Special Weather Statement, NWS Charleston, SC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
351 PM EDT MON JUL 7 2014

.SYNOPSIS...
HIGH PRESSURE WILL EXTEND ACROSS THE AREA FOR MUCH OF THE
PERIOD...WHILE A TROUGH OF LOW PRESSURE REMAINS INLAND THROUGH MID
WEEK. A WEAK FRONT COULD APPROACH THE SOUTHEAST COAST THURSDAY AND
FRIDAY...BEFORE DISSIPATING EARLY NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
REST OF THE AFTERNOON...ANY LINGERING INLAND SHOWER/THUNDERSTORM
ACTIVITY WILL DIMINISH QUICKLY WITH THE LOSS OF DIURNAL HEATING.
CAPE VALUES CONTINUE TO RANGE IN THE 3000-3500 J/KG WITH ELEVATED
DCAPES ON THE ORDER OF 1000 J/KG. SO...IT IS POSSIBLE WE COULD SEE A
STRONG TO SEVERE STORM OR TWO...BUT THE OVERALL THREAT IS QUITE LOW
GIVEN THE LIMITED COVERAGE.

TONIGHT...THE FORECAST AREA WILL BE POSITIONED BETWEEN THE LEE
TROUGH TO THE WEST AND SUBTROPICAL HIGH PRESSURE TO THE EAST. MODEL
SOUNDINGS AND TIME HEIGHTS SHOW CONSIDERABLE DRY AIR IN THE
MID/UPPER LEVELS AND PWATS DROP TO 1.5 INCHES OR EVEN BELOW THROUGH
THE NIGHT. AS SUCH...THE FORECAST IS DRY. THE PRESSURE GRADIENT
BETWEEN THE TROUGH AND THE HIGH WILL KEEP A MODEST FLOW GOING
OVERNIGHT AND PREVENT COMPLETE DECOUPLING IN MOST AREAS. THIS WILL
KEEP LOWS SEVERAL DEGREES ABOVE NORMAL WITH VALUES RUNNING FROM THE
THE LOW/MID 70S INLAND TO THE MID/UPPER 70S ALONG THE COAST.

&&

.SHORT TERM /6 AM TUESDAY MORNING THROUGH THURSDAY/...
TUESDAY AND WEDNESDAY...A TYPICAL SUMMERTIME PATTERN IS EXPECTED
INTO MIDWEEK AS THE AREA REMAINS BETWEEN HIGH PRESSURE OVER THE
WESTERN ATLANTIC AND A LEE TROUGH OF LOW PRESSURE OVER THE MIDLANDS.
THE SETUP SHOULD FAVOR AFTERNOON SHOWERS AND/OR THUNDERSTORMS DURING
PEAK HEATING EACH AFTERNOON...ESPECIALLY AS A WEAKENING H5 SHORTWAVE
SHIFTS OVER THE SOUTHEASTERN UNITED STATES AND INTERACTS WITH AN
INLAND MOVING SEABREEZE. HOWEVER...SOUNDINGS INDICATE A LACK OF DEEP
MOISTURE OVER THE AREA...THUS COVERAGE WILL LIKELY REMAIN SOMEWHAT
MARGINAL...ESPECIALLY ON TUESDAY. HAVE THEREFORE MAINTAINED ONLY
SLIGHT CHANCE POPS IN SOUTHEAST GEORGIA ON TUESDAY AND FOR ALL AREAS
MOST OF WEDNESDAY. WE COULD SEE A SLIGHT INCREASE IN SHOWERS OR
THUNDERSTORMS LATE WEDNESDAY AS A WEAK COLD FRONT APPROACHES THE
AREA FROM THE NORTHWEST...BUT DIURNAL HEAT LOSS SHOULD LIMIT PRECIP
POTENTIAL TO AROUND 20 PERCENT. OVERALL HIGH TEMPS WILL BE WARM
AHEAD OF A WEAK COLD FRONT APPROACHING FROM THE NORTHWEST. EXPECT
AFTERNOON HIGHS IN THE MID 90S OVER MUCH OF THE AREA AWAY FROM THE
IMMEDIATE COAST. OVERNIGHT LOWS WILL RANGE IN THE LOW/MID 70S.

THURSDAY...HIGH PRESSURE WILL BEGIN TO RETREAT OVER THE WESTERN
ATLANTIC...ALLOWING MOISTURE TO BECOME NOTABLY HIGHER WITH PWATS
APPROACHING 2 INCHES ALONG/AHEAD OF A WEAK COLD FRONT APPROACHING
FROM THE NORTHWEST. MODELS CONTINUE TO INDICATE THAT LEE TROUGHING
WILL BECOME MORE AMPLIFIED AS A H5 SHORTWAVE ROUNDS THE BASE OF A
MID LVL TROUGH AXIS CENTERED OVER THE MIDWEST INTO THURSDAY EVENING.
AMPLE FORCING ASSOCIATED WITH THIS FEATURE SHOULD SPAWN SHOWERS AND
THUNDERSTORMS. HAVE THEREFORE MAINTAINED 40-50 PERCENT CHANCES OF
SHOWERS AND/OR THUNDERSTORMS IN THE FORECAST. OVERALL HIGH TEMPS
COULD BE A FEW DEGREES COOLER GIVEN INCREASING CLOUD COVER AND
SHOWERS/THUNDERSTORMS ASSOCIATED WITH THE APPROACHING FRONT. EXPECT
AFTERNOON HIGHS IN THE LOW 90S AWAY FROM THE COAST.

&&

.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
THE SYNOPTIC SCALE PATTERN WILL REMAIN RATHER UNSETTLED THROUGH
THE EXTENDED PERIOD. A WEAK FRONT EMBEDDED WITHIN A SURFACE TROUGH
WILL APPROACH THE COASTLINE FRIDAY AND SATURDAY...REINFORCED BY
STRONG SHORTWAVE ENERGY WITHIN THE AXIS OF AN UPPER TROUGH ALONG
THE EAST COAST. HAVE MAINTAINED RELATIVELY HIGH THUNDERSTORM
CHANCES ACCORDINGLY...PEAKING AT NEAR 50 PERCENT FRIDAY AFTERNOON
AND ONLY DOWN TO THE 40 PERCENT RANGE FOR SATURDAY AFTERNOON. HIGH
TEMPERATURES WILL BE IN THE LOWER 90S EACH DAY...SUPPRESSED
SLIGHTLY BY THICK CLOUDS AND DECENT RAIN COVERAGE.

THE PATTERN WILL WEAKEN BY EARLY NEXT WEEK...WITH EVIDENCE THAT
DEEP LAYER RIDGING COULD REGAIN SOME CONTROL. SOME FORM OF AN
INLAND SURFACE TROUGH APPEARS IN MEDIUM RANGE MODEL
SOLUTIONS...SUGGESTING THAT SOLID RAIN CHANCES ARE STILL JUSTIFIED
FOR SUNDAY AND MONDAY AFTERNOONS. HIGH TEMPERATURES WILL TREND
WARMER BY A DEGREE OR TWO...RANGING FROM 91 TO 94 DEGREES AWAY
FROM THE LOCALLY COOLER COASTLINE.

&&

.AVIATION /20Z MONDAY THROUGH SATURDAY/...
VFR CONDITIONS WILL PREVAIL THROUGH 18Z TUESDAY. THERE WILL LIKELY
BE AN ISOLATED SHOWER OR THUNDERSTORM INLAND OF THE
TERMINALS...BUT THE EXPECTATION IS FOR ANY DEVELOPMENT TO REMAIN
INLAND AND OUT OF THE VICINITY.

EXTENDED AVIATION OUTLOOK...VFR CONDITIONS EXPECTED AT BOTH
TERMINALS THROUGH MID WEEK...WITH ONLY SLIGHT CHANCES OF AFTERNOON
SHOWERS AND THUNDERSTORMS. INCREASING CHANCES FOR BRIEF FLIGHT
RESTRICTIONS LATER IN THE WEEK...AS DEEP LAYER MOISTURE INCREASES
WITHIN A DEVELOPING BROAD UPPER LEVEL TROUGH OVER THE EASTERN UNITED
STATES.

&&

.MARINE...
TONIGHT...THE LOCAL WATERS WILL BE POSITIONED IN THE TIGHTENING
PRESSURE GRADIENT AREA BETWEEN THE INLAND LEE TROUGH AND THE
SUBTROPICAL HIGH OVER THE OPEN ATLANTIC. THIS SETUP WILL RESULT IN
SOME INCREASED NOCTURNAL JETTING OVERNIGHT WITH MUCH OF THE WATERS
OUTSIDE OF THE HARBOR SEEING SOUTHWEST FLOW INCREASE INTO THE 15-20
KT RANGE. THE HARBOR WILL BE 10-15 KTS. SEAS WILL INCREASE A BIT AS
WELL...BECOMING GENERALLY 2-3 FT WITHIN 20 NM AND 3-4 FT BEYOND.

TUESDAY THROUGH FRIDAY...ATLANTIC HIGH PRESSURE IS EXPECTED TO
REMAIN ACROSS THE REGION THROUGH AT LEAST MID WEEK...MAINTAINING
GENERALLY SOUTH TO SOUTHWEST FLOW. NOCTURNAL SURGES ARE POSSIBLE
EACH NIGHT DUE TO A TIGHTENED GRADIENT BETWEEN A LEE TROUGH INLAND
AND HIGH PRESSURE OVER THE WESTERN ATLANTIC. WINDS COULD GUST UP
TO 20 KT...MAINLY BEYOND 10 NM FROM THE COAST DURING THESE SURGES.
OTHERWISE...EXPECT WINDS OF 15 KT OR LESS AND SEAS NO HIGHER THAN
4-5 FT...HIGHEST OVER OUTER GEORGIA WATERS. THE ATLANTIC RIDGE
SHOULD THEN SHIFT EASTWARD LATE IN THE WEEK AS A BROAD TROUGH OF LOW
PRESSURE BUILDS OVER THE EAST AND SOUTHEAST UNITED STATES. THIS
PATTERN CHANGE WILL RESULT IN MORE SOLID SOUTHERLY WINDS AND
INCREASED CHANCES FOR SHOWERS/THUNDERSTORMS.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.

&&

NEAR TERM...BSH
SHORT TERM...DPB
LONG TERM...WMS
AVIATION...BSH
MARINE...BSH/DPB

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE CHARLESTON SC
309 AM EDT MON JUL 7 2014

AMZ330-350-352-354-374-GAZ087-088-099>101-114>119-137>141-SCZ040-
042>045-047>052-080715-
CHARLESTON HARBOR-
WATERS FROM SOUTH SANTEE RIVER TO EDISTO BEACH SC OUT 20 NM-
WATERS FROM EDISTO BEACH SC TO SAVANNAH GA OUT 20 NM-
WATERS FROM SAVANNAH GA TO ALTAMAHA SOUND GA OUT 20 NM...INCLUDING
GRAYS REEF NATIONAL MARINE SANCTUARY-
WATERS FROM SAVANNAH GA TO ALTAMAHA SOUND GA EXTENDING FROM 20 TO
60 NM-JENKINS-SCREVEN-CANDLER-BULLOCH-EFFINGHAM-TATTNALL-EVANS-
INLAND BRYAN-COASTAL BRYAN-INLAND CHATHAM-COASTAL CHATHAM-LONG-
INLAND LIBERTY-COASTAL LIBERTY-INLAND MCINTOSH-COASTAL MCINTOSH-
ALLENDALE-HAMPTON-INLAND COLLETON-DORCHESTER-INLAND BERKELEY-
INLAND JASPER-BEAUFORT-COASTAL COLLETON-CHARLESTON-COASTAL JASPER-
TIDAL BERKELEY-
309 AM EDT MON JUL 7 2014

THIS HAZARDOUS WEATHER OUTLOOK IS FOR ATLANTIC COASTAL
WATERS...SOUTHEAST GEORGIA AND SOUTHEAST SOUTH CAROLINA.

.DAY ONE...TODAY AND TONIGHT.

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY.

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ASSISTANCE IS NOT ANTICIPATED AT THIS TIME.

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE CHARLESTON SC
549 PM EDT MON JUL 7 2014

SCZ045-072230-
INLAND BERKELEY-
549 PM EDT MON JUL 7 2014

...STRONG THUNDERSTORMS WILL IMPACT PORTIONS OF BERKELEY COUNTY
THROUGH 630 PM EDT...
...MARINERS ON LAKE MOULTRIE SHOULD SEEK SAFE HARBOR...

AT 541 PM EDT...NATIONAL WEATHER SERVICE METEOROLOGISTS DETECTED A
STRONG THUNDERSTORM...4 MILES WEST OF SAINT STEPHEN...MOVING EAST AT
10 MPH.

SOME LOCATIONS THAT WILL BE AFFECTED INCLUDE...
JUDGE TOWN...PINEVILLE...RUSSELLVILLE...WILDER...SAINT STEPHEN...

PREPARE NOW FOR THE FOLLOWING HAZARDS...
GUSTY WINDS OF 40 TO 50 MPH...
DIME SIZE HAIL...
FREQUENT CLOUD TO GROUND LIGHTNING...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

FREQUENT LIGHTNING IS OCCURRING WITH THIS THUNDERSTORM. IF
OUTDOORS...STAY AWAY FROM ISOLATED TALL OBJECTS. IF INDOORS...STAY
AWAY FROM WINDOWS AND DOORS. AVOID USING PLUMBING AND ELECTRICAL
APPLIANCES UNLESS IT IS AN EMERGENCY.

&&

LAT...LON 3350 7999 3350 7997 3343 7987 3342 7987
      3342 7986 3341 7986 3338 7982 3329 7985
      3337 8010 3351 8006 3351 8001 3350 8000
      3351 8000
TIME...MOT...LOC 2148Z 276DEG 7KT 3345 7999