Area Forecast Discussion
Issued by NWS Columbia, SC
Issued by NWS Columbia, SC
787 FXUS62 KCAE 121021 AFDCAE Area Forecast Discussion National Weather Service Columbia SC 621 AM EDT Sat Sep 12 2026 .WHAT HAS CHANGED... Separated key messages to reflect on today`s convective potential and a pattern shift into early next week. && .KEY MESSAGES... - 1. Another round of showers and thunderstorms expected today. - 2. Above normal temperatures last into next week with drier conditions returning. && .DISCUSSION... KEY MESSAGE 1: Another round of showers and thunderstorms expected today. Upper troughing continues to move across the southern tier over the next 24-36 hours, with rich moisture continuing to advect into the area. PW will continue to increase above 1.8" and eventually surpass 2" in the next few hours. Convective temps are forecast in the upper 80s and lower 90s again this afternoon, and combined with a weak shortwave passing through the region, there should be enough instability for showers and thunderstorms to go another round. That said, DCAPE values are largely unimpressive and any downbursts will likely be forced mainly by precip loading. CAMs depict more of a linear segment moving through the FA this afternoon and evening, but shear appears to be minimal. Given the high moisture in place, expect fairly decent coverage of precip across the region with the potential for some heavier rainfall totals. Additional uncertainty lies in how long it takes to reach convective temperatures given the remaining debris clouds from Friday`s convection, and whether stratus is able to develop in the pre-dawn hours this morning. This could push back timing of convective initiation. KEY MESSAGE 2: Above normal temperatures last into next week with drier conditions returning. Sunday into early next week, the trough moves offshore and strong ridging builds over the eastern CONUS. Precip chances are expected to diminish as a result, and PW values fall below 1.6". The ridge is then forecast to remain in control much of next week, and temperatures should remain above normal with decent confidence and small IQR`s. Monday should be the warmest day with a notable drop several degrees by Tuesday due to a generally dry backdoor front crossing the region. Surface dewpoints also look to drop further, helping make the airmass more fall-like. Still, highs remain above typical mid-September values. We`ll continue to watch for some weakness on the eastern side of the ridge. Models are depicting an interesting feature mid to late next week regarding an upper low rotating around the high from New England south along the Atlantic Coast and eventually retrograding into the Gulf. There is still plenty of uncertainty regarding this low`s evolution in the extended, including if or when it may influence our sensible weather. && .AVIATION /12Z SATURDAY THROUGH WEDNESDAY/... Restrictions will continue this morning through 15Z. Additional fog/stratus possible tonight. Widespread rain yesterday has led to increased low level moisture over the region. Weak winds early this morning have promoted ceiling and visibility restrictions at all TAF sites. Convective debris clouds seem to be playing a role in limiting the extent of fog/stratus and causing restrictions to periodically lift. As the debris cloudiness continues to clear we should see restrictions become more sustained. Numerous thunderstorms are expected again today with deep moisture over the region. Confidence in thunderstorm restrictions has increased and allowed us to put VCTS in the TAFs after 18Z for all sites. These storms should be efficient rain producers and would lead to brief visibility restrictions. Storms will likely continue into the early evening but diminish overnight. Rainfall may lead to a similar outlook for restrictions tonight with patchy fog expected, at least in locations that receive heavy rain. EXTENDED AVIATION OUTLOOK...Lower rain chances Sunday but the potential for early morning fog/stratus persists into early next week. && .CAE WATCHES/WARNINGS/ADVISORIES... SC...None. GA...None. && $$ DISCUSSION...EC AVIATION...CJR