Area Forecast Discussion
Issued by NWS Knoxville/Tri Cities, TN
Issued by NWS Knoxville/Tri Cities, TN
877 FXUS64 KMRX 071141 AFDMRX Area Forecast Discussion National Weather Service Morristown TN 641 AM EST Fri Nov 7 2025 ...New AVIATION... .KEY MESSAGES... Updated at 633 AM EST Fri Nov 7 2025 - A trough/front will move into the region bringing showers and possibly thunder tonight. - Much colder weather expected by Sunday night behind a second cold front that will move across the region Sunday. Max temperatures will be about 20 degrees below normal on Monday. - Light snow showers expected across the higher elevations of the mountains Sunday night into Monday morning. && .DISCUSSION... Issued at 1237 AM EST Fri Nov 7 2025 A surface low moving through the Great Lakes region will drag a cold front through the MRX forecast area on Friday. Convection will develop along/ahead of the front and sweep through our region during the evening hours. Instability is going to be quite limited, and most likely not surface based. So while there could be some rumbles of thunder, much of the convective activity will just be of the shower variety I believe. That said, there will be sufficient shear in place for there to be some gusty winds with the stronger showers, perhaps in the 45-50mph range. Models show 30-40kt of shear in the lowest 3km during the afternoon hours, which should aid in bringing some stronger gusts to the surface. Additionally, the H85 winds ahead of this system will come up to levels that will support some sub-advisory wind gusts in the foothills. Gusts to 40 mph may perhaps occur, and even then only in the typical wind-prone areas like Cove Mtn or Camp Creek. Otherwise just a breezy day it appears. Zonal flow sets in on Saturday, followed by another front on Sunday as an upper trough begins to rapidly deepens across the eastern CONUS. Rain chances appear limited on Sunday as the front and upper support are northeast of us by the time they strengthen enough to start generating precipitation. However, showers will linger across the area through the afternoon and into the overnight hours. A strong upper low then develops Sunday night into Monday, dropping SSE across central Kentucky and middle/eastern Tennessee. This will bring a reinforcing shot of very cold air and subsequent cold front passage through the area, changing any remaining precipitation over to light snow. Accumulations of 1 to 3 inches look possible in the East Tennessee Mountains given northwest H85 flow. Ground temperatures likely mitigate accumulations in the valley, but it`s worth noting that ensemble probabilities show something on the order of 30 percent odds of measurable snowfall Sun night into Mon in the lower elevations. But again, given the ground temperatures heading into the event, accumulations look unlikely. Monday will be much colder with highs in the upper 30s and lower 40s in the Tennessee Valley! This is about 20 degrees below normal. Temps will rebound fairly quickly getting back to near normal by Wednesday as the deep trough exits. && .AVIATION... (12Z TAFS) Issued at 633 AM EST Fri Nov 7 2025 LLWS conditions will subside once winds translate to the SFC this morning. W-SW winds will increase and gust later today ahead of a cold front. PROB30 adjusted to reflect possible timing of line of showers and storms occurrence tonight. VFR will dominate until the line moves through, where CIG are forecast to drop to MVFR and possibly IFR levels. Calm winds following the system may induce fog development before sunrise Saturday morning. && .PRELIMINARY POINT TEMPS/POPS... Chattanooga Airport, TN 73 57 73 54 / 30 80 10 40 Knoxville McGhee Tyson Airport, TN 72 56 70 51 / 30 90 10 40 Oak Ridge, TN 70 54 69 49 / 50 90 10 40 Tri Cities Airport, TN 70 53 66 46 / 20 90 10 20 && .MRX WATCHES/WARNINGS/ADVISORIES... NC...NONE. TN...NONE. VA...NONE. && $$ DISCUSSION...CD AVIATION...KS