Flash Flood in South Carolina, March 20, 2001

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON NC
150 PM EST TUE MAR 20 2001

...INTENSE STORM OVER THE SE CONTINUES TO SPREAD HVY RAFL AND STRONG
WIND ACROSS THE AREA AND ADJACENT ATLC WATERS...

LATEST SFC ANALYSIS DEPICTS A DOUBLE LOW STRUCTURE W/ ONE LOW OFF
THE GA COAST AND A LOW FILLING ACROSS WRN GA. PER WATER VAPOR THE
MAIN UPPER LOW CENTER WAS POSND ACROSS AL. STRONG DIFLUENCE ALOFT
...COUPLED W/ STRONG LLVL CONVERGENCE HAS RESULTED IN A LARGE SWATH
OF MOD TO HEAVY RAFL ACROSS THE FA. ANOTHER BAND WAS APPROACHING
FROM THE S. THE FCST THIS CYCLE WILL REMAIN VERY COMPLEX AS ONE
WOULD EXPECT...BUT AT LEAST THE ETA/AVN MODELS LOOK REASONABLE.

A DIVERGENT THICKNESS PTN AND HIGH PWS VALUES IMPLY HEAVY RAFL
CONTINUING THROUGH THE REMAINDER OF THE AFTERNOON INTO THE EVENING.
LIKEWISE...VERY STRONG DYNAMICS W/ +100 KT JET NOSING INTO THE AREA
FM THE S AND FAVORABLE QUAD TO PASS OVHD TONIGHT A CHANCE TO SEE
TSTMS. STRONG UVM WILL REMAIN THROUGH MUCH OF THE EVENING UNTIL THE
LOW BEGINS TO PIVOT THROUGH. ALTHOUGH THE DEEPEST MSTR WILL SHIFT
OFF TO THE N AND NE BY LATER TONIGHT W/ DRY SLOT WORKING THROUGH...
THE COLD POOL ALOFT (AOA -24C AT H5) WILL SHARPEN LAPSE RATES
TONIGHT...AND ESPECIALLY ON WED. SO WILL LIKELY SEE SCT SHOWERS AND
TSTMS CONTINUING INTO WED. EXPECT CLEARING TO BEGIN WED NIGHT INTO
THU.

AS THE LOW SHIFTS NWD WILL PROBABLY SEE TEMPS HOLD STEADY OR EVEN
INCREASE ALONG COASTAL AREAS TONIGHT. OTHERWISE THE MAV/FWC GUIDANCE
APPEARS REASONABLE FOR REMAINING PERIODS. WILL ALSO BE WINDY...ESP
ALONG THE IMMEDIATE COASTAL AREAS. WILL RETAIN WIND ADVISORY FOR
COASTAL AREAS THROUGH THIS EVENING...BUT SPEEDS SHOULD BEGIN TO
DIMINISH ONCE THE LOW MOVES INTO THE VICINITY W/ A SHIFT TO THE SW.
WILL ALSO HAVE TO KEEP AN EYE ON STRONGER WINDS MIXING DOWN TO THE
SFC WITHIN THE BANDS OF HVY RAFL.

WATER LEVELS RUNNING 2-3 FT ABV PREDICTED NORMALS. MINOR COASTAL
FLOODING AND SOME BEACH EROSION ARE STILL POSSIBLE...ESPECIALLY
DURING HIGH TIDE LATER THIS AFTERNOON. WE HAVE NOT HAD ANY REPORTS
OF ANY PROBLEMS THUS FAR...AND W/ THE WIND VEERING AROUND TO AN
OFFSHORE DIR...THE THREAT FOR MINOR COASTAL FLOODING WILL DIMINISH
DURING SUBSEQUENT HIGH TIDE CYCLES.

CWF: VERY HIGH SEAS CONTINUE AT THE EDISTO BUOY WHERE SEAS HAVE BEEN
IN EXCESS OF 20 FT WILL LEAVE HVY SURF ADVSRY UP AND GALE CONDS
WILL CONTINUE AS STRONG WIND FIELD PERSISTS. FORTUNATELY...AS THE
LOW MOVE NWD THE STRONGER WINDS WILL SHIFT FARTHER N...THUS THE
GALES MAY ONLY LINGER INTO THE EARLY EVENING FOR THE SC MARINE
AREAS. THE DIR WILL VEER AROUND TO THE SW TONIGHT...BUT SEAS WILL
REMAIN UP THROUGH WED. ADDITIONAL VEERING TO THE NW IS EXPECTED WED
NIGHT AS THE LOW MOVES E OF DELMARVA.

FCSTID = 29
ILM   53  62  44  63 /  80  40  20   0
LBT   46  57  42  62 /  80  40  10   0
FLO   47  58  43  65 /  80  40  10   0
MYR   55  60  45  63 /  80  40  20   0

.ILM...
NC...GALE WARNING SURF CITY TO LITTLE RIVER INLET
     HEAVY SURF ADVISORY SURF CITY TO LITTLE RIVER INLET
     WIND ADVISORY IMMEDIATE COAST NCZ097-100-101.
SC...GALE WARNING LITTLE RIVER INLET TO S SANTEE RIVER
     HEAVY SURF ADVISORY LITTLE RIVER INLET TO S SANTEE RIVER
     WIND ADVISORY IMMEDIATE COAST SCZ034-046.

PFAFF