Area Forecast Discussion
Issued by NWS Columbia, SC
Issued by NWS Columbia, SC
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821 FXUS62 KCAE 110741 AFDCAE Area Forecast Discussion National Weather Service Columbia SC 341 AM EDT Tue Jun 11 2024 .SYNOPSIS... Drier air spreads into the region through mid week as high pressure builds in from the north. Moisture will gradually being returning to the area late in the week leading to increasing chances of mainly afternoon and evening showers and thunderstorms Friday through the weekend. Temperatures will rise to above normal values especially by the weekend. && .NEAR TERM /THROUGH TONIGHT/... Currently, upper air analysis shows a trough over the eastern portions of the CONUS, with the axis generally along the Appalachians. At the surface, temperatures are seasonably mild, generally in the upper 60s to lower 70s. Observations also indicate a noticeable moisture gradient, with dew points around 70 in the southeastern portions of the forecast area and dew points closer to 60 to the northwest. Where the dew points are higher, low to mid level clouds are beginning to fill in at this hour according to satellite imagery. Today: Expect the low clouds to continue to develop and spread westward through the early morning hours. Fog is also expected to develop in the moisture rich areas as well. There is some question just how far west the low clouds and fog travels due to the moisture gradient. It may reach the Columbia area, but don`t anticipate it to get any further west than that. After sunrise, the low clouds and fog should mix out rather quickly. High pressure begins to build over the region as the upper trough slides to the east and temporary upper ridging begins to replace it. As a result, temperatures are forecast to be slightly warmer than Monday, with highs in the mid to upper 80s. Tonight: High pressure remains over the area and ridging begins to flatten some overnight. Off to the west, another trough over the Southern Plains could bring some high clouds to the area, which may limit fog development. Temperatures overnight are forecast to be a little below normal, with lows in the lower to mid 60s. && .SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... High pressure will remain northeast of the area with the remains of the frontal boundary well south and southeast of the area. This will keep drier air over the forecast area however begins a point of uncertainty as models develop a weak circulation off the SE US Coast late Wednesday and Wednesday night. With the circulation offshore this will keep the area under subsidence with models indicating the inversion around 700 mb. Although surface winds will be light from the southeast moisture will be very slow to increase and combined with the inversion cumulus which develop vertically limited so do not expect and convection through the afternoon and evening hours. Conditions on Thursday will be similar with the main uncertainty being the model differences offshore. Regardless of model choice subsidence will persist over the forecast area with cumulus again developing through the late morning and afternoon hours while being limited by the inversion around 700 mb. High temperatures will be in the upper 80s to low 90s Wednesday with low 90s on Thursday. Overnight lows generally in the mid 60s. && .LONG TERM /FRIDAY THROUGH MONDAY/... Models remain in good agreement through the long term with the main difference being the departing features off the coast of the Carolinas. Friday a weak surface boundary will be dropping southward through the eastern US with weak moisture advection from the Gulf. By Saturday the surface boundary has become very diffuse and potentially non-existent over the region with high pressure becoming centered over the eastern Great Lakes. Through Monday the high will slide southeastward and be centered off the NJ coast gradually increasing easterly flow and moisture advection over the area. While this is occurring an upper level ridge will have built over the central US on Friday and moved eastward becoming centered over the eastern US Sunday and Monday. These features will combine to produce slight chance to chance pops for showers and thunderstorms Friday through Monday. Temperatures will be above normal for most of the long term with well above normal expected for Saturday. && .AVIATION /06Z TUESDAY THROUGH SATURDAY/... VFR conditions expected through roughly 09z Tuesday before fog- stratus likely. Mid to low level clouds are developing over the Low Country and spreading westward. Expect the clouds to continue to lower to LIFR conditions after about 09z. Fog is also expected to develop due to elevated low-level moisture. Confidence is highest that these conditions affect OGB, while confidence is a little lower for AGS/DNL/CAE/CUB, so have kept a tempo group at those 4 terminals. VFR cigs and vis return after about 13z and are likely to remain for the remainder of the TAF period. Winds are expected to be light from the north to northeast through the day, except at OGB where winds are anticipated to be more easterly in the afternoon. EXTENDED AVIATION OUTLOOK...No significant restrictions are currently anticipated through mid- week before showers-storms are expected Thursday and Friday. && .CAE WATCHES/WARNINGS/ADVISORIES... SC...None. GA...None. && $$