Area Forecast Discussion
Issued by NWS Knoxville/Tri Cities, TN
Issued by NWS Knoxville/Tri Cities, TN
429 FXUS64 KMRX 071823 AFDMRX Area Forecast Discussion National Weather Service Morristown TN 123 PM EST Fri Nov 7 2025 ...New DISCUSSION, AVIATION... .KEY MESSAGES... Updated at 102 PM EST Fri Nov 7 2025 - A trough/front will move into the region bringing a line of showers and storms through the region. Some storms will be strong with gusty winds. - 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 102 PM EST Fri Nov 7 2025 By this evening, a trough will envelop most of the Eastern U.S. A surface low will be centered near the Great Lakes with a cold front moving into the Ohio/Tennessee Valleys. Currently, 12 PM EST, the cold front is near IL/MO. A line of showers and thunderstorms will move into the region this evening. With strong 850 mb flow around 35 knots, winds will increase Friday late afternoon and evening. Gusts may be enhanced by showers and storms but I would not expect more than 50 mph or so even in the strongest storms. Instability will be low when the line of showers/storms arrive but some guidance suggests ML CAPE may be around 200 to 300 J/kg from about Knoxville southward which is higher than originally thought. Dew points will be lower than 60 for most of the region. CAMs are not overly impressed with the line of showers/storms this evening (the previous HRRR run looked stronger) but some thunder, heavy downpours and gusty winds will be possible. Non-convective winds will be strongest in the East Tennessee Mountains with a wind direction favorable for downslope. Fortunately this system is not very strong and gusts will likely stay below 40 mph (Advisory threshold). The most downslope wind prone spots may hit 40 mph or so briefly as winds peak around sunset to midnight this evening. On Saturday, behind the weak cold front with nearly zonal flow aloft, a lull in activity is expected before another cold front and trough move into the region Saturday night bringing another round of rain. That cold front should be through the region by Sunday morning but low rain chances will linger throughout the day as the trough deepens upstream over the Midwest and Lower Mississippi. With cold air moving in near the surface Sunday night and the trough lagging behind, a changeover to light snow will be likely in the higher elevations. 1 to 3 inches looks possible in the East Tennessee Mountains with 850mb northwest flow increasing lift. Some light snow will be possible in the Tennessee Valley but accumulation is unlikely other than maybe a dusting in the grass. 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... (18Z TAFS) Issued at 102 PM EST Fri Nov 7 2025 Southerly winds are starting to increase as a system approaches. A line of showers and thunderstorms will move through the region this evening. The stronger storms may contain wind gusts up to 45 knots. This line will move through fairly quickly. MVFR CIGs and vis are likely late tonight into the morning hours. LLWS may be present ahead of the storms but that will depend on the exact timing of storms in relation to surface winds. && .PRELIMINARY POINT TEMPS/POPS... Chattanooga Airport, TN 56 73 53 60 / 80 10 30 20 Knoxville McGhee Tyson Airport, TN 54 70 51 59 / 100 0 40 30 Oak Ridge, TN 52 68 48 57 / 90 0 40 30 Tri Cities Airport, TN 52 65 45 58 / 100 0 30 40 && .MRX WATCHES/WARNINGS/ADVISORIES... NC...NONE. TN...NONE. VA...NONE. && $$ DISCUSSION...McD AVIATION...McD