![National Oceanic and Atmospheric Administration](/build/images/header/noaa.d87e0251.png)
![National Weather Service](/build/images/header/nws.4e6585d8.png)
![United States Department of Commerce](/build/images/header/doc.b38ba91a.png)
Area Forecast Discussion
Issued by NWS Charleston, SC
Issued by NWS Charleston, SC
Versions:
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
427 FXUS62 KCHS 140639 AFDCHS Area Forecast Discussion National Weather Service Charleston SC 239 AM EDT Wed Aug 14 2024 .SYNOPSIS... A cold front will move slowly south across the area tonight, then pass through on Wednesday. High pressure will build from the north into late week. Another cold front may approach the area later this weekend or early next week. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... Surface boundary extends off the Atlantic into southeast Georgia with some lower cloud cover expanding down through the region behind the boundary. Quiet weather for the most part, although there is a thin line of convection that has developed off the SE SC coast in the last few hours, perhaps along an old outflow boundary that may be pressing southward through the region per radar imagery. A few showers remain possible along the SC coast as the boundary continues its southward advance. But overall, rain-free conditions should prevail overnight. There could be some shallow ground fog around, especially in areas that received rain earlier this afternoon into the evening, but coverage isn`t expected to be sufficient to warrant carrying fog in the forecast. Lows are expected to be a bit lower than previous nights, generally in the low-mid 70s inland to upper 70s near the beaches. && .SHORT TERM /6 AM THIS MORNING THROUGH FRIDAY/... Wednesday: This will be the wettest day to an otherwise rather unusually dry period. A weak backdoor surface front will be pushing just south of the area by later in the morning, with surface ridging building over the mid Atlantic and northeast states, resulting in northeast low level northeast winds. The area will still be under the backside of an upper level trough, departing off of the mid Atlantic Coast. This feature, combined with modest deep layer moisture of PWs of 2+ inches, will result in scattered showers/thunderstorms, especially south of the Charleston Tri-County area. Highs noticeably cooler over the SC zones, in the mid to upper 80s, and around 90 to the lower 90s southern GA zones and near the Altamaha. Expect any isolated to scattered convection to diminish by the evening. Lows cooler than they have been in quite some time, in the upper 60s to around 70 inland, and lower to mid 70s near the coast. Thursday and Friday: Deep layer ridging shown by all models to build from the west and north, helping to drive drier air southward through the area. PWs falling below 1.5 inches and mean RH values generally below 50%, which is below normal for this time of year. Have no mentionable precipitation chances for both of these days, which will allow for some needed drying out of the many flooded/saturated regions across our area. Highs a tad below normal, in the mid 80s to near 90. Lows in the upper 60s inland/west of I-95 and lower 70s closer to the coast. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... The deep layer ridging over the southeast U.S. is shown by global models to weaken and push southward as a large/broad upper trough forms over the Great Lakes Saturday, pushing into southeast Canada and northern New England Sunday and Monday. This will translate to a gradual increase in precip./convection chances through the period. Have slight chance PoPs Saturday and into Sunday, then chance by Monday, which is around normal for this time of the year. Given the presence of a relatively strong upper level trough axis for mid August, will continue to monitor any potential threat for strong to severe storms, especially by later in the weekend. Temperatures warming slightly through the period, but guidance keeps highs around normal in the lower 90s and lows in the lower to mid 70s, except mid to upper 70s near the coast. && .AVIATION /06Z WEDNESDAY THROUGH SUNDAY/... Some low stratus is expanding across parts of southeast SC and heading toward southeast GA which could bring a period of IFR ceilings at the SAV terminal toward morning. Some afternoon showers/thunder are possible Wednesday afternoon, although confidence for impacts at any one terminal is not high. 06Z forecasts have VCSH during the afternoon hours to account for this. Extended Aviation Outlook: Wednesday: Brief flight restrictions possible with scattered mainly afternoon and early evening showers and thunderstorms, especially KSAV. Thursday and Friday: VFR to prevail with much drier conditions expected, with less than 15% chance for afternoon showers/thunderstorms. Saturday and Sunday: Some moisture starts to return with isolated afternoon showers/thunderstorms Saturday, and scattered by Sunday with a higher chance for brief flight restrictions. && .MARINE... Tonight: A few thunderstorms will continue to shift further offshore and south along a boundary, likely departing all local waters within the next couple hours. An isolated strong thunderstorm is possible, with gusty winds and perhaps even a waterspout. Otherwise, a weak boundary will linger near or just south of the local waters through the night. Winds north of the boundary will turn northeasterly while winds to the south will continue to be southerly. Speeds should top out in the 10-15 knot range, mainly within the northeast flow in the Charleston County waters. Seas are expected to average 2-3 feet. Wednesday through Thursday: No highlights expected as a backdoor cold front pushes south of the waters through this period. Expect east-northeast winds of 10-15 knots with some gusts to near 20 knots possible. Seas generally 3 to 4 feet. Thursday night through Saturday: Seas expected to increase, especially beyond 20nm offshore as swells from Ernesto, which will remain well east of the area, arrive into the marine area. Guidance indicating seas building to 4 to 6 feet, possibly up to 7 feet by later Friday and into Saturday. Decreasing northeast winds through Friday, becoming south and southwest Saturday and Sunday. Winds during this period generally 10 to 15 knots or less and seas 3 to 5 feet. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...None. SC...None. MARINE...None. && $$