


Area Forecast Discussion
Issued by NWS Charleston, SC
Issued by NWS Charleston, SC
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845 FXUS62 KCHS 310027 AFDCHS Area Forecast Discussion National Weather Service Charleston SC 827 PM EDT Sat Aug 30 2025 .SYNOPSIS... High pressure will extend across the area through early next week while a stationary front lingers just off the coast. A cold front will move through on Thursday night. && .NEAR TERM /THROUGH SUNDAY/... Tonight: Surface low pressure will remain quasi-stationary off of the SC/ GA coast with winds out of the northeast. Some guidance is showing convection reforming along the coast overnight. This appears to be due to the surface low remaining weak with a land breeze pushing inland. Other guidance shows the coastal low remaining strong enough to keep the land breeze from forming. Most guidance keeps the surface low strong enough, to prevent the quasi- stationary land breeze from forming. Expect low temperatures in the mid 60s (inland) to near 70 at area beaches. && .SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/... Sunday: As a high pressure continues to build into the region from the north, a nearly stationary front will stall just offshore. Quite a bit of moisture and mid-lvl support will remain in the region and will allow scattered to numerous showers and thunderstorm to develop throughout the day. Majority of the guidance continues to agree that the greatest coverage will likely occur along and south of I-16. Additionally, WPC highlighted the immediate coastline under a Marginal Risk (level 1 of 4) for excessive rainfall. Monday and Tuesday: A mid-lvl low will attempt to cutoff across the Mid-Atlantic and allow for subtle waves of h5 vort. energy to be advected across the Southeast, while this front continues to stall nearby. This sort of setup will produce additional showers and thunderstorms along the immediate coastline, however coverage will be less due to the downward trend of PWATs. Temperatures will remain below normal this weekend into early next week as east-northeasterly winds persist and high pressure builds into the region. Expect highs in the low to mid 80s through early next week. Overnight lows will range in the mid to upper 60s inland and low 70s near the coastline. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... As the surface high pressure shifts northeastward, another weak low pressure tries to form offshore on Wednesday and Thursday. Additionally, deep moisture and isentropic ascent becomes more favorable across the region, and this will aid in higher afternoon shower and thunderstorms coverage in the middle of the week. Thereafter, a cold front approaches the region from the northwest and unsettled conditions could continue through the end of the week. Temperatures will remain below normal through the middle of the week, and then near normal by the end of the week depending on the strength of the high pressure ahead of the front. && .AVIATION /00Z SUNDAY THROUGH THURSDAY/... The 00Z TAFs will feature MVFR cigs to start at KJZI/KSAV and VFR at KCHS. MVFR cigs are likely to develop over KCHS starting around 03Z, remaining through the night at all terminals. There is a chance that KSAV could drop even lower to IFR cigs overnight, however confidence was too low to go prevailing IFR. Models keep most of the precipitation offshore tonight and into tomorrow, however a stray shower is possible along the coastal corridor, therefore a VCSH has been included in the 00Z TAFs. Extended Aviation Forecast: Occasional MVFR ceilings possible through Monday as a weak front remains stalled along the coast, thereafter flight restrictions are possible with afternoon showers and thunderstorms. && .MARINE... Today and Tonight: Coastal low pressure has developed around 40 nm east of Savannah, GA with showers and thunderstorms now focusing over the coastal waters. A few stronger storms are possible near the surface low with gusty winds and an isolated waterspout the primary threats. Wave heights will also start to build this afternoon towards 2 to 4 ft. Sunday through Thursday: As the pressure gradient strengthens, east- northeasterly winds will become rather gusty across the Atlantic until the middle of the week (w/ gusts up to 25 to 30 kts possible). Therefore, Small Craft Advisories were issued for all marine zones beginning on Sunday and lasting until at least Tuesday. Seas will will range from 5 to 7 ft, and then back down to 2 to 4 ft on Wednesday morning. Rip Currents: Due to the increasing strength of the pressure gradient and the holiday weekend, a moderate risk of rip currents has been issued for today and tomorrow (Sunday). Also, a high risk of rip currents has been issued for Monday. && .TIDES/COASTAL FLOODING... Tidal departures could begin to build over the weekend into early next week as low pressure develops offshore and a wedge of high pressure lingers inland. Tides could get close to minor flood thresholds in the Charleston Harbor by Monday yielding a risk for coastal flooding across coastal areas of Charleston and Colleton Counties during mainly the afternoon high tide cycle. This risk may extend into the middle of next week depending on how strong the pinched gradient gets. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...None. SC...None. MARINE...Small Craft Advisory from 10 AM Sunday to 2 AM EDT Monday for AMZ330. Small Craft Advisory from 6 AM Sunday to 8 AM EDT Tuesday for AMZ350-352-354. Small Craft Advisory from 6 AM Sunday to 8 PM EDT Tuesday for AMZ374. && $$ NEAR TERM...Haines SHORT TERM...Dennis LONG TERM...Dennis AVIATION...CPM/Dennis MARINE...Dennis/Haines