FXUS62 KCHS 290544 AFDCHS
Area Forecast Discussion National Weather Service Charleston SC 1244 AM EST Sat Nov 29 2025
.SYNOPSIS...
High pressure will prevail through the weekend. A storm system should bring some impacts to our area late Monday into Tuesday. High pressure returns for the middle to end of next week.
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.NEAR TERM /THROUGH TONIGHT/...
Today will begin with thick cirrus and mid-clouds across the forecast area. Near term guidance indicates that the high clouds will clear from west to east during the afternoon, resulting in several hours of mostly to partly sunny conditions before sunset. Sfc high pressure centered over mid-Atlantic states will ridge across the region today. The pressure gradient will support steady east-northeast winds, gradually increasing to around 10 mph this afternoon. Along the coast, wind gusts near 20 mph is possible at times. Using a blend of MOS, high temperatures are forecast to range from the low to mid 50s across the SC Lowcountry to the low 60s across SE GA.
Tonight, the region will remain under SW H5 flow, with a broad trough over the Mississippi River Valley. High resolution guidance indicates that an inverted sfc trough will develop over the Gulf Stream. Isolated showers are forecast to develop within the sfc trough, generally remaining over the outer GA and SC waters. Cloud cover should gradually increase over the CWA as the trough deepens. Low temperatures may fall to the mid 30s across the inland counties, ranging near 50 along the coast.
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.SHORT TERM /SUNDAY THROUGH TUESDAY/...
For Sunday, the weak coastal trough mixes out ahead of an approaching cold front which will allow for a brief return of warmer temperatures. 850mb temperatures reach back up into the upper single digits expect, so expecting highs in the mid to upper 60s across southeastern South Carolina and upper 60s to mid 70s across southeastern Georgia. Isentropic lift may again result in some weak showers developing during the afternoon hours, but the better chances arrive during the evening and overnight hours as the cold front slips through the area along with some scattered and weak shortwaves.
On Monday, surface high pressure builds into the region from the north throughout the day, with the aforementioned cold front being pushed off to our south into northern Florida. This will drop afternoon temperatures back down into the mid 50s to mid 60s, warmest across southeast Georgia. Chances for rainfall have lowered as the previously expected shortwaves have sped up and moved across with the cold front, though mostly cloudy skies remain expected.
As a trough move towards the area before lifting up into the northeast, a surface low will be moving towards the area across the Gulf which will be increasing rainfall chances late Monday and overnight into Tuesday. Model consensus have shifted the surface low a touch further inland, keeping the heaviest rainfall more across the midlands than the coast. Timing of the heaviest rainfall for the region looks most likely during the morning hours on Tuesday as the surface low traverses the region, though lingering light rain will be possible into the evening hours. Despite precipitable water values approaching the 90th percentile of climatology near 1.5 inches, rainfall amounts look to remain largely in the 0.5-1.0 inch range, highest across inland southeast South Carolina. Given the current drought conditions and lack of recent appreciable rainfall, no flooding concerns are expected.
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.LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...
Chances for rainfall dwindle overnight into Wednesday, with surface high pressure building into the region behind the cold front. With strong zonal flow aloft, the surface high pressure moves offshore fairly quickly into Thursday morning, bringing temperatures back to near normal though likely remaining a few degrees shy in the mid 50s to lower 60s Thursday and Friday. Model consensus remains rather poor for the end of the week as they struggle to determine what to do with the strong shortwave/trough along the west coast, with the NBM bringing back low end (20-40%) chances for rainfall on Friday.
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.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
VFR conditions will prevail at KCHS, KJZI, and KSAV through 06z Sunday.
Extended Aviation Outlook: There are low probabilities of flight restrictions Sunday and Monday, but would most likely be due to low ceilings. A storm system will bring higher probabilities of flight restrictions late Monday into Tuesday, with both low ceilings and lowered vsbys possible.
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.MARINE...
Today through tonight, a ridge of high pressure will remain across the nearshore waters of SC and GA. An inverted trough should gradually deepen over the Gulf Stream late tonight. East-northeast winds around 20 kts should persists across the marine zones today. As the trough develops tonight, winds should veer from the east and subside to 10 to 15 kts. Seas are forecast to range between 3-4 ft, with 5 ft seas possible across the outer GA waters this afternoon and evening.
Sunday through Wednesday: Winds weaken on Sunday, but will be increasing throughout the day on Monday as a cold front approaches the area from the west. Winds may begin to approach small craft criteria on Monday along the southeast South Carolina coast, with some 6 foot seas also possible. Highest rainfall chances will occur early Tuesday morning as a surface low pressure is expected to traverse the region, with winds currently looking sub-advisory, but seas do begin to approach/exceed 6 feet again on Tuesday. High pressure returns on Wednesday, with conditions improving.
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.CHS WATCHES/WARNINGS/ADVISORIES...
GA...None. SC...None. MARINE...None.
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NEAR TERM...NED SHORT TERM...APT LONG TERM...APT AVIATION...APT/NED MARINE...APT/NED