Area Forecast Discussion
Issued by NWS Columbia, SC
Issued by NWS Columbia, SC
397 FXUS62 KCAE 161037 AFDCAE Area Forecast Discussion National Weather Service Columbia SC 637 AM EDT Wed Jul 16 2025 .SYNOPSIS... Weak upper ridging will continue to break down today, leading to lower daytime temperatures and scattered shower/storms during the afternoon and evening. Upper ridging then returns for the late week and this weekend, bringing warming temperatures, muggy conditions, and more typical shower/storm chances. && .NEAR TERM /THROUGH TONIGHT/... Key Message(s): - Isolated to scattered storms this afternoon A weak coastal trough is providing convergence over the coastal plain early this morning with slight moisture advection through onshore flow. This has allowed for a couple of isolated showers from the Lowcountry into the southern Midlands. Only isolated pockets of a few hundredths of an inch of rain should occur. With crossover temps in the low 70s we may see some patchy fog around sunrise but fog should be limited to fog prone locations such as near streams and bodies of water. Surface low pressure will shift further west today into the Gulf. The area of subsidence which kept convection rather limited the previous day will also shift west today. This should allow for higher thunderstorm coverage than the previous day. The highest chances are in the eastern Midlands and Pee Dee where subsidence is weaker and the sea breeze helps trigger convection. Instability remains relatively weak for the season limiting the threat of severe weather. The western Midlands may see only isolated storms with some drier air still in place there. CAMs add confidence to the forecast with HREF neighborhood probs of QPF highest along the I-95 corridor and the Pee Dee. Temperatures today will be near normal. && .SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... Key message(s): - Isolated to scattered showers/storms during the afternoon expected each day. Some weak lee side troughing may linger in the region into Thursday as a low continues across the eastern Gulf. Upper ridging and surface high pressure will slowly near the Southeast from the east through the period, likely bringing temperatures from near normal Thursday to above normal on Friday. 15-20 kts of southerly to southwesterly low level flow extending up to 700 mb continues each day, aiding in keeping PWAT`s near 1.80-1.95". The lingering surface troughing combined with nearing convective temps should allow isolated to scattered convection each afternoon and into the evening with MLCAPE approaching 1000-1500 J/kg. The 00z HREF members and mean solution do suggest coverage remaining more on the isolated side Thursday, and this may repeat again Friday. The more limited coverage is likely owing to a weak subsidence inversion that is noted in GFS and NAM BUFKIT soundings, possibly aiding in keeping convection more suppressed. Either way, the risk for severe weather is low and the aforementioned 15-20 kts of flow should give any storm that does form around 10 kts of motion. && .LONG TERM /SATURDAY THROUGH TUESDAY/... Key message(s): - Warming temperatures into the weekend with muggy conditions. - Typical summertime diurnal convection expected. Upper ridging and surface high pressure should slide into the FA through the weekend and into early next week where GEFS and EC Ensemble solutions suggest that PWAT`s are near normal initially, but then rise to around 120% of normal Sunday through Tuesday as the upper ridge advects deep Gulf moisture along its western periphery. With little forcing, typical isolated to scattered afternoon/evening showers and storms are expected each day but the main talking point will be hot/humid conditions as temperatures above normal are expected under the ridge this weekend and possibly into early next week. NAEFS 850mb and 700mb temperatures reach the 90th percentile starting Saturday and at times, the 97th percentile Sunday and Monday, aiding in maintaining these hot conditions. The EC EFI depicts values up to 0.7-0.8 Sunday and Monday with a 0 Shift of Tails contour into the Midlands, giving more confidence in the signal for hot/muggy weather. Thus, heat indices between 100-105F will be possible this weekend and into the early week, highest Sunday and Monday. && .AVIATION /12Z WEDNESDAY THROUGH SUNDAY/... VFR conditions likely outside of afternoon convection Restrictions not expected this morning with slightly drier air over the region. Models have shown some indications of stratus/fog toward daybreak, but they have been too aggressive over the past few nights. So instead we went more with a persistence forecast keeping VFR conditions in place. Winds will be more out of the S/SSE today with speeds near 10 kts in the afternoon. Convection will develop this afternoon. Yesterday`s area of subsidence which kept showers isolated has shifted west. This will allow scattered thunderstorms with higher coverage than the previous day particularly in the eastern FA and Pee Dee where the sea breeze develops and moisture is deeper. Storms should subside shortly after 00Z as winds become light and variable. EXTENDED AVIATION OUTLOOK...Typical seasonal restrictions continue with daily convection and patchy early morning fog/stratus possible. && .CAE WATCHES/WARNINGS/ADVISORIES... SC...None. GA...None. && $$