494
FXUS62 KCHS 182343
AFDCHS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
743 PM EDT SAT JUL 18 2026
WHAT HAS CHANGED
ALL SECTIONS HAVE BEEN UPDATED.
KEY MESSAGES
- 1) HOT AND HUMID CONDITIONS ARE EXPECTED ACROSS THE AREA THIS
WEEKEND AND THROUGH EARLY NEXT WEEK.
DISCUSSION
KEY MESSAGE 1: HOT AND HUMID CONDITIONS ARE EXPECTED ACROSS THE
AREA THIS WEEKEND AND THROUGH EARLY NEXT WEEK.
SUNDAY AND MONDAY WILL SEE LITTLE CHANGE IN THE SYNOPTIC SET UP,
WITH LOW PRESSURE IN THE NORTHERN GULF AND HIGH PRESSURE POSITIONED
OVER THE WESTERN ATLANTIC. THIS CONTINUED SET UP WILL ALLOW
TEMPERATURES TO REACH INTO THE LOW TO MID 90S EACH DAY, WITH HEAT
INDEX VALUES AROUND 100-105. THE CURRENT FORECAST KEEPS HEAT INDEX
VALUES JUST SHY OF HEAT ADVISORY CRITERIA (>108), HOWEVER HEAT
ADVISORIES CANNOT BE RULED OUT, ESPECIALLY ALONG THE COASTAL
CORRIDOR WHERE THE DEW POINTS WILL BE HIGHEST. THE PATTERN WILL
BEGIN TO SHIFT ON TUESDAY AS AN UPPER LEVEL TROUGH SWINGS EASTWARD.
THIS WILL YIELD GREATER COVERAGE OF AFTERNOON SHOWERS/THUNDERSTORMS
AND LIMIT THE HEAT POTENTIAL EACH AFTERNOON.
AVIATION /00Z SUNDAY THROUGH THURSDAY/
00Z TAFS: VFR. WINDS WILL INCREASE AND BECOME GUSTY SUNDAY
AFTERNOON DUE TO THE FORMATION OF THE SEA BREEZE.
EXTENDED AVIATION OUTLOOK: PREDOMINATELY VFR CONDITIONS THROUGH
THE PERIOD, HOWEVER THERE IS A LOW CHANCE OF BRIEF FLIGHT
RESTRICTIONS EACH AFTERNOON FROM SHOWERS AND THUNDERSTORMS
DEVELOPING ALONG THE SEABREEZE.
MARINE
TONIGHT: AS THE LOCAL WATERS SITUATE BETWEEN AN INLAND TROUGH
AND A SUBTROPICAL HIGH TO THE EAST, THIS WILL CAUSE THE
PRESSURE GRADIENT TO BE ELEVATED. EXPECT WIND SPEEDS TO RANGE
FROM 15 TO 20 KTS WITH GUSTS UP TO 25 KTS (ESPECIALLY ACROSS THE
SC NEARSHORE WATERS). THUS, SMALL CRAFT ADVISORIES ARE IN EFFECT.
WE SHOULD HAVE A SLIGHT DOWNTREND IN WIND SPEEDS LATE TONIGHT,
WITH WINDS RAMPING DOWN JUST PRIOR TO SUNRISE SUNDAY. EXPECT
SEAS TO BE IN THE 3 TO 5 FT RANGE.
SUNDAY THROUGH WEDNESDAY: THE MARINE WATERS WILL REMAIN POSITIONED
BETWEEN HIGH PRESSURE TO THE EAST AND LOW PRESSURE IN THE NORTHERN
GULF INTO EARLY NEXT WEEK. THIS WILL YIELD A PINCHED PRESSURE
GRADIENT AND SW WINDS GUSTING AROUND 20 KNOTS. SUNDAY WILL SEE GUSTS
AS HIGH AS 25 KNOTS ACROSS THE CHARLESTON NEARSHORE WATERS. A SMALL
CRAFT ADVISORY IS IN EFFECT FOR THIS MARINE ZONE THROUGH SUNDAY
EVENING. MID WEEK A TROUGH INLAND WILL SHIFT OFFSHORE AND AGAIN
ENHANCE THE WIND GUSTS. SMALL CRAFT ADVISORIES COULD BE NEEDED MID-
WEEK, ESPECIALLY IN THE CHARLESTON NEARSHORE WATERS AND THE
CHARLESTON HARBOR. THE NATIONAL HURRICANE CENTER IS MONITORING A
SYSTEM IN THE NORTHERN GULF FOR POSSIBLE TROPICAL DEVELOPMENT, WITH
A 40% CHANCE OF DEVELOPMENT IN THE NEXT 7 DAYS. IF THIS SYSTEM WERE
TO DEVELOP AND TRACK UP THE SE COASTLINE THERE WOULD BE ADDITIONAL
WIND AND WAVE CONCERNS ACROSS THE MARINE WATERS.
RIP CURRENTS: THE PINCHED GRADIENT ACROSS THE MARINE ZONES WILL
YIELD SW WIND GUSTS AROUND 20 KNOTS. DUE TO THE ENHANCED WINDS ALONG
THE COASTLINE THERE IS A MODERATE RISK OF RIP CURRENTS AT ALL AREA
BEACHES TOMORROW (SUNDAY).
CLIMATE
RECORD HIGH MINIMUM TEMPERATURES:
JULY 18:
KCHS: 79/2007
KCXM: 81/2007
JULY 19:
KCHS: 79/1986
KCXM: 83/1986
JULY 20:
KCHS: 79/2025
KCXM: 83/2000
KSAV: 79/1942
JULY 21:
KCHS: 80/1986
KCXM: 83/1998
JULY 22:
KCHS: 81/2011
KCXM: 83/2011
CHS WATCHES/WARNINGS/ADVISORIES
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 8 PM EDT SUNDAY FOR AMZ360.
SMALL CRAFT ADVISORY UNTIL 6 AM EDT SUNDAY FOR AMZ362.
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