Special Weather Statement, NWS Columbia, SC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
1015 PM EDT FRI AUG 19 2011

.SYNOPSIS...
A SLIGHT INCREASE IN ATMOSPHERIC MOISTURE WILL PROVIDE A SLIGHT
CHANCE OF MAINLY AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS
THROUGH MONDAY.

&&

.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
RUC MODEL SHOWS WEAK SHORT WAVE DROPPING TO THE SOUTHEAST IN THE
UPPER FLOW OVER THE REGION THIS EVENING. THIS IS HELPING TO TOUCH
OFF SOME SHOWER AND THUNDERSTORM ACTIVITY. HAVE INCLUDED AN AREA
OF 60-80 PERCENT POPS MOVING SOUTHEAST ABOUT 10 KNOTS OVER THE
CENTRAL MIDLANDS INCLUDING CAE FOR NEXT 2-3 HOURS OR ROUGHLY NEAR
MIDNIGHT. DID GRADUALLY LOWER POPS TO 40-60 PERCENT FARTHER TO THE
SOUTH AND EAST AS AREA MOVED TO NEAR SUMTER AND ORANGEBURG. ALSO
INCLUDED ANOTHER AREA OF 30 PERCENT TO COVER ACTIVITY IN WESTERN
PART OF CAE CWA NEAR AIKEN-AGS-BARNWELL FOR SAME TIME PERIOD BUT
LOWERED TO 20 PERCENT LAST HOUR OR TWO. OTHERWISE...LOW
TEMPERATURES STILL OK.

&&

.SHORT TERM /6 AM SATURDAY MORNING THROUGH SUNDAY/...
RELATIVELY LITTLE CHANGE SATURDAY. MODELS INDICATE A LITTLE
DRYING ALOFT...BUT OVERALL ATMOSPHERE APPEARS SIMILAR WITH ONLY
WEAK INSTABILITY. SO WILL MAINTAIN SLIGHT CHANCE POPS. LOWS
TONIGHT FALLING DOWN TO NEAR 70...THEN LOWS SATURDAY NIGHT
SLIGHTLY WARMER WITH READINGS IN THE LOWER 70S. HIGHS DURING THE
DAY ON SATURDAY ABOVE NORMAL...RISING INTO THE MIDDLE 90S.

&&

.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
LITTLE OVERALL CHANGE IN THE MEAN UPPER PATTERN EXPECTED DURING THE
PERIOD WITH RIDGE OVER THE SW US/SOUTHERN PLAINS AND TROUGH EAST
COAST. WEAK COLD FRONT LIKELY APPROACHING THE AREA MONDAY. FRONT
WEAKENS AS IT MOVES INTO THE AREA DURING THE AFTERNOON AND MOISTURE
APPEARS LIMITED...AXIS SHIFTS EAST OF THE AREA EARLY...AND
STRONGER DYNAMICS NORTH OF THE REGION. ENSEMBLE POPS LOW THROUGH
MONDAY AND TRIGGERS HARD TO IDENTIFY/TIME SO SLIGHT CHANCE
THUNDERSTORMS MAINLY AFTERNOON AND EVENING THROUGH MONDAY NIGHT.

SOME UNCERTAINTIES WITH REGARD TO FRONTAL POSITION TUESDAY AND
WEDNESDAY AND EXTENT AND TIMING OF ANY DRIER AIR THAT MAY MOVE
INTO THE FA. ENSEMBLE GUIDANCE SUGGESTS A SLIGHT INCREASE IN POPS
EACH DAY THROUGH EXTENDED AS MOISTURE INCREASES. TEMPERATURES AT
OR ABOVE CLIMATOLOGY.

&&

.AVIATION /02Z SATURDAY THROUGH WEDNESDAY/...
UPDATE...SHRA AND TSRA ARE MOVING SOUTHEAST ACROSS THE FORECAST
AREA THIS EVENING AS AN UPPER LEVEL DISTURBANCE MOVES OVERHEAD.
TAFS HAVE BEEN UPDATED. WENT WITH VCTS FOR CAE/CUB AND AGS/DNL AS
LIGHTNING IS BEING OBSERVED ACROSS THE MIDLANDS AND CSRA. TEMPO
GROUP FOR TSRA AT CAE AS A STORM IS TRACKING TOWARD THE TERMINAL.
ALSO TEMPO GROUP FOR TSRA AT AGS/DNL AS A STORM MOVES DOWN THE
SAVANNAH RIVER.

PREVIOUS DISCUSSION...
TOUGH FORECAST THIS EVENING FOR THE TAF SITES. MODELS GIVING
SOMEWHAT MIXED SIGNALS AS FAR AS FOG/LOW STATUS DEVELOPMENT
OVERNIGHT. GFS/LAMP IS MORE AGGRESSIVE WITH BRINGING IN IFR/LIFR
CONDITIONS AT OGB/AGS BUT FELT SAFER WITH JUST HALF STEPPING TO A
GENERAL 4SM VIS AND CIG AT 1KFT FOR A FEW HOURS IN THE MORNING.
EXPECTED MOSTLY CLOUDY SKIES AND A LOW LEVEL JET OVERNIGHT SHOULD
KEEP LOW LEVELS MIXED ENOUGH TO KEEP VIS FROM REACHING IFR...BUT
IN CONTRAST TO THOSE THOUGHTS HEAVY THUNDERSTORMS WERE OBSERVED AT
OGB AND SHOWERS NEAR AGS EARLIER THIS EVENING SO MOISTURE AT THOSE
SITES IS HIGH. WILL CONTINUE TO MONITOR FOR UPDATES AND A TEMPO
GROUP MAY BE INTRODUCED IN LATER UPDATES IF VIS/CIGS LOOK TO
ACTUALLY BE LOWER. AFTER 14Z ANY FOG/STRATUS SHOULD LIFT TO JUST
SCATTERED SKIES. ONLY SLIGHT CHANCE OF AFTERNOON STORMS.

EXTENDED AVIATION OUTLOOK...MVFR OR IFR CONDITIONS MAY OCCUR IN
EARLY MORNING FOG/STRATUS AS WELL AS IN AFTERNOON AND EVENING
CONVECTION EACH DAY.

&&

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

SYNOPSIS...
NEAR TERM...07
SHORT TERM...
LONG TERM...
AVIATION...31

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE COLUMBIA SC
426 AM EDT FRI AUG 19 2011

GAZ040-063>065-077-SCZ015-016-018-020>022-025>031-035>038-041-200830-
LINCOLN-MCDUFFIE-COLUMBIA-RICHMOND-BURKE-LANCASTER-CHESTERFIELD-
MCCORMICK-NEWBERRY-FAIRFIELD-KERSHAW-EDGEFIELD-SALUDA-LEXINGTON-
RICHLAND-LEE-AIKEN-SUMTER-BARNWELL-ORANGEBURG-CALHOUN-CLARENDON-
BAMBERG-
426 AM EDT FRI AUG 19 2011

THIS HAZARDOUS WEATHER OUTLOOK IS FOR EAST CENTRAL GEORGIA AND
CENTRAL SOUTH CAROLINA.

.DAY ONE...TODAY AND TONIGHT.

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY.

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME.

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE COLUMBIA SC
930 PM EDT FRI AUG 19 2011

SCZ020-021-028-200230-
FAIRFIELD-NEWBERRY-RICHLAND-
930 PM EDT FRI AUG 19 2011

...STRONG THUNDERSTORMS WILL IMPACT PORTIONS OF FAIRFIELD...NEWBERRY
AND RICHLAND COUNTIES THROUGH 1030 PM EDT...

AT 923 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM...9 MILES NORTH OF PEAK...MOVING SOUTHEAST AT 10
TO 15 MPH.

SOME LOCATIONS THAT WILL BE AFFECTED INCLUDE...
IRMO AND WINNSBORO...

PREPARE NOW FOR THE FOLLOWING HAZARDS...
WINDS 30 TO 40 MPH.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

THUNDERSTORMS POSE A VARIETY OF THREATS TO BOATERS ON LAKE
MONTICELLO AND PARR RESERVOIR. YOUR BEST COURSE OF ACTION DURING A
THUNDERSTORM IS TO SEEK SAFE HARBOR. IF YOU ARE CAUGHT IN THE OPEN
LAKE WATERS...STAY BELOW DECK...AND IF POSSIBLE...AWAY FROM
UNGROUNDED METAL OBJECTS.

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 3428 8083 3408 8116 3410 8121 3410 8125
      3415 8131 3416 8130 3420 8134 3419 8136
      3432 8150 3445 8140 3449 8127
TIME...MOT...LOC 0130Z 309DEG 20KT 3434 8126

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE COLUMBIA SC
1033 PM EDT FRI AUG 19 2011

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

0458 PM     TSTM WND DMG     2 N ROWESVILLE          33.40N 80.84W
08/19/2011                   ORANGEBURG         SC   PUBLIC

            PUBLIC REPORTED A TREE DOWN ON HIGHWAY 21 BETWEEN
            ROWESVILLE AND ORANGEBURG.

0503 PM     TSTM WND DMG     2 ENE ROWESVILLE        33.38N 80.81W
08/19/2011                   ORANGEBURG         SC   PUBLIC

            PUBLIC REPORTED A LARGE OAK TREE LIMB DOWN ON THE ROOF OF
            A HOUSE ALONG BETHEL FOREST ROAD. THE LIMB WAS 8 INCHES
            IN DIAMETER. OTHER SMALLER LIMBS WERE DOWN AROUND THE
            YARD.

&&

VAUGHAN

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE COLUMBIA SC
1100 PM EDT FRI AUG 19 2011

SCZ026-027-030-200400-
AIKEN-LEXINGTON-SALUDA-
1100 PM EDT FRI AUG 19 2011

...STRONG THUNDERSTORMS WILL IMPACT PORTIONS OF LEXINGTON...SALUDA
AND AIKEN COUNTIES THROUGH MIDNIGHT EDT...

AT 1052 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM...NEAR LEESVILLE...MOVING SOUTHEAST AT 20 MPH.

SOME LOCATIONS THAT WILL BE AFFECTED INCLUDE...
BATESBURG...LEESVILLE AND RED BANK...

PREPARE NOW FOR THE FOLLOWING HAZARDS...
GUSTY WINDS OF 30 TO 40 MPH...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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 3383 8166 3396 8160 3403 8146 3393 8113
      3363 8143
TIME...MOT...LOC 0300Z 306DEG 16KT 3387 8146

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE COLUMBIA SC
1234 AM EDT SAT AUG 20 2011

GAZ063-064-200515-
COLUMBIA-MCDUFFIE-
1234 AM EDT SAT AUG 20 2011

...STRONG THUNDERSTORMS WILL IMPACT PORTIONS OF MCDUFFIE AND COLUMBIA
COUNTIES THROUGH 115 AM EDT...

AT 1230 AM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM...7 MILES NORTH OF THOMSON...MOVING SOUTHEAST AT
10 MPH.

SOME LOCATIONS THAT WILL BE AFFECTED INCLUDE...
GROVETOWN...HARLEM AND THOMSON...

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

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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 3365 8259 3365 8254 3366 8250 3364 8248
      3364 8246 3366 8241 3345 8216 3341 8222
      3330 8239 3334 8245 3335 8255 3341 8255
      3346 8260 3361 8265
TIME...MOT...LOC 0433Z 337DEG 9KT 3355 8249