545 FXUS62 KCHS 012008 AFDCHS Area Forecast Discussion National Weather Service Charleston SC 408 PM EDT Sat Apr 1 2023 .SYNOPSIS... A cold front will push offshore tonight, followed by high pressure through early next week. Another cold front could approach the area around the middle of next week. && .NEAR TERM /UNTIL 6 AM SUNDAY MORNING/... The line of showers and embedded thunderstorms continues to move through our area. But it's lackluster across most of our area as most of the energy and strongest storms remain south and west of our area. SPC mesoscale still has MLCAPEs peaking around 1,000 J/kg across our area, with higher amounts across the watch box. But this seems overdone given the current radar cover. Though, the shear remains high and could generate a severe thunderstorm or two in the watch box. The main threat is damaging winds. There is some veering of the winds at the lowest levels and decent SRH. For this reason, we can't rule out a brief tornado. But its dropping with each passing minute. Also, mid- level lapse rates of ~6 C/km and cold 500 mb temperatures will bring the potential for large hail. Again, this risk is dropping with each passing minute. The line remains narrow and fast moving, meaning that a prolonged period of rainfall is not expected. Rainfall amounts are expected to mostly be less than 0.5" or slightly higher. The showers/thunderstorms will continue moving eastward and become limited to the immediate coastline early in the evening, then quickly move offshore. The rest of the late evening through the overnight will be dry. Skies will gradually clear out and cooler and drier air will move in. Additionally, the gusty winds will ease, but remain somewhat elevated as they turn to the NW overnight. Low temperatures should fall into the upper 40s to low/mid 50s. && .SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY/... Sunday: At the surface, a large area of high pressure will build across the Eastern U.S. in the wake of a low pressure system moving off the Northeast coast. Flow aloft will transition to a more zonal orientation. Conditions will be rain-free Sunday as a much drier air mass moves into the region, bringing clearing skies with passing high clouds. High temperatures could be tricky Sunday as CAA in the morning rapidly ceases and WNW flow transitions out of the southwest pulling in some moist, Gulf air by night. Currently our forecast reflects low to mid 70s with the SC beaches struggling to reach 70F. Overnight, temperatures will drop to the low to mid 50s, perhaps some upper 40s across northern Berkeley County. It'll stay warmer along the beaches where upper 50s/low 60s are likely. Monday and Tuesday: A weak shortwave embedded in the zonal flow will push across the local area Monday which could provide sufficient forcing for a few afternoon showers, mainly inland. As the wave pushes offshore Monday night into Tuesday, a weak coastal trough could develop, possibly bringing isolated showers and thunderstorms to the coastal areas mainly north of I-16. Any rainfall should cease by the afternoon, with overcast skies diminishing to more scattered coverage. Monday will be a few degrees warmer with highs solidly in the 70s across the area. Monday night temperatures will only dip into the low to mid 60s. Mid-level ridging will push into the Southeast U.S. Tuesday bringing much warmer temperatures. Highs should peak in the low-mid 80s across southeast South Carolina and upper 80s across much of southeast Georgia, about 10 degrees above normal. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... A strong mid-lvl ridge will expand across the region heading into the middle of next week while a southerly wind prevails between high pressure centered across the western Atlantic and a front advancing across the East CONUS mid to late week. Temps will likely soar into the mid-upper 80s Wednesday and Thursday, and could touch 90 degrees across areas well inland. Although a few diurnal showers and/or thunderstorms can not be ruled out Wednesday afternoon, better precip chances should arrive Thursday afternoon and persist into Saturday as a front approaches the region and potentially stalls over/near the local area. High temps will become noticeably cooler during the weekend, generally ranging in the low-mid 70s for most areas, except around 80 degrees near the Altamaha River. Overnight lows will remain mild mid week, generally in the mid-upper 60s, then follow a cooler trend with the arrival of the front, generally ranging in the mid-upper 50s north to lower 60s south during the weekend. && .AVIATION /20Z SATURDAY THROUGH THURSDAY/... 20Z Update: The initial line of showers and thunderstorms dissipated before making it to the TAF sites. But scattered showers and some embedded thunderstorms are following it. We're less certain if they'll impact CHS/JZI in the next few hours, so we removed the TEMPO groups. For SAV, radar trends indicate some impacts are likely, so we made some adjustments to the TEMPO. Overall, the shower/thunderstorm risk will end this evening as they move offshore. However, gusty winds will persist through sunset, then gradually ease. Winds will then clock around to the NW by the end of the TAF time period as a cold front moves through our area. Extended Aviation Outlook: VFR conditions are expected at KCHS/KJZI/KSAV through Wednesday. && .MARINE... Tonight: Showers and maybe some thunderstorms could move through the waters this evening, bringing locally gusty winds. Wind will then start an easing trend after this activity finishes. Then, a cold front will move through the waters after midnight, winds behind the front will clock around to the NW by daybreak Sunday, while easing further. While we still have Small Craft Advisories in place for most of the waters, we anticipate the easing winds and lowering seas will mean all of the Small Craft Advisories should expire by late tonight. Sunday through Wednesday: Offshore winds behind a departing cold front will quickly turn onshore early week, weakening quickly Sunday morning as high pressure becomes centered off the Mid-Atlantic Coast. Winds will generally be less than 15 kt from the northeast Sunday then shifting south-southeast late Monday while seas average 2-3 feet through the period. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...None. SC...Lake Wind Advisory until 6 PM EDT this evening for SCZ045. MARINE...Small Craft Advisory until 8 PM EDT this evening for AMZ330- 352. Small Craft Advisory until 2 AM EDT Sunday for AMZ350. Small Craft Advisory until 11 PM EDT this evening for AMZ374. && $$ NEAR TERM... SHORT TERM...BRM LONG TERM...BRM AVIATION...BRM MARINE...BRM