Area Forecast Discussion
Issued by NWS Knoxville/Tri Cities, TN
Issued by NWS Knoxville/Tri Cities, TN
146 FXUS64 KMRX 150536 AFDMRX Area Forecast Discussion National Weather Service Morristown TN 136 AM EDT Wed Oct 15 2025 ...New DISCUSSION, AVIATION... .KEY MESSAGES... Updated at 135 AM EDT Wed Oct 15 2025 - Dry weather and seasonal temperatures will continue for the rest of the week with Thursday night being cooler than what has been seen the past several nights. - A system will approach the area Saturday night into Sunday with widespread showers and a few storms possible. Strong winds are also possible in the mountains. - Cooler and drier conditions return early next week && .DISCUSSION... Issued at 135 AM EDT Wed Oct 15 2025 Currently early this morning, ridging is to our west with high pressure in place across the eastern U.S. This same general setup will continue the pattern we`ve seen in recent days with dry weather and overall seasonal temperatures. Patchy morning fog is likely in some spots again to start the day, but mostly clear conditions and a persistent northerly to northeasterly wind will remain. By Thursday, ridging will shift to be centered almost directly over the region with surface high pressure moving just to our northeast. This location of the surface high will provide better subsidence and radiational cooling conditions Thursday night, especially in the northeast. Current indications suggest some places to drop into the 30s with patchy frost certainly possible. During the day on Friday, focus will turn towards deepening troughing to our northwest, also accompanied by increasing frontogenesis. The result on Friday (and especially Saturday) will be increasing southerly flow and WAA. As this trough moves east, most sources continue to indicate an increasing negative tilt with an upper jet over 100 kts north of the Ohio River Valley. Ageostrophic vertical wind circulations in the right-entrance region of the jet to our northwest will likely increase nearby 850mb winds to 40 or 50 kts. Robust convection is anticipated to our west ahead of this front on Saturday with continued threat for severe weather in that area. For our area, the currently indicated loss of diurnal instability will limit severe potential of anything that may arrive Saturday night. However, the strong 850mb jet may be sufficient for the first mountain wave high wind event of the season. The MSLP gradient in our area remains uncertain, in addition to the strength and exact direction of the 850mb jet. In any case, widespread showers and a few storms will be supported, likely late Saturday night to Sunday ahead of the front. Behind the front, cooler and drier conditions will return Sunday night into early next week. Latest model guidance differs on the extent of CAA in our area during this time. Some solutions show combinations of CAA and subsidence that would be enough for overnight frost by Monday night. && .AVIATION... (06Z TAFS) Issued at 135 AM EDT Wed Oct 15 2025 Fog is likely again at TRI by the early morning hours with reductions to LIFR anticipated. Fog is not currently anticipated at CHA or TYS. Otherwise, all sites will remain VFR throughout the day with mostly clear conditions and northerly to northeasterly winds of around 10 kts. && .PRELIMINARY POINT TEMPS/POPS... Chattanooga Airport, TN 81 58 79 53 / 0 0 0 0 Knoxville McGhee Tyson Airport, TN 78 53 75 49 / 0 0 0 0 Oak Ridge, TN 78 53 75 48 / 0 0 0 0 Tri Cities Airport, TN 74 45 70 40 / 0 0 0 0 && .MRX WATCHES/WARNINGS/ADVISORIES... NC...NONE. TN...NONE. VA...NONE. && $$ DISCUSSION...BW AVIATION...BW