398 FXUS64 KMRX 070509 AFDMRXArea Forecast Discussion National Weather Service Morristown TN 109 AM EDT Tue Oct 7 2025
...New AVIATION...
.KEY MESSAGES... Updated at 1200 AM EDT Tue Oct 7 2025
- A cold front Tuesday into Wednesday will bring chances of rain and storms back to the region.
- Temperatures will continue to be unseasonably warm; 5 to 10 degrees above normal through Tuesday. More seasonal readings and a return to drier conditions are anticipated by the second half of the week.
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.DISCUSSION... Issued at 129 PM EDT Mon Oct 6 2025
Currently, an upper ridge is in place over the eastern CONUS with a trough axis stretching through the Northern Plains into the Intermountain West. A weak area of surface low pressure sits atop the ArkLaMiss region. Relatively higher cloud coverage and light radar returns have been noted along the Cumberland Plateau and Southern Valley as isentropic lift taps into enhanced moisture advection.
Overall, pretty minimal impacts over the next 12-18 hours - just light precip chances focused over the Cumberland Plateau. As we approach mid-day and into Tuesday afternoon the aforementioned troughing will quickly glide across central and into eastern portions of the CONUS. An approaching cold front will lead to increasing chances of showers and a few thunderstorms. Coverage will be greatest Tuesday night when vort maxima and frontal forcing best align. This is expected to be largely beneficial rainfall for the area despite anomalous PWAT values between 1.6-1.8 inches. This is due to lackluster thermodynamic profiles with NAMBufr soundings showing MUCAPE less than 1000 J/kg. NBM probability of precip greater than 0.25" has increased to 60% or greater across our whole CWA. Prob of precip greater than 1" does reach the 50-60% range along the N Plateau, N valley, into SW Virginia.
Precipitation associated with the front is expected to clear out of the area through late Wednesday morning, with a mostly dry afternoon. A shift to northerly winds will induce a return to more seasonal temperatures Wednesday as well. NBM paints dry conditions through the remainder of the forecast period onwards. Reinforcing shortwaves will enhance troughing over the southern Appalachians, eventually becoming a closed low by the weekend. This will allow near normal temperatures to persist.
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.AVIATION... (06Z TAFS) Issued at 1200 AM EDT Tue Oct 7 2025
Will see some showers, especially late in the period, and a few rumbles of thunder will be possible mainly CHA and perhaps TYS as well late in the period. Will see VFR conditions much of the period, but MVFR conditions likely to occur with showers at CHA, and then a trend toward more prevailing MVFR late in the period at CHA and TYS as showers increase frequency.
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.PRELIMINARY POINT TEMPS/POPS... Chattanooga Airport, TN 81 68 80 59 / 40 80 20 10 Knoxville McGhee Tyson Airport, TN 81 67 75 55 / 30 90 20 10 Oak Ridge, TN 79 65 75 53 / 60 90 20 10 Tri Cities Airport, TN 80 64 71 49 / 30 90 40 0
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.MRX WATCHES/WARNINGS/ADVISORIES... NC...NONE. TN...NONE. VA...NONE. &&
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DISCUSSION...99 AVIATION...99
NWS MRX Office Area Forecast Discussion