


Area Forecast Discussion
Issued by NWS Knoxville/Tri Cities, TN
Issued by NWS Knoxville/Tri Cities, TN
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-- Highlight Changed Discussion --
-- Discussion containing changed information from previous version are highlighted. --132 FXUS64 KMRX 022338 AFDMRX Area Forecast Discussion National Weather Service Morristown TN 738 PM EDT Wed Jul 2 2025 ...New AVIATION... .SHORT TERM... (This evening through Friday) Issued at 137 PM EDT Wed Jul 2 2025 Key Messages: 1. Mainly dry conditions through Friday, with the possible exception of an isolated shower or thunderstorm in the TN mountains and southwest North Carolina. 2. Slightly above normal temperatures but fairly comfortable humidity levels Thursday and Friday. Discussion: A drier air mass has filtered into the area behind yesterday`s frontal passage. Last night`s fog is not expected to be repeated tonight, given the lower dewpoints we are seeing this afternoon compared to 24 hours ago, and the lack of afternoon/evening showers today compared to yesterday. Some patchy fog may be possible near area rivers and lakes, but probably not much outside of those areas. Thursday and Friday will have nice conditions for outdoor activities and Fourth of July celebrations. We will have a mid/upper level ridge building across the region, with a generally N to NE flow through the column. Subsidence under the ridge will warm temperatures into the upper 80s to lower 90s both days (maybe mid 90s around CHA on Friday), but humidity levels should be tolerable for this time of year, with dewpoints dropping into the 60s in the afternoons. The only chance of rain will be in the TN mountains and higher elevations of SW NC Friday afternoon, with coverage expected to be isolated at best as the upper ridge and dry air entrainment will suppress convection. && .LONG TERM... (Friday night through next Wednesday) Issued at 137 PM EDT Wed Jul 2 2025 Key Messages: 1. Thunderstorm chances increase slightly this weekend, but the overall chance of precipitation remains very low (less than 20 percent) and mainly in the mountains. 3. Increasing temperatures and humidity this weekend with heat index values approaching 100 near Chattanooga. 4. Rain chances increase next week for the entire area, but details remain uncertain. Discussion: The upper-level ridge shifts east of our area over the weekend, with weak troughing near the MS Valley region. This will bring a return of weak southerly flow and increasing moisture and humidity. Afternoon thunderstorm chances will begin to increase, mainly across the mountains. With highs in the lower to mid 90s and dewpoints in the southern TN Valley rising into the lower 70s, some locations near CHA may approach 100 degree heat index Saturday and Sunday. By early next week, we will be in between two synoptic systems: troughing across the Great Lakes and upper Mississippi Valley, and a tropical low pressure system near Florida. There is still quite a lot of uncertainty with the placement of these systems and how it will impact our weather, but the most likely outcome at this time is increasing chances of diurnal afternoon thunderstorms each day across our forecast area. && .AVIATION...-- Changed Discussion --(00Z TAFS) Issued at 735 PM EDT Wed Jul 2 2025 VFR conditions forecast through the period at all sites along with light northerly winds less than 10kts. There will likely be some patchy fog tonight but not enough confidence that it will develop directly over any one terminal to include in TAFs.-- End Changed Discussion --&& .PRELIMINARY POINT TEMPS/POPS... Chattanooga Airport, TN 69 91 69 94 / 0 0 0 10 Knoxville McGhee Tyson Airport, TN 67 91 67 93 / 0 0 0 10 Oak Ridge, TN 66 91 67 93 / 0 0 0 10 Tri Cities Airport, TN 64 86 63 90 / 0 0 0 10 && .MRX WATCHES/WARNINGS/ADVISORIES... NC...NONE. TN...NONE. VA...NONE. && $$ SHORT TERM...DGS LONG TERM....DGS AVIATION...