Special Weather Statement, NWS Columbia, SC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
249 PM EDT WED APR 4 2012

.SYNOPSIS...
A COLD FRONT WILL SINK SOUTHWARD AND SLOWLY MOVE THROUGH THE
FORECAST AREA THURSDAY AND THURSDAY NIGHT. IT WILL BE MUCH COOLER
BEHIND THE FRONT. ASSOCIATED LOW PRESSURE WILL BE OFF THE COAST
FRIDAY. THE LOW WILL MOVE FARTHER OFFSHORE AND A DRY AIR MASS WITH
COVER THE FORECAST AREA SATURDAY AND SUNDAY.

&&

.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
THIS AFTERNOON...
STRONG HEATING WITH LEE TROUGHING WILL SUPPORT THUNDERSTORMS THIS
AFTERNOON. EXPECT LITTLE COVERAGE BECAUSE OF SHALLOW MOISTURE.
STRONG LOW-LEVEL LAPSE RATES COULD POSSIBLY SUPPORT NEAR-SEVERE WIND
GUSTS WITH A FEW OF THE THUNDERSTORMS.

TONIGHT...
CONVERGENCE AHEAD OF THE APPROACHING COLD FRONT PLUS A MID-LEVEL
SHORTWAVE TROUGH SUPPORTS THUNDERSTORMS TONIGHT. THE HIGH-RESOLUTION
WRF INDICATES SCATTERED COVERAGE DURING MOST OF THE NIGHT. MOST OF
THE NAM AND GFS MOS PLUS SREF GUIDANCE SUPPORT CHANCE POPS. THIS
APPEARS REASONABLE BECAUSE OF THE DIURNAL TIMING AND SOMEWHAT
SHALLOW MOISTURE. MODERATE INSTABILITY MAY SUPPORT NEAR-SEVERE
WINDS GUSTS WITH A FEW OF THE THUNDERSTORMS DURING THE EVENING. A
DIMINISHED THREAT SHOULD OCCUR BY LATE TONIGHT BECAUSE OF THE LOSS
OF HEATING. USED THE GUIDANCE CONSENSUS FOR THE TEMPERATURE FORECAST.

&&

.SHORT TERM /6 AM THURSDAY MORNING THROUGH FRIDAY NIGHT/...
UPPER LEVEL LOW WILL TRACK EASTWARD FROM THE LOWER MS VALLEY ACROSS
THE NORTHERN PORTIONS OF THE GULF STATES ON THURSDAY AND INTO THE
FORECAST AREA THURSDAY NIGHT. MOVING WITH THE UPPER LOW WITH BE A
SURFACE LOW AND WEAK FRONTAL SYSTEM WHICH WILL MOVE ACROSS THE AREA
LATE THURSDAY AFTERNOON AND THURSDAY NIGHT. AHEAD OF THE SURFACE LOW
THE WINDS WILL BE SOUTHERLY ALLOWING FOR GULF MOISTURE TRANSPORT
INTO THE FORECAST AREA. PWAT VALUES WILL INCREASE THROUGH THE DAY
REACHING AROUND 1.4 INCHES INTO THURSDAY NIGHT. WITH THE MOISTURE
INFLUX INSTABILITY WILL PEAK THURSDAY EVENING/EARLY THURSDAY NIGHT
WITH POTENTIAL FOR THUNDERSTORMS TO CONTAIN HEAVY RAINFALL. WITH A
PROGRESSIVE SYSTEM DO NOT EXPECT ANY THUNDERSTORMS TO REMAIN OVER
AREAS LONG ENOUGH TO BE A FLOODING CONCERN. ON FRIDAY THE LOW WILL
MOVE OFFSHORE WITH THE UPPER LEVEL LOW CROSSING THE AREA FRIDAY
MORNING AND TRACKING EASTWARD FRIDAY AFTERNOON. AS THIS OCCURS HIGH
PRESSURE WILL BEGIN BUILDING IN FROM THE NORTH ALONG WITH MUCH
COOLER AND DRIER AIR. TEMPERATURES THROUGH THE SHORT TERM WILL BE IN
THE UPPER 70S TO AROUND 80 ON THURSDAY AND DROP INTO THE LOWER TO
MIDDLE 60S FOR FRIDAY.

&&

.LONG TERM /SATURDAY THROUGH TUESDAY/...
MODELS ARE IN GOOD AGREEMENT THROUGH THE LONG TERM WITH SOME
DIFFERENCES IN TIMING AND INTENSITY APPEARING LATE IN THE LONG TERM.
HIGH PRESSURE WILL BE OVER THE REGION FOR SATURDAY AND SUNDAY WITH A
WEAK AND DRY BOUNDARY CROSSING THE AREA SUNDAY NIGHT. NEXT SYSTEM
WILL MOVE THROUGH THE AREA ON MONDAY NIGHT/EARLY TUESDAY AND THIS
SYSTEM REMAINS DISORGANIZED SO HAVE REDUCED POPS AS MAIN ENERGY
WILL BE NORTH OF THE FORECAST AREA.

UPPER LEVEL PATTERN WILL REMAIN HIGHLY AMPLIFIED THROUGH THE LONG
TERM WITH A SLOW EASTERLY PROGRESSION. THIS WILL ALLOW THE LONG
WAVE  TROUGH TO PUSH OFF THE COAST ON SATURDAY WITH THE UPPER LEVEL
RIDGE MOVING IN FOR THE WEEKEND. BY EARLY NEXT WEEK ANOTHER TROUGH
MOVES OVER THE REGION AND WILL PERSIST THROUGH THE END OF THE LONG
TERM.

TEMPERATURES THROUGH THE LONG TERM WILL BE NEAR NORMAL THROUGH
MONDAY THEN SLIGHTLY BELOW NORMAL FOR TUESDAY.

&&

.AVIATION /19Z WEDNESDAY THROUGH MONDAY/...
EXPECT MAINLY VFR CONDITIONS THROUGH THE EVENING. STRONG HEATING
WITH MODERATE INSTABILITY SHOULD RESULT IN THUNDERSTORMS LATE THIS
AFTERNOON AND EVENING. HOWEVER...A WELL-DEFINED SURFACE FEATURE
APPEARS LACKING SO EXPECT LITTLE THUNDERSTORM COVERAGE. THE CHANCE
OF THUNDERSTORMS APPEARS TO BE TOO LOW TO INCLUDE IN THE TERMINAL
FORECASTS AT THIS TIME. CONVERGENCE ASSOCIATED WITH A COLD FRONT
SINKING SOUTHWARD AND INTO THE AREA MAY SUPPORT THUNDERSTORMS LATE
TONIGHT AND DURING THE REST OF THE TAF PERIOD. A MID-LEVEL SHORTWAVE
TROUGH MAY AID THUNDERSTORMS DURING THE EVENING. TIMING UNCERTAINTY
WAS TOO HIGH TO INCLUDE THUNDERSTORMS IN THE TERMINALS AT THIS TIME.
DIURNAL COOLING AND LOW-LEVEL MOISTURE MAY SUPPORT STRATUS AND FOG
DURING THE EARLY MORNING HOURS. USED AN AVERAGE OF THE GFS AND NAM
MOS AND FORECASTED MVFR FOG AT CAE...CUB...AND DNL. FORECASTED A
PERIOD OF IFR FOG AT AGS AND OGB.

EXTENDED AVIATION OUTLOOK...NUMEROUS SHOWERS AND THUNDERSTORMS WILL
CAUSE RESTRICTIONS THURSDAY AFTERNOON THROUGH FRIDAY.

&&

.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE COLUMBIA SC
525 AM EDT WED APR 4 2012

GAZ040-063>065-077-SCZ015-016-018-020>022-025>031-035>038-041-050925-
AIKEN-BAMBERG-BARNWELL-BURKE-CALHOUN-CHESTERFIELD-CLARENDON-COLUMBIA-
EDGEFIELD-FAIRFIELD-KERSHAW-LANCASTER-LEE-LEXINGTON-LINCOLN-MCCORMICK-
MCDUFFIE-NEWBERRY-ORANGEBURG-RICHLAND-RICHMOND-SALUDA-SUMTER-
525 AM EDT WED APR 4 2012

THIS HAZARDOUS WEATHER OUTLOOK IS FOR THE MIDLANDS OF SOUTH CAROLINA
AND THE CENTRAL SAVANNAH RIVER AREA OF GEORGIA.

.DAY ONE...TODAY AND TONIGHT
NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY
NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...
SPOTTER ACTIVATION IS NOT ANTICIPATED.

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE COLUMBIA SC
234 PM EDT WED APR 4 2012

GAZ040-064-041900-
COLUMBIA-LINCOLN-
234 PM EDT WED APR 4 2012

...A STRONG THUNDERSTORM WILL IMPACT PORTIONS OF LINCOLN AND
COLUMBIA COUNTIES THROUGH 330 PM EDT...

AT 230 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM WHICH WILL AFFECT THE AREA NEAR THE LINCOLN AND
COLUMBIA COUNTY LINE THROUGH 330 PM.

EXPECT WIND GUSTS NEAR 40 MPH...BRIEF HEAVY DOWNPOURS...AND DANGEROUS
LIGHTNING WITH THIS STORM.

&&

LAT...LON 3376 8245 3379 8230 3378 8229 3375 8225
      3370 8224 3366 8220 3363 8220 3360 8215
      3358 8241 3362 8244 3365 8243 3365 8244
TIME...MOT...LOC 1832Z 263DEG 28KT 3368 8233

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE COLUMBIA SC
313 PM EDT WED APR 4 2012

GAZ064-065-SCZ025-030-042000-
AIKEN-COLUMBIA-EDGEFIELD-RICHMOND-
313 PM EDT WED APR 4 2012

...STRONG THUNDERSTORMS WILL IMPACT PORTIONS OF RICHMOND...
COLUMBIA...EDGEFIELD AND AIKEN COUNTIES THROUGH 400 PM EDT...

AT 311 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM...NEAR MARTINEZ...MOVING EAST AT 25 MPH.

SOME LOCATIONS THAT WILL BE AFFECTED INCLUDE...
GLOVERVILLE...BELVEDERE...CLEARWATER...NORTH AUGUSTA...AUGUSTA...
EVANS AND MARTINEZ...

PREPARE NOW FOR THE FOLLOWING HAZARDS...
GUSTY WINDS OF 30 TO 40 MPH...
BRIEF HEAVY DOWNPOURS...
PEA SIZE HAIL...
OCCASIONAL CLOUD TO GROUND LIGHTNING...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

OCCASIONAL LIGHTNING IS OCCURRING WITH THIS STORM. IF
OUTDOORS...STAY AWAY FROM ISOLATED HIGH OBJECTS SUCH AS TREES. MOVE
INDOORS IF POSSIBLE.

REPORT LARGE HAIL...DAMAGING WINDS OR FLOODING TO YOUR COUNTY
SHERIFF...OR CALL THE NATIONAL WEATHER SERVICE TOLL FREE AT 1...8 7
7...6 3 3...6 7 7 2.

&&

LAT...LON 3367 8221 3363 8220 3359 8214 3360 8211
      3364 8210 3368 8215 3369 8214 3367 8166
      3335 8191 3354 8227
TIME...MOT...LOC 1911Z 292DEG 20KT 3359 8212