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
161 FXUS63 KJKL 081818 AAC AFDJKL AREA FORECAST DISCUSSION...UPDATED National Weather Service Jackson KY 218 PM EDT Sat Jun 8 2024 .KEY MESSAGES... - As moisture increases, there is a small chance for showers into this evening. - The next passing cold front will bring increasing rain chances to eastern Kentucky later tonight into Sunday. - Cooler air will be reinforced across the region early next week, before temperatures modify back to above normal by the end of the period. && .UPDATE... Issued at 1248 PM EDT SAT JUN 8 2024 Hourly grid were updated based on recent observations and trends. Pops through early evening as the weakening convection moves east from central to eastern KY were lowered a bit to mainly just slight chance or sprinkles as few upstream observations had measurable precipitation. Most recent CAMS have generally weak activity as this moves east across the area and the latest HRRR just has mostly just a trace of QPF as this moves into eastern KY. UPDATE Issued at 735 AM EDT SAT JUN 8 2024 No significant changes to the forecast with just the inclusion of the latest obs and trends for the T/Td/Sky grids. These minor adjustments have been sent to the NDFD and web servers. && .SHORT TERM...(Today through Sunday) Issued at 445 AM EDT SAT JUN 8 2024 08Z sfc analysis shows relatively high pressure holding in place over eastern Kentucky as low pressure is approaching from the northwest. This has been able to keep the skies mostly clear overnight allowing for another night of good radiational cooling. As a result, temperatures currently vary from the low 50s in the deeper valleys to around 60 on the ridges - and in more open areas. Meanwhile, amid light winds, dewpoints are fairly dry in the upper 40s to lower 50s, most places. Probably due to the drier air in place, the river valley fog has been more subdued than last night but in evidence from the fog channel satellite imagery. The models, and their individual ensemble suites, are still in good agreement aloft through the short term portion of the forecast. They all depict fairly fast, northwest, mid level flow running through Kentucky on account of a stretched out low height gyre to the north of the state and a large ridge to the south along the Gulf Coast. Within this flow, several impulses will pass through the area during the short term portion of the forecast. The first of these moves through early this afternoon with a slight drop in 5h heights as it passes. The next one slips by to the south later tonight while the northern gyre digs south into the Ohio Valley. The descent of this latter feature continues into Sunday evening with more energy pushing into this part of Kentucky. The model spread is still small enough that the NBM was used as the starting point for the short term grids along with the incorporation of the CAMs` details for PoPs from this afternoon through Sunday evening. Sensible weather features high pressure retreating to the east allowing for some moisture return and showers to arise well out ahead of an area of low pressure stretching east from the Central Plains. A developing front pushes into this part of the state from the west later today and will help to generate a few showers initially but, likely after a lull, we will see lower cloud decks into Sunday along with a better potential for convection in the form of thunderstorms - mainly for the just the southern 2/3rds of the JKL CWA. This shower and thunderstorm threat continues through the afternoon Sunday as that front settles through the Cumberland Valley, before diminishing west to east Sunday evening. The building cloud and convection will limit terrain differences and valley fog potential tonight as well as cap high temperatures both today and Sunday to slightly below normal. The main changes to the NBM starting point again consisted of adjusting the NBM PoPs to include CAMs details for the shower chances starting this afternoon and running through the day Sunday. The temperatures from the NBM were tweaked early this morning and again, to a more limited extent, tonight in order to represent better terrain detail. .LONG TERM...(Sunday night through Friday) Issued at 516 AM EDT SAT JUN 8 2024 The 08/00z suite continues to trend drier as the various model solutions seem to be coalescing on the progressive scenario which favors an upper level trough passing over eastern Kentucky early next week in the wake of Sunday`s cold frontal passage. Any leftover frontal showers will have departed or will quickly depart by around 00z Monday as northwesterly flow ushers in drier and cooler air. The trough axis doesn`t pass over eastern Kentucky until Monday afternoon. Though better forcing will remain to our north, there could still be some isolated shower activity, primarily south of I-64 and east of I-75, warranting a 10 to 20 PoP. Ridging aloft and at the surface then builds in Monday night and persists through Tuesday night. By Wednesday, the surface high pressure ridge will begin to weaken as the ridge flattens aloft ahead of another upper level trough. That trough skirts the northern CONUS later in the week, keeping the better forcing and height falls to our north, though an associated weak cold front likely sags into the Ohio Valley around the end of the forecast period. Rain chances through the remaining portions of the forecast period are diurnally-driven and low, generally 20 percent or less. Outside of any isolated shower activity, sensible weather should feature mostly sunny skies by day and mostly clear skies at night (aside from the typical nocturnal valley fog). Temperatures start the period on the cooler side of normal with highs in the lower to middle 70s on Monday before climbing in the mid 80s to near 90 by Friday. Meanwhile, the coldest nighttime lows of the period, mid 40s to lower 50s, are on tap for Monday night before daily minimum temperatures moderate into the upper 50s to mid 60s by the end of the period. && .AVIATION...(For the 18Z TAFS through 18Z Sunday afternoon) ISSUED AT 214 PM EDT SAT JUN 8 2024 As high pressure continues to depart to the east, mid and high level clouds will continue to increase to begin the period. Isolated showers or sprinkles approaching from the west will work across the region this afternoon to early this evening with some associated low clouds with these. A more potent disturbance and cold front will approach the area during the last 12 hours of the period. Some convection associated with this could affect at least southern portions of the area at that point, with KLOZ and KSME likely to have the highest chances of that. With However, VFR should prevail through at least 12Z. As the front nears and some potential convection moves across the area, a few hours of MVFR is forecast to end the period. Light and generally variable winds are expected through the period. There is some variability in the guidance with the possibility of LLWS from the southwest between 06Z and 12Z at up to 40 kts, with NBM guidance having it and Consshort leaving it out. Although VCTS was not included in more southern locations during the last 12 hours of the period, thunder might occur during that time as well. At this point opted to leave LLWS out late tonight. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...JP SHORT TERM...GREIF LONG TERM...GEERTSON AVIATION...JP