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006
FXUS62 KCHS 271533
AFDCHS

Area Forecast Discussion
National Weather Service Charleston SC
1133 AM EDT Fri Sep 27 2024

.SYNOPSIS...
Helene will pass to our west and then northwest today into
tonight. Multiple impacts are expected across our area this
morning. Drier weather then arrives later this afternoon and
should persist into next week.

&&

.NEAR TERM /THROUGH TONIGHT/...
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This Afternoon through Tonight: A broad cutoff low will be
centered across Tennessee, with the circulation of Helene
migrating north and northwest into the Tennessee Valley and
becoming absorbed by the low into tonight. Strong subsidence and
dry air wrapping along the south and southeast side of Helene
will likely lead to dry weather conditions across all local
areas by the afternoon, but some guidance does suggest a few
showers and/or isolated thunderstorm briefly brushing inland SC
zones into early afternoon, before the precip is anticipated to
end. Tropical storm force wind gusts will linger into early
afternoon hours over the South Carolina zones, thus our
reasoning for maintaining the Tropical Storm Warning. For the
Georgia zones there will still be some wind gusts of 30 or
perhaps 35 mph, but the potential for Tropical Storm Force winds
(39+ mph) has ended.

Breaks in clouds are expected and skies should become mostly
sunny by mid- late afternoon allowing for ample sfc heating. In
general, sfc temps should peak in the mid- upper 80s. Overnight,
conditions improve considerably and remain dry with light
southwesterly winds expected and lows ranging in the mid- upper
60s inland to low-mid 70s closer to the coast.
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&&

.SHORT TERM /SATURDAY THROUGH MONDAY/...
The mid-levels will consist of a rex block over much of the U.S.
A ~565 dam cut-off Low will be over western TN Saturday morning
while a ~594 High will be located off the Southeast U.S. The Low
will gradually weaken, becoming ~575 dam by late Monday, while the
~592 dam High will shift closer to the northern Bahamas. At the
surface, the remnants of Helene will be located to our northwest,
roughly over western TN Saturday morning. A stationary front will be
located just off our coast at the same time. The remnants of Helene
will weaken as time progresses, becoming a broad disturbance located
well to our north by late Monday. Meanwhile, the stationary front
will remain just off our coast. There will be a pocket of drier air
between these two synoptic features. However, it doesn`t mean our
forecast will be completely dry. Saturday, the synoptic models and
long-range CAMs have light showers over the coastal waters moving
onshore during the afternoon. Therefore, we have slight chance POPs
mainly over our coastal counties. These should persist into the
evening, then shift offshore overnight. Sunday, the models keep most
of our area dry, except for maybe a few showers moving onshore along
the GA coast in the afternoon. Additionally, showers could move
onshore along the entire coast late at night. Monday, most of our
area is dry, except for maybe a few showers moving onshore along the
far southern GA coast in the afternoon. High temperatures will be in
the mid to upper 80s each day. Low temperatures will range from the
mid 60s far inland to the lower 70s along the immediate coast.

&&

.LONG TERM /MONDAY NIGHT THROUGH THURSDAY/...
A stationary front will be located just off our coast Monday night.
It`ll shift away late Tuesday as a dry cold front approaches from
our northwest. The dry cold front should move through our area
Wednesday night. Following that, High pressure will build in from
the northwest and north on Thursday. Conditions should remain dry.
High temperatures will be a few degrees above normal Tuesday and
Wednesday, dropping to near normal on Thursday.

&&

.AVIATION /16Z FRIDAY THROUGH TUESDAY/...
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Dry air is then expected to enter the region from the
southwest, resulting in VFR conditions by 18Z today that persist
through 12Z Saturday. At SAV, tempo MVFR cigs are possible
during the next hour or two, but conditions are expected to
become prevailing VFR by 15Z today, then persist through 12Z
Saturday. Gusty tropical force storm winds will also remain a
concern through at late morning hours, with south-southwest wind
gusts up to 40 kt at times at the terminals. By mid afternoon,
will be on the diminishing trend, with south or south-southwest
winds gusting as high as 25 kt into late afternoon.

Extended Aviation Outlook: Mainly VFR. Though, radiational fog
could bring brief flight restrictions late each night and early
each morning.
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&&

.MARINE...
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This Afternoon and Tonight: Conditions will slowly improve as
Helene shifts further away from the area. Gusts up to Tropical
Storm strength will persist on all waters through early
afternoon. Conditions should remain around 25 kt or less
heading into the evening. Thereafter, wind speeds will slowly
diminish to about 15-20 kt after midnight. Seas will also be
subsiding through the day and night, lowering to 5-7 ft across
local waters during the overnight period. Once we end the
Tropical Storm warning, it will likely need to be replaced by a
Small Craft Advisory.

Extended Marine: A stationary front will persist off our coast.
This will yield winds mainly from the SW through early next week.
Seas will start out in the 2-4 ft range on Saturday, subsiding to 2-
3 ft on Sunday, then 1-2 ft on Monday.

Rip Currents and High Surf: Conditions at the beach will be
dangerous through today, as winds and seas remain high/large while
Helene tracks across the interior Southeast. A High Risk of Rip
Currents will be in effect for all beaches today, and breakers of at
least 5 feet in height will persist in the afternoon and/or
evening. Areas of beach erosion are also likely during this time.
For Saturday, remnant swell and changes in the beach bathymetry
from Helene will yield a Moderate Risk at all of our beaches.
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&&

.CHS WATCHES/WARNINGS/ADVISORIES...
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GA...High Risk for Rip Currents until 8 PM EDT this evening for GAZ117-
     119-139-141.
     High Surf Advisory until 8 PM EDT this evening for GAZ117-119-
     139-141.
SC...Tropical Storm Warning for SCZ040-042>045-047>052.
     High Risk for Rip Currents until 8 PM EDT this evening for
     SCZ048>051.
     High Surf Advisory until 8 PM EDT this evening for SCZ048>051.
MARINE...Tropical Storm Warning for AMZ330-350-352-354-374.
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&&

$$

NEAR TERM...
SHORT TERM...
LONG TERM...
AVIATION...
MARINE...