Area Forecast Discussion
Issued by NWS Knoxville/Tri Cities, TN
Issued by NWS Knoxville/Tri Cities, TN
055 FXUS64 KMRX 161630 AFDMRX Area Forecast Discussion National Weather Service Morristown TN 1230 PM EDT Thu Oct 16 2025 ...New DISCUSSION, AVIATION... .KEY MESSAGES... Updated at 1214 PM EDT Thu Oct 16 2025 - Dry and mild conditions will continue today with cooler overnight lows in northeasters areas. Patchy frost is possible across higher elevations and area of southwest Virginia. - A system will affect the region this weekend, bringing potential of strong winds in the mountains Saturday night and Sunday. - More widespread rain, and a few thunderstorms possible, on Sunday as a cold front moves across the region. The severe threat is currently very low. - Drier and cooler conditions return by Monday, followed by a warming trend and possible showers and storms mid-week. && .DISCUSSION... Issued at 1214 PM EDT Thu Oct 16 2025 High pressure will remain in control with dry weather and warmer than normal temperatures into the weekend. A strong upper-level trough will sweep across the Mississippi and Ohio Valleys over the weekend with a cold front moving west to east across our region on Sunday. Timing is still uncertain, but frontal passage is currently expected on Sunday morning. At this time, there is a wide variety of potential outcomes with this system; however, the most likely outcome currently suggests an occluding low pressure system across the Great Lakes with the majority of synoptic jet ascent to our north across the Ohio Valley and Central Appalachians by Sunday. This would limit the overall precipitation coverage, precipitation amounts, and result in a very low to no severe weather risk. On Sunday morning, current deterministic and ensemble probabilities show about a 30 to 40 percent chance of greater than 500 J/Kg of SBCAPE and 30 kt of shear combined around the Chattanooga area. This drops to only a 20 percent chance in the Knoxville area, and a 10 percent chance in the Tri-Cities area. If we do see any severe weather from this system, the main risk would be damaging winds because of the 50 kt LLJ winds at about 5000 ft AGL, and the primary area of concern would be across the southern valley and southern plateau. Strong gradient winds will likely result in gusty winds of 40+ mph across the higher elevations of the mountains, and there is a low potential of a lower-end mountain wave high wind event across portions of the foothills. We will need to continue to monitor the setup, including the cross-mountain pressure gradient and wind magnitude, over the coming days. Behind this system, we dry out next week. A quick moving system will bring a cold front across the region on Tuesday of next week, but at this time, moisture is so limited that precipitation is unlikely for most areas. Air cools down in the wake of the cold front with closer to seasonal normal temperatures. && .AVIATION... (18Z TAFS) Issued at 1214 PM EDT Thu Oct 16 2025 VFR conditions continue with high pressure in control. Winds remain from the NNE this afternoon and become light to calm overnight into Friday morning. && .PRELIMINARY POINT TEMPS/POPS... Chattanooga Airport, TN 53 81 57 83 / 0 0 0 0 Knoxville McGhee Tyson Airport, TN 48 77 54 82 / 0 0 0 0 Oak Ridge, TN 47 77 54 81 / 0 0 0 0 Tri Cities Airport, TN 37 72 49 78 / 0 0 0 0 && .MRX WATCHES/WARNINGS/ADVISORIES... NC...NONE. TN...NONE. VA...NONE. && $$ SHORT TERM...JB LONG TERM....JB AVIATION...JB