Area Forecast Discussion
Issued by NWS Columbia, SC
Issued by NWS Columbia, SC
590 FXUS62 KCAE 190013 AFDCAE Area Forecast Discussion National Weather Service Columbia SC 813 PM EDT Fri Sep 18 2026 .WHAT HAS CHANGED... Aviation discussion updated for 00z TAFs. && .KEY MESSAGES... - 1. Above average temperatures and increased chances for showers and storms continue into early next week. - 2. Cooler and drier air returns by the middle of next week but forecast uncertainty remains. && .DISCUSSION... KEY MESSAGE 1: Above average temperatures and increased chances for showers and storms continue into early next week. The pattern features an upper ridge centered over TX and an upper low off the northeast coast of FL. As the ridge slides slowly wets, the upper low will retrograde westward into the Gulf this weekend. The result is an increase in moisture across the area due to confluent flow between the high and low. There has been a bit more mid level cloud cover across the area than previously expected, which has slowed warming, and temperatures are sitting in the mid to upper 80s with a few low 90s toward the NC/SC border where there has been more sun. A weak shortwave and surface trough are still expected to force some showers and thunderstorms mainly north of the I-20 corridor this evening. However, the timing should be slightly later due to the lingering cloud cover. A cu field is starting to get organized as of this writing, as seen on visible satellite imagery. A few robust storms are observed across central NC and moving south. Mesoanalysis/RAP forecast does show a bit better environment developing in the next few hours, but the severe threat (mainly damaging winds) still appears to be low. The Marginal Risk (1 of 5) will be limited to the north and western portion of the forecast area, with the threat diminishing quickly with loss of heating. A few CAMS continue convection overnight, but coverage should be decreasing overall. The unsettled pattern will continue into early next week with PWATs holding around 125-150% of normal. While widespread forcing will likely be limited, this deep layer moisture and a unseasonably hot and humid air mass will support scattered showers and storms each afternoon through Tuesday. KEY MESSAGE 2: Cooler and drier air returns by the middle of next week but forecast uncertainty remains. There remains some uncertainty as to the exact pattern that evolves towards the middle of next week, but run to run model consistency is increasing. The aforementioned upper low is progged to eject out of the northeast Gulf and up the Eastern Seaboard Tuesday into Wednesday. This will make way for high pressure strengthening over the northeast and ridging down the coast to potentially set up a cold air damming scenario. However, the classic southwest flow aloft doesn`t appear to set in until late in the week or essentially beyond the scope of this forecast package, and drier air is expected to move in from the northwest. This should limit our rain chances late next week. In the meantime, blended guidance favors near normal temperatures for highs though with large IQRs during this period, with the distributions skewed towards lower values. We will need to continue to monitor trends over the coming days. && .AVIATION /00Z SATURDAY THROUGH WEDNESDAY/... VFR conditions generally expected through the forecast period. Convection continues to drift southward through the Midlands this evening with confidence highest in possible restrictions at CAE/CUB, so included a tempo for -TSRA 00z-04z. Wind gusts around 20 to 30 knots possible along a southward moving outflow boundary between 00z-01z. Confidence not high enough to include elsewhere but will amend as needed. Winds have dropped to 5 knots or less and should remain light or become calm overnight. Lingering convection should diminish after midnight with a blanket of mid-high clouds through the night. Some guidance hinting at fog at terminals but think extensive clouds will limit that threat and not including in this forecast. A weak front will sink south into the area on Saturday with winds expected to shift to the northeast around 5 to 7 knots after 15z. Some isolated convection possible in the afternoon but confidence too low at this time range to include in this forecast. EXTENDED AVIATION OUTLOOK...Chances for showers and storms continue through the weekend. Morning cig/vsby restrictions are possible this weekend as well. && .CAE WATCHES/WARNINGS/ADVISORIES... SC...None. GA...None. && $$ DISCUSSION...EC AVIATION...23