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000
FXUS62 KCHS 051126
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
626 AM EST THU DEC 5 2013

.SYNOPSIS...
ATLANTIC HIGH PRESSURE WILL PREVAIL THROUGH FRIDAY. A COLD FRONT IS
EXPECTED TO MOVE INTO THE AREA AND STALL SATURDAY AND SUNDAY...BEFORE
A STRONGER COLD FRONT PUSHES THROUGH THE AREA LATE MONDAY INTO
TUESDAY. STRONG HIGH PRESSURE SHOULD THEN RETURN BY THE MIDDLE OF
NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AN AREA OF LIGHT RAIN IS QUICKLY APPROACHING FROM THE SOUTHWEST
AND WILL TRACK ACROSS FAR INTERIOR SOUTHEAST GEORGIA OVER THE NEXT
FEW HOURS. HAVE INCREASED POPS TO 50 PERCENT ROUGHLY WEST OF A
REIDSVILLE TO ALLENDALE LINE AND INTRODUCED QPF AMOUNTS OF
0.01-0.03 INCHES. ALSO...VSBYS HAVE INCREASED ENOUGH ACROSS INLAND
COLLETON...DORCHESTER AND INLAND BERKELEY COUNTIES TO CANCEL THE
DENSE FOG ADVISORY THERE. THE REST OF THE FORECAST IS ON TRACK.

TODAY...UPPER RIDGING WILL BUILD ACROSS THE SOUTHEAST U.S. TODAY
AS ATLANTIC HIGH PRESSURE CONTINUES TO NUDGE IN FROM THE EAST. THE
REGION WILL REMAIN EMBEDDED WITH THE BROAD WARM SECTOR AHEAD OF A
DEVELOPING WINTER STORM ACROSS THE SOUTHERN PLAINS. H8
TEMPERATURES ARE FORECAST TO RISE TO +13 TO +14C BY THIS
AFTERNOON WHICH COMBINED WITH AT LEAST SOME PARTIAL BREAKS IN THE
CLOUD COVER WILL HELP SURGE TEMPERATURES WELL INTO THE 70S ONCE
AGAIN. HIGH TEMPERATURES IN THE UPPER 70S GENERALLY LOOK ON TRACK
ALTHOUGH AN ISOLATED 80+ DEGREE READING CAN NOT BE COMPLETELY
RULED OUT. TEMPERATURES COULD APPROACH THE RECORD HIGHS AT THE
CHARLESTON AND SAVANNAH AIRPORTS. CONSIDERABLY COOLER TEMPERATURES
WILL BE FOUND AT THE COAST WHERE A LIGHT ONSHORE FLOW WILL KEEP
HIGHS LIMITED TO THE 60S. SEA FOG COULD ALSO LINGER ALONG THE
BEACHES FOR MUCH OF THE DAY AND COULD POTENTIALLY GET DRAWN BACK
INLAND THIS AFTERNOON AS A ROBUST SEA BREEZE CIRCULATION FORMS AND
MEANDERS INLAND.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY/...
TONIGHT...THE AREA IS POISED TO HAVE UNSEASONABLY WARM NIGHT WITH
LOWS IN THE LOWER 60S. INCREASING DEWPOINTS SUGGEST FOG WILL BE
CONCERN ONCE AGAIN...BUT INCREASING LOW-LEVEL JETTING ATOP THE
BOUNDARY LAYER INDICATES THE PRIMARY MODE COULD BE STRATUS.
COMPLICATING MATTERS FURTHER IS THAT SEA FOG WILL LIKELY MOVE
INLAND ACROSS THE COASTAL COUNTIES AS WARM/MOIST AIR FLOWS ACROSS
THE VERY CHILLY SHELF WATERS. WILL CALL FOR AREAS OF FOG ALL AREAS
TONIGHT AND REFRAIN FROM INTRODUCING DENSE WORDING AND LET LATER
SHIFTS GET A BETTER HANDLE ON THE SEA FOG SITUATION. THE COASTAL
COUNTIES ARE THE MOST LIKELY CANDIDATES FOR A DENSE FOG ADVISORY
OVERNIGHT.

FRIDAY...WE SHOULD SEE AREAS OF FOG DURING MORNING HOURS AS A LIGHT
SOUTHERLY FLOW CONTINUES TO BUILD MOISTURE OVER THE REGION ALONG THE
WESTERN EDGE OF ATLANTIC HIGH PRESSURE. SOME AREAS COULD SEE DENSE
FOG AS SFC DEWPTS REACH THE LOW/MID 60S OVER MOST AREAS...BEFORE
MIXING OUT LATE MORNING WITH DIURNAL HEATING. MUCH OF THIS EVENT
WILL BE DEPENDENT ON THE EXTENT OF MID LVL CLOUDS...WITH GREATER
CHANCES OF FOG SHOULD CLOUD COVER BE LESS THAN EXPECTED.

DESPITE FAVORABLE ISENTROPIC ASCENT LIKELY RESULTING IN MOSTLY
CLOUDY SKIES FRIDAY AFTERNOON...HIGH TEMPS WILL REMAIN WELL ABOVE
NORMAL AHEAD OF A COLD FRONT APPROACHING FROM THE WEST/NORTHWEST.
LATEST 1000-850MB THICKNESSES FAVOR OVERALL HIGH TEMPS IN THE UPPER
70S TO AROUND 80 ON FRIDAY...WARMEST OVER SOUTHEAST GEORGIA. WE
COULD SEE RECORD BREAKING TEMPS...ESPECIALLY SOUTH OF THE SAVANNAH
RIVER IN SOUTHEAST GEORGIA. LATEST GUIDANCE ALSO SUGGESTS A SLOWER
PROGRESSION OF THE COLD FRONT INTO THE AREA FRIDAY NIGHT. THUS HAVE
KEPT ONLY SLIGHT CHANCE POPS OVER MOST ZONES UNTIL SATURDAY MORNING.
OVERNIGHT LOWS SHOULD REMAIN MILD...IN THE LOW/MID 60S.

SATURDAY AND SUNDAY...PRECIP CHANCES WILL LIKELY INCREASE THIS
WEEKEND AS A COLD FRONT APPROACHES FROM THE WEST/NORTHWEST SATURDAY
AND THEN STALLS OVER OR JUST SOUTH OF THE ALTAMAHA RIVER SATURDAY
EVENING/NIGHT. WE SHOULD SEE A FAIR AMOUNT OF SHOWERS OVER THE AREA
AS SFC DEWPTS PEAK IN THE MID 60S WHILE PWATS APPROACH 1.5 TO 1.75
INCHES. THE GREATEST PRECIP POTENTIAL STILL REMAINS ALONG THE
NORTHWESTERN PORTION OF THE CWA WHERE MID/UPPER LVL FORCING ARE
GREATEST. HAVE MAINTAINED LIKELY POPS OVER NORTHWESTERN ZONES
SATURDAY NIGHT AND CHANCE POPS OVER MOST OTHER LOCATIONS SATURDAY
NIGHT AND SUNDAY.

HIGH TEMPS SHOULD BE A FEW DEGREES COOLER ON SATURDAY WITH CLOUD
COVER AND EXPANDING PRECIP COVERAGE OVER THE REGION. SOME
UNCERTAINTY REMAINS IN THE FORECAST ON SUNDAY AS FAR AS HIGH TEMPS
DUE TO THE POSITION OF THE STALLED FRONT...BUT THE GENERAL CONSENSUS
IS THAT THE FRONT WILL GRADUALLY LIFT NORTH AS A WARM FRONT SUNDAY
EVENING/NIGHT AHEAD OF A STRONGER COLD FRONT APPROACHING FROM THE
WEST/NORTHWEST EARLY NEXT WEEK. AS A RESULT...WE COULD SEE A LARGE
TEMPERATURE GRADIENT OVER THE AREA ON SUNDAY...WITH TEMPS IN THE
UPPER 50S/LOWER 60S ON THE COOLER SIDE OF THE FRONT AND TEMPS AS
HIGH AS THE MID 70S SOUTH OF THE SAVANNAH RIVER.

&&

.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
SOME UNCERTAINTY REMAINS IN THE FORECAST EARLY NEXT WEEK...BUT
CONFIDENCE IS INCREASING THAT A WARM FRONT WILL SLOWLY LIFT NORTH
SUNDAY NIGHT INTO MONDAY AHEAD OF A STRONGER COLD FRONT SWEEPING
THROUGH THE SOUTHEASTERN UNITED STATES LATE MONDAY INTO TUESDAY.
HIGH PRESSURE SHOULD THEN PREVAIL BEHIND THE DEPARTING COLD FRONT BY
WEDNESDAY WITH COOLER AND DRY CONDITIONS THROUGH THURSDAY. HAVE
MAINTAINED 30-40 PERCENT CHANCES OF SHOWERS SUNDAY NIGHT THROUGH
EARLY TUESDAY...WITH HIGHEST CHANCES EXPECTED DURING COLD FROPA
MONDAY NIGHT INTO TUESDAY. A RAIN-FREE FORECAST IS THEN EXPECTED FOR
WEDNESDAY AND THURSDAY AS HIGH PRESSURE BUILDS OVER THE REGION.

TEMPS SHOULD BRIEFLY WARM INTO THE LOW/MID 70S ON MONDAY BEFORE A
COLD FRONT SHIFTS OFFSHORE. TEMPS SHOULD THEN RETURN TO THE LOW/MID
60S FOR HIGHS ON TUESDAY AS FROPA CONTINUES. WE COULD SEE BELOW
NORMAL TEMPS ON WEDNESDAY AND THURSDAY AS COLDER AIR ARRIVES WITH
HIGH PRESSURE FROM THE NORTHWEST. OVERNIGHT LOWS COULD REACH THE
UPPER 30S TO LOWER 40S BY THE MIDDLE OF NEXT WEEK.

&&

.AVIATION /12Z THURSDAY THROUGH MONDAY/...
KCHS...VSBYS CONTINUE TO BOUNCE AROUND AS POCKETS OF CLEARING
OCCUR IN THE HIGH CLOUD DECK. STEADY IFR CONDITIONS LOOK TO
PREVAIL THROUGH 14Z WITH CONDITIONS HOLDING VERY NEAR AIRFIELD
MINIMUMS. ONCE THE FOG LIFTS...EXPECT VFR CONDITIONS TO PREVAIL
DURING THE DAYTIME HOURS. CONDITIONS FAVOR MORE STRATUS AND FOG
AGAIN TONIGHT. HAVE LIMITED CIGS/VSBYS TO MVFR FOR NOW BEGINNING
AT 04Z...BUT LOWER CONDITIONS ARE CERTAINLY A POSSIBILITY.

KSAV...FOG HAS CLEARED THE TERMINAL...ALTHOUGH DENSE FOG LINGERS
VERY CLOSE BY. WILL CARRY VCFG WITH A TEMPO OF HIGH-END MVFR VSBYS
THROUGH 14Z. ONCE THE FOG BURNS OFF...EXPECT VFR CONDITIONS TO
PREVAIL THROUGH SUNSET. AN AREA OF SHOWERS APPROACHING FROM THE
SOUTHWEST LOOKS TO REMAIN WEST OF THE TERMINAL THIS MORNING.
CONDITIONS FAVOR ANOTHER ROUND OF STRATUS/FOG OVERNIGHT. HAVE
LIMITED CIGS/VSBYS TO MVFR FOR NOW BEGINNING AT 05Z...BUT LOWER
CONDITIONS ARE CERTAINLY A POSSIBILITY.

EXTENDED AVIATION OUTLOOK...MVFR CIGS/VSBYS ARE THEN POSSIBLE
SATURDAY AND SUNDAY WITH SHOWERS THAT OCCUR ALONG A
PASSING/STALLING COLD FRONT. CHANCES OF MVFR CIGS/VSBYS WILL ALSO
BE POSSIBLE MONDAY NIGHT INTO TUESDAY WITH ANOTHER COLD FRONT THAT
SWEEPS THROUGH THE SOUTHEASTERN UNITED STATES.

&&

.MARINE...
TODAY...SEA FOG IS THE PRIMARY CONCERN. PILOT BOAT REPORTS AND
SATELLITE FOG PRODUCTS INDICATE WIDESPREAD DENSE SEA FOG LINGERS
ACROSS THE NEARSHORE WATERS THIS MORNING...PRIMARILY BETWEEN THE
COAST SEAWARD TO ABOUT 10 NM. VSBYS ARE NEAR ZERO AT TIMES WHICH
WILL LINGER THROUGH AT LEAST MID-MORNING. A MARINE DENSE FOG
ADVISORY WILL REMAIN IN FORCE FOR ALL NEARSHORE LEGS...INCLUDING
THE CHARLESTON HARBOR UNTIL 9 AM. VSBYS WILL SLOWLY IMPROVE
TODAY...BUT THE RISK FOR FOG WILL LINGER WELL INTO THE AFTERNOON
HOURS. SEA FOG IS RESILIENT AND ITS VERY POSSIBLE THAT THE FOG WILL
REMAIN DENSE FOR A GOOD PORTION OF THE DAY. FURTHER ADJUSTMENTS TO
THE FOG FORECAST...INCLUDING A POSSIBLE EXTENSION OF THE MARINE
DENSE FOG ADVISORY...ARE LIKELY THROUGHOUT THE DAY. OTHERWISE...
SOUTH WINDS OF 5-10 KT CAN BE EXPECTED WITH SEAS 1-2 FT NEARSHORE
WATERS...2-3 FT OFFSHORE WATERS.

TONIGHT...SEA FOG WILL REMAIN A CONCERN TONIGHT AS WARM/MOIST AIR
INTERACTS WITH THE COOL SHELF WATERS. WILL HIGHLIGHT AREAS OF FOG
FOR ALL NEARSHORE LEGS AND ANOTHER MARINE DENSE FOG ADVISORY MAY
VERY WELL BE NEEDED. WINDS WILL REMAIN SOUTH...BUT INCREASE TO
10-15 KT WITH SEAS 2-3 FT.

FRIDAY THROUGH TUESDAY...THE MAIN CONCERN WILL BE SEA FOG PERSISTING
OVER NEARSHORE WATERS AND THE CHS HARBOR FRIDAY MORNING AND POSSIBLY
INTO SATURDAY BEFORE A COLD FRONT APPROACHES FROM THE WEST/NORTHWEST
AND STALLS OVER OR NEAR THE SOUTHERN GEORGIA WATERS SATURDAY NIGHT
INTO SUNDAY. DENSE FOG IS POSSIBLE AND ADVISORIES MAY BE NEEDED.
WINDS/SEAS SHOULD REMAIN BELOW SMALL CRAFT ADVISORY LEVELS DURING
THIS PERIOD...PEAKING BETWEEN 15-20 KTS AND 4-5 FT...MAINLY OVER
NORTHERN SC WATERS AND OUTER GEORGIA WATERS AS THE FRONT STALLS. THE
STALLED FRONT SHOULD THEN LIFT NORTH AS A WARM FRONT SUNDAY AFTERNOON
INTO MONDAY AHEAD OF A COLD FRONT PUSHING OVER THE WATERS LATE
MONDAY INTO TUESDAY. WE COULD SEE CONDITIONS APPROACH SMALL CRAFT
ADVISORY LEVELS LATE TUESDAY AS COLD AIR ADVECTION OCCURS BEHIND THE
DEPARTING COLD FRONT.

&&

.TIDES/COASTAL FLOODING...
LOOKS LIKE TIDES IN THE CHARLESTON HARBOR WILL RISE TO BETWEEN 7.0
AND 7.2 FT MLLW WITH HIGH TIDE THIS MORNING. WILL THEREFORE HOIST
A COASTAL FLOOD ADVISORY FOR THE LOWER SOUTH CAROLINA COAST VALID
8 AM UNTIL 12 PM. TIDES AT FORT PULASKI LOOK TO REMAIN BELOW
ADVISORY THRESHOLDS.

&&

.CLIMATE...
RECORD HIGHS FOR THU 12/05...
KCHS... 80/1998
KSAV... 79/1998
KCHL... 78/1922

RECORD HIGHS FOR FRI 12/06...
KCHS... 81/1998
KSAV... 80/1998
KCHL... 80/1998

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...DENSE FOG ADVISORY UNTIL 9 AM EST THIS MORNING FOR GAZ119.
SC...DENSE FOG ADVISORY UNTIL 9 AM EST THIS MORNING FOR SCZ048>052.
     COASTAL FLOOD ADVISORY UNTIL NOON EST TODAY FOR SCZ048>051.
MARINE...DENSE FOG ADVISORY UNTIL 9 AM EST THIS MORNING FOR AMZ330-350-
     352-354.

&&

$$

ST/DPB