829
FXUS62 KCHS 220618
AFDCHS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
118 AM EST THU JAN 22 2026
WHAT HAS CHANGED
THE AVIATION SECTION HAS BEEN UPDATED FOR THE 06Z THURSDAY TAF
ISSUANCE. KEY MESSAGE 1 HAS BEEN UPDATED TO REFLECT UNCERTAINTY
IN WINTER WEATHER PRECIPITATION. KEY MESSAGE 2 HAS BEEN UPDATED
TO REFLECT LOWER CONFIDENCE IN COLDEST TEMPERATURES WEDNESDAY
MORNING NEXT WEEK.
KEY MESSAGES
- 1) WIDESPREAD PRECIPITATION IS EXPECTED TO OCCUR THIS
WEEKEND, BRINGING THE POTENTIAL FOR A WINTER WEATHER EVENT
ACROSS PORTIONS OF THE REGION.
- 2) VERY COLD TEMPERATURES WILL OCCUR EARLY NEXT WEEK.
DISCUSSION
KEY MESSAGE 1: WIDESPREAD PRECIPITATION IS EXPECTED TO OCCUR THIS
WEEKEND, BRINGING THE POTENTIAL FOR A WINTER WEATHER EVENT ACROSS
PORTIONS OF THE REGION.
FOCUS ON THE FORECAST REMAINS THE POTENTIAL FOR WINTER WEATHER
ACROSS PORTIONS OF SOUTHEAST SOUTH CAROLINA AND GEORGIA THIS
WEEKEND. THERE HAS NOT BEEN ANY DRASTIC SHIFTS WITH THIS FORECAST
CYCLE, WITH HIGH UNCERTAINTY REMAINING IN THE POTENTIAL EXTENT AND
MAGNITUDE OF ANY WINTER WEATHER. STRONG HIGH PRESSURE WILL WEDGE
SOUTH INTO THE REGION SATURDAY AND SATURDAY NIGHT. THEN THE FEATURE
OF INTEREST WILL BE AN AREA OF LOW PRESSURE PROGGED TO DEVELOP
SOMEWHERE OVER/NEAR THE GULF COAST STATES WHICH WILL TRACK NORTHEAST
OVER OR NEAR THE LOCAL AREA SUNDAY BEFORE THE MAIN COLD FRONT SWINGS
THROUGH SUNDAY NIGHT.
AS HAS BEEN THE RECENT TREND, THE GEFS FAVORS A MORE PROMINENT
WEDGE, WITH COLDER TEMPERATURES AND A RESULTING HIGHER THREAT FOR A
WINDOW OF FREEZING RAIN OVER PORTIONS OF THE AREA. MEANWHILE, THE
ENS AND GEPS LEAN ON THE WARMER SIDE AS THE AFOREMENTIONED LOW
PRESSURE TRACKS MORE INLAND OVER THE AREA, KEEPING MOST OF THE
WINTER WEATHER THREAT OVER THE MIDLANDS AND UPSTATE, AND A
PREDOMINATELY RAIN FORECAST OVER SOUTHEAST SOUTH CAROLINA AND
SOUTHEAST GEORGIA. ULTIMATELY, THE QUESTION WILL BE THE STRENGTH OF
THE WEDGE AND THE TRACK OF PASSING LOW PRESSURE. TYPICALLY, THE
WEDGE HOLDS STRONGER THAN WHAT MOST MODELS WOULD INDICATE, SO THIS
WILL CERTAINLY BE A CRITICAL FEATURE WE WILL NEED TO PAY CLOSE
ATTENTION TO. IT'S ALSO WORTH NOTING THAT THE MAIN AXIS OF
PRECIPITATION COULD REMAIN ORIENTED TO OUR WEST WHEN TEMPERATURES
ARE COLDEST, SO IT COULD BE A FAIRLY LIMITED POTENTIAL WINDOW AND
SPATIAL EXTENT.
THE MAIN TIME PERIOD OF CONCERN WOULD BE SATURDAY EVENING INTO
SUNDAY MORNING, WITH HIGHEST PROBABILITIES OF ACCUMULATING ICE
ROUGHLY ALONG AND WEST OF A LINE FROM MONCKS CORNER TO WALTERBORO TO
SYLVANIA AND MILLEN. IN THESE LOCATIONS, LATEST NBM PROBABILITIES
INDICATE A 30-50% CHANCE FOR FREEZING RAIN >0.01", WITH A 10-20% FOR
>0.25". PROBABILITIES DECREASE FURTHER EAST AND TOWARDS THE COAST.
AGAIN, THERE REMAINS HIGH UNCERTAINTY IN THE MAGNITUDE AND EXTENT OF
POTENTIAL WINTER WEATHER, HOWEVER IT DOES CONTINUE TO LOOK LIKE
FREEZING RAIN WOULD BE THE PRIMARY THREAT AS THE FREEZING OR SUB-
FREEZING LAYER NEAR THE SURFACE IS VERY SHALLOW WITH A PROMINENT
WARM NOSE ABOVE.
PRECIPITATION SHOULD COME TO AN END SUNDAY NIGHT INTO EARLY MONDAY
WITH PASSAGE OF THE COLD FRONT. THERE COULD BE A BRIEF OVERLAP WITH
PRECIP AND COLDER TEMPERATURES, RESULTING IN SOME LINGERING P-TYPE
CONCERNS, BUT A LESSER THREAT.
KEY MESSAGE 2: VERY COLD TEMPERATURES WILL OCCUR EARLY NEXT WEEK.
STRONG HIGH PRESSURE WILL USHER ARCTIC AIR INTO THE REGION MONDAY
NIGHT INTO TUESDAY MORNING, WHICH SHOULD THEN LINGER THROUGH EARLY
WEEK BEFORE AIRMASS MODIFICATION TAKES SHAPE. AS A RESULT, LOW TEMPS
ARE FORECAST TO DIP INTO THE TEENS WEST OF I-95 AND ACROSS MUCH OF
THE FRANCIS MARION FOREST WHILE LOW TO MID 20S ARE ANTICIPATED ALONG
THE COAST TUESDAY MORNING. THESE TEMPS IN COMBINATION WITH A
NORTH/NORTHEAST WIND GENERALLY IN THE 5-10 MPH RANGE COULD RESULT IN
WIDESPREAD WIND CHILL VALUES IN THE MID-UPPER TEENS. A COLD WEATHER
ADVISORY COULD EVENTUALLY BE NEEDED FOR THE ENTIRE AREA ACROSS
SOUTHEAST SOUTH CAROLINA AND SOUTHEAST GEORGIA.
LATEST GUIDANCE HAS TRENDED SLIGHTLY WARMER TUESDAY NIGHT INTO EARLY
WEDNESDAY AS WEAK HIGH PRESSURE CENTERED JUST NORTH OF THE LOCAL
AREA SLIDES EAST AND SOUTH, BECOMING POSITIONED ALONG THE MID-
ATLANTIC AND SOUTHEAST COASTAL AREAS. ALTHOUGH A RADIATIONAL COOLING
SETUP REMAINS, SOME CLOUDS ENTER THE LOCAL AREA LATE NIGHT AND COULD
LIMIT OVERNIGHT LOWS TO THE LOW-MID 20S INLAND AND UPPER 20S/LOWER
30S NEAR THE COAST. ADDITIONALLY, THE PRESSURE GRADIENT APPEARS
WEAKER WITH HIGH PRESSURE CENTERED CLOSER TO THE AREA, SUGGESTING
LITTLE WIND CHILL. ALTHOUGH CHANGES IN THE SYNOPTIC PATTERN WILL
HAVE IMPACTS TO OVERNIGHT LOWS, ESPECIALLY BEING SEVERAL DAYS OUT,
CONDITIONS APPEAR LESS SUPPORTIVE FOR A COLD WEATHER ADVISORY
COMPARED TO THE PREVIOUS NIGHT/MORNING.
AVIATION /06Z THURSDAY THROUGH MONDAY/
VFR CONDITIONS WILL PREVAIL AT CHS/JZI/SAV TERMINALS THROUGH 06Z
FRIDAY.
EXTENDED AVIATION FORECAST: VFR CONDITIONS ARE EXPECTED AT
CHS/JZI/SAV TERMINALS THROUGH FRIDAY. PERIODS OF MVFR AND/OR IFR
CONDITIONS ARE POSSIBLE AT ALL TERMINALS THIS WEEKEND AS A STORM
SYSTEM IMPACTS THE AREA. THERE IS ALSO A THREAT FOR A MIX OF FROZEN
PRECIP LATE SATURDAY NIGHT INTO SUNDAY, PRIMARILY AT CHS/JZI
TERMINALS.
MARINE
TODAY AND TONIGHT: HIGH PRESSURE CENTERED NORTHWEST OF THE REGION
WILL GRADUALLY SLIDE EAST AS THE DAY PROGRESSES, FAVORING A WEAK
PRESSURE GRADIENT ACROSS LOCAL WATERS AND WIND/SEAS THAT REMAIN WELL
BELOW SMALL CRAFT ADVISORY LEVELS THROUGH THE PERIOD. IN GENERAL,
NORTHERLY WINDS AROUND 10 KT OR LESS WILL BECOME MORE DIRECTLY
ONSHORE AND WEAKEN LATE DAY AND TONIGHT. SEAS WILL SLOWLY BUILD
ABOUT A FOOT DURING THE NEXT 24 HOURS, GENERALLY UP TO 3-4 FT
(LARGEST BEYOND 15NM FROM THE COAST).
FRIDAY THROUGH TUESDAY: QUIET MARINE CONDITIONS CONTINUE FOR MUCH OF
FRIDAY PRIOR TO A COLD FRONT ADVANCING ACROSS LOCAL WATERS FRIDAY
NIGHT. STRONG COLD AIR ADVECTION AND ENHANCED PRESSURE GRADIENT
ACROSS LOCAL WATERS SUPPORT DETERIORATING CONDITIONS ACROSS ALL
LOCAL WATERS FRIDAY NIGHT, POSSIBLY REACHING SMALL CRAFT ADVISORY
LEVELS ACROSS ALL COASTAL WATERS BY DAYBREAK SATURDAY. CONDITIONS
SHOULD CONTINUE TO DETERIORATE DURING THE WEEKEND AS LOW PRESSURE
ATTEMPTS TO DEVELOP NEAR THE COLD FRONT OFFSHORE WHILE WEDGING
OCCURS INLAND. GUIDANCE INDICATES SOLID SMALL CRAFT ADVISORY
CONDITIONS ACROSS MOST WATERS SATURDAY INTO SUNDAY WITH EVEN THE
POSSIBILITY OF LOW-END GUSTS TO GALE FORCE ACROSS NORTHERN SOUTH
CAROLINA WATERS DURING THE PEAK OF THE EVENT. NORTHEAST WINDS
GUSTING UP TO 25-30 KT APPEAR COMMON ACROSS MOST WATERS WHILE SEAS
BUILD UPWARDS TO 7-10 FT (LARGEST AWAY FROM THE COAST). HIGH SEAS
COULD LINGER ACROSS MOST WATERS MONDAY, SUPPORTING THE POTENTIAL FOR
SMALL CRAFT ADVISORIES THROUGH LATE DAY ACROSS NEARSHORE WATERS
(EXCEPT FOR THE CHARLESTON HARBOR) AND INTO TUESDAY ACROSS OUTER
GEORGIA WATERS.
EQUIPMENT
THE BEAUFORT/GREEN POND NOAA WEATHER RADIO TRANSMITTER (WXJ-23)
IS OPERATING AT LOW POWER WITH DIMINISHED SERVICE. REPAIRS ARE
SCHEDULED TO BE MADE TODAY TO RESTORE FULL SERVICE.
CHS WATCHES/WARNINGS/ADVISORIES
GA...NONE.
SC...NONE.
MARINE...NONE.
DPB/ETM
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