686 FXUS62 KCHS 231537 AFDCHS Area Forecast Discussion National Weather Service Charleston SC 1037 AM EST Wed Jan 23 2019 .SYNOPSIS... A warm front will move north through the area today. A cold front will then move through late tonight into Thursday morning followed by high pressure through early next week. Another cold front will move through next Tuesday. && .NEAR TERM /THROUGH TONIGHT/... Today: No significant changes were made with the latest forecast update. A low-level warm front will shift north through the area bringing an end to the inland high pressure wedging. A few showers are expected across the area today, generally shifting from GA into SC with the band of greater low-level moisture. Although we should see a bit of sun especially in GA we think it will be more cloudy than not overall. However, despite the clouds, temperatures will increase to above normal levels given the strengthening low-level warm advection. Highs should range from the in the mid/upper 60s for most of SC and along the GA coast with lower 70s across inland portions of GA. Southeast winds will shift more southerly and increase to 15 to 20 mph with gusts near 25 mph during the afternoon. Tonight: Mainly dry conditions should prevail for much of the early evening hours. Winds will continue to increase with turbulent low level mixing resulting in steady to slowly rising temps across the region. Tonight's low temps could certainly occur at many locations not long after sunset before the stronger winds kick in. A progressive and vigorous upper wave will sweep into the lower Gulf Coast region and reach North GA by dawn on Thursday. Significant upper dynamics and Pwats exceeding 1.5 inches will accompany a strong cold front into the region late tonight. Mostly shallow convective rains and perhaps a narrow strongly-forced line of heavier rains will move into the forecast area after midnight, nearing the coast toward daybreak. We will begin to see breezy to windy conditions develop as a 55-65 kt low level jet sweeps atop the region. It would not be surprising to see wind speeds nearing wind advisory levels along some of the coastal zones for a period later tonight. Mid level instability is quite weak and very little CAPE progged at the boundary layer suggest any thunder or deeper convection will be quite limited. Rains are expected to be at least briefly heavy at times late tonight with amounts ranging from 1/2 inch to over an inch in some areas. && .SHORT TERM /THURSDAY THROUGH SATURDAY/... The cold front will be pushing off the coast Thursday morning, taking with it the widespread rain showers. Cold advection will quickly begin following the front, causing temps to fall through the morning hours. Increasing sunshine and downslope flow developing by early afternoon should offset the cold advection and cause temps to level off. The daytime high temperature may well occur around sunrise at many sites. Although low-level wind speeds will decrease quickly during the day, cold advection will support deeper mixing, thus breezy conditions expected. Cool and dry high pressure will build over the area Friday through Saturday, resulting in clear skies, highs in the low/mid 50s and lows in the upper 20s to lower 30s. && .LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/... Dry weather and moderating temperatures expected Saturday night through Tuesday as high pressure gradually shifts east. A mostly dry cold front will sweep through Tuesday night, followed by a considerable cool down. && .AVIATION /15Z WEDNESDAY THROUGH SUNDAY/... VFR for much of the period through midnight, although MVFR cigs are possible at times during the day. Winds will veer to a southerly component later today and become quite gusty by late today and this evening as a strong low level jet builds into the coastal corridor. Isolated to scattered light showers possible with a warm front and building moist low level wind field today. After Midnight: Convective rains are expected to spread into the coastal corridor, timing is mainly after 08Z/24. Strong surface winds are expected with speeds perhaps 20G30KT at times in the warm sector ahead of the rains. IFR cigs and vsbys are possible late in the period. Extended Aviation Outlook: MVFR/IFR ceilings/vsbys will clear out by late Thursday morning, though breezy conditions will occur through Thursday afternoon. && .MARINE... Today: A coastal trough will shift through the area as a warm front with southeast to east winds shifting to more southerly. Small Craft Advisories will remain in effect for elevated winds gusting near 25 kt and at least 6 ft seas across the Charleston nearshore waters and offshore GA waters. Tonight: Winds will increase as strong low-level wind fields spread over the waters due to an approaching cold front. There is some concern for gales to develop, mainly out closer to the Gulf Stream waters, and we have raised a Gale Watch for all waters outside Charleston Harbor. Seas will build substantially as well, especially beyond the pilot buoys, and thus hazardous to dangerous conditions are expected across all waters. Thursday through Sunday: The southerly low-level jet will be at its peak around 12Z Thursday before the cold front moves through. Winds will shift to offshore during the day as the cold front moves farther offshore. Though low-level winds will decrease considerably as the day wears on, deeper mixing in cold air advection will allow gusty winds to persist. Small Craft Advisory conditions will continue for all waters through at least Thursday afternoon, though most waters will continue to see 6+ ft seas through parts of Thursday night or into Friday morning. High pressure will build over the waters late Friday through early next week, yielding relatively quiet marine weather. && .TIDES/COASTAL FLOODING... A Coastal Flood Advisory for minor salt water flooding remains in effect for the entire coast through 11 am. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...Coastal Flood Advisory until 11 AM EST this morning for GAZ117- 119-139-141. SC...Coastal Flood Advisory until 11 AM EST this morning for SCZ048>051. MARINE...Gale Watch from 7 PM EST this evening through Thursday morning for AMZ350-352-354-374. Small Craft Advisory until 7 PM EST this evening for AMZ350- 374. Small Craft Advisory from 7 PM this evening to 4 PM EST Thursday for AMZ330. && $$ NEAR TERM...RJB SHORT TERM...JRL LONG TERM...JRL AVIATION... MARINE... TIDES/COASTAL FLOODING...