Area Forecast Discussion
Issued by NWS Knoxville/Tri Cities, TN
Issued by NWS Knoxville/Tri Cities, TN
732 FXUS64 KMRX 280644 AFDMRX Area Forecast Discussion National Weather Service Morristown TN 144 AM EST Fri Nov 28 2025 ...New DISCUSSION, AVIATION... .KEY MESSAGES... Updated at 101 AM EST Fri Nov 28 2025 - Dry and colder weather continues through Saturday. - A system will bring a return of rain chances and gusty winds for the mountains and foothills Saturday night into Sunday. Higher elevation areas may see a brief wintry mix early Sunday and again Sunday night. - Another system will bring rain to the area Monday night through Tuesday. Some northeastern mountain areas may see initial wintry mix with precipitation ending as light snow Tuesday night. && .DISCUSSION... Issued at 101 AM EST Fri Nov 28 2025 Currently early Friday morning, troughing is centered to our east with broad Canadian high pressure expanding into the region. Dry conditions are expected this afternoon, with just a light breeze as mixing heights in excess of 4kft tap into weak H85 flow near 15-20kts. Stronger subsidence will provide better radiational cooling conditions with temperatures dropping well into the 20s and even possibly teens for some in the northeast tonight. Focus will then shift towards a deepening shortwave and developing system expected to eject out of the Rockies for Saturday. This system is expected to track towards the Great Lakes throughout the day. Based on the latest data, its 850mb jet is expected to increase to above 40 kts with the surface high to our east helping to create a stronger MSLP gradient along the mountains. Overall, the direction of this flow is a bit westerly for significant mountain waves, but the other factors still suggest some enhancement. Latest NAM gudiance suggest gusts between 45 to 55 mph possible between 00Z-18Z Sunday. A wind product may need to be considered with future forecast packages. As precipitation moves into the region with this system after 06Z Sunday, most sources suggest portions of the northeastern mountains and possibly southwest Virginia to be near or below freezing. With a warm nose aloft due to the strong 850flow, this could provide a period of mixed precipitation, including freezing rain. However, WAA is likely to quickly warm temperatures above freezing soon after onset, yielding minimal impact. This will then give way to a cold rain throughout the day on Sunday. By Sunday evening, CAA returns, but moisture will exit rather quickly. A brief period of light snow is possible in the higher elevations. Another area of high pressure to the north will keep the region cool and largely dry on Monday with focus then turning towards our southwest. Troughing is expected to deepen again as it ejects out of the Rockies with another area of low pressure expected to deepen along the northern Gulf. This system will then progress northeast with the recent high pressure then becoming centered over New England. The high pressure over the northeast will give a cold air damming setup just to our east as evidenced by surface troughing. With this system tracking to our south and east, the question of precipitation types will arise again, especially late Monday night into early Tuesday morning. The latest consensus largely keeps freezing low-level temperatures to our east, but some sources do show this for our northeastern mountains. With 850mb temperatures ranging from 4 to 8 degrees Celsius, a strong warm nose will exist once again, likely keeping most places above freezing below this level. Still, some periods of mixed precipitation are possible in the mountains before the area warms. During the day on Tuesday, this system tracks up the Atlantic Coast with stronger northwesterly flow and CAA presenting chances for a changeover to light snow in the evening. This would be more prominent along the mountains but still possible elsewhere, depending on how long moisture lingers. High pressure will provide cool and drier conditions on Wednesday. Late in the week, additional troughing will provide another return of precipitation chances with a lot of uncertainty in any details. && .AVIATION... (06Z TAFS) Issued at 101 AM EST Fri Nov 28 2025 VFR conditions and northwest winds between 5 to 10 kts will prevail through the period. Some gusts to around 20kts will be possible at TRI this afternoon due to a stronger pressure gradient in closer proximity of a departing surface low over New England. && .PRELIMINARY POINT TEMPS/POPS... Chattanooga Airport, TN 47 27 50 41 / 0 0 0 60 Knoxville McGhee Tyson Airport, TN 42 23 49 37 / 0 0 0 60 Oak Ridge, TN 42 23 48 36 / 0 0 0 70 Tri Cities Airport, TN 38 20 48 33 / 0 0 0 30 && .MRX WATCHES/WARNINGS/ADVISORIES... NC...NONE. TN...NONE. VA...NONE. && $$ DISCUSSION...BW AVIATION...BW