510 FXUS64 KMRX 141712 AFDMRX Area Forecast Discussion National Weather Service Morristown TN 112 PM EDT Sat Oct 14 2023 ...New AVIATION... .UPDATE... Issued at 1033 AM EDT Sat Oct 14 2023 Pockets of scattered light rain followed by quick bouts of sunshine will persist ahead of the cold front. The front should skirt through the forecast area by 2 pm, however, some residual light rainfall and cloudiness will continue until late afternoon. Wind gusts to 25 mph will be likely throughout the day before subsiding close to 8pm. No changes to ongoing forecast at this time. && .SHORT TERM... (Today and tonight) Issued at 225 AM EDT Sat Oct 14 2023 Key Messages: 1. Sprinkles and/or light rain showers will continue today and tonight, although mainly north of I-40 after this morning. Rainfall amounts will be light. 2. Breezy conditions expected for Saturday afternoon. Discussion: An upper low will move through the Ohio Valley today. The trough stretches down to the Gulf Coast. The Tennessee Valley will be in westerly or northwesterly upper level flow today and tonight. At the surface, the cold front is currently near the Mississippi River. The cold front will move through the region late this morning or early afternoon with gusty westerly winds moving in by early afternoon. The cold, dry air will move in by late afternoon or early evening. Mostly cloudy with light rain off and on is expected through this morning and early afternoon. Clearing is likely late this afternoon for the Southern and possibly Central Tennessee Valleys. Light rain will continue through the afternoon, evening and overnight periods for Southwest Virginia, Northeast Tennessee and the higher elevations of the East Tennessee Mountains. Rain totals will be very low but some models are picking up higher amounts in the highest peaks of the East Tennessee Mountains due to orographic lift with the northwest flow. Gusty westerly winds will move into the region this afternoon with gusts up to 25 mph possible in the Tennessee Valley. Winds will be higher in the East Tennessee Mountains with gusts up to 35 mph possible. Winds will decrease after sunset but lower gusts will continue overnight. Lingering cloud cover will keep temps fairly mild tonight with lows in the upper 40s and lower 50s. The higher elevations in the East Tennessee Mountains will get down to the mid to upper 30s by Sunday morning. Some flurries will be possible mainly on the tallest peaks, but accumulation is not likely with temps staying above freezing. The HREF ensemble has zero for max and min snow accumulation during this timeframe. && .LONG TERM... (Sunday through Friday) Issued at 225 AM EDT Sat Oct 14 2023 Key Messages: 1. Much colder Sunday into the early part of the week. 2. There will be some mainly light showers around at times Sunday through Monday night, especially north and mountains. However, rainfall amounts will be light. 3. Dry with a warming trend mid week, with rain possible again Friday. Discussion: The upper trough will continue to deepen across the region Sunday as additional energy dives south, and a cutoff upper low will likely form to our northeast and drift southeast then east. Sunday and especially Monday will be much colder, with max temperatures around 15 degrees below normal Sunday and around 18 to 20 degrees below normal Monday. We will be in an extended period of cold advection and low level northwest flow for Sunday through Monday night, although there will not be be much forcing other than orographic lift over the terrain. However, with at least low level moisture lingering over the area we will see some light showers/sprinkles at times Sunday through Monday night. Higher elevations where orographic lift is strongest may see a quarter of an inch or more of rainfall, but most lower elevations locations in the valley are likely to receive less than a tenth of an inch of rainfall from Sunday through Monday night. The higher peaks of the mountains may see some light snow showers or flurries mainly Sunday night into early Monday night, and some very light snow accumulation cannot be ruled out over the highest peaks mainly above 5000 feet. The upper trough will lift out mid-week with upper-level ridging building in from the west. Expect moderating temperatures and dry weather for the region. By Friday the next upper trough will be approaching, so showers will return to the forecast. && .AVIATION... (18Z TAFS) Issued at 108 PM EDT Sat Oct 14 2023 Cold front marching across East Tennessee with winds becoming westerly in its wake. Wind gusts will persist until an hour or so after sunset with the exception of KTRI where occasional gusts of 20 knots will remain possible overnight along with light rain. MVFR ceilings return by early morning through the end of the TAF period. && .PRELIMINARY POINT TEMPS/POPS... Chattanooga Airport, TN 54 60 46 58 / 10 10 10 10 Knoxville McGhee Tyson Airport, TN 53 59 45 55 / 20 20 20 20 Oak Ridge, TN 51 59 43 54 / 10 20 10 20 Tri Cities Airport, TN 49 56 42 51 / 50 40 30 40 && .MRX WATCHES/WARNINGS/ADVISORIES... NC...NONE. TN...NONE. VA...NONE. && $$