679 FXUS62 KCHS 300202 AFDCHS Area Forecast Discussion National Weather Service Charleston SC 1002 PM EDT Fri Oct 29 2021 .SYNOPSIS... A low pressure system will move northeast away from the area through Saturday. High pressure will return on Sunday and prevail through the middle of next week. A cold front will drop through the area on Wednesday. && .NEAR TERM /UNTIL 6 AM SATURDAY MORNING/... A deep cyclone aloft near the central and southern Appalachians, and its associated broad trough will impact the local region through the night. The forecast challenges for tonight involve the amount of cloud cover and how cool it gets. Time cross-sections and soundings indicate that there is sufficient moisture around 5-8K feet to result in variable cloudiness throughout. We'll be mostly clear or partly cloudy early on, but as the upper low draws a bit closer late, cloud cover will transition more into partly or mostly cloudy skies. The combination of mixing and these clouds will limit how much radiational cooling will occur. But there is enough cold air advection to allow for min temps to get down near or even slightly below normal. If we stayed with little or no clouds for a long enough period of time we could get a little cooler. && .SHORT TERM /6 AM SATURDAY MORNING THROUGH MONDAY/... The powerful upper low will gradually move over the area on Saturday while the comma head of the surface low rotates through the western Carolinas. Cooler, drier air will continue to filter in from the west. Scattered to broken low/mid clouds will likely persist across the western half of the area during the day. Highs will be in the mid/upper 60s. Sunday through Monday will feature dry weather, clear skies, and a gradual warming trend with highs reaching the mid 70s by Monday. && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... A zonal upper pattern will favor a backdoor cold front dropping into the area mid-week and a high pressure wedge building from the north. Rain chances do not look particularly impressive, though a few showers are possible late in the week. At a minimum, clouds will be on the increase and temps will likely be a few degrees below normal. && .AVIATION /02Z SATURDAY THROUGH WEDNESDAY/... VFR with the 00Z TAFs. Gusty westerly winds expected at KCHS, KJZI and KSAV during much of Saturday, with peak gusts close to 20 kt. Extended Aviation Outlook: VFR. && .MARINE... Tonight: The local waters will remain under the influence of a large area of low pressure and the resulting cyclonic flow, which will generate SW and W winds. Basing the forecast on recent trends, we have a Small Craft Advisory for all waters outside of the Charleston Harbor. Seas were high to begin with, but with the offshore trajectories, seas will gradually drop about a foot or two through the night. The gradient on Saturday will slowly relax as the powerful surface low moves farther away to the northeast and high pressure builds in from the west. Although gusty west winds are expected, conditions should remain just below advisory levels. Fairly quiet marine conditions then expected through mid-week before a cold front drops through the area and a enhanced northeast gradient develops. We cannot rule out some headlines during the mid to late part of next week. Rip Currents: A small, 12-second swell will persist into Saturday which, combined with gusty winds, could result in a few rip currents. Therefore a Moderate risk continues through Saturday evening. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...None. SC...None. MARINE...Small Craft Advisory until 1 AM EDT Saturday for AMZ352. Small Craft Advisory until 8 AM EDT Saturday for AMZ374. Small Craft Advisory until 4 AM EDT Saturday for AMZ350. Small Craft Advisory until 11 PM EDT this evening for AMZ354. && $$ NEAR TERM... SHORT TERM...JRL LONG TERM...JRL AVIATION... MARINE...