Area Forecast Discussion
Issued by NWS Knoxville/Tri Cities, TN
Issued by NWS Knoxville/Tri Cities, TN
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
773 FXUS64 KMRX 140253 AFDMRX Area Forecast Discussion National Weather Service Morristown TN 1053 PM EDT Tue Aug 13 2024 ...New UPDATE... .UPDATE... Issued at 1049 PM EDT Tue Aug 13 2024 Overall the forecast has remained in pretty good shape this evening. A few isolated showers have appeared on radar in the far northeast but will continue to diminish over the next hour or so suggested by latest CAMs. Most notable tweaks with the forecast were to adjust sky cover upwards based off recent satellite trends. The increased clouds also lead to a slight upward adjustment hourly temperatures but no significant changes to the expected over night lows were made. && .SHORT TERM... (This evening through Wednesday) Issued at 257 PM EDT Tue Aug 13 2024 Key Messages: 1. Slightly below normal temperatures tonight and near normal temperatures tomorrow. 2. Mostly dry through Wednesday. Discussion: Overall, same story different day. We remain in a northwest flow pattern with troughing to our northeast and an upper level ridge axis to west-northwest. Outside of a slight chance for a shower or storm across the northeast TN mountains, all areas will be dry through tonight. Also, slightly below normal low temps will be in place again tonight due to the dry air that remain in place. Tomorrow, mostly dry weather continues as high pressure shifts further east and the ridge becomes centered over the eastern U.S. Slight chance for an afternoon shower or storm across southwest NC and the east TN mountains. && .LONG TERM... (Wednesday night through next Tuesday) Issued at 257 PM EDT Tue Aug 13 2024 Key Messages: 1. Mostly dry weather Thursday. Warmer Friday with increasing chances of showers and storms heading into the weekend. 2. Cold front forecast to cross the area sometime on Saturday with possibly drier conditions to finish off the weekend and start the new work week. Discussion: Troughing setting up across the northern tier of the U.S. by Thursday will feature three upper lows; along west coast, over the Upper Plains and over the Canadian Maritimes. The one furthest east will steer Ernesto over open waters in the coming days, while the closed low yet to form over the Upper Plains/Upper Mississippi Valley, will bring us increased chances for showers and thunderstorms by the weekend. Before that happens, Thursday should be mostly dry with any activity confined to the higher terrain. Friday appears will be the warmest day when SWly flow is at its height ahead of the approaching front. Precipitation will increase from the west and northwest, the best chances headed into Saturday. As noted in this morning`s discussion, an eye will be kept on the time period of frontal passage, as CAPE up to 1500 J/kg is possible as well as an increase in effective shear. SPC currently isn`t confident on a 15% anywhere this far out due to convergence along the front may not be as strong and antecedent convection hampering severe potential. To finish the period, temperatures will fall back into the 80s in the valley and chances for precipitation may linger. Longwave troughing will move to the northeast, allowing ridging to build out west. Our area will remain under northwesterly flow with weak disturbances supporting development, but the further out in time, the greater the uncertainty of coverage and timing. && .AVIATION... (00Z TAFS) Issued at 718 PM EDT Tue Aug 13 2024 VFR conditions are expected to persist at all three sites overnight. The exception to this could be brief fog at TRI in the morning hours. Isolated showers have appeared in the northeast areas of the region, however they are not expected to last long enough to include VCSH at TRI. Winds should remain less than 10 kts from the NNW at all sites. && .PRELIMINARY POINT TEMPS/POPS... Chattanooga Airport, TN 67 90 70 91 / 0 0 0 10 Knoxville McGhee Tyson Airport, TN 65 89 66 89 / 0 0 0 10 Oak Ridge, TN 65 88 66 89 / 0 0 0 10 Tri Cities Airport, TN 61 86 62 86 / 10 10 0 10 && .MRX WATCHES/WARNINGS/ADVISORIES... NC...NONE. TN...NONE. VA...NONE. && $$ SHORT TERM... LONG TERM....KS AVIATION...KRS