608 FXUS62 KCHS 161519 AFDCHS Area Forecast Discussion National Weather Service Charleston SC 1019 AM EST Sat Jan 16 2021 .SYNOPSIS... Cool, dry high pressure will prevail over the weekend into early next week. A weak cold front is expected to pass over the region near the end of next week. && .NEAR TERM /THROUGH TONIGHT/... Today: A large mid-upper lvl low will track across the Midwest toward the Northeast United States with a strong h5 shortwave rounding the southern periphery across the region. At the sfc, low pressure centered along the Mid-Atlantic and Northeast Coast will shift north and further away from the area while dry and much cooler high pressure filters into the local area within a west flow. Despite a full day of sun, strong cold air advection into the region will limit temps this afternoon with 1000-850mb thickness levels suggesting highs only in the upper 40s well inland to lower 50s elsewhere. Even with these cooler temps, the strength of cold air advection aloft will help promote abundant low-lvl mixing, leading to gusty winds across the area late morning into early evening (up to 25-30 mph). Expect winds to quickly decrease near sunset. Lake Winds: West winds will strengthen across Lake Moultrie late this morning. Frequent gusts to or just above 25 knots can be expected over the lake and around the lake shore. A Lake Wind Advisory is in effect from 10am-6pm. Tonight: Winds will diminish this evening with the loss of low-lvl mixing and the relaxing of the pressure gradient. Clear skies will prevail and a cold night is on tap. Lows are forecast to range from the upper 20s inland to the low to mid 30s closer to the coast. && .SHORT TERM /SUNDAY THROUGH TUESDAY/... Sunday through Tuesday: Broad surface high pressure will gradually build/deepen over the Southeast throughout the period. Meanwhile, a closed H5 low will open and lift as it shifts over the Northeast Monday. Moisture associated with the trough keeps well to our north. With subsidence controlling the region, stable, dry, and rain-free conditions are expected through the period. Slightly warmer conditions are anticipated through Tuesday with max temps increasing by a few degrees each day. Low to mid 50s are expected Sunday and by Tuesday highs will be in the upper 50s/low 60s. Increased cloud coverage Sunday night will keep min temps just above freezing, and near 40F along the beaches. Clear skies thereafter will result in cooler conditions Monday night with lows in the the low to mid 30s inland and near 40F along the coast. && .LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/... Surface high pressure will continue to dominate over the Southeast US, eventually advecting moisture from the Gulf into the Tennessee Valley. Shortwave energy and upper forcing looks to bring showers just outside the forecast area on Wednesday. However, little moisture over southeast SC/GA and surface dew points around 40F should keep any showers over the area elevated with little to no mentionable precipitation. On Thursday, a weak, slow-moving cold front approaches the region from the northwest. Showers ahead/along the front are possible Thursday afternoon into the overnight period. A second round of showers is possible Friday night/Saturday due to shortwave energy extending from an upper trough over the Northeast US. Overall, a gradual warming trend is anticipated through the period with highs climbing well into the 60s late week. && .AVIATION /15Z SATURDAY THROUGH WEDNESDAY/... VFR conditions will prevail at KCHS and KSAV through 12Z Sunday. West winds will be gusty beginning late morning and should peak during early afternoon hours. Both sites advertise frequent gusts up to around 30 knots. Gusts will diminish significantly around and just after sunset. Extended Aviation Outlook: VFR expected to prevail. && .MARINE... Today and Tonight: Cold high pressure will spread across the local waters today along the southern periphery of a large low pressure system positioned north of the region. A strong pressure gradient associated with the pattern will persist through much of the day, likely supporting gusty winds across local waters as cold air advection helps tap into enhanced low-lvl wind fields traversing the area. Confidence remains high in gale force gusts for the Charleston County waters where a Gale Warning is now in effect through this evening. Gusts into the 35-40 knot range can be expected. Elsewhere, Small Craft Advisories are in effect where frequent wind gusts up to 30 kt are expected, including in the Charleston Harbor. There is still a low chance of seeing a few gale force wind gusts across offshore Georgia waters this afternoon, but the duration does not warrant a Gale Warning at this time. Conditions will steadily improve overnight as the pressure gradient begins to relax and cold air advection weakens. All warnings and advisories will come down at various times through the night. Sunday through Wednesday: High pressure continues to spread into the region from the west; however, by Sunday morning winds/seas should be well below Small Craft Advisory criteria. Elevated winds will return late Sunday into Monday, with gusts near Small Craft Advisory criteria across the waters especially in the GA waters from 20nm to 60nm. W/SW winds will prevail through the period and seas will generally range from 2-4 ft with some possible 5 footers in the outer GA waters Monday evening. Thereafter, westerly winds are expected to be 15 kt or less. Seas will also decrease, with 1-2 footers across all waters by Tuesday. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...None. SC...Lake Wind Advisory until 6 PM EST this evening for SCZ045. MARINE...Small Craft Advisory until midnight EST tonight for AMZ352. Gale Warning until 6 PM EST this evening for AMZ350. Small Craft Advisory until 10 PM EST this evening for AMZ330- 354. Small Craft Advisory until 4 AM EST Sunday for AMZ374. && $$ NEAR TERM...DPB SHORT TERM...BRM LONG TERM...BRM AVIATION...BRM/BSH MARINE...BRM/DPB