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
603 FXUS63 KJKL 240816 AFDJKL AREA FORECAST DISCUSSION National Weather Service Jackson KY 416 AM EDT Mon Jun 24 2024 .KEY MESSAGES... - A fleeting sampling of drier and somewhat cooler air will be noticed today. - Heat and humidity climbs Tuesday and Wednesday before another cold front arrives with a decent shot at thunderstorms Wednesday evening. - The midweek cold front will be less impressive, with even hotter weather expected to make a comeback by Friday and Saturday. && .SHORT TERM...(Today through Tuesday) Issued at 416 AM EDT MON JUN 24 2024 Cooler and drier air continues to slowly filter into eastern Kentucky early this morning behind the passage of a cool front. Rainfall varied widely from nothing to over an inch. Fog has formed in many locations, especially in valleys, where rainfall occurred. Temperatures presently range from the upper 60s in the cooler northern valleys and in the lower to middle 70s elsewhere. At 730z, a surface analysis suggests that the poorly defined cold front is pressing southeast of the Hal Rogers Parkway/Highway 80 corridor. A 500H analysis shows a trough axis extends from the Ottawa Valley down into the Mid-Ohio Valley/Central Appalachians. Further west, a positively-tilted, upper-level ridge axis extends from an ~593 dam high centered over New Mexico, northeastward through the Central Plains into Northern Ontario and is reflected at the surface by high pressure extending from the Upper Midwest down into the Mid-Mississippi Valley. The 500H trough over our region will shift off to the east today while the upstream ridge axis will drop southeastward and cross the Ohio Valley late tonight. Precipitable water falling to between 0.6 and 0.8 inch and 850 mb temperatures falling to between 13 and 16C will allow for a very comfortable late June afternoon. Heading into tonight, the corresponding surface high crests over the eastern Kentucky Coalfields around 3z tonight; with weak westerly return flow commencing by early Tuesday morning and continuing throughout the day tomorrow. This will buoy 850mb temperatures back to around 20C by late in the day. The next trough will drop into the Great Lakes late Tuesday evening/night, sending another cold front toward eastern Kentucky early in the long-term. In sensible terms, look for patchy low clouds and fog (especially in southeastern valleys) this morning. After sunrise, the fog should lift and the patchy low clouds will become an extensive cumulus field. It will be cooler and less humid with highs in lower to middle 80s. Mostly clear skies follow for tonight along with fog forming in the favored valley locales and low temperatures in the mid 50s cooler northern hollows to the mid 60s on the thermal belt ridgetops/slopes. Abundant sunshine and hotter temperatures follow on Tuesday with highs in the upper 80s and lower 90s. However, moderate dew points in the lower to middle 60s will prevent the heat from being to oppressive -- heat indices generally peak in the upper 80s to lower 90s. .LONG TERM...(Tuesday through Sunday) Issued at 330 PM EDT SUN JUN 23 2024 The extended period will start off with an extensive ridge of high pressure centered over the southwest CONUS and southern Plains. The ridging will extend northward up the West Coast and into the Pacific Northwest and into the western Gulf of Mexico on Tuesday. A fast moving trough of low pressure will make its way east through the Great Lakes and upper Ohio Valley, with a stronger trough exiting extreme northern New England into the open Atlantic. Weaker ridging will be in place across the Tennessee Valley and Gulf Coast states to begin the period. The models were in pretty good agreement with this starting set up and were showing a general eastward progression of a cold front extended southward from the northern trough and into the Ohio and Tennessee Valleys Tuesday night and Wednesday. That will be the period where we see our best rain chances in the extended, as the front moves through and interacts with a northward surge of warm, moist air off the Gulf of Mexico. A line of showers and storms is progged to advance through the region from very late Tuesday night, through the day on Wednesday, as the cold front moves through and then slow greatly late Wednesday. In fact, the boundary may even stall out near the VA border, and keeping scattered showers and storms around the end of the day on Thursday for our southeastern counties. Once the first cold front moves away, another ridge of high pressure will move in and bring another period of hot and muggy weather to eastern Kentucky Thursday and Friday. We could see highs on those days in the low to mid 90s. The ridge will bring conditions favorable for modest ridge valley temperature differences to the area Tuesday night, Thursday night, and Friday night. Another area of low pressure will bring another round of rain and storms to the area Saturday through Sunday. The primary weather concerns in the extended will be how strong any storm we see on Wednesday are able to become and the hot and muggy conditions that will be returning on Friday and Saturday. && .AVIATION...(For the 06Z TAFS through 06Z Monday night) ISSUED AT 155 AM EDT MON JUN 24 2024 A cold front is dropping southeastward across the Eastern Kentucky Coalfields early his morning as the last showers and thunderstorms exit into Tennessee and Virginia. As the front departs and clears away the deeper moisture, some patchy low clouds are likely to linger overnight but are not anticipated to cause widespread sub- VFR ceilings at this point. Fog is also forecast to develop in valleys early this morning, especially in southeast KY, but the extent of the fog is uncertain. Moisture is present from earlier rainfall, but drier air is also trying to advect into the area behind the front, fighting the fog. Confidence in seeing at least minor visibility restrictions was high enough to include 6SM BR at SYM, LOZ, and SME terminals closer to sunrise. Sub-VFR visibility restrictions are more likely at SJS and JKL. Fog will dissipate after sunrise Monday morning and leave VFR conditions through the remainder of the period. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...GEERTSON LONG TERM...AR AVIATION...GEERTSON