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-- Discussion containing changed information from previous version are highlighted. --
000
FXUS62 KCHS 232310
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
710 PM EDT THU MAY 23 2013

.SYNOPSIS...
A COLD FRONT WILL MOVE THROUGH THE REGION LATE TONIGHT...WITH DRY
HIGH PRESSURE BUILDING IN THROUGH THE MIDDLE OF NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
-- Changed Discussion --
THIS EVENING...ISOLATED/SCATTERED SHOWERS/THUNDERSTORMS...WITH
BEST COVERAGE ACROSS FAR NORTHERN COUNTIES...WILL CONTINUE TO FIRE
AND DISSIPATE ALONG AN INLAND DEWPOINT BOUNDARY AND THE SEA BREEZE
PINNED NEAR THE COAST. AFTER DARK...DIURNAL COOLING WILL TRANSLATE
TO DECREASING PRECIPITATION COVERAGE.

A COLD FRONT ACROSS THE OHIO/TENNESSEE VALLEY WILL MAKE STEADY
PROGRESS SOUTHEAST OVERNIGHT. ANY SHOWERS OR THUNDERSTORMS WILL
ACTUALLY HAVE DISSIPATED WELL BEFORE THE FRONT PUSHES INTO THE
REGION DURING THE PRE DAWN HOURS. HAVE THUS CAPPED RAIN CHANCES
BELOW 15 PERCENT BY MIDNIGHT. WINDS WILL STEADILY VEER FROM WEST
TO NORTHWEST BY DAYBREAK FRIDAY...WITH SKIES LIKELY MOSTLY CLEAR
BY SUNRISE.

LOW TEMPERATURES WILL RANGE FROM THE LOW TO MID 60S AWAY FROM THE
IMMEDIATE COASTLINE.
-- End Changed Discussion --

&&

.SHORT TERM /6 AM FRIDAY MORNING THROUGH SUNDAY/...
THE WEATHER WILL BE RELATIVELY QUIET DURING THIS PERIOD AS HIGH
PRESSURE BUILDS IN FROM THE NORTH ON FRIDAY...SETTLING OVER THE AREA
FOR THE WEEKEND. FRIDAY WILL BE THE WARMEST OF THE THREE DAYS AS
NORTHWESTERLY DOWNSLOPE FLOW WILL ALLOW FOR A LITTLE COMPRESSIONAL
HEATING AT LOW LEVELS. AFTERNOON MAX TEMPS WILL MANAGE TO GET TO
NEAR NORMAL UNDER MOSTLY SUNNY SKIES. THE WINDS MAY GET A BIT BREEZY
DURING THE LATE MORNING AND EARLY AFTERNOON HOURS WITH GOOD MIXING
IN THE BOUNDARY LAYER ALLOWING SOMEWHAT STRONGER WINDS TO MIX TO THE
SURFACE.

FRIDAY NIGHT...STRONG COOL ADVECTION SETTLES IN...WITH TEMPERATURES
DROPPING ALL NIGHT. RISING HEIGHTS ALOFT WILL HELP PROMOTE LOW LEVEL
SUBSIDENCE...KEEPING SKIES CLEAR. TEMPS WILL DROP INTO THE UPPER 40S
TO NEAR 50 WEST OF INTERSTATE 95...WITH LOWER 50S ELSEWHERE. A
PERSISTENT 5 TO 10 KNOT WIND WILL KEEP TEMPS FROM DROPPING EVEN
LOWER.

SATURDAY WILL BE COOL AND SUNNY AS A BUBBLE AREA OF HIGH PRESSURE
SETS UP IN THE NEIGHBORHOOD. DEW POINTS WILL DROP INTO THE 30S BY
AFTERNOON AWAY FROM THE COAST...WHICH IS VERY LOW FOR MEMORIAL DAY
WEEKEND. RELATIVE HUMIDITY VALUES BY THEMSELVES WOULD BE LOW
ENOUGH FOR FIRE WEATHER CONCERNS...BUT THE WINDS WILL BE GENERALLY
LESS THAN 10 KNOTS.

NOT MUCH CHANGE EXPECTED ON SUNDAY WITH THE HIGH REMAINING CLOSE BY.
A WEAK LEE TROF MAY DEVELOP BY AFTERNOON IN THE MIDLANDS...ALLOWING
FOR A BIT MORE ROBUST SEA BREEZE TO FORM...BUT THE LACK OF LOW LEVEL
MOISTURE WILL PREVENT ANY CONVECTIVE ACTIVITY. THERE COULD BE A
LITTLE MORE IN THE WAY OF CIRRUS AS A WEAK DISTURBANCE ALOFT ROTATES
AROUND THE DEEP UPPER LOW EXPECTED OVER NEW ENGLAND...BUT IT WONT
SIGNIFICANTLY DENT THE AMOUNT OF SUNSHINE.

&&

.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
THE REGION WILL BE SANDWICHED BETWEEN TWO AREAS OF HIGH PRESSURE
EARLY IN THE WEEK...THE STRONGER OF THE TWO PASSING ACROSS THE
MID-ATLANTIC REGION AND THE OTHER OVER THE NORTHEAST GULF OF
MEXICO. DEEPENING MOISTURE WILL RESULT IN AT LEAST AN INCREASE IN
CLOUD COVER...BUT IT APPEARS THE RAIN-FREE CONDITIONS SHOULD
PERSIST THROUGH MEMORIAL DAY. ATLANTIC HIGH PRESSURE WILL THEN
BECOME ESTABLISHED THROUGH THE MIDDLE OF NEXT WEEK...SUPPORTING
MAINLY DIURNAL ISOLATED CONVECTION EACH AFTERNOON ALONG AND AHEAD
OF THE SEA BREEZE TUESDAY THROUGH THURSDAY. TEMPERATURES WILL
MODERATE TO NEAR NORMAL BY EARLY NEXT WEEK AND CONTINUE NEAR
SEASONAL NORMS THROUGH THE END OF THE FORECAST PERIOD.

&&

.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
-- Changed Discussion --
VFR THROUGH FRIDAY.

EXTENDED AVIATION...VFR CONDITIONS THROUGH THE WEEKEND.
-- End Changed Discussion --

&&

.MARINE...
SOUTHERLY WINDS THIS AFTERNOON WILL VEER OFFSHORE OVERNIGHT...AS A
COLD FRONT SHIFTS THROUGH THE AREA BY DAYBREAK FRIDAY. WIND SPEEDS
WILL PEAK AROUND 15 KT...YET THE OFFSHORE FETCH WILL LIMIT THE
SEAS TO NO HIGHER THAN 4 FT.

THE MAIN PERIOD OF CONCERN WILL BE FRIDAY NIGHT BEHIND THE COLD
FRONT AS WINDS ACCELERATE FROM THE NORTH AND EVENTUALLY NORTH
NORTHEAST. WINDS AND SEAS WILL BE RIGHT AROUND SCA CRITERIA
OFFSHORE...BUT TOO MARGINAL TO ISSUE ANY HEADLINES AT THIS TIME.
WINDS AND SEAS WILL QUICKLY COME BACK DOWN SATURDAY AS THE
PRESSURE GRADIENT COLLAPSES WHILE HIGH PRESSURES SETTLES OVER THE
WATERS.

WINDS WILL BECOME DIURNALLY DRIVEN NEXT WEEK AS THE SURFACE
HIGH MOVES INTO THE ATLANTIC WITH A WEAK RIDGE STRETCHING WESTWARD
OVER THE CWA. SPEEDS SHOULD BE 15 KNOTS OR LESS THE FIRST HALF OF
NEXT WEEK.

&&

.TIDES/COASTAL FLOODING...
HIGH ASTRONOMICAL TIDES AND FAVORABLE NORTH/NORTHEAST WINDS COULD
LEAD TO MINOR SALTWATER INUNDATION NEAR THE COAST DURING THE HIGH
TIDE FRIDAY AND SATURDAY EVENINGS. BY THE TIME OF THE HIGH TIDE
SUNDAY EVENING AND MONDAY EVENING...WINDS WILL NOT BE AS
CONDUCIVE...YET MINOR SALTWATER FLOODING WILL STILL BE POSSIBLE AS
ASTRONOMICAL FACTORS WILL CAUSE HIGHER THAN TYPICAL TIDES.

&&

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

&&

$$

SYNOPSIS...
NEAR TERM...SPR/WMS
SHORT TERM...FWA
LONG TERM...JAQ
AVIATION...SPR
MARINE...FWA/JAQ/SPR
TIDES/COASTAL FLOODING...