565 FXUS62 KCHS 081708 AFDCHS Area Forecast Discussion National Weather Service Charleston SC 1208 PM EST Fri Mar 8 2019 .SYNOPSIS... A weak backdoor cold front will approach from the north today and stall, before shifting back north of the area on Saturday. A cold front is expected to shift over the region late weekend into early next week. High pressure will return for the middle of next week. && .NEAR TERM /THROUGH TONIGHT/... Surface high pressure will remain just off the coast today, providing a weak warm advection flow. A patch of mid and high clouds associated with a morning shortwave is moving off the coast at this time, with mostly sunny skies prevailing, though another batch of mid-clouds is spreading in from the west. Temps warmed quickly this morning and highs should top out in the low to mid 70s. Tonight: The quasi-stationary front will linger across the Carolinas, perhaps dipping into our far northern zones around the Santee Cooper Lakes. Periods of clouds should be more common across SC zones than in GA zones. We have small POPs for our zones closest to the front during the evening hours as a weak mid level short wave skirts through. Dry weather will otherwise prevail with mild low temps in the lower 50s many areas, with temps closer to 60 degrees overnight on the land/sea interface. && .SHORT TERM /SATURDAY THROUGH MONDAY/... Saturday: A weak front draped across the Tri-County area will lift north of the region early, setting up a warmer southerly flow for much of the day. 1000-850 mb lvl thickness values support temps in the mid/upper 70s during the afternoon, warmest across Southeast Georgia. Despite some moisture over the area, forcing will remain limited and thus dry conditions are expected for the day and night. Overnight, temps will be noticeably warmer as a light southerly wind persists under some clouds. In general, lows should range in the upper 50s to lower 60s, warmest near the coast. Sunday: A south/southwest flow will help drive warm and moist conditions to the area on well ahead of a cold front arriving during the night. Despite a fairly zonal flow aloft, latest guidance suggests the front will be slow to move into the area with a large degree of separation from the parent low center shifting over the Great Lakes region. Given the setup, strongest low-lvl wind fields should remain north of the area while the timing of greatest forcing associated with the sfc front arrives late Sunday night into early Monday, when conditions are typically less supportive of severe weather due to diurnal heat loss. However, a fair amount of sfc sfc heating will occur Sunday afternoon with temps approaching the upper 70s/lower 80s across the area. These temps along with PWATs approaching 1.50-1.75 should result in a marginal swath of instability ahead of the front and should help produce showers and/or thunderstorms as weak h5 shortwaves pass aloft late in the day into the night, a few of which could be strong should they occur by late evening. Overnight lows should remain mild, ranging in the upper 50s to lower 60s, warmest south of the front. Monday: A cold front should slowly depart southern most zones during morning hours, giving way to drier and slightly cooler conditions as high pressure begins to build over the region from the northwest during the afternoon and evening. A slight chance to chance of showers will be possible near/south of the front early. Afternoon highs should peak in the low/mid 70s, warmest across Southeast Georgia. && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... Dry/cooler conditions are expected through Tuesday as northeast winds prevail within high pressure spreading across the area from the north/northwest. In general, highs should peak in the mid/upper 60s across northern areas and lower 70s across Southeast Georgia. Overnight lows should range in the upper 40s/lower 50s inland to mid/upper 50s near the coast Monday night and Tuesday night. By Wednesday, the center of high pressure to the northwest will gradually slide east through late week, setting up east winds over the area mid week, then south by early next weekend. Given the pattern, conditions should warm mid to late week with afternoon temps in the low/mid 70s on Wednesday warming to the upper 70s to around 80 by Friday. && .AVIATION /17Z FRIDAY THROUGH TUESDAY/... VFR at KSAV/KCHS through 18Z Saturday. Mainly just mid and high clouds expected. Extended Aviation Outlook: VFR conditions are expected at both CHS and SAV terminals Saturday. Flight restrictions are possible at both terminals Sunday into Monday due to showers or thunderstorms associated with a passing cold front. && .MARINE... Through tonight: A weak cold front will stall just north of the waters with a weak pressure gradient persisting. South to southwest flow is expected to increase a bit along the SC land/sea interface where thermal gradients will tighten with land mass heating later today. Speeds will still be mainly below 15 kt SC waters and 10 kt or less and seas through tonight will range from 1 to 3 ft. Saturday through Wednesday: Conditions will remain quiet across the coastal waters late weekend, but winds should begin to increase heading into early next week as a cold front approaches the coastal waters Sunday night. The cold front is expected to shift offshore early Monday with southerly winds turning northeast once fropa occurs and increasing up to around 15 kt. Seas should build as high as 3-4 ft Sunday, then subside to 1-3 ft into Tuesday, before building once again to 3-5 ft mid week. Winds/seas are likely to remain below Small Craft Advisory levels. Sea Fog: There remains a potential for sea fog to develop ahead of a cold front beginning early Sunday as southerly winds move warm and moist air over the cooler shelf waters. Sea fog could possibly linger into Monday until the cold front slowly departs the area. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...None. SC...None. MARINE...None. && $$ NEAR TERM...JRL SHORT TERM...DPB LONG TERM...DPB AVIATION...JRL MARINE...