


Area Forecast Discussion
Issued by NWS Columbia, SC
Issued by NWS Columbia, SC
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159 FXUS62 KCAE 090549 AFDCAE Area Forecast Discussion National Weather Service Columbia SC 149 AM EDT Wed Jul 9 2025 .SYNOPSIS... A bit cooler Wednesday with widespread showers and storms likely as a upper trough approaches. Some damaging winds and flash flood possible with the stronger storms and heavy rainfall Wednesday and Thursday. Temperatures slowly rise in the late week and into this weekend with typical summertime showers/storms. && .NEAR TERM /THROUGH TONIGHT/... Key Message(s): - Widespread storms expected this afternoon with an associated flash flood and damaging wind threat this afternoon & evening. An approaching mid-level trough across the TN Valley will provide sufficient synoptic scale forcing for widespread convection this afternoon and evening across the area. As southwesterly flow strengthens, moisture convergence ahead of this trough will increase and push PWAT`s over 2.0" for much of the area. With surface dew points remaining in 70`s throughout the day, sufficient instability with over 2000 j/kg ML CAPE is expected to develop by the afternoon. DCAPE however will be limited today as deep moisture advection will yield a fairly saturated sounding aloft. Overall, this combination of factors will present both a flash flood and severe thunderstorm today. The flash flood threat is supported by the high PWAT`s and expected training storm motion with unidirectional light southwesterly shear; HREF LPPM highlights potential of 3- 5" in isolated spots which seems reasonable. While a favorable flash threat setup exists, thankfully soil moisture is still quite dry and our basins are not primed. As for severe, the threat is from classic saturated pulse thunderstorms, bringing a damaging wind threat primarily. Based on the environment and coverage expected, this will be a quantity over quality when it comes to severe, with some strong- severe storms possible given the widespread coverage. The HREF shows some signs of organization later this evening, closer to the shortwave forcing across the northern Midlands and Pee Dee; this will likely be dependent on cold pool development in the afternoon. WPC has expanded their Slight ERO for our entire area and SPC has continued their Slight Risk for the northern Midlands, with Marginal elsewhere. && .SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... Key Message(s): - Partly to mostly cloudy with seasonable daytime temperatures. - Potential for convective development during the afternoon and evening hours both days. A few thunderstorms may become strong, especially on Thursday. - Flash flood potential continues through the period due to high moisture and weak steering flow. The upper trough moves out of the Great Lakes region at the start of the short term, passing to our north and being replaced with weak ridging by Friday night. This will likely result in unsettled weather across our FA during the short term, with showers and thunderstorm possible both days. The expected clouds and rain will result in more typical daytime temperatures for early July with forecast highs in the lower 90s. Given the lack of overall forcing, pulse convection will be favored and largely driven by where instability is able to develop and any lingering mesoscale boundaries from the previous day`s convection. While organized severe thunderstorms are unlikely, any robust thunderstorm has the potential to produce damaging downburst winds and perhaps some small hail. This is reflected in the wind driven Marginal (1/5) risk for severe weather across the CWA on the latest Day 3 SPC SWO. Long, skinny CAPE profiles in modeled soundings indicate a continued flash flood potential, with the entire FA in at least a Marginal (1/4) risk for excessive rainfall on Thursday. A Slight (2/4) risk is maintained near the North Carolina border. The northern half of the CWA is in Marginal risk for excessive rainfall on Friday. Outside of locations that are normally prone to flash flooding such as Five Points, the flash flood risk should be highest in areas that receive several days of heavy rainfall as antecedent conditions are not particularly concerning for a more widespread flooding event. Having said that, any slow moving and/or training thunderstorms can cause issues given the ample atmospheric moisture available. && .LONG TERM /SATURDAY THROUGH TUESDAY/... Key Message(s): - Temperatures return to above normal values this weekend into Monday as upper ridging redevelops. - The ridging should limit diurnal convection with lower probabilities expected through Monday. - The ridge may break down early next week as an upper level low attempts to move in from the southeast. Upper ridging should be in control of the Southeastern US during much of the extended, resulting in hotter daytime temperatures and lower chances for showers and thunderstorms. Hot and humid conditions are expected this weekend with heat indices around 105 degrees on Sunday and Monday. More isolated showers and thunderstorms are expected as convection is likely suppressed by the aforementioned upper ridging. This ridging could begin to weaken near the end of the period as an upper low to the southeast attempts to move in. This potential is indicated in the mid-range guidance by a decrease in temperatures and an increase in precipitation chances. && .AVIATION /06Z WEDNESDAY THROUGH SUNDAY/... Stratus expected this morning with IFR restrictions. Widespread storms likely this afternoon and evening. Increasing moisture across the region will yield a stratus deck that is expected to develop between 09z and 11z for all TAF sites (although it will be close to OGB). Expected some IFR (possibly LIFR) cigs with this deck, lasting through 13z or so this morning. Elevated winds aloft should keep this is as a cig restriction only with vsby likely remaining VFR or MVFR. Beyond this morning, typical summer cu expected before widespread storms develop across the area this afternoon and evening. Timing is still a little uncertain, but tempo and predominant groups will likely be needed in the next TAF updates. Lingering convection is expected well into the evening, possibly as late as 06z Thursday. EXTENDED AVIATION OUTLOOK...There is the possibility of diurnally driven showers and thunderstorms this week with the potential for periodic restrictions. && .CAE WATCHES/WARNINGS/ADVISORIES... SC...None. GA...None. && $$