Area Forecast Discussion
Issued by NWS Knoxville/Tri Cities, TN
Issued by NWS Knoxville/Tri Cities, TN
847 FXUS64 KMRX 172330 AAA AFDMRX Area Forecast Discussion...UPDATED National Weather Service Morristown TN 730 PM EDT Fri Oct 17 2025 ...New AVIATION... .KEY MESSAGES... Updated at 724 PM EDT Fri Oct 17 2025 - Warm and dry conditions will continue Saturday ahead of an approaching system. - Late Saturday night into Sunday morning, showers and a few storms are likely across the region. The threat for severe storms remains low. Also, breezy conditions are likely, especially across the mountains. - Drier and cooler conditions return by Monday with little to no rain chances next week. && .DISCUSSION... Issued at 1251 PM EDT Fri Oct 17 2025 High pressure and ridging across the region will result in continued warm, dry conditions on Saturday. Southwest flow begins to increase in advance of an approach trough across the Mississippi Valley by Saturday night. With a pressure gradient and SSW/SW LLJ around 50 kt, strong winds are expected across the mountains. Lower-end mountain wave winds are possible, but this does not appear to be a strong mountain wave wind event at this time. As the trough shifts eastward Sunday morning, a surface cold front will move eastward across the region with widespread precipitation. As stronger jet streak dynamics supporting ascent shift to our north, precipitation along the frontal boundary is expected to decrease in coverage and intensity as it moves into our region Sunday morning. This will also expected to be the diurnal minimum for instability during the day, so severe weather and overall thunder chances remain low. While most should see rainfall with this system, overall amounts are expected to be low and generally less than one-half inch with localized amounts up to one inch, especially west of Interstate 75. Behind the cold front, high pressure builds across the region with drier and cooler air arriving early next week. Another quick moving cold front will move across the region on Tuesday night, but limited moisture should keep us dry with measurable precipitation not expected. Otherwise, temperatures remain near normal for most of next week with chances for frost across the higher elevations and northeast Tennessee and southwest Virginia. && .AVIATION... (00Z TAFS) Issued at 724 PM EDT Fri Oct 17 2025 Currently have dry, VFR conditions through the period in the 00z TAFs, with light winds and a mid level deck around 10k ft coming in tomorrow morning. It`s worth nothing that several guidance sources have some ISOLD to SCT SHRA developing south of I-40 tomorrow afternoon, primarily over the plateau region. Forecast soundings show clouds in the BKN040-060 range developing over KCHA and INVOF KTYS after 16-18z timeframe. It`s late in the period, and I`m not sold on the showers and low clouds part just yet so I didn`t include either in the TAFs. && .PRELIMINARY POINT TEMPS/POPS... Chattanooga Airport, TN 82 59 84 64 / 0 0 10 70 Knoxville McGhee Tyson Airport, TN 78 56 83 63 / 0 10 10 50 Oak Ridge, TN 78 56 82 61 / 0 10 10 60 Tri Cities Airport, TN 74 47 79 59 / 0 0 10 20 && .MRX WATCHES/WARNINGS/ADVISORIES... NC...NONE. TN...NONE. VA...NONE. && $$ DISCUSSION...99 AVIATION...CD