302
FXUS62 KCHS 022320
AFDCHS

Area Forecast Discussion
National Weather Service Charleston SC
720 PM EDT Thu May 2 2024

.SYNOPSIS...
Atlantic high pressure will remain across the Southeast through
much of next week.

&&

.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
Early this evening: Radar imagery shows that the sea breeze has
nearly cleared the entire forecast area and the one or two
showers that developed along its inland progression in the
afternoon have now dissipated. The chance for any convection is
over and the rest of the night is expected to be dry. Attention
turns to the main forecast challenge which is once again fog and
stratus. Overall, we view the forecast as having a large
persistence component given that the airmass has not chance
appreciably and the setup remains conducive to fog development.
Surface winds will be calm for most of the night and we still
have plenty of moisture with most sites expected to reach or
fall below their crossover temperatures. Given that we had
widespread dense fog last night, the potential seems high yet
again tonight. The forecast features areas of fog, with patchy
dense, just about everywhere. One thing that will be interesting
is that near surface flow will be out of the southeast, albeit
light. This could help push for just inland of the coast,
potentially leaving the immediate coastline mostly fog free. Its
not clear how likely this is at this time, but certainly
something to consider. Expect a mild night with lows in the low
60s inland and more into the mid 60s closer to the coast. Such
values are several degrees above normal for early May.

&&

.SHORT TERM /6 AM FRIDAY MORNING THROUGH SUNDAY/...
Mid level ridge axis transitions off the Southeast coast Friday
with shortwave energy to move through the region over the
weekend. High pressure will remain the primary feature at the
surface. A few showers and thunderstorms could sneak into inland
areas Friday, but convection should be a bit more active over
the weekend. Coverage will be highest in the daytime when
instability is maximized, but with some upper forcing in play
activity will be possible overnight as well.

High temperatures generally peak in the mid to upper 80s. Lows
only drop to the mid to upper 70s.

&&

.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
Atlantic high pressure will persist during the early to middle
of next week. Convection looks to be most active early in the
period, then the chances for showers/thunderstorms decrease
towards mid week as ridge rebuilds overhead. Temperatures will
also be creeping up, possibly approaching record levels by
Wednesday/Thursday.

&&

.AVIATION /23Z THURSDAY THROUGH TUESDAY/...
The main forecast challenge for the 00z TAF period will again be
fog and stratus. Given that the airmass has changed very little,
and the overall setup has changed very little, confidence is
relatively high that dense fog will be common across the area.
We have not made any significant changes from the 18z TAF`s as
we think they reflect the situation very well. Current timing
favors fog beginning to develop in the 04-06z time period. We
have continued dense fog at all 3 TAF sites bewteen 09-13z.
Conditions should return to VFR in the 13-14z time period, and
remain VFR thereafter. If there is one potential concern is it
is that near surface winds will be out of the southeast, albeit
very light. This could help push the fog just inland of the
immediate coast. This would be a bigger issue at KJZI than at
KCHS or KSAV, but it is something to keep an eye on.

There are no significant concerns for afternoon thunderstorms
near the terminals on Friday.

Extended Aviation Outlook: Flight restrictions possible in
overnight/early morning fog and stratus. Isolated to scattered
showers and thunderstorms are possible Saturday through Monday.

&&

.MARINE...
Tonight: East to southeast winds will prevail tonight with high
pressure centered well offshore. Fog could become an issue in
the Charleston Harbor as fog oozes into the harbor from nearby
areas. The fog could become locally dense with vsbys <1NM. A
Marine Dense Fog Advisory could be needed at some point
overnight. Fog could impact harbor operations in the Charleston
Harbor and Port of Savannah. The fog could not be too much of a
concern over the Atlantic coastal waters given the onshore flow
regime that is in place. This should limit the fog to areas
inland from the beaches. Wind speeds will average less than 10
kt with seas 1-2 ft.

Friday through Tuesday: No marine concerns. Atlantic high
pressure will maintain rather benign conditions over the marine
area. Winds are generally no higher than 10-15 kt with seas 2-3
ft.

&&

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

&&

$$

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