Area Forecast Discussion
Issued by NWS Charleston, SC

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000
FXUS62 KCHS 261546
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
1046 AM EST WED NOV 26 2014

.SYNOPSIS...
A STRENGTHENING AREA OF LOW PRESSURE OFF THE CAROLINA COAST EARLY
THIS MORNING WILL TRACK NORTHEAST ALONG A STALLED FRONT...LIFTING
AWAY FROM THE REGION BY THIS AFTERNOON. HIGH PRESSURE WILL THEN
BUILD INTO THE SOUTHEAST UNITED STATES AND PREVAIL THROUGH EARLY
NEXT WEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
AN AMPLIFIED MID LATITUDE AND DEEP LAYERED TROUGH IS CENTERED OVER
THE EASTERN US INTO THE GULF THIS MORNING...WITH A ROBUST SHORT
WAVE TROUGH EMBEDDED WITHIN THAT WILL SWEEP THROUGH THE ENTIRE
FORECAST AREA BY EARLY AFTERNOON. THIS PROMINENT DISTURBANCE
DRIVEN BY A POWERFUL 175 KT OR GREATER UPPER JET IS RESPONSIBLE
FOR THE DEEPENING AREA OF LOW PRESSURE THAT IS FOUND HUGGING THE
MID ATLANTIC COAST AND WILL INTENSIFY FURTHER AS IT HEADS RAPIDLY
TO THE SOUTH OF LONG ISLAND BY NIGHTFALL.

NOW THAT THE PERSISTENT FETCH OF DEEP TROPICAL MOISTURE HAS
FINALLY CLEARED INTO THE ATLANTIC...ONCE THE SHORT WAVE ALOFT
MOVES THROUGH AROUND 11 AM-2 PM FROM WEST/SW TO EAST/NE WE/LL
EXPERIENCE AN END TO OUR LINGERING RAINS AND DRIZZLE. THIS WILL BE
FOLLOWED BY A FAIRLY RAPID CLEARING IN A SIMILAR FASHION FROM
WEST/SW TO EAST/NE. THIS CLEARING IS DEFINED BY A SHARP
DEMARCATION THAT FOLLOWS QUICKLY ON THE HEELS OF THE SHORT
WAVE...AND IS CLEARLY EVIDENT ON SATELLITE IMAGERY. THE BACK EDGE
OF THE DEEP LAYERED CLOUDS ARE MOVING EAST AT ALMOST 40
MPH...WHICH IF IT MAINTAINS THAT VELOCITY WOULD ALLOW FOR SUNSHINE
TO BEGIN RETURNING AT PLACES SUCH SPRINGFIELD AND HINESVILLE BY
12 PM...SAVANNAH AND RIDGEVILLE BY 1 PM...BEAUFORT AND SUMMERVILLE
BY 2 PM AND FINALLY THROUGH CHARLESTON BY 2-3 PM. THERE IS STILL
GOOD LOW LEVEL MOISTURE THAT LAGS BEHIND THE DEEPER MOISTURE...SO
AT PATCHY TO AREAS OF STRATOCUMULUS WILL LINGER.

WHAT INSOLATION WE DO GET TODAY WILL SPEND A GOOD DEAL OF ENERGY
EVAPORATING ALL THE RECENT RAINS WE HAVE RECEIVED. AND THAT
ALONG WITH CONTINUED COOL ADVECTION...ALBEIT WEAK...WILL LIMIT
HIGHS THIS AFTERNOON TO THE MID 50S NORTH AND UPPER 50S TO MAYBE
NEAR 60 SOUTH.

LAKE WINDS...BASED ON RECENT OBSERVATIONS AND CONTINUED DECENT
ISALLOBARIC PRESSURE RISES ACROSS LAKE MOULTRIE...WE HAVE
EXTENDED THE LAKE WIND ADVISORY INTO EARLY AFTERNOON.

TONIGHT...THE AXIS OF THE UPPER LEVEL TROUGH WILL MOVE THROUGH...ALONG
WITH A REINFORCING COLD FRONT AT THE SURFACE. THE FRONTAL PASSAGE
AND WILL BE DRY GIVEN LIMITED MOISTURE...BUT SOME MID LEVEL CLOUDS
COULD ACCOMPANY THE FRONT WITH A SIGNIFICANT UPPER DISTURBANCE
PASSING INTO THE CAROLINAS. WINDS COULD BECOME LIGHT IN THE
EVENING...BUT MAY RECOUPLE AS COLD AIR ADVECTION DEVELOPS IN WAKE
OF THE FRONT LATE. EXPECT LOWS IN THE UPPER 30S TO AROUND 40.

&&

.SHORT TERM /THURSDAY THROUGH SATURDAY/...
THURSDAY THROUGH SATURDAY...THE AXIS OF AN UPPER LEVEL TROUGH WILL
LIFT ACROSS THE NORTHEAST COASTLINE ON THURSDAY...FOLLOWED BY A
LESS AMPLIFIED PATTERN ALOFT FRIDAY AND SATURDAY. STRONG SURFACE
HIGH PRESSURE WILL BUILD INTO THE REGION FROM THE NORTHWEST
THURSDAY AND EVENTUALLY BECOME SITUATED ALONG THE EAST COAST
THROUGH SATURDAY. DRIER AIR AND THE LACK OF ANY NOTABLE SYNOPTIC
FORCING WILL SUPPORT RAIN FREE WEATHER LATE WEEK INTO THE
WEEKEND...AND WILL CONTINUE TO ADVERTISE RAIN CHANCES AT ZERO.
COLD ADVECTION ON THE PERIPHERY OF THE BUILDING SURFACE HIGH WILL
SUPPORT UNSEASONABLY COOL CONDITIONS FOR THURSDAY AND
FRIDAY...WITH HIGH TEMPERATURES SUPPRESSED IN THE 50S BOTH
AFTERNOONS. LOW TEMPERATURES THURSDAY AND FRIDAY NIGHTS WILL ALSO
REFLECT THE COLD AIR MASS IN PLACE. COLD ADVECTION THURSDAY NIGHT
WILL ALLOW TEMPERATURES TO FALL INTO THE LOW TO MID 30S...WHILE
IMPROVED RADIATIONAL COOLING CONDITIONS UNDER CLEAR SKIES AND
LIGHT WINDS FRIDAY NIGHT WILL SUPPORT TEMPERATURES RIGHT AROUND
FREEZING FOR INLAND AREAS. EXPECT A WARMING TREND TO BEGIN ON
SATURDAY...AS THE SURFACE HIGH PUSHES TOWARD THE COASTLINE AND A
RIDGE BUILDS ALOFT. HIGHS ON SATURDAY WILL REACH THE UPPER 50S FAR
NORTH TO THE LOW/MID 60S FARTHER SOUTH...STILL SEVERAL DEGREES
BELOW NORMAL.

&&

.LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/...
THE CENTER OF SURFACE HIGH PRESSURE WILL SLOWLY SETTLE OVER THE
NEARBY ATLANTIC WATERS LATE SATURDAY INTO MONDAY...WHILE AN UPPER
RIDGE BUILDS FROM THE EASTERN GULF OF MEXICO. EXPECT A WARMING
TREND TO CONTINUE THROUGH MONDAY AS A RESULT...WITH HIGH
TEMPERATURES REBOUNDING INTO THE UPPER 60S TO AROUND 70 DEGREES
SUNDAY AND MONDAY AFTERNOON...AND NIGHTTIME LOWS FALLING INTO THE
40 DEGREE RANGE. A COLD FRONT FORMING THE LEADING EDGE OF ANOTHER
STRONG SURFACE HIGH PRESSURE WILL APPROACH FROM THE NORTHWEST ON
TUESDAY. THE FRONT COULD STALL OVER OR JUST NORTH OF THE FORECAST
AREA WEDNESDAY...AS THE SURFACE HIGH BUILDS AN INLAND WEDGE FROM
THE MID ATLANTIC STATES INTO THE CAROLINAS AND NORTHERN GEORGIA.
NORTHEAST FLOW WITHIN THIS PATTERN WILL CONTRIBUTE TO A SLIGHT
COOL DOWN FOR THE MID WEEK PERIOD. A COASTAL TROUGH ON THE EDGE OF
THE INLAND WEDGE COULD SUPPORT A SLIGHT CHANCE FOR RAIN LATE
TUESDAY INTO WEDNESDAY.

&&

.AVIATION /16Z WEDNESDAY THROUGH SUNDAY/...
FLIGHT RESTRICTIONS WILL CONTINUE AT THE TERMINALS THROUGH 17-18Z
AT KSAV AND UNTIL 19-20Z AT KCHS BEFORE VFR WEATHER FINALLY
RETURNS.

EXTENDED AVIATION OUTLOOK...VFR CONDITIONS WILL PREVAIL.

&&

.MARINE...
INTENSIFYING LOW PRESSURE OFF THE MID ATLANTIC COST WILL CONTINUE
TO DEEPEN BUT PULL FURTHER AWAY TODAY. CONDITIONS WILL BE IN AN
IMPROVING STATE...WITH LINGERING SMALL CRAFT ADVISORIES OVER
CHARLESTON HARBOR AND THE 0-20 NM LEGS DROPPING OFF THIS
AFTERNOON. A MARGINAL GALE WARNING FOR AMZ374 WILL END BY 1 PM AND
WILL TRANSITION INTO A SMALL CRAFT ADVISORY FOR SEAS.

THE IMPROVEMENT IN CONDITIONS WILL BE SHORT-LIVED AS ANOTHER
SURGE OF COLD AIR ADVECTION IS EXPECTED LATER TONIGHT AS A STRONG
UPPER DISTURBANCE MOVES THROUGH. SMALL CRAFT ADVISORIES COULD
THEREFORE BE NEEDED AGAIN FOR PORTIONS OF THE MARINE ZONES IN THE
LATE TONIGHT TIME FRAME.

THURSDAY THROUGH SUNDAY...ANOTHER SURGE OF COLD AIR ADVECTION IS
EXPECTED THURSDAY...ALONG WITH A TIGHTENING PRESSURE GRADIENT ON
THE EDGE OF HIGH PRESSURE BUILDING INLAND. SMALL CRAFT ADVISORIES
COULD THEREFORE BE NEEDED AGAIN FOR PORTIONS OF THE MARINE ZONES
THROUGH THURSDAY. MARINE CONDITIONS WILL THEN IMPROVE FOR FRIDAY
INTO THE WEEKEND...AS THE SURFACE HIGH SHIFTS TOWARD THE WATERS
AND THE GRADIENT RELAXES.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...LAKE WIND ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR SCZ045.
MARINE...SMALL CRAFT ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR AMZ330-
     352-354.
     SMALL CRAFT ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR AMZ350.
     GALE WARNING UNTIL 1 PM EST THIS AFTERNOON FOR AMZ374.

&&

$$

NEAR TERM...
SHORT TERM...WMS
LONG TERM...WMS
AVIATION...
MARINE...WMS






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