![National Oceanic and Atmospheric Administration](/build/images/header/noaa.d87e0251.png)
![National Weather Service](/build/images/header/nws.4e6585d8.png)
![United States Department of Commerce](/build/images/header/doc.b38ba91a.png)
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
931 FXUS63 KJKL 170205 AAA AFDJKL AREA FORECAST DISCUSSION...UPDATED National Weather Service Jackson KY 1005 PM EDT Fri Aug 16 2024 .KEY MESSAGES... - Humidity, along with the possibility of showers and thunderstorms, will last into Saturday night. - Below normal temperatures are expected Sunday through Wednesday behind a cold front passage late Saturday night. - Showers and thunderstorms will remain possible Sunday and Monday, especially in the afternoon and early evening, with a drying trend for Tuesday into Wednesday. && .UPDATE... Issued at 1005 PM EDT FRI AUG 16 2024 Aloft, very subtle, weak short wave energy is currently passing through the Ohio Valley. This is responsible for the isolated to widely scattered convection that continues to fire over portions of the area this evening. However, this activity is expected to dissipate over the next several hours as this features continues to pass off to our east. Another two, better defined or more organized short wave lobes rotating around the base of Great Lakes low pressure system will pass through eastern Kentucky over the next 24 to 36 hours. The first appears to fire off some convection during the day Saturday, with the second (most substantial) impulse moving into the region very late in the afternoon or more likely during the evening time frame. This second impulse appears to be the upper level feature that finally drives the surface cold front that has been residing to our northwest through eastern Kentucky Saturday night into Sunday morning. Main forecast challenge this evening is the potential for fog overnight. The frontal zone appears to be close enough to our area that a light southwest gradient wind continues through the overnight, at least based on model guidance. The persistent gradient wind combined with the residual cloud cover across much of the area through the overnight will tend to help keep the boundary layer from decoupling fully, and in turn help to mitigate any widespread fog formation. However, ensemble probabilistic products do suggest the potential of the development of some stratus and light to moderate fog through the overnight. This potential will be monitored through the remainder of the evening. Did update grids for recent hourly trends in surface obs and the initial incoming 0Z cycle products. Also updated the zone product to reflect these changes and thoughts. All products have been issued. && .SHORT TERM...(This evening through Saturday night) Issued at 409 PM EDT FRI AUG 16 2024 The latest surface and upper air analyses reveal that a well developed area of low pressure is in place over the western Great Lakes, with a warm front extended southeastward from the parent low and across the central and eastern Great Lakes into far northeast Ohio and southwest Pennsylvania. A cold front extends southward from the low through eastern Wisconsin and through northeastern and central Illinois, and across central Missouri. Another area surface low pressure is analyzed over the Oklahoma panhandle, with a surface trough extending southwestward from there into New Mexico. High pressure is currently dominating the southeastern CONUS, with a mix of weak ridging and troughing in place across the western third of the country. The cold front to the west of our area will continue to be our primary weather maker heading into the weekend, as it moves slowly or direction. Scattered showers and storms will continue across our area this evening into early tonight, but should steadily taper off overnight after we`ve lost daytime heating and instability. The latest model data has been all over the place with timing and coverage of convection this evening and tonight. Based on the uncertainty in the models, went with the best precipitation chances very early tonight, with decreasing chance overnight. Based on the latest data, showers and storms should be done by 7 to 9Z tonight, with a lull in activity through Saturday morning. Showers and storms should begin to fire back up by early Saturday afternoon, as the cold front makes another eastward push and interacts with incoming warm, moist air from the Gulf. Enough instability and shear may be present Saturday afternoon and evening to produce a few strong to severe thunderstorms across our area. The Storm Prediction Center currently has eastern Kentucky in a slight risk, 15-20% chance, for severe weather on Saturday, with a slight chance for damaging wind gusts, large hail, and even isolated tornadoes all on the table. Shower and storm activity will likely persist through Saturday and into early Sunday morning, as a cold front and then trough of low pressure aloft both move through the region. There is also still a marginal, 5 to 14%, chance for excessive rainfall Saturday and Saturday night. .LONG TERM...(Sunday through Friday) Issued at 356 PM EDT FRI AUG 16 2024 There remains a good amount of agreement on the overall pattern in the various ensembles and deterministic model guidance for the long term period. An upper level low will continue to work across the Great Lakes and eventually into the Northeast to begin the period. The associated trough axis will swing through the Ohio Valley and will keep the weather active through Monday. The main cold front will push through Sunday and this coupled with the trough axis will keep around a 60 to 90 percent chance of rain across eastern Kentucky. By Monday, the chance of rain decrease with most in the 50 to 80 percent range and the better forcing begins to move eastward and PWAT values decrease in the 1.2 to 1.4 range. Tuesday, there is good agreement on an area of surface high pressure pushing into the Great Lakes. This will help to usher in a much drier airmass under northerly flow at the surface. This northerly flow will also help to provide a fall like feel to the area, with afternoon highs in the mid to upper 70s. This surface high will eventually pull east through the remainder of the long term forecast. However, before it does it will provide several cool crisp mornings, with lows in the 50s and even upper 40s in some cases. The coldest mornings will be Wednesday and Thursday and those days you could see valleys make it into the upper 40s. Given this needed to adjust toward the NBM 10th percentile in the valleys to provide better temperature splits. As mentioned, the surface high will push east and this will eventually lead to some return flow and highs will creep back up toward normal with low to mid 80s being the story to end the period. && .AVIATION...(For the 00Z TAFS through 00Z Saturday evening) ISSUED AT 707 PM EDT FRI AUG 16 2024 Showers and storms that plowed through the area today into early this evening, have since exited the area and/or dissipated. Based on quite a bit of the latest model data, only isolated activity is expected the rest of the night. That being said, there is the potential for a few showers and storms to fire up tonight, but not to the point that they are worth mentioning in the TAFs. A very challenging forecast to say the least. Showers and storms should begin firing up again late Saturday morning into early Saturday afternoon, as a cold front approaches, with the higher rain chances coming toward the end of the TAF period. VFR conditions in place currently at the TAF sites, and this may not change overnight, but will need to be watched closely leading up to the 6Z TAF issuance later tonight. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...RAY SHORT TERM...AR LONG TERM...DJ AVIATION...AR