272 FXUS62 KCHS 181401 AFDCHS Area Forecast Discussion National Weather Service Charleston SC 1001 AM EDT Wed May 18 2022 .SYNOPSIS... High pressure will gradually build into the region through the end of the week. A cold front will approach the region this weekend, bringing unsettled weather to the area through early next week. && .NEAR TERM /THROUGH TONIGHT/... Weak high pressure will prevail through tonight. Expect dry weather and mostly sunny skies with just some diurnal cumulus clouds. High temperatures are forecast to range from around 90 to the mid 90s further inland, except cooler at the beaches. Lower dew points will keep heat indices from getting much higher than those values. Temperatures tonight will remain mild, generally in the 60s and lower 70s. && .SHORT TERM /THURSDAY THROUGH SATURDAY/... A strengthening Bermuda High will largely dominate the surface pattern. Zonal flow transitioning to increasing ridging aloft as well as a dry air mass especially above H85, will keep rain chances non-existent through Friday. There could be just enough moisture at the low-levels which could produce some fair weather cumulus during the afternoon Thursday and Friday. However, model soundings indicate a decent capping inversion both days; indicative of a fairly stable environment. The next chance for rainfall is expected Saturday as prevailing southerly return flow advects deep Gulf moisture into the region. PWATS increase from just over an inch to about 1.75" Saturday evening. Showers and thunderstorms look most promising in the late afternoon and evening mainly across southeast Georgia where likely POPs have been placed. Unfortunately, overall rainfall (QPF totals) looks minimal especially in those places where soils are driest and are most needed. Convection should begin to subside once nocturnal stabilization kicks in after sunset. The most notable feature of the short-term forecast are the above- normal temperatures. Highs in the mid to upper 90s are expected Thursday and Friday. Some areas in southeast Georgia south of the Altamaha River could reach a degree or two shy of 100F Thursday, which is looking to be the hottest day of the trio. The only sign of respite will occur from dew points in the upper 50s across the hottest locations during peak heating, keeping heat indices from topping 100 degrees. Saturday will be a few degrees cooler as overcast skies moderate temps in the upper 80s/low 90s. Warm overnight conditions are expected Thursday and Friday with lows only dipping into the upper 60s to low 70s. There is a possibility that new record highs and/or record high min temperatures could be set Thursday and/or Friday (see the Climate section below). && .LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/... A large shortwave will drop a cold front into the region Sunday night and showers and thunderstorms are possible ahead of the advancing front. Unsettled weather could persist into at least the middle of next week as deep moisture lingers and a coastal trough looks to develop. Some much needed widespread rainfall looks possible as WPC's Day 1-7 QPF totals range from 0.5" to 1.5" across the forecast area, with the majority of that rainfall occurring from Saturday evening through Tuesday night. Relief from the heat is expected next week as above normal temperatures are forecast to drop to below normal early next week in the wake of the front. && .AVIATION /14Z WEDNESDAY THROUGH SUNDAY/... 12Z TAFs: VFR. SSE winds could gust to 20 kt this afternoon, mainly with the passage of the sea breeze. Extended Aviation Outlook: Mainly VFR. Brief flight restrictions are possible in showers/thunderstorms over the weekend. && .MARINE... Today and Tonight: Weak high pressure will prevail over the region. Light and variable winds this morning will veer and increase into this afternoon, especially along the land/sea interface due to the formation of the sea breeze. In the Charleston Harbor, winds should be gusty with the passage of the sea breeze this afternoon, peaking around 20 kt. This evening and overnight, winds will shift to the SW and increase to around 15 kt due to the formation of a nocturnal jet. Seas will average 2 ft within 20 nm and 2-3 ft for the GA waters beyond 20 nm. Rip Currents: Onshore winds this afternoon and a 1-2 ft swell near 8 seconds could generate an elevated risk of rip currents today, especially at Tybee Island. Our internal calculator indicates it's borderline between Low risk and Moderate risk at all of our beaches. Since we might be overdone with the winds this afternoon (which is helping to push the calculations up), we backed off the winds and maintained the Low risk. Thursday through Monday: Surface high pressure will prevail across the southern Atlantic. South to southwest winds will increase through the day Thursday as the pressure gradient briefly pinches across the waters. By the evening gusts could reach up to 25 kt and Small Craft Advisories could be needed across the local waters, through Thursday night. Conditions will improve by Friday morning and southerly winds around 10 to 15 knots will prevail. Seas will average 2-4 feet through the period. && .TIDES/COASTAL FLOODING... Tides continue to be elevated along our entire coast. Moderate coastal flooding is forecasted with this evening's high tide in Charleston Harbor. At Fort Pulaski, the tide may come close to reaching the level for minor coastal flooding. Additional minor to perhaps moderate coastal flooding will be possible during the late evening high tides through Thursday due to astronomical influences, mainly for Coastal Colleton and Charleston Counties. Although, less favorable southerly winds should help mitigate the effects of coastal flooding. && .CLIMATE... May 19 Record High Temperatures: KCHS: 96/1996 KSAV: 97/1996 May 20 Record High Min Temperatures: KCHS: 72/1997 May 20 Record High Temperatures: KCHS: 97/1938 KSAV: 96/2006 && .CHS WATCHES/WARNINGS/ADVISORIES... GA...None. SC...None. MARINE...None. && $$ NEAR TERM... SHORT TERM...BRM LONG TERM...BRM AVIATION...BRM MARINE...BRM TIDES/COASTAL FLOODING... CLIMATE...