907 
FXUS62 KCHS 280149
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
949 PM EDT THU MAR 27 2014

.SYNOPSIS...
HIGH PRESSURE WILL STEADILY DRIFT OFF THE MID ATLANTIC COAST TONIGHT
WHILE LOW PRESSURE APPROACHES THE AREA FROM THE WEST THROUGH FRIDAY
NIGHT. A COLD FRONT WILL MOVE THROUGH THE AREA AND OFFSHORE LATE 
SATURDAY...WITH HIGH PRESSURE THEN BUILDING OVER THE REGION THROUGH
THE MIDDLE OF NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
MAINLY CLEAR SKIES ALONG AND NORTH OF I-16 THIS EVENING WITH 
A SHIELD OF CIRROSTRATUS STREAMING OVER SOUTH GEORGIA. MOISTURE
RETURN IN THE LOWER LEVELS RUNNING A BIT SLOWER THAN EARLIER 
MODEL PROJECTIONS TO THIS POINT...THUS WE MADE SOME SKY COVER
ADJUSTMENTS FOR THE NEXT SEVERAL HOURS TO TREND. OVERNIGHT...DRY
WEATHER SHOULD PREVAIL WITH ONLY A SMALL RISK FOR ISOLATED SHOWERS
NEAR THE SOUTH CAROLINA COAST BY DAYBREAK. WE LOWERED MIN TEMPS A
BIT MANY AREAS GIVEN THE STRONGER INITIAL RADIATIONAL COOLING AND
LATEST SURFACE OBSERVATIONS. BY LATE TONIGHT...READINGS COULD RISE
A FEW DEGREES AS CLOUDS INCREASE.

&&

.SHORT TERM /6 AM FRIDAY MORNING THROUGH SUNDAY/...
FRIDAY... ATLANTIC HIGH PRESSURE WILL MAINTAIN A MOISTENING 
SOUTHERLY FLOW ACROSS THE AREA. THE BEST CHANCE OF SHOWERS...AND 
MAYBE A THUNDERSTORM...WILL BE OVER THE ATLANTIC WATERS AND ALONG 
THE SC COAST IN THE MORNING. LATER IN THE DAY THE BEST CHANCE WILL 
LIKELY BE ALONG THE GA COAST AND FARTHER INLAND AS AN AREA OF PRECIP 
MOVES IN FROM THE WEST WHERE THE DEEPER MOISTURE WILL BE FOUND. 
ALTHOUGH SKIES SHOULD BE RATHER CLOUDY TEMPERATURES SHOULD STILL 
REACH THE LOWER TO MID 70S AWAY FROM THE LOCALLY COOLER COASTAL 
AREAS. A BIT MORE UNCERTAINTY ENTERS THE FORECAST FRIDAY NIGHT AS 
MUCH DEPENDS ON THE TIMING/STRENGTH OF SHORTWAVES ALOFT. IN GENERAL 
WE STILL THINK COASTAL SC AND INTERIOR AREAS WILL SEE THE BEST 
CHANCES. THE CLOUDS AND HIGHER DEWPOINTS WILL KEEP LOW TEMPS 
GENERALLY AROUND 60.  

SATURDAY...A STRONGER UPPER SHORTWAVE TROUGH MOVING TOWARD THE OHIO 
VALLEY WILL CAUSE A SURFACE COLD FRONT TO MOVE TOWARD SOUTHEAST 
SC/GA DURING THE DAY. SHOWERS AND THUNDERSTORMS WILL BE LIKELY ALONG 
AND AHEAD OF THE FRONT WHICH SHOULD BE NEAR THE COAST TOWARD 
EVENING. WIND FIELDS WILL BE ELEVATED AND THERE SHOULD BE SUFFICIENT 
INSTABILITY IN PLACE FOR SOME STRONG TO POSSIBLY SEVERE STORMS. 
CONFIDENCE IN SEVERE WEATHER OVERALL IS STILL LOW GIVEN THE 
UNCERTAINTY IN CLOUD COVER/POSSIBLE SEA FOG ALONG THE COAST AS WELL 
AS FAIRLY WEAK MID-LEVEL INSTABILITY. PREFER TO WAIT TO INTRODUCE 
INTO THE HAZARDOUS WEATHER OUTLOOK FOR NOW BUT ANYONE WITH OUTDOOR 
PLANS ON SATURDAY SHOULD CLOSELY MONITOR THE FORECAST. TEMPS COULD 
PUSH 80 IN A FEW SPOTS GIVEN SOME PRE-FRONTAL CONVERGENCE BUT MUCH 
DEPENDS ON AMOUNT OF CLOUD COVER. PRECIP WILL BE ENDING FROM WEST 
TO EAST EARLY SATURDAY EVENING AS THE FRONT PUSHES OFFSHORE ALLOWING 
COOLER AND DRIER AIR TO FILTER IN. LOWS SHOULD BE IN THE UPPER 
40S/AROUND 50 INLAND BY DAYBREAK SUNDAY.  

SUNDAY...COOL/DRY AIRMASS WILL BE IN PLACE SUNDAY BEHIND THE 
DEPARTING COLD FRONT...ALTHOUGH THERE IS SOME UNCERTAINTY IN HOW 
CHILLY IT WILL BE GIVEN THE TIMING OF THE UPPER TROUGH. HIGHS WILL 
LIKELY BE A BIT BELOW NORMAL...GENERALLY AROUND 70 MOST 
LOCALES...ESPECIALLY ACROSS GEORGIA.

&&

.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
MEDIUM RANGE GUIDANCE IS IN VERY GOOD AGREEMENT THROUGH THE LONG 
TERM PERIOD. MID AND UPPER LEVEL RIDGING WILL BUILD ALOFT EARLY IN 
THE WEEK AS SURFACE HIGH PRESSURE SETTLES OVER THE SOUTHEAST STATES 
ON MONDAY THEN SHIFTS INTO THE WESTERN ATLANTIC ON TUESDAY. THE 
RIDGE ALOFT WILL FLATTEN SOME DURING THE MIDDLE OF THE WEEK AS A 
WEAK BACKDOOR COLD FRONT APPROACHES BUT STALLS NORTH OF THE AREA 
WEDNESDAY. THE RIDGING ALOFT WILL AMPLIFY FURTHER LATE IN THE WEEK 
ALLOWING THE STALLED FRONT TO LIFT NORTHWARD...MEANWHILE ATLANTIC 
HIGH PRESSURE WILL PREVAIL AS A COLD FRONT APPROACHES FROM THE WEST 
ON THURSDAY. 

AS FOR SENSIBLE WEATHER...EXPECT THE RIDGING ALOFT...SURFACE HIGH  
AND LIMITED MOISTURE TO RESULT IN RAIN-FREE CONDITIONS THROUGH MOST 
OF THE LONG TERM PERIOD. HOWEVER...THERE IS A SLIGHT CHANCE FOR 
SHOWERS AND THUNDERSTORMS BY THURSDAY AS THE COLD FRONT NEARS. 
TEMPERATURES START OFF NEAR NORMAL EARLY NEXT WEEK...THEN GRADUALLY 
WARM ABOVE NORMAL THROUGH THE LONG TERM PERIOD.

&&

.AVIATION /02Z FRIDAY THROUGH TUESDAY/...
VFR CONDITIONS SHOULD CONTINUE TO PREVAIL AT BOTH KCHS AND KSAV
THROUGH 00Z SATURDAY...ALTHOUGH THERE ARE INCREASING CHANCES FOR 
MVFR CIGS LATER TONIGHT THEN PERIODICALLY ON FRIDAY AS LOW LEVEL
MOISTURE BUILDS. BREEZY CONDITIONS WILL DEVELOP AFTER MIDDAY ON
FRIDAY WITH SOUTHERLY SURFACE WINDS CLOSE TO 15 KT BY MID AFTERNOON
WITH GUSTS UP TO 25 KT. BRIEF SHOWERS ARE POSSIBLE AROUND KCHS
LATE TONIGHT AND FRIDAY MORNING BUT COVERAGE POTENTIAL AND MODEL
PROGS BOTH SUGGEST LOW CONFIDENCE OF OCCURRENCE AROUND THE TERMINAL. 
DEEPER MOISTURE INVADES LATE IN THE TAF PERIOD AFTER 20Z FRIDAY
AND SHOWER CHANCES EXPECTED TO ALSO INCREASE. UPCOMING TAF RELEASES
WILL LIKELY BEGIN TO INTRODUCE RAIN MENTIONS AFTER THAT TIME.

EXTENDED AVIATION OUTLOOK...LOW CHANCES FOR PERIODIC FLIGHT 
RESTRICTIONS IN SHOWERS/THUNDERSTORMS FRIDAY NIGHT THROUGH
SATURDAY. OTHERWISE...VFR CONDITIONS TO PREVAIL THROUGH TUESDAY.
BREEZY CONDITIONS LIKELY FRIDAY THROUGH SUNDAY...MAINLY DURING THE
AFTERNOON.

&&

.MARINE...
OVERNIGHT...A FAIRLY ENHANCED PRESSURE GRADIENT WILL REMAIN OVER THE 
COASTAL WATERS ALONG THE SOUTHWESTERN EDGE OF HIGH PRESSURE SHIFTING 
FURTHER OFF THE MID ATLANTIC COAST AND INTO THE WESTERN ATLANTIC. 
HOWEVER...WINDS/SEAS SHOULD REMAIN BELOW SMALL CRAFT ADVISORY LEVELS 
THROUGH THE OVERNIGHT PERIOD. IN GENERAL...WINDS SHOULD PEAK BETWEEN 
15-20 KT BEYOND 10 NM FROM THE COAST. AN EASTERLY SWELL ALONG THE 
SOUTHERN PERIPHERY OF THE HIGH WILL SUPPORT GRADUALLY BUILDING
SEAS FROM 3-4 FT TO 4-5 FT...HIGHEST OVER OUTER GEORGIA WATERS.

FRIDAY THROUGH TUESDAY...ATLANTIC HIGH PRESSURE WILL EVENTUALLY GIVE 
WAY TO A COLD FRONT SATURDAY EVENING WITH COOLER/DRIER HIGH PRESSURE 
RETURNING EARLY NEXT WEEK. EXPECT BREEZY CONDITIONS FRIDAY THROUGH 
THE WEEKEND WITH SEAS HOVERING NEAR 5 FT BUT THE CHANCE OF 
ADVISORIES APPEAR LOW FOR NOW...BEST CHANCES BEING BEYOND 20 NM. THE 
POST-FRONTAL SURGE SATURDAY NIGHT INTO SUNDAY SHOULD PRODUCE THE 
BEST CHANCE FOR ADVISORIES. MUCH MORE TRANQUIL CONDITIONS THEN 
EXPECTED THROUGH TUESDAY.  

AS LOW-LEVEL MOISTURE INCREASES OVER THE WATERS AHEAD OF THE COLD 
FRONT FRIDAY INTO SATURDAY WE WILL NEED TO WATCH FOR THE POTENTIAL 
FOR SOME SEA FOG DEVELOPMENT.

&&

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

&&

$$

SYNOPSIS...
NEAR TERM...
SHORT TERM...RJB
LONG TERM...JAQ
AVIATION...
MARINE...