


Area Forecast Discussion
Issued by NWS Charleston, SC
Issued by NWS Charleston, SC
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871 FXUS62 KCHS 081132 AFDCHS Area Forecast Discussion National Weather Service Charleston SC 732 AM EDT Wed Oct 8 2025 .SYNOPSIS... High pressure will persist across the region today. A cold front will drop south through the area tonight into Thursday with inland high pressure prevailing into early next week. Low pressure will develop off the Southeast U.S. coast this weekend. && .NEAR TERM /THROUGH TONIGHT/... Today: Aloft, mid-upper lvl ridging will remain stretched across region from the northeast Gulf Coast to the western Atlantic ahead of a large trough advancing across the Great Lakes region to the Northeast and Mid-Atlantic states by mid- late afternoon. The trough will help advance a cold front toward the region, but the front will remain west of the local area through daylight hours. Ahead of this feature, weak high pressure will hold across the local area under the ridge axis aloft, supporting warmer temps across Southeast South Carolina and Southeast Georgia within a light east-southeast flow. In general, high temps should peak in the mid-upper 80s, warmest across the Georgia interior. A few spots could even touch 90 well inland in this area. Initial h5 vort energy associated with the mid- upper lvl trough arrives mid afternoon, and given ample heating and a stretch of PWATs approaching 2 inches should favor few to perhaps scattered showers/thunderstorms across areas well inland prior to sunset. Tonight: A cold front will approach from the northwest, nudging a few to scattered showers and thunderstorms toward the coast during evening hours. Fropa should be slow to occur during the overnight, becoming further displaced from the mid-upper lvl trough passing across the Northeast and offshore. Sfc winds will flip to the northeast after midnight as high pressure builds in wake of the front, leading to breezy conditions late as the pressure gradient tightens and cold air advection takes place. Timing of the front along with cold air advection will be key to how gusty winds are able to get prior to daybreak, which could lead to a Lake Wind Advisory across Lake Moultrie starting around daybreak. Temps will remain mild prior to fropa, but eventually dip into the low-mid 60s after midnight. && .SHORT TERM /THURSDAY THROUGH SATURDAY/... In the wake of a cold front high pressure will build into the region on Thursday morning, centered over New England. Aloft, the region will remain in the southern periphery of large scale troughing over the eastern CONUS. Some lingering showers post-FROPA are possible, mainly along the southeastern GA coastline. Otherwise, most other areas will remain rain free. The cold front will usher in a cooler airmass, with temperatures Thursday forecast to only reach into the low to mid 70s, with a steady NE wind gusting to around 20 mph in the afternoon. Gusts will be higher along the direct coastline. Overnight lows will drop into the mid 50s far inland, with around 60 along the coastal counties. An upper low will develop over the southeastern states Friday and into Saturday. In association with this upper low, surface cyclogenesis is expected off the southeastern coast. A wedge of high pressure will remain in place over the local forecast areas. There is a chance of rain mainly along the coastline Friday and Saturday, however the rainfall will likely be dependent on the position of cyclogenesis off the coast. With the region pinched between the high pressure inland and the cyclogenesis offshore breezy conditions will prevail over the area, strongest along the beaches. High temperatures in the low to mid 70s Friday will warm into the mid to upper 70s on Saturday. Overnight lows will be in the 50s inland and 60s near the coast. Lake Winds: Winds on Lake Moultrie will become elevated early Thursday morning and into the weekend as a strong, pinched gradient develops in response to building high pressure across the region and cyclogenesis off the coast. Winds look to reach Lake Wind Advisory level criteria (sustained 20 kt or frequent gusts to 25 kt) during this time and a Lake Wind Advisory will likely be required. && .LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/... The region will be under the influence of cyclonic flow aloft centered over the Mid-Atlantic. High pressure will prevail at the surface, reinforced by the cyclonic flow aloft. A rain-free forecast has been maintained through the period. Temperatures will slowly warm to slightly above normal by the middle of next week. && .AVIATION /12Z WEDNESDAY THROUGH SUNDAY/... Shallow ground fog is possible at CHS/JZI/SAV terminals through 13Z this morning. VFR conditions are then expected to prevail through 12Z Thursday, although a few showers could briefly result in MVFR conditions at all terminals tonight. Confidence is too low to include in the 12Z TAF issuance. A cold front will shift across the area tonight, resulting in winds turning northeast and gusting upwards to 15-20 kt prior to daybreak Thursday. Extended Aviation Outlook: Gusty N to NE winds will impact KCHS/KJZI/KSAV Thursday and Friday, possibly lingering into the weekend as high pressure builds over the region. && .MARINE... Today and Tonight: Weak high pressure will prevail across local waters for much of the day well ahead of a cold front arriving overnight. Once fropa occurs, conditions are expected to deteriorate late night, with winds increasing and seas building as strong high pressure builds in wake of the front and cold air advection begins. During the day, easterly winds will be no higher than 5-10 kt with seas 3-4 ft across nearshore waters and 4-5 ft across outer Georgia waters. Overnight, winds become northeasterly, increasing to 15-20 kt after midnight. Gusts around 25 kt begin across nearshore waters off the Charleston County Coast late, but seas will initially be slow to build across remaining waters until after daybreak. A Small Craft Advisory has been issued for nearshore waters off Charleston County at 5 AM, with remaining waters following at 8 AM. Thursday through Monday: A cold front will push into the marine waters Thursday morning, bringing rapidly deteriorating marine conditions as high pressure builds across inland zones and low pressure develops off the southeast coast. NE winds will increase to 20 to 25 knots Thursday morning, with seas 4 to 5 ft across the nearshore waters and 5 to 6 ft in the 20 to 60 nm offshore GA waters. A Small Craft Advisory has been issued for all waters including the Charleston Harbor starting Thursday morning. Winds are expected to continue to increase into the afternoon hours, with gusts approaching 35 knots. A Gale Watch has been issued for all waters outside of the Charleston Harbor through the weekend. Due to the low pressure development off the southeast coast seas will build into the weekend, peaking Friday night into Saturday with 8 to 10ft in the nearshore waters and up to 12 ft in the 20 to 60 nm offshore GA waters. As the low pressure departs to the northeast and high pressure begins to weaken inland conditions will begin to improve on Monday, however 25 knot wind gusts could linger across the marine zones. Rip Currents: A lingering 8-9 sec swell will keep the rip current risk into the moderate range for all beaches today. A blend of the latest rip current MOS with local rip current calculations support a high risk of rip currents at all area beaches on Friday. An enhanced risk of rip currents will persist into the weekend due to building surf and increasing winds associated with the building high pressure. High Surf: The risk for high surf will increase Thursday night into the start of the weekend as wave heights increase across the local waters. A High Surf Advisory may be required for some area beaches. && .TIDES/COASTAL FLOODING... Wednesday morning high tides: Based on recent tidal trend departures, tide levels were increased to 7.7 ft MLLW at Charleston Harbor and 9.8 ft MLLW at Fort Pulaski, GA. Coastal Flood Advisories are in effect from 7 to 11 AM for Charleston and coastal Colleton Counties and 8 to 11 AM from Beaufort south to McIntosh County. Astronomical tides will continue to increase this week due to the full moon today (Oct 7) and perigee (Oct 8). Additionally, tidal departure values will begin to increase again late week and into the weekend due to strong NE winds. As a result, the threat for minor to moderate coastal flooding continues through mid-week. Late week the threat for major coastal flooding arrives for the late morning high tides. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...Coastal Flood Advisory until 11 AM EDT this morning for GAZ117- 119-139-141. SC...Coastal Flood Advisory until 11 AM EDT this morning for SCZ048- 051. Coastal Flood Advisory until 11 AM EDT this morning for SCZ049- 050. MARINE...Small Craft Advisory from 8 AM Thursday to 6 AM EDT Sunday for AMZ330. Small Craft Advisory from 5 AM to 2 PM EDT Thursday for AMZ350. Gale Watch from Thursday afternoon through late Saturday night for AMZ350. Small Craft Advisory from 8 AM to 2 PM EDT Thursday for AMZ352- 354-374. Gale Watch from Thursday afternoon through Saturday evening for AMZ352. Gale Watch from Thursday afternoon through Saturday afternoon for AMZ354. Gale Watch from Thursday afternoon through Sunday morning for AMZ374. && $$ NEAR TERM...DPB SHORT TERM...CPM LONG TERM...CPM AVIATION...CPM/DPB MARINE...CPM/DPB