339
FXUS62 KCHS 021209
AFDCHS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
709 AM EST FRI DEC 2 2022
SYNOPSIS
HIGH PRESSURE WILL RETREAT OVER THE NORTH ATLANTIC THROUGH
FRIDAY NIGHT. A FRONT WILL THEN SHIFT INTO THE AREA SATURDAY
AND SATURDAY NIGHT, AND COULD LINGER IN THE VICINITY INTO EARLY
NEXT WEEK.
NEAR TERM /THROUGH TONIGHT/
EARLY MORNING UPDATE: STRATOCU IN THE COASTAL WATERS REMAINS
HELD AT BAY ALONG THE COOL LAND BREEZE EDGING THROUGH THE
NEARSHORE WATERS. SUNNY START TO THE DAY FOR ALL. BUT AS WE GET
INTO THE DAYTIME HEATING CYCLE, STILL THINKING WE SEE A FAIR
AMOUNT OF CLOUD COVER DEVELOP INLAND WITH CONDITIONS TRENDING
TOWARD THE PARTLY SUNNY SIDE OF THINGS. FOR NOW, OTHER THAN SOME
ADJUSTMENTS TO HOURLY TEMPERATURES, NO SIGNIFICANT CHANGES WERE
MADE TO THE FORECAST.
PREVIOUS DISCUSSION...
PATTERN SYNOPSIS/FORECAST: OVERNIGHT COMPOSITE ANALYSIS REVEALS
ELONGATED UPPER-LEVEL HIGH PRESSURE STRETCHED ACROSS THE GULF
OF MEXICO AND SHORT-WAVE RIDGE AXIS EXTENDING UP ALONG THE EAST
COAST. SURFACE HIGH PRESSURE IS CENTERED OVER THE MID ATLANTIC
BUT ENCOMPASSES THE ENTIRE ATLANTIC COAST. SOME SEMBLANCE OF A
DEVELOPING COASTAL TROUGH IS JUST OFFSHORE, WITH ABUNDANT
STRATOCU EAST OF THE TROUGH AXIS INTO THE ATLANTIC. STRATOCU HAS
BEEN PRESSING TOWARD THE COAST THROUGH THE NIGHT, BUT THUS FAR
HAS BEEN HELD AT BAY BY THE LAND BREEZE AND NORTHERLY OFFSHORE
COMPONENT TO THE LOW LEVEL WIND. SURFACE HIGH PRESSURE AND
SHORT-WAVE RIDGING ALOFT WILL REMAIN THE DOMINANT PLAYER ACROSS
THE SE STATES THROUGH TONIGHT.
TODAY: OTHER THAN A LITTLE BIT OF CIRRUS ALOFT AND SOME STRATOCU
PRESSING INTO THE GA COAST, MOSTLY SUNNY SKIES WILL START THE
DAY. COASTAL TROUGH IS EXPECTED TO REMAIN OFFSHORE BEFORE
FINALLY GETTING SHOVED TO THE COAST AND BREAKING DOWN LATER THIS
AFTERNOON INTO TONIGHT WITHIN THE PERSISTENT SOUTHEASTERLY MEAN
LOW LEVEL FLOW. BIGGER FORECAST QUESTION REVOLVES AROUND THE
MOIST LAYER/STRATOCU SITTING OFF THE COAST. WITH THE PERSISTENT
SOUTHEASTERLY LOW LEVEL MOIST ADVECTION OFF THE ATLANTIC,
DAYTIME HEATING AND AN EXPANDING BOUNDARY LAYER, I DO THINK THAT
A FAIR AMOUNT OF CLOUD COVER WILL EVENTUALLY DEVELOP INLAND AS
WE GO THROUGH THE DAY, TRENDING TOWARD PARTLY SUNNY SKIES FOR
MOST AREAS. TEMPERATURES TODAY WILL RUN A LITTLE WARMER AS
COMPARED TO THURSDAY, OVERALL THE MIDDLE 60S FOR MUCH OF THE
FORECAST AREA, PERHAPS UPPER 60S TO 70 IN THE FAR SOUTHERN
COUNTIES.
TONIGHT: WITH CONTINUING SOUTHEAST TO SOUTH LOW LEVEL FLOW, WE
WILL LIKELY MAINTAIN SOME DEGREE OF LOWER CLOUD COVER THROUGH
THE OVERNIGHT HOURS. THAT, ALONG WITH SOME MID AND HIGH CLOUD
COVER SNEAKING INTO THE REGION FROM THE WEST/NORTHWEST, THE
FORECAST WILL FEATURE MOSTLY CLOUDY SKIES FOR ALL AREAS. THUS
WARMER TEMPERATURES ARE ANTICIPATED WITH LOWS RANGING FROM THE
UPPER 40S WELL INLAND TO THE MIDDLE 50S NEAR THE COAST.
SHORT TERM /SATURDAY THROUGH MONDAY/
A COLD FRONT WILL APPROACH THE REGION ON SATURDAY THEN PUSH OFFSHORE
OVERNIGHT. ALTHOUGH, THE FRONT WILL LINGER IN THE VICINITY THROUGH
AT LEAST LATE SUNDAY. THEREAFTER, HIGH PRESSURE WILL PREVAIL. IN
REGARDS TO RAIN CHANCES EACH DAY, A MOSTLY DRY SATURDAY IS EXPECTED.
THE ONLY EXCEPTION IS ALONG THE CHARLESTON COUNTY COAST AND JUST
OFFSHORE WHERE COULD BE A FEW SHOWERS DUE TO SHORTWAVE ENERGY.
FOR SUNDAY, THERE ARE STILL INCONSISTENCIES BETWEEN THE GFS(WET) AND
ECMWF(DRY). EVEN WITH A "WETTER" GFS, HAVE DECIDED TO LEAN TOWARDS
THE ECMWF AND HAVE A DRY FORECAST IN PLACE ACROSS LAND AREAS AS
PWATS IN BOTH MODELS ARE NOT OVERLY IMPRESSIVE. THEN ON MONDAY,
EXPECT A MOSTLY DRY DAY WITH SOME BREAKS IN CLOUD COVER.
ON SATURDAY, HIGH TEMPERATURES WILL BE IN THE 70S, THEN IN THE 60S
ON SUNDAY AND MONDAY. LOW TEMPERATURES ON SATURDAY WILL BE IN THE
50S, THEN MID 40S TO MID 50S ON SUNDAY NIGHT.
LONG TERM /MONDAY NIGHT THROUGH THURSDAY/
OVERNIGHT MONDAY, THE AREA WILL BE SLIGHTLY UNSETTLED AS THE
AFOREMENTIONED FRONT LINGERS OFFSHORE AND TO THE WEST OF THE REGION.
THERE ARE ALSO HINTS THAT SHORTWAVE ENERGY COULD RIPPLE THROUGH THE
REGION. THEREFORE, THE HIGHEST RAIN CHANCES THROUGH THE LONG-TERM IS
OVERNIGHT MONDAY. THEREAFTER, THERE IS UNCERTAINTY ON HOW UNSETTLED
THE REST OF THE WEEK WILL BE. OVERALL, A DRY FORECAST IN MOSTLY IN
PLACE BUT COULD SEE A FEW SHOWERS EACH DAY. THEN BY LATE WEEK,
ANOTHER COLD FRONT IS EXPECTED TO IMPACT THE REGION. HIGH
TEMPERATURES WILL BE IN THE 70S THROUGH THURSDAY, THEN IN THE 60S TO
LOW 70S ON FRIDAY. LOW TEMPERATURES WILL BE IN THE 50S TO LOW 60S
THROUGH WEDNESDAY NIGHT THEN A FEW DEGREES COOLER ON THURSDAY NIGHT.
AVIATION /12Z FRIDAY THROUGH TUESDAY/
KCHS/KJZI/KSAV: VFR WILL PREVAIL THROUGH SATURDAY MORNING.
WITH PERSISTENT MOIST FLOW OFF THE ATLANTIC, CLOUD COVER IS
EXPECTED TO DEVELOP LATER THIS MORNING AND THROUGH THE AFTERNOON
HOURS, THEN PERSIST THROUGH TONIGHT AS WELL. BUT CLOUD HEIGHTS
ARE EXPECTED TO REMAIN AT OR ABOVE 4K FEET THROUGH THE PERIOD.
OTHERWISE, NORTHEASTERLY WINDS THIS MORNING WILL VEER EASTERLY
THROUGH THE DAY AND LIGHT SOUTHEASTERLY TONIGHT.
EXTENDED AVIATION OUTLOOK: VFR.
MARINE
NORTHEASTERLY WINDS REMAIN A BIT GUSTY IN THE COASTAL WATERS
EARLY THIS MORNING, OCCASIONALLY GUSTING TO 25 KNOTS OR BETTER
IN SOME OF THE NEARSHORE MARINE ZONES. WINDS SHOULD TREND WEAKER
AS WE GO THROUGH THE MORNING HOURS WITH NO NEW MARINE HEADLINES
PLANNED. SMALL CRAFT ADVISORY REMAINS IN EFFECT THE OUTER
GEORGIA WATERS, LARGELY DUE TO SEAS PUSHING 6 FEET. BUT SEAS
WILL SUBSIDE THROUGH THE AFTERNOON AND INTO TONIGHT. THUS, I
HAVE TRIMMED THE END TIME BACK TO 6 PM THIS EVENING.
SATURDAY THROUGH WEDNESDAY: ON SATURDAY, WEST TO SOUTHWEST WINDS
WILL PREVAIL BEFORE A COLD FRONT SETTLES INTO THE AREA OVERNIGHT.
THEREAFTER, A NORTH TO NORTHEAST FLOW WILL PERSIST THROUGH LATE
MONDAY, THEN BECOME SOUTHERLY. WIND SPEEDS WILL BE 5 TO 10 KNOTS
WITH SEAS LESS THAN 4 FEET.
EQUIPMENT
TEMPERATURE DATA AT THE KSAV ASOS ARE SUSPECT. PARTS ARE ON
ORDER AND WILL ARRIVE NEXT WEEK. USE DATA WITH CAUTION.
CHS WATCHES/WARNINGS/ADVISORIES
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EST THIS EVENING FOR AMZ374.
NEAR TERM...TBA
SHORT TERM...RAD
LONG TERM...RAD
AVIATION...RAD/TBA
MARINE...RAD/TBA
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