Area Forecast Discussion
Issued by NWS Columbia, SC
Issued by NWS Columbia, SC
Versions:
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
156 FXUS62 KCAE 260612 AFDCAE Area Forecast Discussion National Weather Service Columbia SC 212 AM EDT Wed Jun 26 2024 .SYNOPSIS... Hot temperatures with heat indices over 100 F are expected to continue through the period. Isolated to scattered showers and thunderstorms should occur each afternoon and evening, particularly in the eastern Midlands and coastal plain. As a front approaches, better coverage is likely Thursday. Increasing heat impacts Friday through the weekend. Another weak front will move into near the area Monday with possible better convective coverage. && .NEAR TERM /UNTIL 8 AM THIS MORNING/... KEY MESSAGES: -Mostly clear with lows in the mid-70s. Evening satellite imagery shows convective debris clouds diminishing across the eastern Midlands with a few lingering cumulus elsewhere. Mostly clear skies and dry conditions are expected through the overnight hours with the potential for low stratus and/or patchy fog towards daybreak. It will be a muggy night as dewpoints rise into the 70s throughout the forecast area. Temperatures meanwhile only fall into the mid-70s. && .SHORT TERM /8 AM THIS MORNING THROUGH THURSDAY NIGHT/... KEY MESSAGES: -Hot conditions to continue with max heat indices of 105-110 likely on Wednesday. -Isolated to scattered afternoon/early evening thunderstorms, greatest coverage in the southeast Midlands Wednesday. -Highest chances of showers and thunderstorms Thursday, some possibly severe. Wind damage is the main threat. Wednesday: Broad troughing to our north will steadily help drive some weak height falls across the area as we move into Wednesday. Moisture will pull northward as the lingering boundary lifts along southerly low level flow. So much of the area will yield dew points into the 70`s again as PWAT`s climb to around 1.5". PWAT`s will be a bit limited by some weak downsloping flow aloft and the relatively dry northwest flow above 850mb but this allow for strong solar heating. So again high temps will cruise into the upper 90`s or low 100`s and with the enhanced moisture, heat indices will likely top out around 110; a heat advisory will likely be needed for parts of the area. Shower and storm activity will remain generally confined to the sea breeze and coastal plain, but will likely push further west into the Midlands compared to Tuesday. Thursday: Troughing will continue to dig across the eastern US with an associated low pressure system and front dragging southward towards our area. While the best height falls will shift north of us across the Mid-Atlantic, low level moisture and plenty of heating will allow for some modest destabilization in the afternoon; even the over-mixed GEFS still yields a mean near 1500 MU CAPE and near 1000 ML CAPE. So while the forecast soundings are not extremely impressive for severe weather, anytime we have a synoptic- mesoscale lift source, dew points in the upper 60`s or 70`s, and high temps in the upper 90`s, severe weather is possible. && .LONG TERM /FRIDAY THROUGH TUESDAY/... KEY MESSAGES: -Increasing heat impacts expected Friday through the weekend with heat index values 105 to 110. -Scattered afternoon thunderstorms each day. Behind the boundary and trough passage on Thursday, broad flat ridging will develop across much of the Southeast US. GEFS and EC members are consistent in pulling the primary jet well north across the Great Lakes, positioning us under the zonal, slightly northwesterly flow regime of the ridge. Temps will steadily climb each day through this period as the ridge builds further and shifts east slightly. The warmest temps are expected likely on Sunday with some downsloping component below 700mb in the GEFS and EC means; NBM 75th percentile, which is verifying well recently, is 100 F both Saturday and Sunday. Rain chances increase sharply into Monday and Tuesday as the ridge breaks down and more troughing digs to our north. Confidence is relatively low on how this will materialize however given the current pattern. && .AVIATION /06Z WEDNESDAY THROUGH SUNDAY/... Brief restrictions due to low clouds possible this morning but otherwise VFR. Low clouds have developed in the Pee Dee early this morning which guidance has continued to trend towards overspreading over the Columbia terminals along with OGB. Confidence remains highest in restrictions at OGB where low level moisture is highest, although still uncertainty as to whether ceilings will be IFR or low MVFR. Have included a tempo group for IFR ceilings just before sunrise. Shortly after sunrise, any low clouds will dissipate with high based cumulus possible and winds increasing out of the south around 10 knots. Winds remain elevated overnight which should limit potential for restrictions. EXTENDED AVIATION OUTLOOK...Increased chance of rain and restrictions each afternoon Thursday through Sunday as additional moisture moves over the region. && .CAE WATCHES/WARNINGS/ADVISORIES... SC...None. GA...None. && $$