Area Forecast Discussion
Issued by NWS Jackson, KY
Issued by NWS Jackson, KY
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
42
43
44
45
46
47
48
49
50
548 FXUS63 KJKL 190006 AAA AFDJKL AREA FORECAST DISCUSSION...UPDATED National Weather Service Jackson KY 806 PM EDT Sat May 18 2024 .KEY MESSAGES... - Dry weather expected area wide from Sunday through Tuesday night. - Rain chances ramp back up Wednesday into Saturday. - Warm weather will be the story Sunday through Wednesday, with afternoon highs topping out in the mid to upper 80s. && .UPDATE... Issued at 800 PM EDT SAT MAY 18 2024 Pops were reduced across the northern portions of the area based on recent radar trends. Thunder was removed across these more northern locations as well where lightning has not been detected for a considerable amount of times. && .SHORT TERM...(This evening through Sunday night) Issued at 417 PM EDT SAT MAY 18 2024 A very slow eastward moving, positively tilted upper trough lies overhead late today. Drying aloft is making its way in from the north as the trough advances. This is helping to limit convection. Extensive clouds in the south also limited heating/destabilization and have helped to hold back convection there, despite greater deep moisture as compared to the north. As the trough continues heading east and heating is lost, any remaining precip will die out tonight. Much drier air aloft and clearing skies will allow for good radiating conditions. Meanwhile, only slightly drier surface air will try to advect in on weak north to northeast flow. The combination will favor fog development. Will expect it to be abundant in valleys, growing in breadth and depth with time during the night. As heating occurs on Sunday morning, the fog will dissipate and likely transition to a rising cu deck. Although forecast soundings show development of weak mixed layer CAPE which is deep, it is a skinny profile in an extremely dry atmosphere aloft. Without upper level support, it`s unlikely that convective columns will be able to persist and develop precip, and a dry forecast is being used on Sunday. The same regime aloft carries through Sunday night. With cu drying up and giving clear skies, along with weak low level flow, valley fog will again develop. However, after good mixing and a bit more drying during the day Sunday, the fog should be a little more restricted. .LONG TERM...(Monday through Saturday) Issued at 338 PM EDT SAT MAY 18 2024 The period begins with shortwave ridging extending into the Northeast states. This ridging will keep the weather quiet and warm through mid week ahead of an advancing cold front, with good agreement noted in the ensembles and deterministic guidance. The afternoon high temperatures Monday and Tuesday are forecast to climb into the mid to upper 80s. By Wednesday, we see the leeside low that develops Monday night will be pushing northeast into the Great Lakes and Canada by Tuesday night. While there are slight differences in the guidance during this period the overall pattern looks fairly close. It gets a little trickier across the Ohio Valley going into mid- week. This is because the various ensembles and deterministic are struggling on how far south and east this cold front can go given it looses the greater upper level support and the low pressure pushes northward further into Canada. Right now, it looks like the diffuse cold front would arrive Sometimes Wednesday night into Thursday. This would usher in better chances of showers and thunderstorms, with around a 20-40 percent chance Wednesday and 50-60 percent chance Thursday. Now there have been some indication in machine learning products of severe weather potential with this system. If this was to occur it would be late Wednesday into Wednesday night before better storms arrive based on the latest trends. However, confidence is low given the better shear and instability stay northwest of the area. Past this the guidance becomes more divergent, but it looks like another mid-level shortwave rides in Friday. This would lead to a renewed chance of showers and thunderstorms going into the weekend, as an area of low pressure forms along the left over boundary mentioned above. The best chances of showers and thunderstorms right now would be Friday at 50-60 percent. && .AVIATION...(For the 00Z TAFS through 00Z Sunday evening) ISSUED AT 805 PM EDT SAT MAY 18 2024 Outside of shower and thunderstorm activity where MVFR or lower was occurring in some instances, VFR was reported at issuance time. Convection should dissipate by 02Z or 03Z and clouds will also diminish after sunset. Good radiating conditions will lead to development of fog, especially in the valleys by the 04Z to 06Z timeframe. This fog should grow in breadth and depth through dawn with VLIFR in some of the deeper valleys toward 12Z. The fog may lift into or develop at the TAF sites generally after 06Z and reductions there should be at least MVFR or IFR at times. The fog will lift and dissipate by around 14Z, leaving VFR conditions through the end of the period. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...JP SHORT TERM...HAL LONG TERM...DJ AVIATION...JP