276 FXUS64 KMRX 181407 AFDMRX Area Forecast Discussion National Weather Service Morristown TN 1007 AM EDT Tue Oct 18 2022 ...New UPDATE... .UPDATE... Issued at 945 AM EDT Tue Oct 18 2022 No major updates made to the forecast this morning. Freeze warning has expired and most surface observations outside of the mountains have come back up above freezing this morning. Hourly temperatures remain on track for this morning as well across the area. Made minor changes to the sky coverage forecast to come into align with satellite imagery. && .SHORT TERM... (Today and tonight) Issued at 252 AM EDT Tue Oct 18 2022 Key Messages: 1. Freeze again tonight through Wednesday morning that will likely end the growing season. 2. Strong shortwave moves southeast today with some clouds and isolated flurries across the higher elevations of northeast Tennessee and southwest Virginia. Discussion: Satellite WV imagery and surface observations show the anomalous upper low across the Great Lakes extending southward through the Ohio Valley. Relatively strong pressure gradient across our region has kept winds elevated overnight as high pressure builds into the forecast area. Winds have began to relax some early this morning, and expect this trend to continue through the morning hours, which has allowed temperatures to drop quickly within the very dry air and clear sky. As this longwave troughing amplifies across the Appalachians today, very cold temperatures are expected. Temperatures will likely be 15 to 20 degrees below normal with near record low max temperatures today. As a strong shortwave moves southeast and a reinforcing shot of cold air settles into our northern and northeast zones, an increase in low clouds is expected across northeast Tennessee and southwest Virginia. The Great Lakes moisture contribution will be enough to aid in this additional cloud cover, and perhaps a few flurries across the higher elevations of northeast Tennessee and southwest Virginia. The trough axis shifts eastward late tonight with a clearing sky and lighter winds. This will bring another very cold night with a widespread freeze expected. For this reason, will issue another Freeze Warning for sensitive vegetation area-wide for tonight through Wednesday morning. With this morning's freeze and tonight's upcoming freeze, this will likely end the growing season for most, if not all, of the forecast area. && .LONG TERM... (Wednesday through Tuesday) Issued at 252 AM EDT Tue Oct 18 2022 Key Messages: 1. Cold mornings through Friday morning, then a warm-up. 2. Highs in the mid 70s across the Valley this weekend. Discussion: Quite a swing is on tap this week, with temps well below normal through Friday morning, then daytime highs much above normal for the weekend and Monday. As the long term opens, strong troughing aloft will be in place, but slowly filling and lifting, keeping cold mornings but with afternoon temps moderating upward. By Friday, expect general ridging to initiate a substantial warming trend through the weekend. Deep troughing over the Rockies by Sunday will set up strong ridging over our area, sending those daytime highs well into the 70s. Convective precip looks to be in the offing in the central and southern plains states by Monday, but models disagree on how strong and sharp the responsible trough axis will be. That may affect timing of its impacts here, but may see impacts from a convective fropa around next Tuesday. && .AVIATION... (12Z TAFS) Issued at 718 AM EDT Tue Oct 18 2022 Gusty NW winds are expected again this afternoon with gusts around 20 to 25 kt. VFR conditions are expected to prevail at all sites, but low clouds are expected around TRI with cigs in the 3k to 4k ft range. Winds are expected to decrease after sunset late in the period with a general decrease in cloud cover. && .PRELIMINARY POINT TEMPS/POPS... Chattanooga Airport, TN 51 32 58 33 / 0 0 0 0 Knoxville McGhee Tyson Airport, TN 49 31 55 32 / 0 0 0 0 Oak Ridge, TN 51 30 55 30 / 10 0 0 0 Tri Cities Airport, TN 46 29 51 28 / 10 10 0 0 && .MRX WATCHES/WARNINGS/ADVISORIES... NC...Freeze Warning until 10 AM EDT this morning for Cherokee-Clay. Freeze Warning from 2 AM to 10 AM EDT Wednesday for Cherokee- Clay. TN...Freeze Warning until 10 AM EDT this morning for Anderson-Bledsoe- Blount Smoky Mountains-Bradley-Campbell-Claiborne-Cocke Smoky Mountains-East Polk-Grainger-Hamblen-Hamilton-Hancock- Hawkins-Jefferson-Johnson-Knox-Loudon-Marion-McMinn-Meigs- Morgan-North Sevier-Northwest Blount-Northwest Carter- Northwest Cocke-Northwest Greene-Northwest Monroe-Rhea- Roane-Scott TN-Sequatchie-Sevier Smoky Mountains-Southeast Carter-Southeast Greene-Southeast Monroe-Sullivan-Unicoi- Union-Washington TN-West Polk. Freeze Warning from 2 AM to 10 AM EDT Wednesday for Anderson- Bledsoe-Blount Smoky Mountains-Bradley-Campbell-Claiborne- Cocke Smoky Mountains-East Polk-Grainger-Hamblen-Hamilton- Hancock-Hawkins-Jefferson-Johnson-Knox-Loudon-Marion-McMinn- Meigs-Morgan-North Sevier-Northwest Blount-Northwest Carter- Northwest Cocke-Northwest Greene-Northwest Monroe-Rhea- Roane-Scott TN-Sequatchie-Sevier Smoky Mountains-Southeast Carter-Southeast Greene-Southeast Monroe-Sullivan-Unicoi- Union-Washington TN-West Polk. VA...Freeze Warning until 10 AM EDT this morning for Lee-Russell- Scott VA-Washington VA-Wise. Freeze Warning from 2 AM to 10 AM EDT Wednesday for Lee-Russell- Scott VA-Washington VA-Wise. && $$ SHORT TERM... LONG TERM....GC AVIATION...JB