


Area Forecast Discussion
Issued by NWS Columbia, SC
Issued by NWS Columbia, SC
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525 FXUS62 KCAE 081800 AFDCAE Area Forecast Discussion National Weather Service Columbia SC 200 PM EDT Tue Jul 8 2025 .SYNOPSIS... Temperatures remain above normal today before cooling some tomorrow and Thursday with diurnally driven showers and thunderstorms as a upper trough approaches. A couple stronger storms and heavy rainfall could be possible 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): - Hot with scattered thunderstorms expected this afternoon; some isolated damaging winds possible. Very hot and unsettled conditions expected this afternoon, as scattered showers and thunderstorms have already developed across the area. For areas that are still dry, temperatures have reached the mid 90s with dewpoints in the low 70s, leading to heat indices in the low 100`s. That said, temperatures have decreased quickly for locations that have already gotten rained on, with temperatures a full 10 degrees cooler in the low to mid 80s. Low level lapse rates remain steep, but mid level lapse rates are quite weak which has inhibited much vertical development. The result is storms that are quickly dropping their cores and producing weak outflow boundaries. However, atmospheric moisture levels remain high with PW values ranging from 1.7" to 2.2". In combination with weak steering flow and therefore slow (if any) storm motions, we`ll continue to keep a close eye on rain rates/rainfall amounts and the potential for stronger downburst winds mainly due to precip loading. CAM depictions of ongoing convection have been doing quite well, showing the main area of development along the I-20 corridor, which coincidentally lines up well with the 1.9" PW delineation via satellite estimates. Cannot totally rule out some isolated strong to damaging wind gusts, but overall the severe threat still looks low today. Convection should decrease quickly with the loss of heating around sunset, and the overnight period should be mild with temperatures in the 70s. && .SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... Key Message(s): - A bit cooler Wednesday and Thursday with increased cloud cover. - Scattered to widespread showers/storms each afternoon and evening where couple strong to marginally severe storms cannot be ruled out. - High PWATs each day combined with weak steering flow suggest an isolated flash flood potential with convection. Wednesday and Thursday look to be fairly similar days, though Wednesday is perhaps a bit more interesting. A upper trough moving into the region is expected to dominate each day as ridging becomes increasingly suppressed by this and increasing southwesterly flow yields PWAT`s that approach 2.1-2.2", perhaps a bit lower into Thursday. At the surface, some lee troughing is expected and evident in most CAM`s by enhanced convergence toward the northern FA and into the upstate. While forcing is generally on the weaker side each day, moderate to strong instability is depicted with the HREF mean SBCAPE approaching 2500 to 2800 J/kg Wednesday afternoon, and forecasting soundings showing around 1500 to 2000 J/kg on Thursday. This should allow scattered to widespread showers and pulse to a couple messy clusters of storms to form in the convergent zone and also along the inland pushing sea-breeze during the afternoon and into the evening each day. Strong inverted v profiles bring moderate to strong DCAPE and when combined with nearly saturated profiles aloft, weak deep layer, and weak steering flow, precipitation loading could lead to solid downbursts in the strongest storms and thus damaging wind gusts would be the primary threat in any marginally severe storm. Due to this, the SPC has maintained a Marginal Risk (level 1 out of 5) each day across the FA, with a Slight Risk (level 2 out of 5) that clips the far NW CWA on Wednesday. This seems reasonable, especially for Wednesday where the greater instability will be. Outside of any severe risk, another concern is the isolated flash flooding risk, where WPC has a Marginal Risk (level 1 out of 4) for excessive rainfall over the whole CWA Wednesday and a Slight Risk that clips the northern FA (level 2 out of 4). Another Marginal Risk is seen mainly across the Pee Dee region on Thursday. HREF members on Wednesday generally depict a batch a showers/storms forming toward the northern FA along a convergent zone, as well as along the inland pushing sea-breeze. Interactions with the outflow from storms to the north and storms along the sea breeze coupled with weak steering flow and high PWAT`s, bring the risk for areas of locally heavy rainfall and flash flooding each day, especially along areas of interacting storms/boundaries. && .LONG TERM /FRIDAY THROUGH TUESDAY/... Key Message(s): - Near average temperatures Friday with gradual warming trend into the early week with hot/muggy conditions possible. - More typical isolated to scattered convection expected during the extended. The EC Ensemble and GEFS generally show this upper trough starting to move out on Friday, with weak ridging starting to build back in, before fully building in for the weekend and into early next week. This brings temperatures back near normal Friday and slightly above normal through the weekend and into early next week. Hot and muggy conditions are possible over the weekend as PWAT`s remain seasonably high. In terms of shower/storm chances, coverage should be greatest on Friday as ridging still remains somewhat suppressed before returning to typical isolated to scattered chances over the weekend and into early next week. && .AVIATION /18Z TUESDAY THROUGH SUNDAY/... VFR conditions through early afternoon, with scattered convection likely in the mid afternoon-evening along with possible restrictions. VFR will dominate the forecast period with FEW-SCT cumulus field around 4k-6kft MSL this afternoon. ISOLD-SCT -SHRA/-TSRA should then develop at all TAF sites, particularly after 08/18z with the potential for gusty winds to around 25 kts. There may also be some brief CIG/VSBY restrictions with the stronger TSRA. Otherwise, sfc winds mainly SLY less than 10 kts with convection diminishing after 09/00z. Some overnight fog and stratus are possible depending on rainfall totals and coverage as winds become light and variable. Very similar conditions expected to develop on Wednesday, though precipitation coverage may be greater. 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. && $$