Area Forecast Discussion
Issued by NWS Columbia, SC
Issued by NWS Columbia, SC
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121 FXUS62 KCAE 281842 AFDCAE Area Forecast Discussion National Weather Service Columbia SC 242 PM EDT Fri Jun 28 2024 .SYNOPSIS... Hot and humid conditions continue into the weekend. Afternoon and evening rain and storm chances increase through the weekend with noticeably higher moisture building into the region. A cold front is expected to bring slightly cooler and drier conditions to start off the work week, but building high pressure will allow the return of temperatures near the century mark by mid- week. && .NEAR TERM /THROUGH TONIGHT/... KEY MESSAGES: - Muggy and hot conditions developing with highs in the 90`s and dew points in the mid 70`s. - Additional scattered thunderstorms develop during the afternoon, especially in the CSRA. Deep moisture continues to pool across the area with PWAT`s rising to around 2" today as ridging builds aloft. Widespread cumulus will develop this afternoon with some pop up showers and thunderstorms likely, again mainly south and east of I-20. Instability is expected to remain fairly weak based on recent obs and HREF guidance, only climbing to around 500-700 ML CAPE by 21z. But as seen in the water vapor imagery, some noticeable mid level dry air is present, which could help increase the downburst potential thanks to the steep surface to mid-level theta-e difference. So much like the last 4-5 days, an isolated severe thunderstorm is possible but not expected to be widespread. && .SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/... Key messages: - Excessive heat concerns continue this weekend with headlines likely on Sunday. Additional rainfall likely. Little change in the forecast for Saturday as the remains of the diffuse frontal boundary remain across the area. Pwat values will remain above 2 inches with moderate instability so expect scattered showers and thunderstorms during the afternoon and evening hours. With some dry air in the mid levels DCAPE values will be 5-600 J/Kg so there is some potential for wind gusts from the stronger thunderstorms. On Sunday the pattern will change as a frontal boundary moves into the area with the upper level trough also swinging into the region. Although the best dynamics will remain north of the forecast area there will be plenty of instability for the front to interact with which is expected to create thunderstorms across much of the forecast area Sunday afternoon into the early overnight hours. The drier air in the mid levels from Saturday will have eroded however instability will be greater and pwat values will be nearing 2.5 inches. As such the potential for severe thunderstorms appears low however with weak steering flow aloft there will be increasing potential for locally heavy rainfall. Afternoon high temperatures will be in the low to mid 90s Saturday with heat index values between 102 and 107 with the highest reading in the eastern Midlands where a heat advisory may be needed. On Sunday high temperatures will be in the mid to upper 90s with heat index reaching 105-110. A heat advisory is likely on Sunday with the possibility of an excessive heat warning. && .LONG TERM /MONDAY THROUGH FRIDAY/... Key Messages: - Near normal temperatures Monday and Tuesday with the heat returning by the Fourth of July. The frontal boundary is expected to be just southeast of the forecast area Monday however with the boundary becoming increasingly diffuse expect another round of afternoon and evening showers and thunderstorms. Little change Tuesday as the remains of the boundary continue to become more diffuse and continue slowly sagging southward. With the boundary just south of the area temperatures will be slightly cooler with highs generally in the upper 80s to low 90s. Wednesday and Thursday will see the return of the upper level ridge and with plenty of moisture remaining over the region the summertime chances of showers and thunderstorms will continue each day. The heat on Thursday will be the main concern as temperatures once again will push into the mid 90s to around 100 with the heat index again between 105 and 110. && .AVIATION /18Z FRIDAY THROUGH WEDNESDAY/... VFR conditions likely this afternoon and evening, outside of some showers-storms at AGS and DNL. Stratus-fog likely Saturday morning. Widespread cumulus developing across the area this afternoon, generally low based around 3k feet. Some showers and thunderstorms are moving into the AGS and DNL area, with some impacts possible. Timing and coverage confidence is a bit low however so went with a VCTS through 21z at those sites. Additional shra and tsra possible at all sites this afternoon and evening. Winds will remain relatively light, out of the southeast, with gusts 10-12 mph. Stratus and fog are possible again Saturday morning for all sites starting after 09z. EXTENDED AVIATION OUTLOOK...Scattered showers-storms with restrictions each afternoon into early next week as additional moisture moves over the region. Early morning fog-stratus likely each as well. && .CAE WATCHES/WARNINGS/ADVISORIES... SC...None. GA...None. && $$