087
FXUS62 KCHS 270625
AFDCHS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
225 AM EDT MON JUL 27 2026
WHAT HAS CHANGED
ALL SECTIONS HAVE BEEN UPDATED.
KEY MESSAGES
- 1) DANGEROUS HEAT AND HUMIDITY WILL IMPACT SOUTHEAST GEORGIA
AND SOUTHEAST SOUTH CAROLINA THROUGH THE MIDDLE OF THE WEEK.
DISCUSSION
KEY MESSAGE 1: DANGEROUS HEAT AND HUMIDITY WILL IMPACT
SOUTHEAST GEORGIA AND SOUTHEAST SOUTH CAROLINA THROUGH THE
MIDDLE OF THE WEEK.
TODAY: ALOFT, THE FORECAST AREA WILL SIT WITHIN THE CORRIDOR OF
NORTHWEST FLOW WELL TO THE EAST OF THE LARGE RIDGE CENTERED
NEAR THE FOUR CORNERS REGION. AT THE SURFACE, THE SETUP IS
RATHER SUBTLE WITH A WEAKLY DEFINED BOUNDARY SITUATED ACROSS
SOUTH GA. THE SURFACE GRADIENT WILL BE QUITE DIFFUSE WHICH WILL
ALLOW THE SEA BREEZE TO DEVELOP AND GRADUALLY PUSH INLAND.
DEWPOINTS ALONG AND BEHIND THE FRONT WILL RISE INTO THE UPPER
70S WITH HIGH TEMPERATURES REACHING WELL INTO THE 90S. THIS
SETUP WILL YIELD AN AREA OF HEAT INDICES INTO THE 105-110 DEGREE
RANGE, WITH THE BEST CHANCE OF 108 AND HIGHER ALONG THE GA
COAST UP THROUGH BEAUFORT COUNTY. THEREFORE, A HEAT ADVISORY HAS
BEEN ISSUED FOR THIS AREA. WE COULD SEE A FEW ISOLATED
OBSERVATIONS GET INTO THE 108-110 DEGREE RANGE ACROSS COASTAL
COLLETON AND CHARLESTON COUNTIES AS WELL. WITH THE BOUNDARY
SAGGING TO THE SOUTH AND PRECIPITABLE WATER VALUES DROPPING TO
LESS THAN 2 INCHES, MODEL CONSENSUS IS FOR CONSIDERABLY LOWER
CONVECTION CHANCES TODAY. THEREFORE, THE POTENTIAL FOR
THUNDERSTORM DEVELOPMENT TO DISRUPT HEATING AND MAX HEAT INDEX
VALUES IS REDUCED.
TUESDAY AND WEDNESDAY: A STRONG MID-LEVEL RIDGE WILL PREVAIL
OVER THE ROCKIES AND PLAINS INTO THE MIDDLE OF THE WEEK, WITH
THE EASTERN PERIPHERY BUILDING INTO THE SOUTHEASTERN STATES. AT
THE SURFACE, WEAK HIGH PRESSURE WILL DEVELOP OVER THE SOUTHEAST.
BETWEEN THE RIDGING ALOFT AND THE WEAK HIGH PRESSURE AT THE
SURFACE, TEMPERATURES ON BOTH TUESDAY AND WEDNESDAY WILL SOAR
INTO THE MID TO UPPER 90S. DEW POINTS ARE FORECAST TO REACH INTO
THE MID TO UPPER 70S, HIGHEST ALONG THE COASTAL CORRIDOR BEHIND
THE SEA BREEZE. THIS SET UP WILL YIELD HEAT INDEX VALUES ON
TUESDAY IN THE 108-113 RANGE AND WEDNESDAY IN THE 105-110 RANGE.
AN EXCESSIVE HEAT WATCH MAY BE REQUIRED FOR COASTAL LOCATIONS
ON TUESDAY AND A HEAT ADVISORY MAY BE REQUIRED ON WEDNESDAY FOR
THE SAME LOCATIONS. DECREASING MOISTURE ON TUESDAY WILL LEAD TO
LOWER PRECIPITATION CHANCES, ALLOWING TEMPERATURES TO REACH
HIGHER VALUES FOR A LONGER DURATION. AFTERNOON SHOWERS AND
THUNDERSTORMS ARE POSSIBLE ON WEDNESDAY, POSSIBLY LIMITING THE
VALUES/DURATION OF THE HEAT. HEAT AND HUMIDITY WILL DROP TO NEAR
NORMAL VALUES TOWARDS THE END OF THE WEEK AS A FRONT APPROACHES
THE REGION.
AVIATION /06Z MONDAY THROUGH FRIDAY/
THE 06Z TAF PERIOD BEGINS WITH VFR CONDITIONS AT KCHS, KJZI,
AND KSAV. THE FIRST FORECAST ISSUE COMES WITH THE POTENTIAL FOR
AN AREA OF IFR STRATUS TO DEVELOP AROUND SUNRISE, PRIMARILY
IMPACTING KCHS AND KJZI. WE HAVE INTRODUCED TEMPO GROUPS TO
ACCOUNT FOR THIS IN THE 10-13Z TIME PERIOD. THEREAFTER,
ATTENTION TURNS TO THUNDERSTORM POTENTIAL IN THE AFTERNOON.
OVERALL THUNDERSTORM COVERAGE IS EXPECTED TO BE LESS THAN
PREVIOUS DAYS. WE HAVE MAINTAINED THE PROB30 AT KCHS STARTING AT
20Z. THERE IS POTENTIAL FOR THUNDERSTORM IMPACTS AT KJZI AND
KSAV AS WELL, THOUGH CONFIDENCE IS LOWER.
EXTENDED AVIATION OUTLOOK: BRIEF FLIGHT RESTRICTIONS ARE
POSSIBLE WEDNESDAY AND THURSDAY DUE TO SHOWERS AND
THUNDERSTORMS.
MARINE
THROUGH TONIGHT: OVERALL, THE GRADIENT ACROSS THE LOCAL WATERS
WILL BE QUITE WEAK THROUGH THE PERIOD. WINDS WILL BE STRONGEST
IN THE AFTERNOON AND EVENING WITH THE DEVELOPMENT OF THE SEA
BREEZE ALONG THE LAND/SEA INTERFACE. WIND SPEEDS SHOULD MOSTLY
TOP OUT IN THE 10-15 KNOT RANGE DURING THIS TIME PERIOD. SEAS
ARE EXPECTED TO AVERAGE AROUND 2 FEET, BUT COULD BE UP TO 3 FEET
IN THE OUTER WATERS.
TUESDAY THROUGH SATURDAY: AS A WEAK FRONT APPROACHES THE MARINE
WATERS LATE ON TUESDAY, WINDS AND SEAS ARE FORECAST TO SURGE.
WIND GUSTS COULD APPROACH 25 KNOTS ACROSS PORTIONS OF THE MARINE
WATERS, WITH THE GREATEST CHANCES IN THE OFFSHORE CHARLESTON
AND 20 TO 60 NM OFFSHORE GA WATERS. SMALL CRAFT ADVISORIES MAY
BE REQUIRED LATE TUESDAY INTO WEDNESDAY. THEREAFTER, MARINE
CONDITIONS WILL REMAIN BELOW SMALL CRAFT ADVISORY CRITERIA INTO
THE WEEKEND.
CLIMATE
RECORD HIGH TEMPERATURES:
JULY 28:
KCHS: 101/1949
KCXM: 100/1936
KSAV: 102/1949
JULY 29:
KCHS: 100/1993
KCXM: 99/1999
KSAV: 103/1993
RECORD HIGH MINIMUM TEMPERATURES:
JULY 29:
KCHS: 80/2016
KCXM: 85/1999
KSAV: 82/1878
CHS WATCHES/WARNINGS/ADVISORIES
GA...HEAT ADVISORY FROM 11 AM THIS MORNING TO 7 PM EDT THIS EVENING
FOR GAZ137-216>219-238>241.
SC...HEAT ADVISORY FROM 11 AM THIS MORNING TO 7 PM EDT THIS EVENING
FOR SCZ148-151.
MARINE...NONE.
BSH/CPM
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