Area Forecast Discussion
Issued by NWS Knoxville/Tri Cities, TN
Issued by NWS Knoxville/Tri Cities, TN
598 FXUS64 KMRX 070547 AFDMRX Area Forecast Discussion National Weather Service Morristown TN 1247 AM EST Sun Dec 7 2025 ...New DISCUSSION, AVIATION... .KEY MESSAGES... Updated at 1247 AM EST Sun Dec 7 2025 - Cloudy conditions persist through the morning, with some sunshine breaking in through in the afternoon for some areas. - Next system arrives Sunday night into Monday with very light precipitation. Some snow could occur in mountains and SW VA, but accumulations and impacts should be negligible. && .DISCUSSION... Issued at 1247 AM EST Sun Dec 7 2025 Fog has developed in parts of the area, and lowered visibilities are expected to expand over the next few hours in southern sections. Northern sections are likely to have more cloud cover based on satellite trends, and should have less fog. With forecast lows in the lower 30s to upper 20s, this could be freezing fog that could cause some slick spots on bridges and overpasses. Through the day, high and midlevel clouds will be increasing ahead of the approaching shortwave trough that will bring rain in the evening. Forcing for this precipitation will be driven mainly by a midlevel shortwave trough, but no strong surface level forcing is depicted by the models. Therefore, any precip should be fairly light over the area. Measurable precip begins the area between 00Z and midnight as the column moistens from the top down. By early Monday morning, cold air advection ramps up and temperatures drop behind the low level trough and a weak surface cold front, allowing for a transition to snow for northern parts of our area. This will be mainly in southwest VA and the eastern TN mountains, but outside the highest elevations, any snow accumulations will be light and not likely to be impactful. For the higher elevations of northeast TN, the NW flow behind this shortwave that persists through Monday could result in a inch or two accumulation through Monday evening, mainly along the peaks of the mountains near the NC border. Amounts should stay under Advisory criteria for populated areas. Generally zonal flow throughout the atmosphere is expected through the middle of the week, with temperatures warming a little (into the 50s for Wednesday) before our next system moves in towards the end of the week. Temperatures appear to be fairly warm on the front end with a big cooldown behind the low and front expected to move through Thursday into Friday. We should see much colder temperatures behind the front for the upcoming weekend, possibly dropping into the teens for the weekend mornings with highs in the 20s and 30s. && .AVIATION... (06Z TAFS) Issued at 1247 AM EST Sun Dec 7 2025 The main aviation impact overnight will be development of patchy fog, which is most likely to occur at CHA. TYS and TRI have chances for fog, but it was left out of the TAF. Fog will be slow to lift into low clouds at CHA before VFR through the day. VFR is also expected to continue at the other sites. Light and variable winds are also expected. && .PRELIMINARY POINT TEMPS/POPS... Chattanooga Airport, TN 52 41 48 29 / 10 40 10 0 Knoxville McGhee Tyson Airport, TN 50 39 43 28 / 10 40 30 0 Oak Ridge, TN 50 38 44 26 / 10 40 20 0 Tri Cities Airport, TN 50 35 38 26 / 10 50 60 10 && .MRX WATCHES/WARNINGS/ADVISORIES... NC...NONE. TN...NONE. VA...NONE. && $$ DISCUSSION...DGS AVIATION...BW