Area Forecast Discussion
Issued by NWS Knoxville/Tri Cities, TN
Issued by NWS Knoxville/Tri Cities, TN
101 FXUS64 KMRX 301137 AFDMRX Area Forecast Discussion National Weather Service Morristown TN 737 AM EDT Wed Sep 30 2026 ...New AVIATION... .KEY MESSAGES... Updated at 633 AM EDT Wed Sep 30 2026 - Dry conditions continue through through Thursday, along with a continued warming trend. - Widespread rainfall is likely this weekend with locally heavy totals possible. && .DISCUSSION... Issued at 113 AM EDT Wed Sep 30 2026 A strong ridge of high pressure will remain anchored over the southeast through Thursday. This will allow for the continuation of dry conditions and warming temperatures, back to above normal by around 10 degrees. On Friday, the ridge begins to break down and push south as a deep and broad long wave trough approaches from the north. Friday should start out dry, but chances of rain and storms begin to increase during the afternoon hours ahead of the approaching trough and cold front. The front moves into our area Friday night and remains in place through Saturday, with chance to likely POPS. During this time, periods of moderate to locally heavy rainfall are also possible as PWs max out around 1.75 to 2.00 inches. These values are near the max PW values for this time of year based on BNA sounding climatology. Tall skinny CAPE profiles as seen on the NAM soundings, 0-6km shear around 20kts, and warm layer cloud depths greater than 10k feet, are all supportive of a moderate to heavy rainfall environment. Higher POPs extend into Sunday as well as the front stalls just to our south. Between Friday and Sunday, several inches or rainfall are expected across the area. Current event total amounts range between 2 to 3 inches, with locally higher amounts upwards of 4 inches possible. Isolated flooding issues are certainly possible, especially as we get into Sunday. The front pushes south on Monday and cooler and drier air filter in from the north. Highs will back in the 70s and overnight lows in the 40s/50s. && .AVIATION... (12Z TAFS) Issued at 633 AM EDT Wed Sep 30 2026 No significant fog so far at TRI this morning, but as usual this time of year it is still possible it could drift over the terminal from nearby Boone Lake briefly before dissipating. Same concern for possibility of fog late tonight at TRI, but will lean toward a persistence forecast for now (no fog). Will have a VFR forecast for the period all sites. Winds will generally be light. && .PRELIMINARY POINT TEMPS/POPS... Chattanooga Airport, TN 91 63 92 67 / 0 0 0 0 Knoxville McGhee Tyson Airport, TN 88 60 89 65 / 0 0 0 0 Oak Ridge, TN 86 59 87 63 / 0 0 0 0 Tri Cities Airport, TN 83 56 85 59 / 0 0 0 0 && .MRX WATCHES/WARNINGS/ADVISORIES... NC...NONE. TN...NONE. VA...NONE. && $$ DISCUSSION...99 AVIATION...99