478 FXUS62 KCHS 010232 AFDCHS Area Forecast Discussion National Weather Service Charleston SC 932 PM EST Sat Nov 30 2019 .SYNOPSIS... A cold front will approach from the west tonight then cross the area on Sunday. Cooler high pressure will return through the middle of next week. Another storm system could impact the area late next week. && .NEAR TERM /UNTIL 6 AM SUNDAY MORNING/... This evening: As warm air advection strengthens overnight ahead of a cold front, we generally expect clouds to be on the increase. Mid level clouds had been expanding over southern SC since sunset, while latest satellite imagery shows low clouds were developing over the Florida Panhandle and parts of southern GA. Later tonight, layered clouds will be common across the region with a good bit of stratus and lower stratocu along and west of I-95. Dry weather is on tap until the eastern fringes of a broad area of frontal rains should be approaching the far western zones after 6 AM. Pops around 20% late tonight look reasonable in the Metter- Allendale corridor. Temperatures should bottom out into the lower 50s north with mid-upper 50s prior to midnight, then begin slowly rise during the early morning hours Sunday as low- level jetting intensifies. Most areas should be in the upper 50s/lower 60s by sunrise. && .SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY/... A strong mid-level low and associated surface low will move into the Great Lakes region on Sunday. As this occurs, a cold front will push through the forecast area. Showers will accompany the front, but it will be moving quickly, so rainfall totals are expected to be a quarter of an inch or less on average. There could be a couple rumbles of thunder, but overall marginal is quite limited so not expecting much. Otherwise, an enhanced pressure gradient will make for a breezy day. Gusts 25-30 mph will be common. Ahead of the front, temperatures should peak well above normal. Areas near the coast that remain in the warm sector longest should see highs in the mid to upper 70s. The atmosphere will quickly dry out Sunday evening, bringing an end to precipitation. Lows Sunday night will be near normal. Quiet weather expected Monday and Tuesday as model soundings indicate deep dry air through the column. Winds will still be a bit gusty on Monday, before the gradient relaxes on Tuesday. Plenty of sun expected, with temperatures cooler than normal. Lake Winds: Wind gusts near 25 knots are possible Sunday into Monday over Lake Moultrie due to the passage of a strong cold front. Conditions appear marginal on Sunday as mixing should be limited ahead of the front. More favorable mixing profiles are expected Sunday night into Monday within cold advection regime behind the front. A Lake Wind Advisory could be needed. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... High confidence through Thursday with low confidence thereafter as the timing of a quick-moving weak storm system is a bit uncertain. Cool and dry weather will prevail through Thursday with temperatures near/below normal. Could see some rain as early as Thursday night mainly through Friday night with temperatures likely pretty close to normal. && .AVIATION /02Z SUNDAY THROUGH THURSDAY/... VFR for most of the night, then there looks to be a period of MVFR cigs developing around daybreak at both KCHS and KSAV. We maintained TEMPO groups for these conditions. Gusty winds will develop by mid-morning Sunday ahead of a cold front. We timed some pre-frontal showers in at KSAV and KCHS mainly between 16Z and 20Z, earliest at Savannah. VFR conditions and slightly lower winds should be returning late in the day on Sunday. Extended Aviation Outlook: VFR will return Sunday evening and persist into mid-week. && .MARINE... Tonight: Light S to SE winds will veer to the southwest and increase overnight as low-level jetting takes hold ahead of an approaching cold front. Winds will reach 15 kt across the nearshore waters with 15-20 kt with gusts to 25 kt over the Georgia offshore waters by daybreak. Seas 1-3 ft will build 2-4 ft nearshore and 4-5 ft offshore late. A Small Craft Advisory will take hold for the Georgia offshore waters beginning at 4 AM EST. Sunday through Thursday: Marine conditions will deteriorate on Sunday as the pressure gradient tightens with an approaching cold front. Winds and seas will be supportive of Small Craft Advisories for all waters, including the Charleston Harbor. Gale force gusts will be possible, and a Gale Watch for the Charleston county nearshore and outer Georgia waters remains in effect. Elevated winds and seas will continue into Monday night. Conditions are expected to improve on Tuesday as the gradient relaxes, and at this time no additional Small Craft Advisories are anticipated at this time. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...None. SC...None. MARINE...Small Craft Advisory from 7 AM Sunday to 7 PM EST Monday for AMZ330. Small Craft Advisory from 7 AM Sunday to 1 AM EST Tuesday for AMZ352-354. Gale Watch from Sunday morning through Sunday evening for AMZ350. Gale Watch from Sunday afternoon through Monday morning for AMZ374. Small Craft Advisory from 4 AM to 1 PM EST Sunday for AMZ374. && $$ NEAR TERM... SHORT TERM... LONG TERM... AVIATION... MARINE...