


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
924 FXUS64 KMRX 142333 AFDMRX Area Forecast Discussion National Weather Service Morristown TN 733 PM EDT Mon Jul 14 2025 ...New AVIATION... .SHORT TERM... (This evening through Tuesday) Issued at 103 PM EDT Mon Jul 14 2025 Key Messages: 1. Isolated to scattered showers and thunderstorms through this evening. Locally gusty winds and heavy downpours possible with the strongest storms. 2. Hot and humid conditions on Tuesday, with isolated showers and storms. Central and southern TN valley will see Heat Indices in upper 90s to low 100s. Heat Indices in the low to mid 90s more likely for NE TN, SW VA, and SW NC. Discussion: We are currently in zonal flow due to high pressure to our south and a weak upper trough to our north-northeast. This will allow for another day of isolated to scattered showers and storms through this evening. Storms will be of the summer-time pulse variety due to little to no shear in the atmosphere. MLCAPE values should average around 1500 J/kg through the afternoon. Any stronger storm could lead to gusty winds up to 40mph as well as isolated flash flooding. Patchy dense fog possible yet again tonight for areas that see decent rainfall today. On Tuesday, the trough is well to our northeast. This allows high pressure to push further north. This should result in the more traditional summer-time terrain driven showers and storms that occur during the afternoon hours. This should result in less coverage across valley locations compared to the last few days. The bigger story will be the heat and Heat Indices. Heat indices in the upper 90s to near 100 are expected for the central East Tennessee valley, with the southern valley reaching near or into the low 100s. Slightly lower Heat Indices in the low to mid 90s are expected for northeast Tennessee, southwest Virginia, as well as southwest North Carolina. That being said, the exact timing of convective initiation and coverage of storms could impact these values. Less storm coverage and later initiation means higher probability that these forecast Heat Indices occur. Earlier initiation and greater coverage means these forecast values are much less likely. && .LONG TERM... (Tuesday night through next Monday) Issued at 103 PM EDT Mon Jul 14 2025 Key Messages: 1. Daily chances of PM showers and storms continue through the extended period. With each day, the strongest storms could produce locally gusty winds and heavy downpours, with possible flash flooding. 2. Upper ridge remains strong through the long term. Upper 90s to low 100s Heat Indices will be common across the central and southern TN valley. Discussion: Upper level ridging will likely remain strong through the period. The only exception may be on Thursday, as a shortwave trough passes to our north. High pressure may be strong enough to prevent this feature from dipping to far south and into our area. Otherwise, the hot and humid airmass will promote Heat Indices in the upper 90s to low 100s across the central and southern TN valley. Lower Heat Indices in the low to mid 90s are expected across north TN, southwest VA an NC. Please practice heat safety during this time. Diurnal summer-time showers and storms expected each day. The greatest focus will be along the high terrain of the Cumberland Plateau and mountains of east TN, southwest NC, and southwest VA. On any given day, any stronger storm will be capable of producing strong gusty winds and heavy rainfall which could lead to isolated flash flooding. && .AVIATION... (00Z TAFS) Issued at 723 PM EDT Mon Jul 14 2025 MVFR vis or CIGs will be possible at TRI in the morning hours but confidence is low. Otherwise, VFR conditions are expected outside of thunderstorms. Showers and storms will be mainly in the higher terrain tomorrow afternoon/evening but isolated activity is likely near the terminals. && .PRELIMINARY POINT TEMPS/POPS... Chattanooga Airport, TN 74 96 75 94 / 10 30 20 60 Knoxville McGhee Tyson Airport, TN 73 94 74 93 / 10 40 30 60 Oak Ridge, TN 71 93 72 92 / 10 40 30 60 Tri Cities Airport, TN 69 91 69 90 / 20 60 30 70 && .MRX WATCHES/WARNINGS/ADVISORIES... NC...NONE. TN...NONE. VA...NONE. && $$ SHORT TERM... AVIATION...McD