089 FXUS64 KMRX 062252 AFDMRX AREA FORECAST DISCUSSION National Weather Service Morristown TN 652 PM EDT Mon Sep 6 2021 .UPDATE... FOR 00Z AVIATION. && .SHORT TERM...(Tonight through Tuesday)... Key Messages: 1. Mostly dry, with slightly above normal temperatures. Discussion. Upper flow is somewhat zonal overhead and to our north tonight as a trough exits the New England area and the next one begins digs across the upper midwest. Locally, a stalled front to our south and southeast today will remain there overnight and into Tuesday. However, on Tuesday as the second trough digs into the upper midwest, low level flow, especially at H85, begins to turn back around to the south and advect higher moisture back into the CWA. Surface front stays south, but the added moisture will probably be enough to kick off some showers in the far southern valley and in the TN mountains south of the Smokies. Have some slight to chance PoPs in those areas to account for this but expect coverage to be on the sparse side. Otherwise, not much going on in the short term. Dry air advection will keep fog development rather limited tonight, if it occurs at all. Furthermore, this will also keep much of the area dry tomorrow aside from the PoPs mentioned above. Expect highs in the low to mid 80s tomorrow. CD .LONG TERM...(Tuesday night through Monday)... Key Messages: 1. Best chance for rain over the next week will be Wed afternoon into Wed night, but the coverage will be scattered and light. 2. After the front cools us down, dry conditions and a slow warming trend will begin Thursday through the weekend. Discussion: Tuesday Night through Sunday... By Tuesday night most of the lingering showers and storms will be moving off east of the mountains as another approaching front moves in from the northwest. Forecast timing of this front and associated precipitation remains pretty close to previous forecasts with the frontal passage occurring Wednesday into Wednesday evening. Moisture ahead of and along the frontal boundary will be fairly low, and overall forcing ahead of the front also looks like it will be pretty weak. Expect scattered coverage of showers and possibly thunderstorms to be pretty limited, with the highest PoP chances being in northeast TN, southwest VA, and along the southern Appalachian Mountains After the front pushes through the area by early Thursday morning expect we'll remain in broad mid-level troughing, and surface ridging which will help keep temperatures fairly mild for the second half of the work week. As we head into the weekend a ridge begins to build in from the west and help steadily raise temperatures each day through the rest of the 7-day forecast. We'll get back near (or just above) normal temperatures by the end of the weekend and Monday as the ridge strengthens. No precipitation is expected through the weekend... But another front may approach the Appalachian Region early next week leading to an increase in shower and thunderstorm chances. Models are in poor agreement with the timing and location of any potential system early next week, so will remain fairly conservative on PoP chances this far out and wait for better model agreement. ABM && .AVIATION... 00Z TAF DISCUSSION. VFR conditions expected to prevail through the period. An old frontal boundary to the south looks to lift back northward on Tuesday which could favor a low VFR to high MVFR sct layer at CHA, while low VFR cu prevails elsewhere. Some precipitation is also possible at CHA, however confidence is very low at this point thus withheld from TAF. Did include brief tempo for fog at TRI in the morning as most guidance favors fog development, but xover temperatures suggest minimal chances thus went with 4SM for now. Winds will remain lgt/vrb tonight, lgt/sly on Tuesday. CDG && .PRELIMINARY POINT TEMPS/POPS... Chattanooga Airport, TN 64 85 69 87 65 / 10 20 20 20 10 Knoxville McGhee Tyson Airport, TN 61 85 68 86 64 / 0 20 20 30 20 Oak Ridge, TN 61 84 67 86 61 / 0 10 20 20 20 Tri Cities Airport, TN 57 84 65 84 61 / 0 10 10 30 30 && .MRX WATCHES/WARNINGS/ADVISORIES... NC...NONE. TN...NONE. VA...NONE. && $$