Area Forecast Discussion
Issued by NWS Columbia, SC
Issued by NWS Columbia, SC
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286 FXUS62 KCAE 231046 AFDCAE Area Forecast Discussion National Weather Service Columbia SC 646 AM EDT Sun Jun 23 2024 .SYNOPSIS... Above normal temperatures are expected through the middle of next week. Heat Advisories may be possible from Monday through Wednesday. Expect scattered diurnally driven showers and thunderstorms for much of the short and long term forecast. && .NEAR TERM /THROUGH TONIGHT/... KEY MESSAGE: - Heat continues to build today with max heat indices between 100-105F. Gradual warming continues into today with models indicating 850mb temperatures a couple degrees warmer. As a result, expect highs a bit warmer today, in the mid-90s. Winds aloft a bit stronger, especially in the western portion of the area, which should lead to deeper mixing with dew points at the surface dropping a bit but still remaining humid across the area. The resulting heat index will top out between 100 and 105F today, a bit below heat advisory criteria. Shower and storm chances expected to be more limited than yesterday with water vapor imagery this morning showing a layer of dry air aloft. Forcing will be limited as well. HiRes guidance indicates weak to moderate instability will develop, however, into the afternoon and evening, so isolated showers and storms will be possible, although coverage will be limited. A front tonight will drop in from the northwest which will keep temperatures up overnight as winds remain out of the SW ahead of the front along with increased cloud coverage. Lows will be in the mid-70s. && .SHORT TERM /MONDAY THROUGH MONDAY NIGHT/... KEY MESSAGES: - Heat building into Monday - Afternoon/Evening showers and thunderstorms will remain widely scattered with best chances in the east Upper level trough over the northeast amplifies a bit across the Mid Atlantic into the Carolinas. A weak short wave trough will move through in the morning along with an axis of higher precipitable water. Models suggest a few showers upstream in the morning will weaken as they move southeast into the area. A weak "cold front"/trough moves into the area during the day and it appears to hang up near Columbia. 1000-500mb thickness actually increases in the afternoon so not much air mass change, although slightly drier air will filter into the SC Piedmont and north Midlands in the afternoon by weak to moderate downslope flow. Higher precipitable water values in the coastal plain in the afternoon and expect precipitable water around 1.6 to 1.7 inches in the east Midlands. With strong diabatic heating and instability expected to be weak to moderate in the east Midlands with CAPE 1000-2000 J/kg but continued dry air above 3km limiting factor. Mid level capping stronger in the west. Lift strongest in the east possibly enhanced by sea breeze and approaching front/trough. So chance pops east and slight chance west in line with NBM mean pops. Temperatures quite hot with downslope but a little drier in the central and west with NBM and Mos dew points in the mid 60s in the afternoon with mixing. High temps in the upper 90s to around 100 degrees. This results in a max heat index around 105 degrees. If its a little more moist values will be near heat advisory criterion of 108 degrees. Either way a hot day and dependent on shower and thunderstorm development. SPC has I-95 corridor in a marginal risk severe thunderstorms. Shear increases but not very strong...may be 20-35 kts deep shear. Inverted V sounding possible with deep mixed layer so pulse storms with damaging wind main threat. Any convection should diminish in the evening and low temps in the low 70s. && .LONG TERM /TUESDAY THROUGH SATURDAY/... KEY MESSAGES: - Hot even by local standards Tuesday and Wednesday - Best chance for thunderstorms will be Thursday. High pressure aloft builds over the Southeast U.S. during the middle of next week. The air mass appears drier on Tuesday. An upper level trough passes well to the north of the region in the Wednesday to Thursday time frame which pushes a surface front into the Carolinas. There is a good probability that this front becomes diffuse over the region given the late June climatology and the ensemble forecasts. Thursday appears to be the most likely day to experience a higher chance of diurnal convection due to this diffuse frontal boundary. Otherwise isolated to scattered diurnal convection is anticipated through the end of next week. && .AVIATION /12Z SUNDAY THROUGH THURSDAY/... Widespread LIFR restrictions in place early this morning with improvement expected over the next few hours. LIFR ceilings in place at all terminals, except AGS just after sunrise this morning. With large amounts of low level moisture in place, expect at least IFR conditions to continue to be possible for the next couple hours. After the low clouds and fog dissipate by mid-morning, cumulus field develops into the afternoon around 5kft. Winds will shift out of the south and SSW around 5 kts through the period. With a front moving in tonight, winds should stay elevated with lingering mid-level clouds to prevent widespread restrictions. EXTENDED AVIATION OUTLOOK...Increasing chances for afternoon scattered showers and thunderstorms and associated restrictions Monday through Thursday. && .CAE WATCHES/WARNINGS/ADVISORIES... SC...None. GA...None. && $$