158
FXUS62 KCHS 171111
AFDCHS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
611 AM EST SUN NOV 17 2024
SYNOPSIS
HIGH PRESSURE WILL PREVAIL UNTIL A STRONG COLD FRONT MOVES
THROUGH THE AREA MID WEEK.
NEAR TERM /THROUGH TONIGHT/
TODAY: ALOFT, THE FORECAST AREA WILL BE SOLIDLY UNDER THE
INFLUENCE OF A LARGE RIDGE CENTERED TO THE SOUTH NEAR WESTERN
CUBA WITH THE RIDGE AXIS EXTENDING NORTHWARD THROUGH THE MID
ATLANTIC AND INTO NEW ENGLAND. AT THE SURFACE, HIGH PRESSURE
WILL BE CENTERED RIGHT ON TOP OF THE SC/GA COASTLINE. THE VERY
WEAK PRESSURE GRADIENT WILL RESULT IN VARIABLE WINDS WITH SPEEDS
MOSTLY NO MORE THAN 5 MPH. SKIES WON'T BE TOTALLY CLEAR AS
CIRRUS STARTS TO SPREAD ACROSS THE REGION, BUT WE SHOULD STILL
SEE PLENTY OF SUN. LOW-LEVEL THICKNESS VALUES ARE PROGGED TO BE
A BIT HIGHER WHICH WILL SUPPORT HIGHS A FEW DEGREES WARMER THAN
SATURDAY. THE FORECAST ADVERTISES TEMPERATURES MOSTLY IN THE LOW
70S, WITH A FEW MID 70S POSSIBLE ACROSS SOUTHEAST GA SOUTH OF
THE I-16 CORRIDOR.
TONIGHT: DRY HIGH PRESSURE WILL REMAIN CENTERED NEARLY RIGHT ON
TOP OF THE FORECAST AREA, AND ANOTHER VERY QUIET NIGHT IS ON
TAP. THIN CIRRUS WILL CONTINUE TO MOVE THROUGH, KEEPING SKIES
FROM BEING COMPLETELY CLEAR. HOWEVER, WE SHOULD AGAIN SEE CALM
WINDS AND GOOD RADIATIONAL COOLING CONDITIONS. LOWS WON'T BE
QUITE AS CHILLY AS THE NIGHT BEFORE, BUT WE SHOULD STILL SEE LOW
TO MID 40S AWAY FROM THE IMMEDIATE COAST. THERE COULD AGAIN BE
SOME SHALLOW GROUND FOG, THOUGH FOG HAS NOT BEEN EXPLICITLY
ADDED TO THE FORECAST AT THIS POINT.
SHORT TERM /MONDAY THROUGH WEDNESDAY/
HIGH PRESSURE BOTH AT THE SURFACE AND ALOFT WILL CONTINUE TO
DOMINATE THE WEATHER ON MONDAY. EXPECT MOSTLY SUNNY SKIES WITH
SEASONALLY WARM TEMPERATURES IN THE MID 70S. SHOULD SEE SOME
INCREASE IN CLOUDS LATE MONDAY NIGHT WHICH WILL PREVENT
TEMPERATURES FROM GETTING QUITE AS COOL AS PREVIOUS NIGHTS. LOWS
ARE FORECAST TO BE IN THE UPPER 40S TO LOWER 50S AWAY FROM THE
IMMEDIATE COAST.
SHORTWAVE ENERGY IS POISED TO LIFT OUT OF SOUTHWEST FLOW ALOFT
AND PASS ACROSS THE REGION TUESDAY INTO TUESDAY NIGHT. THIS IS
COINCIDENT WITH AN AXIS OF DEEPER MOISTURE MOVING IN. THE FIRST
HALF OF THE DAY SHOULD BE DRY THEN RAIN CHANCES WILL INCREASE
DURING THE LATTER HALF OF THE DAY INTO THE OVERNIGHT. STILL A
BIT UNCLEAR HOW MUCH COVERAGE THERE WILL BE, BUT THE BETTER
POTENTIAL WILL BE OVER SOUTHEAST GEORGIA. CURRENT POPS PEAK IN
THE 40-60% RANGE. TEMPERATURES STAY ABOVE NORMAL.
STRONG MID LEVEL TROUGH SHIFTS INTO THE EASTERN CONUS ON
WEDNESDAY. A COLD FRONT WILL APPROACH THE LOCAL AREA WITH
PERHAPS A WEAK LOW PASSING WELL TO THE SOUTH. ISOLATED TO
SCATTERED SHOWERS WILL BE POSSIBLE, ESPECIALLY IN THE MORNING,
BEFORE RAIN CHANCES DECREASE FROM WEST TO EAST WITH DRIER AIR
MOVING IN. ONE MORE WARM DAY WITH HIGHS BACK IN THE MID TO UPPER
70S.
LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/
MID LEVEL TROUGH WILL LARGELY PERSIST OVER THE EASTERN U.S.
LATE WEEK INTO THE WEEKEND. SURFACE LOW PRESSURE WILL SPIN OVER
THE NORTHEAST, BEFORE EXITING LATE IN THE PERIOD AND ALLOWING
HIGH PRESSURE TO BUILD. QUIET WEATHER IS EXPECTED PRECIP-WISE,
WITH NO MENTIONABLE POPS IN THE FORECAST. ONE ITEM OF NOTE IS
THE GUSTY WEST WINDS EXPECTED BEGINNING WEDNESDAY NIGHT
FOLLOWING FROPA, WHICH WILL PERSIST TO SOME EXTENT INTO FRIDAY.
A LAKE WIND ADVISORY FOR LAKE MOULTRIE APPEARS LIKELY.
OTHERWISE, UNSEASONABLY COOL TEMPERATURES ARE EXPECTED WITH
HIGHS FORECAST TO BE IN THE UPPER 50S TO AROUND 60. LOWS WILL
DIP INTO THE 30S ACROSS MANY INLAND LOCATIONS, ESPECIALLY FRIDAY
NIGHT.
AVIATION /11Z SUNDAY THROUGH THURSDAY/
VFR CONDITIONS WILL PREVAIL AT KCHS, KJZI, AND KSAV THROUGH 12Z
MONDAY.
EXTENDED AVIATION OUTLOOK: PREVAILING VFR. BRIEF FLIGHT
RESTRICTIONS POSSIBLE IN SHOWERS TUESDAY NIGHT INTO WEDNESDAY IN
ADVANCE OF A COLD FRONT. GUSTY WEST WINDS ARE EXPECTED THURSDAY
AND FRIDAY.
MARINE
TODAY AND TONIGHT: VERY QUIET CONDITIONS ARE EXPECTED FOR THE
LOCAL WATERS AS HIGH PRESSURE IS CENTERED RIGHT ON TOP OF THE
AREA. THIS WILL KEEP THE GRADIENT QUITE WEAK AND THE RESULTING
WINDS WILL MOSTLY BE AROUND 5 KNOTS, AND CERTAINLY NOT MORE THAN
5-10 KNOTS. SEAS WILL CONTINUE TO DIMINISH, AND WILL MOSTLY
AVERAGE AROUND 2 FEET FOR THE NEARSHORE WATERS AND AS HIGH AS
3-4 FEET FOR THE OUTER WATERS.
MONDAY THROUGH FRIDAY: RELATIVELY BENIGN MARINE CONDITIONS
EXPECTED MONDAY INTO TUESDAY. WINDS AVERAGE AROUND 10 KNOTS OR
LESS WITH SEAS 1-2 FEET. WINDS AND SEAS INCREASE ON WEDNESDAY
AHEAD OF A COLD FRONT, WHICH WILL THEN CLIMB EVEN HIGHER
WEDNESDAY NIGHT INTO THURSDAY FOLLOWING FROPA. SMALL CRAFT
ADVISORIES WILL LIKELY BE NEEDED FOR ALL WATERS INCLUDING THE
CHARLESTON HARBOR. THERE IS ALSO A RISK FOR GUSTS TO NEAR GALE
FORCE OVER PORTIONS OF THE WATERS. ADVISORY-LEVEL CONDITIONS
PERSIST THROUGH FRIDAY.
TIDES/COASTAL FLOODING
UPCOMING MORNING HIGH TIDE (~8:45AM): WE ARE NOW PAST THE PEAK
ASTRONOMICAL TIDES FOR THIS PARTICULAR STRETCH, AS BOTH
CHARLESTON AND FORT PULASKI ASTRONOMICAL TIDES WILL BE DOWN
~0.15 FT FROM SATURDAY MORNING. WE CONTINUE TO SEE LARGE
POSITIVE TIDAL DEPARTURES AT BOTH SITES, PRIMARILY DUE TO EXCESS
WATER BEING TRAPPED IN THE TIDAL SYSTEM FROM THE LAST SEVERAL
DAYS. THE BIGGEST DECISION POINT IS WHETHER OR NOT CHARLESTON
WILL HIT MAJOR FLOOD STAGE OF 8 FT MLLW. OVER THE LAST TWO HIGH
TIDE CYCLES, THE DEPARTURE HAS COME DOWN FROM 1.22 FT TO 1.15
FT. WITH NO SUPPORT FROM THE WIND WE EXPECT THIS TO CONTINUE TO
COME DOWN WHICH SHOULD BE SUFFICIENT TO KEEP THE UPCOMING PEAK
TIDE FROM REACHING 8 FT MLLW. HOWEVER, IT WILL LIKELY BE VERY
CLOSE. SIMILARLY, FORT PULASKI IS EXPECTED TO PEAK RIGHT AROUND
ITS MODERATE FLOOD STAGE OF 10 FT MLLW. THEREFORE, WE HAVE OPTED
TO ISSUE A COASTAL FLOOD ADVISORY FOR THE ENTIRE COAST.
ELEVATED TIDES WILL CONTINUE EARLY THIS WEEK. MINOR COASTAL
FLOODING IS POSSIBLE, MAINLY ALONG THE CHARLESTON AND COASTAL
COLLETON COUNTY COASTS, WITH THE MONDAY AND POSSIBLY TUESDAY
MORNING HIGH TIDES. FURTHER SOUTH AND ALONG THE GEORGIA COAST,
TIDE LEVELS ARE CURRENTLY FORECAST TO STAY BELOW MINOR FLOOD
CRITERIA.
CHS WATCHES/WARNINGS/ADVISORIES
GA...COASTAL FLOOD ADVISORY UNTIL 11 AM EST THIS MORNING FOR GAZ117-
119-139-141.
SC...COASTAL FLOOD ADVISORY UNTIL 11 AM EST THIS MORNING FOR
SCZ048>051.
MARINE...NONE.
NEAR TERM...BSH
SHORT TERM...ETM
LONG TERM...ETM
AVIATION...BSH/ETM
MARINE...BSH/ETM
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page