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
36
37
38
39
40
41
065 FXUS62 KCAE 140028 AFDCAE Area Forecast Discussion National Weather Service Columbia SC 828 PM EDT Mon May 13 2024 .SYNOPSIS... Unsettled weather will remain with some rainfall possible through midweek. A bit drier air moves in for Thursday before moisture returns for the weekend. Temperatures near to slightly below average. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... Isentropic lift strengthens over the area tonight which will lead to numerous showers into early Tuesday morning moving from SW to NE. Though elevated instability will be limited, PWAT values around 1.5 inches, or 150% of normal, will allow for periods of moderate rainfall. Localized probability-matched means from the SPC HREF suggest some areas could get 0.5 inches of rain in some of the heavier showers. The strongest convection will stay well south of the area, along the Gulf Coast. Temperatures will generally only drop into the low to mid 60s as clouds slow the overnight drop. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH WEDNESDAY NIGHT/... Uncertainty remains in the short term period as to the progression of precipitation through Tuesday. A strong MCS is expected to move to the south of the area which typically limits convective potential for our area but recent runs of the CAMs have trended this slightly faster which may allow for the potential for some destabilization across the area into the afternoon with PWATs expected to be anomalously high. It appears the most likely evolution is a round of rain for the area associated with strong isentropic lift, with a warm front to the south, followed by a bit of a lull in precip chances before a strong shortwave moves through the forecast area. This should generate numerous showers and thunderstorms during the afternoon. The overall severe threat remains low with HREF mean indicating around 1000 J/kg of sbCAPE across the area during the afternoon, although deep layer shear will be sufficient to support organized storms. As a result, we do remain in a day 2 marginal risk from SPC mainly for the potential for isolated damaging wind gusts. Locally heavy rain will likely be observed with any storms but they should be moving fast enough to prevent flooding issues, unless significant training is observed. As the upper forcing associated with the shortwave continues moving to the northeast, precip chances will continue to decrease overnight Tuesday. Models remain consistent in bringing the main upper low through the area Wednesday which even with a slight decrease in moisture, LREF members indicate there remains a high probability (65 to 75 percent) of PWATs remain above an inch and a quarter, especially across the northwestern portion of the forecast area. With pops remaining low in the morning, this should allow moderate destabilization into the afternoon. Deep layer shear expected to be slightly lower than Tuesday but still should be sufficient to support at least multi-cellular convection which with some drier and cooler air aloft, could lead to the potential for hail or some stronger wind gusts. I-95 corridor is in a marginal risk for severe weather for now but would not be surprised if that is expanded to include more of the NE portion of the area. && .LONG TERM /THURSDAY THROUGH MONDAY/... Ensemble means remain consistent in ridging building over the area Thursday which will lead to relatively quiet weather. Quite a bit of uncertainty for the end of the week into the weekend with the overall 500 mb generally supporting southwesterly flow, although ensemble members remain split as to how amplified this pattern will become which is leading to significant differences in timing of the progression of shortwaves through the flow. At the very least, moisture will be anomalously high across the area Friday into early next week which will at least support diurnally driven convection each day through the end of the period. Blended guidance also supports near average temperatures each day, which for reference this time of year, is mid-80s for highs to low 60s for lows. && .AVIATION /01Z TUESDAY THROUGH SATURDAY/... Restrictions expected to dominate the TAF period. VFR conditions remain across the terminals however restrictions are just SW of AGS/DNL. By 04z expect restrictions to move into all terminals as the inversion traps moisture near the surface and cigs lower to IFR. With MCS moving south of the area have removed mention of VCSH for a few hours late this evening through the early morning hours. Increasing confidence in showers returning to the area during the early morning hours and becoming widespread around daybreak keeping cigs IFR and vsbys in the MVFR range. Showers will begin diminishing during the afternoon however cigs are expected to remain MVFR through the end of the period. Winds will be southeasterly at 7 knots or less through early afternoon then turn southerly for the remainder of the period. EXTENDED AVIATION OUTLOOK...Showers and thunderstorms and associated restrictions are possible Tuesday night through Wednesday and again Friday and Saturday. && .CAE WATCHES/WARNINGS/ADVISORIES... SC...None. GA...None. && $$