FXUS64 KMRX 270516 AAA AFDMRX Area Forecast Discussion...UPDATED National Weather Service Morristown TN 116 AM EDT Mon Oct 27 2025 ...New AVIATION... .KEY MESSAGES... Updated at 113 AM EDT Mon Oct 27 2025 - An active upper level pattern is expected this week, with distinct periods of rain tonight into Monday, and then again Wednesday into Thursday. - Areas prone to mountain wave winds will see breezy conditions tonight through Monday night, with gusts occasionally exceeding 40 mph. Another round of winds is expected on Wednesday as well. && .DISCUSSION... Issued at 153 PM EDT Sun Oct 26 2025 An upper low will slowly move east along the I-40 corridor from Arkansas through Tennessee today through Monday night. Ahead of this, widespread light to moderate rainfall will spread across the forecast area with most of the rainfall focused on roughly the pre- dawn hours through mid morning hours tomorrow. We'll have some light precipitation, similar to what's been seen in some areas already today, that moves in later this evening and then also some showers lingering into Monday night as well driven largely by increased lapse rates aloft with the passing upper low. Another period of rainfall is expected Wednesday into Thursday as a large and deep upper trough setups over over the eastern CONUS, with an embedded upper low swinging through the base of the trough over deep south Wednesday night. Rainfall looks to be a little heavier with this event due to stronger and more favorably aligned jet dynamics, and similar to tonight/Monday there doesn't seem to be a threat of any heavy rains or flooding as PWATs aren't very high and there's little to no instability to work with. The only other topic of discussion would be the potential for mountain wave winds. While confidence remains high that we won't reach high wind criteria over the next 24 to 36 hours, I think some gusts into wind advisory criteria still seem plausible. The latest HREF probabilities of at least 35kt reach 30-40 percent over the typical areas prone to mountain wave winds like the Smokies and Cocke and Greene counties for instance. Certainly the H85 wind field is stronger over northern Georgia and the common GA/TN/NC border areas tonight. But as that upper low moves overhead tomorrow most all models show signatures in the surface winds that is consistent with mountain wave activity. The question is, how strong will the winds get. I have gusts to 35-40 mph in the forecast grids and that seems reasonable for now, but I woulnd't be at all surprised to see a few 40-50 mph gusts at Cove Mountain and even Camp Creek between tonight and Monday night. The H85 wind direction will be almost purely southeast and I think it has potential to outperform what the background H85 wind speeds would suggest, especially given how strong the CAD will be on the east side of the Appalachians. On Wednesday, ahead of the next system, there's potential for another mountain wave wind event. This one will have a stronger wind field across the board with another bout of purely southeast H85 wind direction, so advisory or even warning level winds seem possible. && .AVIATION... (06Z TAFS) Issued at 113 AM EDT Mon Oct 27 2025 Rain is picking up at CHA and will lower vis and cigs to IFR levels overnight. LLWS will also be present there. At TYS and TRI, rain will move in late tonight and tomorrow morning, but downslope winds off the mountains will likely keep cigs at VFR levels. Some pockets of heavier rain may lower vis to MVFR at times. Rain will taper off in the afternoon, but some MVFR to IFR vis/cigs may linger behind it. && .PRELIMINARY POINT TEMPS/POPS... Chattanooga Airport, TN 57 52 63 50 / 90 50 10 70 Knoxville McGhee Tyson Airport, TN 56 50 62 50 / 100 80 10 60 Oak Ridge, TN 55 49 60 48 / 100 70 10 70 Tri Cities Airport, TN 56 46 59 45 / 90 100 30 50 && .MRX WATCHES/WARNINGS/ADVISORIES... NC...NONE. TN...NONE. VA...NONE. && $$ DISCUSSION...CD AVIATION...DGS