National Weather Service National Headquarters

• Home
• Site Map
• News
• Organization
• Search for: NWS All NOAA 

-- Discussion containing changed information from previous version are highlighted. --
000
FXUS62 KCHS 241147
AFDCHS

Area Forecast Discussion
National Weather Service Charleston SC
647 AM EST Thu Jan 24 2019

.SYNOPSIS...
A strong cold front will move offshore this morning. High
pressure will then prevail through early next week. Another
cold front will move through Tuesday, followed by high
pressure.

&&

.NEAR TERM /THROUGH TONIGHT/...
Nearing-dawn: A wind advisory is in effect for much of coastal
SC ahead of a strong cold front. The 12Z KCHS sounding measured
55 kt at 1000 ft early this morning. Rains were already tapering
off from west to east prior to daybreak.

Today: The surface cold front is forecast to race offshore
after mid morning. Rains will end quickly from west to east
over the region between 12Z-16Z. Strong southwest winds in
the 25-35 mph range just ahead of the front along coastal areas
at 12Z, will veer to west by later this morning in the wake
of the front. Speeds will remain elevated but tend to come
down from the peak gusts that occur around daybreak. Cold
air advection will battle an increasing downslope component
resulting in steady afternoon temps in the upper 50s over
inland GA zones to the lower/mid 60s toward the coast. It
is likely that most locales realize their daily max temp prior
to mid morning today, despite the increasing afternoon sunshine.

Tonight: A secondary surge of cold air advection this evening
will result in temps falling into the 30s overnight. Light
northwest winds will persist as high pressure builds from the
west.

Lake Winds: Cold lake waters keeping conditions largely below
15 kt ahead of the cold front, but gusty conditions were
occurring around portions of the lake shores. This will change
after mid morning as cold air advection initiates with the
passage of the cold front and improving mixing conditions take
place and winds increase across the open lake waters.

&&

.SHORT TERM /FRIDAY THROUGH SUNDAY/...
Dry high pressure will prevail Friday through Sunday. Mostly
clear skies are anticipated Friday through Saturday night, then
some increasing cloudiness expected Sunday as an upper shortwave
moves through. Highs will be in the low to mid 50s with lows in
the upper 20s to lower 30s.

&&

.LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/...
Dry weather and moderating temperatures expected Sunday night
through Tuesday as high pressure gradually shifts east. A cold
front is forecast to move through late Tuesday or Tuesday night,
potentially accompanied by scattered showers. There is considerable
model uncertainty regarding how cold the airmass will be
following the front.

&&

.AVIATION /12Z THURSDAY THROUGH MONDAY/...
Strong low level wind fields early this morning, currently
peaking prior to a cold front later this morning. Skies will
clear this afternoon with VFR conditions. Gusty west winds
should subside by sunset with clear skies overnight.

Extended Aviation Outlook: VFR conditions will prevail.

&&

.MARINE...
A very strong low-level jet struggling to mix over the cool and
relatively stable shelf waters this morning with gales ongoing
over warmer waters beyond 20 NM off the SC/GA coasts. We held
onto the Gale Warning along Charleston County with respect to
gusts that were occurring near the land/sea interface prior to
the cold front. We lowered the Gale Warning to the south of
Edisto across Beaufort Waters and issued a SCA through the day
into this evening when seas are forecast to subside. Winds will
veer to west in the wake of the front today and this will allow
seas to diminish near shore, although choppy seas are still
likely with better mixing of the jetting flow.

Tonight: Winds will remain elevated as cold air advection in
the low levels strengthen. Speeds will mainly be below SCA
levels however and seas out near the Gulf Stream will tend to
subside, albeit slow.

A relatively quiet marine pattern is in store for Friday through
early next week as high pressure remains the dominant feature.
The next wind surge is expected Tuesday night into Wednesday
following the next cold front.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...None.
SC...Lake Wind Advisory until 4 PM EST this afternoon for SCZ045.
     Wind Advisory until 9 AM EST this morning for SCZ048>050-052.
MARINE...Small Craft Advisory until 9 PM EST this evening for AMZ330-
     352.
     Gale Warning until 10 AM EST this morning for AMZ350-374.
     Small Craft Advisory until 4 PM EST this afternoon for AMZ354.

&&

$$
NEAR TERM...
SHORT TERM...JRL
LONG TERM...JRL
AVIATION...
MARINE...