013
FXUS62 KCHS 070600
AFDCHS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
100 AM EST SAT MAR 7 2026
WHAT HAS CHANGED
MINOR CHANGES WERE MADE TO KEY MESSAGE 1. MINOR CHANGES TO KEY
MESSAGE 2 WERE MADE TO REFLECT THE ONGOING WARM WEATHER PATTERN
INTO THE MIDDLE OF NEXT WEEK. THE MARINE AND AVIATION (07/06Z
TAFS) SECTIONS WERE UPDATED.
KEY MESSAGES
- 1) DENSE FOG POSSIBLE THIS MORNING ACROSS THE SOUTH CAROLINA
LOWCOUNTRY, SOUTHEAST GEORGIA AND THE ADJACENT COASTAL WATERS.
- 2) UNSEASONABLY WARM TEMPERATURES CONTINUE INTO THE MIDDLE OF
NEXT WEEK, WITH INCREASING RAIN CHANCES DURING THE LATER HALF
OF THIS WEEKEND.
DISCUSSION
KEY MESSAGE 1: DENSE FOG POSSIBLE THIS MORNING ACROSS THE SOUTH
CAROLINA LOWCOUNTRY, SOUTHEAST GEORGIA AND THE ADJACENT COASTAL
WATERS.
EARLY MORNING GOES-E FOG PRODUCTS, VIIRS NIGHTTIME VISIBLE
IMAGERY AND SURFACE OBSERVATIONS SHOW AREAS OF STRATUS EXPANDING
ACROSS INTERIOR SOUTHEAST GEORGIA WITH PATCHY SEA FOG OVER THE
COASTAL WATERS. THE FORECAST CONFIDENCE CONCERNING THE FOG
FORECAST IS LOW WITH ALL OF THE NEAR TERM HIGH-RESOLUTION
GUIDANCE AND THE 07/00Z SYNOPTIC GUIDANCE INITIALIZING VERY
POORLY. MOST OF THE GUIDANCE WOULD SUGGEST WIDESPREAD DENSE FOG
IS ALREADY IN PLACE ACROSS THE COASTAL WATERS AND NEARBY COASTAL
COUNTIES WHICH IS JUST NOT THE CASE. CONDITIONS ARE SUPPORTIVE
OF STRATUS BUILDING DOWN TO PRODUCE FOG ACROSS THE INTERIOR
THROUGH DAYBREAK WITH 1000 HPA CONDENSATION PRESSURE DEFICITS
PROGGED TO DROP BELOW 2 HPA AS DEWPOINTS DEPRESSIONS APPROACH
ZERO WITHIN A DECOUPLED BOUNDARY LAYER. HOWEVER, AT THE COAST,
SOUTHEAST WINDS ARE EXPECTED TO PERSIST, WHICH IS TYPICALLY NOT
OVERLY FAVORABLE FOR WIDESPREAD SEA FOG FORMATION GIVEN THE
LIMITED THE WARM PARCEL RESIDENCE TIMES ACROSS THE COLD ATLANTIC
SHELF WATERS.
GIVEN CURRENT OBSERVATIONAL TRENDS AND LIMITED USEFUL MODEL
DATA, IT IS NOT EXACTLY CLEAR HOW WIDESPREAD INLAND FOG WILL
BECOME OR HOW MUCH SEA FOG WILL DEVELOP AND EXPAND ONSHORE
THROUGH SUNRISE. THE PREVIOUS FOG FORECAST WAS MOSTLY
MAINTAINED, ALTHOUGH THE "WIDESPREAD" FOG QUALIFIER WAS REMOVED
UNTIL MORE DEFINITIVE FOG TRENDS CAN BE IDENTIFIED. A DENSE FOG
ADVISORY MAY STILL BE NEEDED OVER THE COMING HOURS, HOWEVER.
KEY MESSAGE 2:
DEEP-LAYERED HIGH PRESSURE EXTENDING ACROSS THE WESTERN
ATLANTIC WILL PREVAIL ACROSS THE SOUTHEAST UNITED STATES THIS
WEEKEND INTO THE MIDDLE OF NEXT WEEK, WITH ENSEMBLE SITUATIONAL
AWARENESS TABLES CONTINUING TO SHOW THAT GEOPOTENTIAL HEIGHTS AT
VARIOUS LEVELS PEAK AT OR ABOVE THE 90TH PERCENTILE WRT
CLIMATOLOGY. THIS PATTERN FAVORS A WARM SOUTHERLY FLOW UNDER
AMPLE SUNSHINE EACH DAY AHEAD OF A STALLING/DISSIPATING FRONT
UPSTREAM MONDAY, WITH WELL ABOVE NORMAL TEMPERATURES IN THE
UPPER 70S TO MID 80S, COLDEST ALONG THE COAST.
DESPITE SUFFICIENT MOISTURE, HIGH RESOLUTION CONVECTION
ALLOWING MODELS SHOW PERSISTENT SUBSIDENCE ASSOCIATED WITH THIS
PATTERN WHICH LOOKS TO HINDER PRODUCTION OF SHOWERS/STORMS OVER
THE AREA TODAY. SCATTERED WEAK SHORTWAVES WORK TO FLATTEN THE
RIDGE ON SUNDAY BRINGING SCATTERED CHANCES (30-45%) FOR SHOWERS
AND THUNDERSTORMS, THOUGH MODELS ARE INDICATING THEY WILL BE
FAIRLY QUICK MOVING LEADING TO LOW RAINFALL AMOUNTS AT UNDER A
QUARTER OF AN INCH, ENDING OVERNIGHT INTO MONDAY. NOT CURRENTLY
EXPECTING ANY SEVERE WEATHER OR FLOODING WITH THIS ACTIVITY, BUT
SEVERE WEATHER CAN'T BE FULLY RULED OUT PER SOME OF THE AI/ML
GUIDANCE. ANOTHER CHANCE FOR LIGHT RAIN LATE MONDAY INTO TUESDAY
FROM A WEAK PASSING SHORTWAVE MAY PRESENT ITSELF, THOUGH MODEL
CONFIDENCE IS LOW ON THE TRACK THUS LEADING TO POPS REMAINING AT
OR BELOW 30%. WARM TEMPERATURES CONTINUE AHEAD OF A MORE
SUBSTANTIAL COLD FRONT ARRIVING TO THE LOCAL AREA DURING THE
SECOND HALF OF THE WEEK, BRINGING NORMAL TEMPERATURES AND
RENEWED CHANCES FOR RAIN.
THE LATEST FORECAST TIES THE RECORD WARM LOW TEMPERATURE AT
SAVANNAH ON TUESDAY, AND IS WITHIN 3 DEGREES OF RECORD HIGHS AND
RECORD WARM LOWS SATURDAY THROUGH WEDNESDAY.
AVIATION /06Z SATURDAY THROUGH WEDNESDAY/
07/06Z TAF DISCUSSION:
KCHS/KJZI/KSAV: LOW CONFIDENCE FOR ALL TERMINALS THROUGH
DAYBREAK AS IT IS VERY UNCLEAR HOW WIDESPREAD/DENSE FOG WILL BE.
MODELS ARE SUGGESTING A VERY FOGGY OUTCOME FOR ALL SITES, BUT
THEY HAVE NOT INITIALIZED VERY WELL. CALM WINDS AND SATURATED
SURFACE CONDITIONS UNDER CLEAR SKIES CERTAINLY SUGGEST SOME
DEGREE OF FOG WILL DEVELOP. GIVEN THE OVERALL LOW CONFIDENCE AND
MODEL TRENDS, NO MAJOR CHANGES WERE MADE FROM THE 00Z TAF CYCLE,
ALTHOUGH THE FOG WAS PUSHED BACK SOME AT BOTH KCHS AND KSAV
BASED ON NEAR TERM OBSERVATIONAL TRENDS. ANY FOG/STRATUS SHOULD
LIFT BY MID-MORNING WITH VFR CONDITIONS PREVAILING THEREAFTER.
SOME FOG, SHOULD IT DEVELOP, SHOULD LINGER NEAR KJZI FOR MOST OF
THE DAY, MAINLY JUST OFFSHORE.
EXTENDED AVIATION OUTLOOK: RESTRICTIVE CEILINGS AND
VISIBILITIES ARE POSSIBLE OVERNIGHT INTO THE EARLY MORNING HOURS
EACH NIGHT INTO EARLY NEXT WEEK DUE TO LOW STRATUS/FOG. CHANCES
FOR SCATTERED SHOWERS AND THUNDERSTORMS RETURN SUNDAY
AFTERNOON/EVENING, LEADING TO CHANCES FOR TEMPORARY FLIGHT
RESTRICTIONS.
MARINE
THROUGH TONIGHT: SEA FOG IS THE MAIN CONCERN OVER THE WATERS
THROUGH TONIGHT. SATELLITE AND WEBCAMS SHOW PATCHES OF SEA FOG
SLOWLY EXPANDING OVER THE WATERS. IT IS UNCLEAR HOW WIDESPREAD
THE FOG WILL BECOME ESPECIALLY WITH SOUTHEAST WINDS LIKELY
LIMITING PARCEL RESIDENCE TIMES. THE MARINE DENSE FOG ADVISORY
WAS EXPANDED TO INCLUDE THE SOUTH SANTEE-EDISTO BEACH NEARSHORE
LEG TO MATCH UP WITH WFO WILMINGTON'S ADVISORY TO THE NORTH.
OTHERWISE, FAIRLY LIGHT SOUTHEAST WIND SWILL VEER TO THE SOUTH
AND SOUTHWEST TONIGHT AS THE GRADIENT BETWEEN HIGH PRESSURE
CENTERED WELL OFFSHORE AND AN APPROACHING COLD FRONT TIGHTENS.
THE RISK FOR SEA FOG WILL PERSIST.
SUNDAY THROUGH WEDNESDAY: HIGH PRESSURE WILL REMAIN THE
DOMINANT WEATHER FEATURE ACROSS LOCAL WATERS INTO NEXT WEEK,
FAVORING A SOUTH/SOUTHEAST WIND IN THE 10-15 KT RANGE AND SEAS
GENERALLY BETWEEN 2-4 FT, WELL BELOW SMALL CRAFT ADVISORY
THRESHOLDS. SFC WINDS COULD TIP MORE SOUTH/SOUTHWEST HEADING
INTO EARLY NEXT WEEK, BUT WILL CONTINUE TO REMAIN WELL BELOW
SMALL CRAFT ADVISORY LEVELS BETWEEN ATLANTIC HIGH PRESSURE AND A
STALLING/DISSIPATING FRONT WELL INLAND. AS THAT FRONT CONTINUES
TO PUSH EASTWARDS, THE PRESSURE GRADIENT RISES AND MAY RESULT
IN WINDS REACHING SMALL CRAFT ADVISORY LEVELS WEDNESDAY INTO
THURSDAY, WHICH WILL CONTINUE TO BE MONITORED.
CLIMATE
RECORD HIGH TEMPERATURES:
MARCH 7:
KCHS: 87/2023
KCXM: 84/2023
KSAV: 86/2023
MARCH 8:
KCHS: 86/1974
KCXM: 86/1951
KSAV: 86/1974
MARCH 9:
KCHS: 87/1974
KCXM: 84/1974
KSAV: 88/1974
MARCH 10:
KCHS: 90/1974
KCXM: 87/1974
KSAV: 91/1974
MARCH 11:
KCHS: 85/2015
KCXM: 82/1997
KSAV: 87/2015
RECORD HIGH MINIMUM TEMPERATURES:
MARCH 7:
KCHS: 63/1992
KCXM: 65/2023
KSAV: 68/1880
MARCH 8:
KCHS: 63/2022
KCXM: 65/2022
KSAV: 65/1880
MARCH 9:
KCHS: 66/2022
KCXM: 65/2022
KSAV: 65/2022
MARCH 10:
KCHS: 64/1974
KCXM: 65/1974
KSAV: 63/1909
MARCH 11:
KCHS: 63/2015
KCXM: 64/2016
KSAV: 64/1974
MARCH 12:
KCHS: 62/1985
KCXM: 64/1973
KSAV: 65/1973
CHS WATCHES/WARNINGS/ADVISORIES
GA...NONE.
SC...NONE.
MARINE...DENSE FOG ADVISORY UNTIL 10 AM EST THIS MORNING FOR AMZ350-352-
354.
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