
                                          HALF DOZEN TREES DOWN
                                          THROUGHOUT THE COUNTY. A
                                          FEW POWER OUTAGES SOUTHERN
                                          END.

1115 PM    5 N SYLVA                 NC   NON TSTM WINDS
03/19/00   JACKSON                        COUNTY REPORTS TREES DOWN
                                          ON HIGHWAY 19 NORTH.

HG
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PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREENVILLE SPARTANBURG SC
333 AM EST MON MAR 20 2000

TIME (EST) .....CITY LOCATION....... ST   ...EVENT/REMARKS...
           .....COUNTY LOCATION.....

1224 AM    4 NW ASHEVILLE            NC   NON TSTM WINDS
03/20/00   BUNCOMBE                       COUNTY 911 CENTER REPORTS
                                          TREES DOWN...SOME ON POWER
                                          LINES... IN THE LEICESTER
                                          AREA.

150 AM     3 W ASHEVILLE             NC   NON TSTM WINDS
03/20/00   BUNCOMBE                       COUNTY 911 CENTER REPORTS
                                          TREES DOWN...SOME ON POWER
                                          LINES...IN ENKA. SOME
                                          LOCAL ROADS BLOCKED.

100 AM     HOT SPRINGS               NC   NON TSTM WINDS
03/20/00   MADISON                        HIGH WINDS DOWNED A FEW
                                          TREES IN HOT SPRINGS. SOME
                                          POWER OUTAGES. REPORT FROM
                                          MADISON COUNTY 911.

200 AM     CLARKESVILLE              GA   NON TSTM WINDS
03/20/00   HABERSHAM                      COUPLE OF TREES DOWN ALONG
                                          LIBERTY AND RAPER MOUNTAIN
                                          ROADS. REzPORT FROM
                                          HABERSHAM COUNTY 911.

SAB
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