textproduct: Columbia

SYNOPSIS

Near record temperatures today and Saturday. Isolated showers or thunderstorms are possible late this evening into Saturday as a cold front passes, before high pressure and dry conditions return for the start of Thanksgiving week. Rain chances then move back in during the middle of next week.

NEAR TERM /THROUGH TONIGHT/

Key message(s):

- Areas of dense fog continues through mid-morning.

- Near record high temperatures this afternoon and isolated showers this evening.

Abundant moisture near the surface and calm winds have allowed for the redevelopment of fog and low stratus tonight. Dewpoints depressions continue to be 3 degrees or less across most of the area. A Dense Fog Advisory is out through later this morning given multiple locations with less than 1/4 mile visibility and likely some decreasing visibility around sunrise.

A weak shortwave is still moving north of the area, mainly across NC. Associated showers are mainly remaining outside of our CWA, but a weak shower or sprinkle along the NC/SC border can't be ruled out. Otherwise, rain-free conditions are expected to continue today, with highs pushing near-record levels (upper 70s to low 80s) after the fog and stratus mix out. This is due to upper ridging and warm advection ahead of the next weather system. Strengthening southwesterly flow will continue to advect moisture into the area, with PWAT's near 1.25" through today and closer to 1.5" by Saturday morning. Dew points also look to be toward the low to mid 60s so it should feel unseasonably humid as well during the afternoon. Isolated rain showers become possible late this evening and tonight with subtle height falls ahead of a shortwave. Any accumulations should be light, generally less than 0.10".

SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/

Key message(s):

- Very warm with showers-storms around Saturday, turning cooler and drier Sunday.

By Saturday morning, the diffuse surface front and associated mid- level shortwave will crawl across the region. Relatively impressive southwesterly moisture return and WAA ahead of the front will develop some scattered showers and storms across the area, especially early Saturday. Some non-zero instability will also develop thanks to the very surface temps, so a few thunderstorms are possible Saturday. HREF members are fairly consistent in bringing through a few waves of scattered showers-storms as a result. Given the diffuse nature of the front, WAA advection will continue into the afternoon and near record temps are likely again despite the precip around; EC EFI pegs out over 0.9 for portions of the area, along NAEFS surface-850mb temps over the 95th percentile. So temps climbing into the low 80's are expected Saturday afternoon. Eventually this slow moving front will push late Saturday into Sunday, shifting winds out of the north and bringing some notable CAA and dry advection throughout Sunday. So precip chances drop off and high temps will fall into the upper 60's or low 70's Sunday.

LONG TERM /MONDAY THROUGH THURSDAY/

Key message(s):

- Brief cooldown early in the week with rain chances increasing Tuesday-Thursday.

Following the front on Sunday, northwesterly flow will develop across the area with significant dry air and surface ridging moving in for Monday. Tuesday is when the forecast becomes uncertain and inconsistent across guidance as the persistent cutoff low in the western CONUS ejects northeast. ECE and GEFS guidance show a similar pattern, with a lifting surface low into the Great Lakes and progression, but are about a day different in timing. For now, confidence is only high enough to say that rain chances will increase starting late Tuesday and last through Thursday as a relatively moving front transverses the area. Depending on how quick the progression of the front is, moisture convergence could support some notable precip and possible QPF; GEFS is pretty consistent in pushing PWAT's to around 1.75".

AVIATION /12Z FRIDAY THROUGH TUESDAY/

Restrictions in fog and stratus are expected to continue this morning.

Widespread dense fog and stratus will cause IFR/LIFR conditions this morning. Winds should be relatively light to near calm through the night before picking up from the southwest around 5 to 10 knots after 15z. This should help restrictions ease and return to VFR with mixing between 15z-17z. Southwest winds continue this evening and overnight ahead of the next system, so expect SCT-BKN high clouds to persist as moisture increases.

EXTENDED AVIATION OUTLOOK...VFR conditions likely continue this afternoon. Increasing moisture Friday night into Saturday will lead to chances for rain and possible restrictions.

CAE WATCHES/WARNINGS/ADVISORIES

SC...Dense Fog Advisory until 10 AM EST this morning for SCZ016-018- 020>022-025>031-035-037-038-041-115-116-135>137. GA...Dense Fog Advisory until 10 AM EST this morning for GAZ040- 063>065-077.