913
FXUS62 KCHS 210603
AFDCHS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
203 AM EDT SUN JUN 21 2026
WHAT HAS CHANGED
ALL KEY MESSAGES AND SECTIONS HAVE BEEN UPDATED.
KEY MESSAGES
- 1) A FAIRLY TYPICAL SUMMERTIME PATTERN IS FORECAST WITH DAILY
SHOWER AND THUNDERSTORM CHANCES THROUGH THE WEEK.
DISCUSSION
KEY MESSAGE 1: A FAIRLY TYPICAL SUMMERTIME PATTERN IS FORECAST
WITH DAILY SHOWER AND THUNDERSTORM CHANCES THROUGH THE WEEK.
THROUGH TONIGHT, A CLASSIC SUMMERTIME AIRMASS WILL PREVAIL WITH
THE REGION POSITIONED ALONG THE WEST SIDE OF ATLANTIC HIGH
PRESSURE CENTERED TO THE SOUTHEAST OF BERMUDA. WARM AND HUMID
CONDITIONS WITHIN A WEAKLY FORCED ENVIRONMENT WILL SUPPORT
ISOLATED TO PERHAPS SCATTERED SHOWERS/TSTMS THIS AFTERNOON WHICH
COULD LINGER INTO THE EVENING HOURS, ESPECIALLY ACROSS SOUTHEAST
GEORGIA WHERE SOME OF THE HIGH RESOLUTION CAMS SUGGEST A MORE
CONCENTRATED BAND OF WEAKENING CONVECTION COULD SPREAD NORTH OF
THE ALTAMAHA RIVER ALONG AN OUTFLOW BOUNDARY CLOSER TO SUNSET.
GUIDANCE SUGGESTS A SUBTLE MID-LEVEL SHORTWAVE WILL PASS WEST-
EAST OVER THE LOWCOUNTRY AND SOUTHEAST GEORGIA DURING PEAK
HEATING. NO MEANINGFUL FORCING IS NOTED WITH VARIOUS MODEL
CROSS SECTIONS HIGHLIGHTING VERY LITTLE, IF ANY, UPWARD VERTICAL
VELOCITIES (UVVS) WITH THIS FEATURE. CONVECTION WILL LIKELY
REMAIN PULSY IN NATURE WITH UPDRAFTS BEING HEAVILY INFLUENCED
BY MESOSCALE PROCESSES SUCH AS BOUNDARY COLLISIONS. AN ISOLATED
STRONG TO LOCALLY SEVERE TSTM WILL BE POSSIBLE JUST ABOUT
ANYWHERE WHERE UPDRAFTS CAN BECOME LOCALLY ENHANCED.
STRONG/DAMAGING WINDS, FREQUENT CLOUD-TO-GROUND LIGHTNING AND
LOCALLY HEAVY RAINFALL WILL BE THE PRIMARY HAZARDS. POPS 30-50%
WERE HIGHLIGHTED FOR TODAY WITH THE HIGHEST POPS CONFINED TO
AREAS NEAR THE ALTAMAHA RIVER. CONVECTION WILL GRADUALLY WIND
DOWN THIS EVENING WITH DRY CONDITIONS EXPECTED TO PREVAIL
THROUGH THE OVERNIGHT HOURS. HIGHS TODAY WILL WARM INTO THE
UPPER 80S/LOWER 90S AWAY FROM THE BEACHES WITH A FEW MID 90S
POSSIBLE ACROSS INTERIOR SOUTHEAST SOUTH CAROLINA WHERE
INFLUENCES FROM MORNING STRATUS OVER SOUTHEAST GEORGIA AND
POSSIBLY FAR SOUTHERN SOUTH CAROLINA WILL BE LESS. LOWS TONIGHT
WILL RANGE FROM THE LOWER 70S INLAND TO THE UPPER 70S AT THE
BEACHES AND DOWNTOWN CHARLESTON.
MONDAY EVENING, THE FORECAST AREA WILL BECOME POSITIONED
BETWEEN SURFACE HIGH PRESSURE IN THE ATLANTIC AND AN APPROACHING
COLD FRONT FROM THE NORTHWEST. GUIDANCE SUGGESTS THE FRONT WILL
MOVE INTO NORTHERN GEORGIA AND THE SOUTH CAROLINA MIDLANDS
TUESDAY EVENING AND THEN STALL, REMAINING THROUGH THE END OF THE
WEEK. THE MID-LEVELS WILL CONSIST OF A SERIES OF WEAK
DISTURBANCES MOVING OVER THE SOUTHEAST DURING THE WEEK. ISOLATED
SHOWERS AND THUNDERSTORMS ARE POSSIBLE MONDAY, WITH COVERAGE
INCREASING TUESDAY ONWARD, OWING TO THE FRONT IN THE VICINITY.
SHOWERS AND THUNDERSTORMS ARE EXPECTED TO PEAK IN THE AFTERNOON
AND EVENINGS WHEN INSTABILITY IS HIGHEST. THE THREAT FOR
ORGANIZED SEVERE WEATHER IS LOW, BUT CANNOT RULE OUT A COUPLE OF
STRONG TO SEVERE STORMS.
AVIATION /06Z SUNDAY THROUGH THURSDAY/
21/06Z TAF DISCUSSION:
KCHS/KJZI: VFR. ISOLATED TO SCATTERED SHOWERS/TSTMS COULD
DEVELOP JUST TO THE WEST OF KCHS BY AFTERNOON-MID AFTERNOON.
CAMS ARE MIXED ON EXACTLY WHERE CONVECTION WILL CONCENTRATE
WHICH IS NOT UNUSUAL IN THIS TYPE OF WEAKLY FORCED ENVIRONMENT.
PROB30 FOR TSRA WAS INTRODUCED FROM 17-20Z TO ACCOUNT FOR
POSSIBLE CONVECTION TO ACCOUNT FOR THIS. CONVECTION SHOULD
REMAIN INLAND OF KJZI, THUS NO MENTION WAS INCLUDED.
KSAV: SATELLITE AND SURFACE OBSERVATIONS SHOW LOW STRATUS
BEGINNING TO EXPAND ACROSS PARTS OF SOUTHEAST GEORGIA EARLY THIS
MORNING. KSAV WILL LIKELY REMAIN ALONG THE EASTERN/NORTHEASTERN
FLANKS OF THESE AREA OF STRATUS AND GUIDANCE REMAINS MIXED ON
WHETHER IT WILL IMPACT THE TERMINAL. A TEMPO GROUP FOR MVFR CIGS
WAS INTRODUCED 10-13Z TO TEND, BUT AMENDMENTS MAY BE NEEDED AS
TRENDS BECOME MORE APPARENT. STATUS WILL MIX OUT BY MID-MORNING
WITH VFR PREVAILING THEREAFTER. ISOLATED TO SCATTERED
SHOWERS/TSTMS ARE EXPECTED TO DEVELOP NEAR THE TERMINAL LATER
THIS AFTERNOON. PROB30 FOR TSTMS FROM 22-01Z WAS INTRODUCED FOR
NOW.
EXTENDED AVIATION OUTLOOK: BRIEF FLIGHT RESTRICTIONS ARE POSSIBLE
WITH ANY SHOWERS AND THUNDERSTORMS.
MARINE
THROUGH TONIGHT: A SOUTHERLY FLOW REGIME NEAR 10 KT WITH SEAS
1-2 FT WILL PREVAIL THROUGH TONIGHT WITH THE WATERS POSITIONED
ALONG THE WESTERN FLANKS OF ATLANTIC HIGH PRESSURE.
MONDAY THROUGH FRIDAY: THE COASTAL WATERS WILL BECOME
POSITIONED BETWEEN HIGH PRESSURE CENTERED WELL OFFSHORE AND AN
APPROACHING COLD FRONT MONDAY NIGHT, LEADING TO INCREASING WINDS
AND BUILDING SEAS. GUSTS COULD APPROACH 25 KNOTS AT TIMES
MONDAY EVENING INTO TUESDAY EVENING, BUT LOOKS FAIRLY MARGINAL
FOR SMALL CRAFT ADVISORIES. CONDITIONS SHOULD STAY BELOW
ADVISORY LEVELS THROUGH FRIDAY.
CLIMATE
RECORD HIGH MINIMUM TEMPERATURES:
JUNE 23:
KCHS: 78/2024
KSAV: 77/2017
CHS WATCHES/WARNINGS/ADVISORIES
GA...NONE.
SC...NONE.
MARINE...NONE.
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