237
FXUS62 KCHS 251105
AFDCHS

Area Forecast Discussion
National Weather Service Charleston SC
705 AM EDT Fri Jul 25 2025

.SYNOPSIS...
Atlantic high pressure will prevail into early next week, while
a trough of low pressure resides inland.

&&

.NEAR TERM /THROUGH TONIGHT/...
Near term guidance indicates that the center of a 595 dm H5 ridge
will build over the Carolinas and GA by this afternoon. At the sfc,
the forecast area will remain between broad low pressure over the
Deep South and high pressure over the western Atlantic. This pattern
will support steady south-southwest across the forecast area today.
As temperatures warm into the low to mid 90s this afternoon, a weak
sea breeze should advance inland across the CWA. The sea breeze is
forecast to trigger isolated showers across SE GA and the lower SC
Lowcountry this morning into early this afternoon. Otherwise,
conditions should remain rain-free and hot. Heat index values are
forecast to generally range between 103 to 106 this afternoon, some
spots near the Savannah River could briefly reach 108.

Tonight, the forecast area will remain under deep ridging. Dry and
very warm conditions are forecast through the overnight hours. Low
temperatures are expected to range from the mid 70s inland to the
upper 70s along the coast.

&&

.SHORT TERM /SATURDAY THROUGH MONDAY/...
Main focus for the period will be the long-duration heat set to
impact the region. Heat Advisories and/or Extreme Heat
Watches/Warnings will likely be needed.

A strong mid level ridge, noted by 500 mb heights 2-3 standard
deviations above normal per NAEFS, will become situated overhead for
the weekend and early next week. At the surface, a trough of low
pressure will reside inland, while high pressure remains offshore.

Temperatures...Near record high temperatures are forecast through
early next week (see climate section below). Temperatures will be
hottest Sunday and Monday when highs could exceed 100F in several
locations away from the immediate coast. Heat indices will be even
higher, likely reaching Heat Advisory criteria (108F) and even
approaching or exceeding Extreme Heat Warning criteria (113F) in
many spots. Little relief is expected overnight with lows only in
the upper 70s to around 80.

Convection-wise...The weekend should be fairly quiet with just
isolated showers/thunderstorms possible on Sunday, mainly from
Colleton County northward. The ridge will expand and shift slightly
westward on Monday. This could bring a slightly higher chance for
showers/thunderstorms with some signals of a weak shortwave dropping
through the area on periphery of the ridge. PoPs are generally in
the 20-30% range.

&&

.LONG TERM /MONDAY NIGHT THROUGH THURSDAY/...
The forecast area will remain under the influence of an expansive
upper ridge centered over the south central U.S. through the middle
of next week. Consensus shows a larger scale trough moving into the
northeastern U.S. late. Scattered showers and thunderstorms will be
possible each day, primarily during the afternoon when instability
is maximized. Main forecast concern remains the prolonged heat. Heat
indices have the potential to reach Heat Advisory and/or Extreme
Heat Watch/Warning criteria through at least Wednesday, perhaps
extending into Thursday as well.

&&

.AVIATION /11Z FRIDAY THROUGH TUESDAY/...
12Z TAFs: VFR conditions expected through the TAF period.
Isolated showers may pass near KSAV from sunrise to around 19Z,
the TAF will mention VCSH. SSW winds expected to range between 5
to 10 kts through the period.

Extended Aviation Forecast: Prevailing VFR. Brief flight
restrictions are possible in afternoon showers/thunderstorms next
week.

&&

.MARINE...
The sfc pattern will support steady south winds around 10 kts across
the marine zones today, shifting from the southwest tonight. Wave
heights should generally range between 2 to 3 ft.

Saturday through Wednesday: No marine concerns are anticipated over
the weekend and into the middle of next week. Generally expect
southerly flow with speeds less than 15 knots. Seas will average 1-3
feet.

&&

.CLIMATE...
Record High Temperatures:

July 26:
KCHS: 99/2010

July 27:
KCHS: 100/2005
KSAV: 100/2010

July 28:
KCHS: 101/1949
KSAV: 102/1949

Record High Minimum Temperatures:

July 26:
KCHS: 78/2012

July 27:
KCHS: 80/2014
KCXM: 84/2021
KSAV: 80/1885

July 28:
KCHS: 80/2016
KCXM: 83/1999
KSAV: 81/1878

July 29:
KCHS: 80/2016

July 30:
KCHS: 81/2016
KCXM: 83/2016
KSAV: 81/1878

July 31:
KCHS: 80/2022
KSAV: 80/2010

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...None.
SC...None.
MARINE...None.

&&

$$

NEAR TERM...NED
SHORT TERM...ETM
LONG TERM...ETM
AVIATION...ETM/NED
MARINE...ETM/NED