FXUS62 KCHS 261116 AFDCHS
Area Forecast Discussion National Weather Service Charleston SC 716 AM EDT Sun Oct 26 2025
.SYNOPSIS...
High pressure will prevail through the weekend. An upper disturbance and complex surface frontal system will impact the area late Sunday through Monday night. A strong cold front could move through during the middle of next week before high pressure returns late week into next weekend.
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.NEAR TERM /THROUGH TONIGHT/...
Today: The sfc pattern will feature a ridge centered over the east facing slopes of the southern Appalachians as low pressure organizes along the Gulf shore of the FL Panhandle. PW will begin the day around 1 inch, increasing to 1.5 inches across SE GA by late this afternoon. This morning, cloud cover should gradually thicken as isolated to scattered light showers remains over the adjacent Atlantic waters. This afternoon, forcing should gradually increase as the H5 closed low swings over the Mississippi River Valley. Isolated showers are possible along the coast and over extreme SE GA. Given gusty northeast winds and thick cloud cover, high temperatures may remain limited to the 60s inland to the low 70s along the coast and SE GA.
Tonight, deep moisture will continue to stream across the forecast area, exceeding 1.8 inches by daybreak Monday over portions of SE GA. H5 Q-vector convergence is timed to approach from the Deep South by the pre-dawn hours. The combination of synoptic scale forcing and deep moisture should support scattered to numerous showers across the CWA by late tonight. Some coastal areas may see rainfall amounts reach a quarter of an inch by late tonight. Low temperatures are forecast to range from the mid 50s inland to the low 60s along the coast.
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.SHORT TERM /MONDAY THROUGH WEDNESDAY NIGHT/...
Monday: Approaching upper trough will deepen low pressure off the SE coast through the morning Monday, with the pattern remaining progressive and the low shifting well north and east of the area by later in the day. Still, ample low level moisture advection across the quasi-stationary boundary to our south will keep widespread light to moderate rainfall in place through midday, with coverage decreasing from south to north through the afternoon and evening. Predicted total rainfall amounts remain around 1-1.5 inches for Monday and Monday night. Hi-res guidance indicates that the heaviest rainfall -total amounts approaching 3 inches - should remain immediately along the beaches or offshore. In addition to the rainfall, northeasterly winds will continue to increase throughout the day on Monday as the local pressure gradient remains pinched.
Tuesday through Thursday: Expect winds to shift more northerly on Tuesday as high pressure ridges down the coast, persisting into Wednesday. Guidance indicates that some showers could linger into Tuesday, but expect coverage to be very limited given strengthening upper subsidence and drier low level air.
By later Wednesday, a cold front will work across the Southeast, with a cutoff low aloft lifting across the Tennessee and toward the Ohio Valley. While the parent low fills, a new wave developing within the approaching front will become dominate, lifting across the Mid-Atlantic Thursday and helping usher the strong front across out area later Wednesday/early Thursday. The moisture available with the frontal passage is very uncertain, with the most likely solution being a mostly dry frontal passage at this point. Strong high pressure builds in from the West behind the front, through the later part of the day Thursday.
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.LONG TERM /THURSDAY THROUGH SATURDAY/...
Cool high pressure builds overhead Friday and Saturday as mainly dry conditions prevail. Saturday morning has trended a bit cooler, with very favorable radiational cooling conditions bringing temps into the upper 30s for inland areas. We will need to monitor this period for the potential first frost hazards of the season.
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.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
12Z TAFs: The sfc pattern will feature ridging high pressure centered over the western Carolinas as low pressure organizes near the Mississippi Delta. This pattern will support gusty northeast winds across the terminals, with the highest gusts above 20 kts at KJZI during the daylight hours. Light rainfall should gradually increase in coverage from south to north this evening. KSAV and KJZI will feature VCSH by 3Z. Overnight, deep forcing and moisture should build across the terminals by late night. Restrictive ceilings and periods of MVFR vis with light rainfall appears possible at KSAV and KJZI by 9Z.
Extended Aviation Outlook: Widespread rainfall is expected through late Monday morning as low pressure develops off the coast, bringing the potential for additional flight restrictions into later Monday. VFR should then prevail Tuesday through late week.
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.MARINE...
Today and Tonight: The sfc pattern will feature a ridge centered over the east facing slopes of the southern Appalachians as low pressure organizes along the Gulf shore of the FL Panhandle. This pattern will support gusty NE winds, with gusts generally around 25 kts. Afternoon mixing may aid in gusts across the CHS Harbor to reach 25 kts this afternoon. A Small Craft Advisory for the Harbor will begin early this afternoon, with all marine zones in effect through the near term. Wave heights should build through the period, ranging between 6 to 9 ft by late tonight.
Monday through Thursday: Low pressure developing off the SE coast will bring the potential for winds to approach gale strength, especially along the SC coast, Monday into Monday night. Otherwise, breezy northeasterly winds will persist through at least the middle of the week as high pressure ridges inland. This, in combination with a complex mix of northeast windswell and developing longer periods swell from TC Melissa passing well off the coast mid-to-late week, will keep Small Craft Advisories in place into at least Friday.
Rip Currents: There is a high rip current risk for all beaches today as breezy NE winds bring building swell. It's likely there will be an enhanced risk on Monday into next week due a combination of increasing winds and seas.
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.CLIMATE...
Record Precipitation:
October 27: KCXM: 1.49/1985
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.CHS WATCHES/WARNINGS/ADVISORIES...
GA...High Risk for Rip Currents through this evening for GAZ117-119-139-
141.
SC...High Risk for Rip Currents through this evening for SCZ048>051. MARINE...Small Craft Advisory from 2 PM this afternoon to midnight EDT
Tuesday night for AMZ330. Small Craft Advisory until 6 AM EDT Friday for AMZ350-374. Small Craft Advisory until 11 PM EDT Thursday for AMZ352. Small Craft Advisory until 2 PM EDT Thursday for AMZ354.
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NEAR TERM... SHORT TERM... LONG TERM... AVIATION... MARINE...