223 FXUS64 KMRX 291059 AFDMRXArea Forecast Discussion National Weather Service Morristown TN 659 AM EDT Mon Sep 29 2025
...New AVIATION...
.KEY MESSAGES... Updated at 657 AM EDT Mon Sep 29 2025
- After patchy morning fog, most areas will remain dry today with chances for showers remaining in far eastern areas.
- Scattered showers and a few thunderstorms are possible on Tuesday, focused mainly in the eastern half of the area.
- Dry seasonal fall weather is expected Wednesday through the weekend.
&&
.DISCUSSION... Issued at 134 AM EDT Mon Sep 29 2025
Currently early this morning, broad ridging is in place across the eastern U.S. with a weak embedded closed low. A jet streak is centered to our east with Tropical Storm Imelda located in The Bahamas at the time of this update. High pressure also remains in place across the eastern U.S. Throughout the day, Imelda is forecast to track north, well to the east of Florida before strengthening to a hurricane and taking a sharp easterly turn. For today, most places will stay dry with moisture advection and upper divergence sufficient for rain chances in far eastern areas. Instability will be minimal, supporting just showers. On Tuesday, another shortwave will move through the area with a jet streak of 50 kts arriving from the west. Moisture advection will strengthen, evidenced by PWATs exceeding 1.5 inches for many areas, along with instability reaching 500 J/kg. With western portions of the area in the left entrance region of this jet, upper convergence will limit ascent and overall rain chances. Regardless, the latest CAMs continue the trend of minimal coverage and little to no impact in our area.
By Wednesday, Imelda will advance further out into the Atlantic with a closed low tracking along the northern Gulf. For our area, broadening ridging will take place, in addition to expansion of surface high pressure to the north with no effect from the closed low. This broad pattern looks to continue through the end of the week and the weekend, keeping rain chances out of the area. 500mb heights remaining at or above 5,850m suggest daily highs to remain mild but with subsidence promoting cooler nights than seen in recent days.
&&
.AVIATION... (12Z TAFS) Issued at 657 AM EDT Mon Sep 29 2025
Morning fog has developed at TRI with MVFR conditions but is expected to lift within an hour or so. CHA has also reported a 6 mile visibility, but no reductions are expected. Throughout the day, northeasterly winds and mid-level clouds will continue. A few showers are possible around TRI by the afternoon, but VCSH was left out.
&&
.PRELIMINARY POINT TEMPS/POPS... Chattanooga Airport, TN 85 65 85 64 / 10 0 20 10 Knoxville McGhee Tyson Airport, TN 83 63 82 62 / 10 10 20 0 Oak Ridge, TN 83 63 83 61 / 10 10 20 0 Tri Cities Airport, TN 79 61 77 56 / 20 30 40 0
&&
.MRX WATCHES/WARNINGS/ADVISORIES... NC...NONE. TN...NONE. VA...NONE. &&
$$
DISCUSSION...BW AVIATION...BW
NWS MRX Office Area Forecast Discussion