Area Forecast Discussion
Issued by NWS Charleston, SC

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FXUS62 KCHS 031725

Area Forecast Discussion
National Weather Service Charleston SC
125 PM EDT Mon Oct 3 2022

High pressure will prevail this week with a cold front pushing
offshore Friday night.


No major changes for the early afternoon update, other than to
trim the hourly and max temps down a tad in some places as
thick cloud cover will persist within an unusual early season
wedge. Havn`t seen any observations with drizzle so far, and
with actually a couple of breaks trying to occur, the risk for
any drizzle is diminishing.

Previous discussion...
Today: An upper level low will spin over Maryland and northern
Virginia, while a surface low just off the Great Dismal Swamp
and Virginia Tidewater will move little through the day. The
local pressure gradient will tighten between the surface low and
strong high pressure extending south and southeast out of the
Great Lakes will reinforce a cool, northerly flow across the
local counties.

A fairly prominent inversion around 1500-2000 feet and
considerable moisture underneath will produce extensive
stratocumulus and stratus through the day. Based on recent
satellite imagery, the simulated satellite product which want to
show the cloud cover attempting to erode some this afternoon, we
have trended toward an even cloudier forecast through the day.
There could even be a bit of spotty, intermittent drizzle at

The thick cloud cover and northerly flow will limit temps from
climbing much more than the lower 60s far north, 65-70F most
elsewhere. If some far interior Georgia sites get any glimpses
of sunshine they could reach the lower 70s. It is certainly
possible that we will be trimming temps down even more in the
next update. We could actually flirt with record high mins for
the date at KCHS and KSAV. Although the latest forecast shows
highs a bit warmer than the record low maximums for those two
sites (see CLIMATE section below).

Tonight: Clouds will thin this evening with mostly clear to
clear skies dominating overnight. It will down right chilly for
early October, especially for the interior, with lows ranging
from the upper 40s/near 50 inland to the upper 50s/lower 60s at
the beaches.


High pressure will build into the region throughout the week. A dry
forecast is in place due to a plethora of dry air and limited
moisture. On Tuesday, an enhanced pressure gradient will gradually
weaken. But before it does, gusty winds are expected to persist for
much of the day. Overall though, the biggest story of the period
will focus on the temperatures. A cool Tuesday with highs in the
upper 60s will start the period then gradually warm each day. By
Thursday, high temperatures will be in the mid 70s to mid 80s. Lows
will be in the mid 40s to low 50s inland and mid 50s to low 60s
across coastal locations.


High pressure will continue to prevail through the period. On
Friday, one last day of high temperatures in the 80s is expected
before a cold front swiftly moves through the area. Overnight, lows
will be in the mid 50s to mid 60s. Then come Saturday, high
temperatures in the 70s will return. Lows will be in the upper 40s
to low 50s inland with mid 50s to low 60s along the coast.
Otherwise, with limited moisture, no rain is in the forecast for
land areas.


The terminals remain stuck within a wedge, leading to MVFR
ceilings persisting into early tonight. Soundings, time cross-
sections and simulated satellite all suggests that VFR will
return by around 03Z at all sites. We shall see. meanwhile,
occasional gusts around 15 kt will occur at KCHS and KJZI this
afternoon where the gradient is a little tighter than at KSAV.

Extended Aviation Outlook: VFR.


There still hasn`t been or expected to be enough gusts of 25 kt
or greater over the AMZ352 and AMZ354 waters. So we still aren`t
raising a Small Craft Advisory at this time.

Previous discussion...
Through Tonight: Gusty north winds of 15-20 kt will continue
through tonight as an enhanced pressure gradient between low
pressure off the North Carolina Outer Banks and inland high
pressure remains. The frequency of gusts 25 kt or greater is
expected to increase later this afternoon and especially
tonight over mainly the Charleston County nearshore waters and
the Georgia offshore waters. A Small Craft Advisory been issued
for these areas to account for this. The advisory may need to be
expanded to include the Georgia and far southern South Carolina
nearshore legs for tonight, but confidence is not high enough
in these conditions occurring just yet to justify hoisting flags
at this time. Seas will build to 3-5 nearshore with 5-6 over
the Georgia offshore waters.

Tuesday through Saturday: Low pressure centered to the north will
shift eastward as high pressure builds into the region. On Tuesday,
an enhanced pressure gradient will remain. Northerly winds at 15-20
knots are expected with lingering 6 feet seas across the outer
Georgia waters. Hence, a Small Craft Advisory will be in the effect
through Tuesday night for the outer Georgia waters. Thereafter, the
pressure gradient will relax and winds will be variable at 5 to 10
knots with seas less than 4 feet.

Rip Currents: A moderate risk of rip currents is in effect for
Tuesday due to gusty winds and long period swells. An enhanced
risk could persist into mid week.


Recent tidal trends indicate that tides will come close to
producing shallow coastal flooding with the mid afternoon high
tide over Charleston and coastal Colleton County. We will
closely monitor trends to determine whether or not we issue a
Coastal Flood Advisory.

Due to astronomical influences and gusty north/northeast winds
at times, minor coastal flooding will be possible with the
afternoon high tides this week, especially in tidal areas of
Charleston and Colleton Counties.


Record low maximum temperatures for 3 October:
KCHS: 61/1974
KCXM: 60/1974
KSAV: 65/1908


MARINE...Small Craft Advisory from 5 PM this afternoon to 8 AM EDT
     Tuesday for AMZ350.
     Small Craft Advisory until 4 AM EDT Wednesday for AMZ374.



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