Area Forecast Discussion
Issued by NWS Columbia, SC
Issued by NWS Columbia, SC
385 FXUS62 KCAE 171844 AFDCAE Area Forecast Discussion National Weather Service Columbia SC 244 PM EDT Fri Oct 17 2025 .SYNOPSIS... Dry and cooler conditions are expected today with temperatures warming up on Saturday ahead of the next storm system. A cold front will cross the FA on Sunday bringing breezy winds and the next chance for showers and maybe a storm or two. Dry weather is likely to follow next week. && .NEAR TERM /UNTIL 6 AM SATURDAY MORNING/... Key message(s): - None Surface high pressure has settled over the Carolinas with afternoon dew points into the upper 30s in the Pee Dee and mid 40s elsewhere. Winds will be light and variable through much of the next 24 hours with high pressure overhead. An upper level ridge will build over the Southeast through the near term leading to increasing high clouds this evening and tonight. This should hinder fog development and radiational cooling. Highs will be in the 70s with lows in the low to mid 50s and river valley fog around sunrise Saturday. && .SHORT TERM /6 AM SATURDAY MORNING THROUGH SUNDAY NIGHT/... Key message(s): - Dry weather continues Saturday with dry weather. - A cold front moves through Sunday with a chance of showers and thunderstorms along with breezy winds. Saturday and Saturday Night: The upper ridge moves overhead with high pressure hanging on during the day Saturday before both features get ushered off shore with a potent trough digging into the Midwest and down into the Southern Plains. This will help turn low level flow out of the southwest during the day, allowing moisture to slowly increase and bring afternoon temperatures up into the upper 70s to low 80s. A surface cold front associated with the upper trough creeps closer overnight, but is expected to remain west of the region and thus dry weather likely continues, though cloud cover may increase toward Sunday morning. Overnight lows in the mid to upper 50s are expected. Sunday and Sunday Night: 12z model guidance has given a bit more confidence in the progression of the potent upper trough and surface cold front Sunday, but some timing differences remain. In general, longer duration CAMs, and the deterministic RAP/NAM/GFS/ECMWF, show the cold front in the western Appalachians between 12z and 15z with a line of convection ahead of it, likely also forced by a shortwave ahead of the main trough axis. How this convection progresses is a bit more uncertain, with discrepancies between guidance on the amount of moisture that pools ahead of the front, and the overall propagation speed of the convection. Majority of guidance does show a general weakening trend in the line as it moves across GA, likely due to a lack of instability from overspreading debris clouds and a 90+ knot upper jet streak pulling away north of the region. The ECMWF is the most aggressive in terms of moisture ahead of the front with a broad tongue of PWAT`s between 1.70-1.80" while the GFS is a bit more conservative. In terms of timing, the ECMWF/NAM are on the slower side, with weakly organized convection reaching the western FA between 18-21z while the GFS/RRFS/RAP are a bit quicker and less organized, with activity moving in between 15-18z. Overall, very little instability is forecast ahead of the front (MUCAPE under 500 J/kg) but deep layer shear is expected to be on the order of 40-50 kts with generous low level shear as well. With the expected limited instability and timing differences, confidence in thunderstorm activity across the FA is on the lower side with the best chance being in the western FA at this time and the remainder of area looking at isolated to scattered showers before the front clears by the overnight hours. Some breezy winds will be possible ahead of the front also with gusts to 20-25 mph expected at this time. Dry conditions likely move in behind the front overnight with lows back into the upper 40s. && .LONG TERM /MONDAY THROUGH FRIDAY/... Key message(s): - Dry weather likely returns for the extended period. Not much change in the extended period forecast as cool and very dry air filters in with high pressure for the early week (PWAT`s likely under 0.50"), leading to temperatures that are initially below average Monday, then near average on Tuesday. Another cold front is expected to pass late Tuesday and into Wednesday, but the very dry airmass should preclude any rain. This will bring another push of cooler air with just below average temperatures Wednesday and Thursday, though dry conditions likely prevail as surface high pressure builds back in, possibly continuing into the the end of the week. With this cool and very dry air across the region, multiple nights next week of near ideal radiational cooling conditions are expected where chilly lows into the 40s will be possible. && .AVIATION /19Z FRIDAY THROUGH WEDNESDAY/... Apart from shallow fog at AGS and OGB, VFR conditions expected High pressure over the area will keep winds light and variable through the TAF period. An upper level ridge will shift east across the Southeast allowing high clouds to advect into the region this evening and tonight. High clouds will limit radiational cooling and fog development tonight. Crossover temperatures will be in the 40s with lows expected in the 50s so widespread fog is unlikely. That said, river valley fog near AGS and OGB may bring typical, periodic vis restrictions. This would be most likely right around sunrise because the high clouds may be clearing out by then allowing a few hours of stronger radiational cooling. With high pressure shifting offshore on Saturday, winds will pick up out of the SW around 5 to 10 kts after 15Z. Dry weather is expected to continue with just a few afternoon cumulus. EXTENDED AVIATION OUTLOOK...The next chance for widespread restrictions will be Sunday morning ahead of a cold front which will move across the Southeast. && .CAE WATCHES/WARNINGS/ADVISORIES... SC...None. GA...None. && $$