385
FXUS62 KCHS 222204
AFDCHS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
604 PM EDT WED APR 22 2026
WHAT HAS CHANGED
AN AIR QUALITY KEY MESSAGE WAS INTRODUCED.
KEY MESSAGES
- 1) POOR AIR QUALITY WITH SMOKEY CONDITIONS TO LINGER INTO
THURSDAY, POSSIBLY LONGER.
- 2) ABOVE NORMAL TEMPERATURES WITH LOW AFTERNOON HUMIDITY
EXPECTED THROUGH FRIDAY.
- 3) A COLD FRONT COULD PROVIDE SOME MUCH NEEDED RAINFALL
ACROSS SOUTHEAST GEORGIA AND SOUTH CAROLINA THIS WEEKEND.
DISCUSSION
KEY MESSAGE 1: POOR AIR QUALITY WITH SMOKEY CONDITIONS TO
LINGER INTO THURSDAY, POSSIBLY LONGER.
THE SOUTH CAROLINA DEPARTMENT OF ENVIRONMENTAL SERVICES (SCDES)
HAS ISSUED AN AIR QUALITY ALERT FOR ALL OF THE LOWCOUNTRY
THROUGH LATE THURSDAY EVENING.
A BAND OF SMOKE GENERATED BY WILDFIRES OVER SOUTHERN GEORGIA
CONTINUES TO IMPACT FAR INLAND PORTIONS OF SOUTHEAST GEORGIA
INTO THE LOWCOUNTRY. VISIBILITIES IN THIS AREA OF SMOKE WERE
RUNNING ABOUT 3-5 MILES AT 22/22Z, BUT COULD DROP LOWER
OVERNIGHT AS THE NOCTURNAL INVERSION SETS UP. IT IS UNCLEAR IS
THE SMOKE WILL BECOME DENSE ENOUGH FOR A DENSE SMOKE ADVISORY,
BUT TRENDS WILL BE MONITORED. SOME DEGREE OF SMOKE COULD LINGER
ACROSS EXPAND EAST BACK TO THE COAST AS THE INVERSION DEEPENS.
SMOKE WITH "AREAS OF" AND "PATCHY" QUALIFIERS WERE INTRODUCED
THROUGH TONIGHT.
FOR THURSDAY, THE LATEST VERTICALLY INTEGRATED SMOKE GUIDANCE
EXPANDS SMOKE ACROSS ALL OF THE LOWCOUNTRY AND SOUTHEAST GEORGIA
AS THE WILDFIRES TO THE SOUTH PERSIST. IT IS UNCLEAR HOW MUCH
SMOKE WILL REMAIN AT THE SURFACE GIVEN THE FAIRLY HIGH MIXING
HEIGHTS EXPECTED, BUT AT LEAST SOME DEGREE IS LIKELY TO PERSIST.
AGAIN, SMOKE WITH A "PATCHY" QUALIFIER WAS INTRODUCED TO TREND.
SMOKE MAY LINGER INTO THE WEEKEND DEPENDING ON HOW MUCH RAIN
FALLS AND HOW THE PRIMARY STEERING TRAJECTORIES CHANGE WITH
TIME.
KEY MESSAGE 2: ABOVE NORMAL TEMPERATURES WITH LOW AFTERNOON
HUMIDITY EXPECTED THROUGH FRIDAY.
QUIET WEATHER CONDITIONS WILL PREVAIL ACROSS THE REGION THROUGH
LATE WEEK WHILE SFC HIGH PRESSURE REMAINS CENTERED ACROSS THE
WESTERN ATLANTIC UNDER MODEST RIDGING BUILDING FROM THE WEST-
SOUTHWEST ALOFT. HIGH TEMPS WILL PEAK ABOVE NORMAL THIS
AFTERNOON, GENERALLY IN THE LOW-MID 80S AWAY FROM THE COAST
(WARMEST ACROSS INLAND GEORGIA). AFTERNOON TEMPS WILL BE A FEW
DEGREES WARMER FOR THURSDAY AND FRIDAY AS SUBTLE RIDGING
PERSISTS ALOFT, WITH HIGHS IN THE MID- UPPER 80S AWAY FROM THE
COAST WHERE A SEA BREEZE TURNS SFC FLOW ONSHORE DURING PEAK
HEATING. DRY CONDITIONS WILL PREVAIL DURING THIS PERIOD AND
MOISTURE RETURN REMAINS MODEST, SUGGESTING RH VALUES DROPPING
INTO THE LOW-MID 20S WEST OF I-95 EACH AFTERNOON AS STRONG SFC
HEATING PROMOTES DEEP MIXING INTO DRIER AIR. ALTHOUGH RH VALUES
ARE CONSIDERED CRITICAL, SFC WINDS ARE ONLY EXPECTED TO GUST UP
TO AROUND 15 MPH, STRONGEST IN HIGHER RH LOCATIONS (NEAR THE
COAST) WHERE A MARINE LAYER/INFLUENCE OCCURS WITH AN AFTERNOON
SEA BREEZE EACH DAY. GIVEN VERY DRY FUELS AND LOW RH, FIRE
DANGER WILL REMAIN THE PRIMARY CONCERN EACH AFTERNOON. IN FACT,
RECENT/ONGOING FIRES ACROSS SOUTHERN GEORGIA COULD RESULT IN AIR
QUALITY ISSUES ACROSS THE LOCAL AREA DURING THE NEXT FEW DAYS.
KEY MESSAGE 3: A COLD FRONT COULD PROVIDE SOME MUCH NEEDED
RAINFALL ACROSS SOUTHEAST GEORGIA AND SOUTH CAROLINA THIS
WEEKEND.
LATEST GUIDANCE CONTINUES TO SUPPORT H5 VORT ENERGY RIPPLING
ACROSS THE SOUTHEAST UNITED STATES ON SATURDAY, HELPING FORCE A
SFC COLD FRONT ACROSS THE REGION LATE DAY AND OVERNIGHT. AHEAD
OF THE FRONT, WEAK INSTABILITY AND INCREASING
MOISTURE/CONVERGENCE ASSOCIATED WITH A SEA BREEZE COULD SUPPORT
FEW TO SCATTERED SHOWERS/THUNDERSTORMS SATURDAY AFTERNOON.
HOWEVER, PRECIP COVERAGE IS LIKELY TO INCREASE SATURDAY EVENING
WITH THE PASSAGE OF THE COLD FRONT. THE BULK OF PRECIP SHOULD
OCCUR WITH FROPA AND ALTHOUGH PRECIP DOESN'T LOOK PARTICULARLY
HEAVY, SOME LOCATIONS COULD EXPERIENCE UPWARDS TO 0.25- 0.50
INCHES OF RAINFALL ACCUMULATION. SOME GUIDANCE CONTINUES TO
SUGGEST THAT RAINFALL COULD LINGER INTO SUNDAY AS WEAK LOW
PRESSURE ATTEMPTS TO DEVELOP ALONG THE FRONT OFFSHORE.
AVIATION /21Z WEDNESDAY THROUGH MONDAY/
23/00Z TAF DISCUSSION:
KCHS/KJZI/KSAV: VFR THROUGH 24/00Z FOR ALL TERMINALS. LARGE
WILDFIRES BURNING OVER SOUTHERN GEORGIA CONTINUE TO PRODUCE
SMOKE. SOME OF THIS MAY REACH KSAV AROUND BREAK AND COULD SPREAD
INTO KCHS JUST BEFORE THE SEA BREEZE PUSHES THROUGH THURSDAY
AFTERNOON. VSBYS WERE LIMITED TO 6SM IN FU FOR NOW, BUT THERE IS
A CHANCE LOWER VSBYS COULD OCCUR. CONFIDENCE IN THE SMOKE/VSBY
FORECAST IS LOW.
EXTENDED AVIATION OUTLOOK: VFR CONDITIONS WILL PREVAIL
THROUGH FRIDAY WITH A SEA BREEZE LIKELY TO OCCUR DURING
AFTERNOON HOURS. SCATTERED SHOWERS AND/OR THUNDERSTORMS COULD
IMPACT THE TERMINALS LATE SATURDAY AND SUNDAY.
MARINE
CONDITIONS ARE EXPECTED TO REMAIN BELOW SMALL CRAFT ADVISORY
THRESHOLDS THIS WEEK WITH HIGH PRESSURE REMAINING CENTERED
ACROSS THE WESTERN ATLANTIC. THE SETUP CONTINUES TO FAVOR A
SOUTHERLY FLOW ACROSS LOCAL WATERS INTO SATURDAY WITH WIND
SPEEDS GENERALLY IN THE 10-15 KT RANGE AT TIMES, ALTHOUGH SLIGHT
ENHANCEMENT IS LIKELY ALONG THE LAND/SEA INTERFACE WHERE A
DAILY SEABREEZE DEVELOPS, THEN SHIFTS INLAND. A COLD FRONT
SHOULD THEN SHIFT ACROSS THE REGION THIS WEEKEND, TIGHTENING THE
PRESSURE GRADIENT ACROSS LOCAL WATERS AND FAVORING 15-20 KT
WINDS ON SATURDAY THAT TURN MORE OFFSHORE WITH FROPA SATURDAY
NIGHT INTO SUNDAY. SEAS SHOULD GENERALLY RANGE BETWEEN 2-3 FT
THROUGH LATE WEEK, THEN SLIGHTLY BUILD TO 3-4 FT NEAR FROPA LATE
WEEKEND. HOWEVER, BOTH WINDS/SEAS ARE ANTICIPATED TO REMAIN BELOW
SMALL CRAFT ADVISORY LEVELS THIS WEEKEND INTO EARLY NEXT WEEK.
CHS WATCHES/WARNINGS/ADVISORIES
GA...NONE.
SC...AIR QUALITY ALERT UNTIL MIDNIGHT EDT THURSDAY NIGHT FOR SCZ040-
042>045-147>152.
MARINE...NONE.
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