Area Forecast Discussion
Issued by NWS Charleston, SC

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
000
FXUS62 KCHS 231922
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
322 PM EDT THU OCT 23 2014

.SYNOPSIS...
HIGH PRESSURE WILL PERSIST ACROSS THE REGION THROUGH LATE WEEK.
A DRY COLD FRONT WILL DISSIPATE OVER OR NEAR THE REGION THIS
WEEKEND...FOLLOWED BY HIGH PRESSURE THROUGH THE MIDDLE OF NEXT
WEEK.

&&

.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
THIS EVENING AND TONIGHT...COOL/DRY HIGH PRESSURE WILL PERSIST OVER
THE REGION WHILE A CUTOFF MID/UPPER LVL LOW SLOWLY SHIFTS FURTHER
OFF THE NORTHEASTERN SEABOARD. AS A RESULT...VERY LITTLE CHANGE IS
ANTICIPATED IN REGARDS TO A DRY WEATHER PATTERN OVER THE AREA THIS
EVENING AND TONIGHT.

THE MAIN ISSUE FOR TONIGHT WILL DEAL WITH LOW TEMPS. MODEL SOUNDINGS
ARE HINTING AT THE DEVELOPMENT OF SOME MID AND/OR HIGH CLOUDS
THROUGH THE NIGHT...WHICH COULD MAINTAIN SLIGHTLY WARMER TEMPS THAN
IN THE CURRENT FORECAST. HOWEVER...LATEST TRENDS CONTINUE TO SHOW A
CLOUD-FREE SKY...WHICH LIKELY SUPPORTS DECOUPLING WINDS EARLY
TONIGHT AND FAIR TO STRONG RADIATIONAL COOLING THROUGH THE OVERNIGHT
PERIOD. OVERNIGHT LOW TEMPS ARE THEREFORE EXPECTED TO DIP INTO THE
LOW 40S INLAND WHERE DECOUPLING IS ANTICIPATED FIRST...AND INTO THE
UPPER 40S TO LOWER 50S NEAR THE COAST.

&&

.SHORT TERM /6 AM FRIDAY MORNING THROUGH SUNDAY/...
POPS REMAIN ESSENTIALLY ZERO FRIDAY THROUGH SUNDAY.

FRIDAY...WEAK HIGH PRESSURE WILL PREVAIL AT THE SURFACE...WHILE AN
UPPER LEVEL TROUGH WILL PUSH THROUGH THE REGION FROM THE NORTHWEST
LATE DAY AND FRIDAY NIGHT. WHILE 23/12Z GUIDANCE DEPICTS A
DEEPENING/ POSITIVELY TILTED UPPER TROUGH...LOW/MID LEVELS REMAIN
VERY DRY. THUS...THE TROUGH SHOULD CROSS THE REGION WITH NOTHING
MORE THAN HIGH CLOUDS. OTHERWISE...TEMPS FRIDAY WILL TOP OUT CLOSE
TO NORMAL FOR THIS TIME OF YEAR...IN THE MID 70S AT MOST LOCATIONS.
GIVEN THE PASSAGE OF THE UPPER SHORT WAVE TROUGH FRIDAY
NIGHT...RADIATIONAL COOLING CONDITIONS WILL REMAIN LESS THAN IDEAL.
EVEN SO...LOWS ARE EXPECTED TO RANGE FROM THE LOWER/MID 40S WELL
INLAND TO MID 50S ON THE BEACHES.

IN THE WAKE OF THE UPPER TROUGH SATURDAY...HEIGHTS WILL RISE ALOFT
AND SURFACE HIGH PRESSURE WILL EXPAND INTO THE REGION. LIGHT
OFFSHORE WINDS AND SUNSHINE WILL SUPPORT HIGH TEMPS A BIT ABOVE
NORMAL...IN THE UPPER 70S TO LOWER 80S.

SATURDAY NIGHT...EXPECT TYPICALLY COOL LOWS IN THE UPPER 40S TO
UPPER 50S...WARMEST ON THE BEACHES. GUIDANCE DEPICTION OF LOW/MID
LEVEL THICKNESS TRENDS HINTS AT A WEAKENING/DRY COLD FRONT SLIPPING
INTO THE REGION FROM THE NORTH LATE SATURDAY NIGHT OR SUNDAY.
HOWEVER...THE UPPER RIDGE CENTERED OVER THE NORTHERN/WESTERN GULF
WILL CONTINUE TO EXTEND NORTHEAST INTO THE REGION. THUS...THIS WEAK
COLD FRONT WILL LIKELY DISSIPATE IN THE VICINITY BY SUNDAY. OFFSHORE
LOW-LEVEL FLOW AND SUNSHINE WILL ONCE AGAIN SUPPORT SLIGHTLY ABOVE
NORMAL TEMPS IN THE UPPER 70S/LOWER 80S.

&&

.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
SUNDAY NIGHT...A SURFACE RIDGE WILL BE CENTERED OVER THE MID
ATLANTIC WITH SLIGHT RIDGING ALOFT. WITH MOSTLY CLEAR SKIES AND
LIGHT WINDS...SHOULD GET MINS BACK DOWN INTO THE LOWER TO MID 50S.

MONDAY AND TUESDAY...THE DEEP LAYER RIDGE SHIFTS EAST INTO THE
ATLANTIC. THIS WILL SETUP LOW LEVEL SOUTHEAST FLOW AND A GRADUAL
RETURN OF LOW LEVEL MOISTURE. GLOBAL MODELS CONTINUE TO INDICATE THE
POTENTIAL FOR ISOLATED SHOWERS BEGINNING MONDAY NIGHT OVER THE
ATLANTIC WATERS AND THEN MAINLY NEAR THE COAST TUESDAY. HIGHS BOTH DAYS
ABOVE NORMAL AROUND 80 TO THE LOWER 80S. LOWS IN THE MID TO UPPER
50S.

WEDNESDAY AND THURSDAY...A BROAD UPPER TROUGH FORMS OVER THE CENTRAL
U.S. AND THEN SLOWLY MOVES EASTWARD TOWARD THE REGION BY THURSDAY.
MODELS CONTINUE TO HANDLE THE PROGRESSION AND STRENGTH OF THIS
TROUGH DIFFERENTLY. HAVE NOT BEEN ABLE TO SEE THE ECMWF SOLUTION
THIS MORNING...SO MAINLY GOING WITH GFS. THE GFS NOW LOOKS WETTER
THURSDAY AS IT DEEPENS THE UPPER TROUGH TO THE WEST AND DRAWS IN
BETTER DEEP LAYER MOISTURE AHEAD OF THE SURFACE FRONT. HAVE KEPT
SLIGHT CHANCE POPS BOTH DAYS FOR NOW GIVEN UNCERTAINTY. TEMPERATURES
A LITTLE ABOVE NORMAL FOR THIS PERIOD WITH HIGHS AROUND 80 AND LOWS
IN THE MID 50S TO AROUND 60.

&&

.AVIATION /19Z THURSDAY THROUGH TUESDAY/...
VFR.

EXTENDED OUTLOOK...VFR.

&&

.MARINE...
THIS EVENING AND TONIGHT...WINDS/SEAS WILL REMAIN WELL BELOW SMALL
CRAFT ADVISORY LEVELS AS HIGH PRESSURE CONTINUES TO SETTLE OVER THE
WATERS. NORTHWEST FLOW AT OR BELOW 10-15 KTS WILL BECOME MORE
NORTHERLY TONIGHT AS THE CENTER OF SFC HIGH PRESSURE SLOWLY SLIDES
EASTWARD TO OUR NORTH. SEAS WILL CONTINUE TO SUBSIDE THROUGH THE
NIGHT...RANGING BETWEEN 1-3 FT...HIGHEST IN OFFSHORE GEORGIA WATERS.

NO HIGHLIGHTS EXPECTED THROUGH EARLY NEXT WEEK WITH WINDS 15 KT OR
LESS ACCOMPANIED BY SEAS 3 FT OR LESS. WIND DIRECTION WILL BE
PRIMARILY MODULATED BY THE POSITION...STRENGTH AND ORIENTATION OF
SURFACE HIGH PRESSURE CENTERED NORTH AND WEST OF THE WATERS. NORTH
WINDS 10 KT OR LESS FRIDAY AND FRIDAY NIGHT COULD BRIEFLY SURGE TO
10-15 KT SATURDAY MORNING AS AN UPPER TROUGH PUSHES OFFSHORE AND THE
SURFACE HIGH EXPANDS INTO THE REGION. A WEAKER PRESSURE GRADIENT
WILL PREVAIL SATURDAY PM INTO EARLY NEXT WEEK...WITH OFFSHORE WINDS
10 KT OR LESS GIVING WAY TO ONSHORE WINDS AS THE HIGH EXPANDS NORTH
OF THE WATERS.

&&

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

&&

$$

NEAR TERM...DPB
SHORT TERM...SPR
LONG TERM...RFM
AVIATION...DPB/SPR
MARINE...DPB/SPR






USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.