


Area Forecast Discussion
Issued by NWS Columbia, SC
Issued by NWS Columbia, SC
520 FXUS62 KCAE 271838 AFDCAE Area Forecast Discussion National Weather Service Columbia SC 238 PM EDT Thu Mar 27 2025 .SYNOPSIS... Dry conditions and elevated fire concerns continue this afternoon and into Friday, before moisture starts to increase this weekend. Rain chances rise Saturday night with showers and thunderstorms possible Sunday and especially on Monday. Near to above normal temperatures will continue through the next seven days. && .NEAR TERM /THROUGH TONIGHT/... Key Message(s): - Increased fire danger continues this afternoon and evening. Surface high pressure is centered over the region this afternoon as we keep clear skies and very dry air with PWAT`s around 0.40". At the upper levels a ridge is seen across the central US with a sharp trough just west of Texas, slowly working toward the western Gulf. Light and variable winds are being seen this afternoon as dewpoints are falling into the low to mid 20s. This is leading to another afternoon of elevated fire danger as RH values reach the teens to low 20 percents with very dry fuels. High temperatures look to reach the mid 70s for most to around 70 in northern spots, before winds become calm at many locations shortly after sunset and strong radiational cooling sets up. The main inhibitor for cooling later in the night will be increasing moisture aloft and increasing high clouds into Friday morning. There is some uncertainty in the coverage of these clouds and thus if less cloud cover is seen, strong cooling conditions will allow temperatures to quickly fall, but currently I expect cloud cover will affect radiational cooling conditions enough to keep overnight lows into the mid to upper 40s. && .SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/... Key Message(s): - One more day of elevated fire danger on Friday as moisture gradually rises through the period. - Rain chances increase Saturday night ahead of an approaching shortwave. Friday and Friday Night: Upper ridging will build overhead on Friday while the center of surface high pressure drifts east towards Bermuda. This pattern favors warmer temperatures with forecast highs in the upper 70s to lower 80s despite have some more clouds around. Southerly winds around the aforementioned high pressure will allow for some moisture return so RH values should be higher than recent days, especially across the southern and eastern FA. Clouds increase in coverage Friday night ahead of an approaching shortwave limiting nocturnal cooling with forecast lows in the mid to upper 50s. Saturday and Saturday Night: Shortwave trough moves over the upper ridge on Saturday but will be weakening as it approaches our region. However, there should be enough lift, combined with southwesterly flow leading to increasing moisture aloft, to produce partly to mostly cloudy skies. The lower atmosphere remains fairly dry so rain chances are low until late Saturday night when the shortwave gets closer. With surface high pressure centered near Bermuda, winds will remain generally out of the south at the surface on Saturday, becoming southeasterly at night. The onshore flow should aid in eroding the dry air mass in place further lowering the threat of increased fire danger. The increased cloudiness should result in slightly lower temperatures but still above seasonal values. A few showers are possible towards daybreak, especially across the western Midlands and CSRA, but amounts through daybreak Sunday should be generally light. && .LONG TERM /SUNDAY THROUGH THURSDAY/... Key Message(s): - Chance of showers and thunderstorms on Sunday, and especially Monday. - A few thunderstorms may become strong to severe on Monday as a cold front sweeps through the region. - Near to above normal temperatures continue through the extended. Rain chances are higher during the extended with the best chance for rain expected Monday afternoon when a cold front crosses through the region. The latest run of the deterministic GFS shows several opportunities for showers and thunderstorms. The first comes with the passage of the aforementioned shortwave on Sunday when we could see periods of showers, and a few thunderstorms in the afternoon. Currently it appears that any convection that develops on Sunday should be sub-severe with only a low, less than 20 percent, chance of CAPE in excess of 1000 J/kg across the southern Midlands and CSRA. The amount of instability we see on Sunday will depend on how quickly rain moves out Sunday morning and if we can get any clearing. The second, and most likely best, opportunity for significant rainfall comes on Monday with the passage of the cold front. With several days of increasing moisture leading up to the event, the main potential deterrent for severe weather will be the amount of instability that can develop. The SPC Day 5 SWO maintains a Slight (15%) risk of severe weather across the FA on Monday. This seems reasonable considering that we will have the ingredients for at least modest convective development in place. The probability of CAPE in excess of 1000 J/kg rises into the low to moderate category, 30 to 60 percent chance, again favoring the southern CWA. While it is too early to confidently say what, if any, severe hazards are most likely, the situation bares watching as we get closer. Forecast confidence decreases through the remainder of the long term as model guidance diverges. DESI shows daily PoP chances around 20 percent each afternoon with above normal temperatures, possibly warming to well above normal values near the end of next week. && .AVIATION /18Z THURSDAY THROUGH TUESDAY/... VFR conditions continue during the TAF period. Light and variable winds are seen at all locations this afternoon under mostly clear skies. These light winds continue into Friday morning where many places will go calm shortly after sunset this evening. Model guidance continues to show upper level moisture increasing into Friday morning and thus have put some high level clouds in the TAF, but no restrictions are expected. There is also the possibility of some patchy river fog into Friday morning at the usual fog prone locations but with the fairly dry air mass remaining in place, confidence in this is not high and I have not put this in the TAF at this time. Winds turn more out of the south toward the end of the period at 5-10 kts. EXTENDED AVIATION OUTLOOK...Widespread restrictions remain unlikely outside of patchy river fog into Saturday morning. The next chance of restrictions and rainfall continues to look to move in late Saturday and Sunday. && .FIRE WEATHER... The South Carolina Forestry Commission has issued a statewide burn ban until further notice. Elevated fire concerns continue this afternoon and evening as RH values fall between 15-20 percent, but with light and variable winds with high pressure building overhead. Tonight, better RH recovery is expected than was seen last night but by Friday afternoon, RH values once again fall to near critical levels with southerly winds gusting to 15-20 mph. Moisture is expected to start increasing Saturday. && .CAE WATCHES/WARNINGS/ADVISORIES... SC...None. GA...None. && $$