018 FXUS64 KMRX 161758 AFDMRXArea Forecast Discussion National Weather Service Morristown TN 158 PM EDT Tue Sep 16 2025
...New DISCUSSION...
.DISCUSSION... Issued at 141 PM EDT Tue Sep 16 2025
Key Messages:
1. Isolated to widely scattered showers and embedded thunderstorms through early this evening.
2. Unseasonably warm temperatures for the latter half of the week through the weekend.
Discussion:
A frontal boundary is pulling southwestward across southwest Virginia with easterly winds with dewpoints in the 40s/50s east of this boundary and southwest winds and dewpoints in the 60s west.
This boundary along with spokes of energy rotating around mid- Atlantic upper low, combined with orographic lift will produce isolated to widesly scattered showers. SPC meso-analysis shows MLCAPES of 500-1000 so enough instability to produce embedded thunder.
For tonight through the rest of the week, ensemble cluster analysis and deterministic models show a drier airmass and upper ridge building into the Tennessee valley. PWs of 0.8 to 1 inch will be common keeping conditions mostly dry into the weekend. The upper ridge will weekend early next week as a series of short- waves ride over the ridge. However, airmass stays quite dry with surface ridging into the southeast United States keep Gulf moisture limited.
The building ridge and dry conditions will allow for unseasonably warm afternoons for late this week through the weekend.
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.AVIATION... (18Z TAFS) Issued at 128 PM EDT Tue Sep 16 2025
A frontal boundary is pulling westward across southwest Virginia with easterly winds with dewpoints in the 40s/50s east of this boundary and southwest winds and dewpoints in the 60s west.
This boundary along with spokes of energy rotating around mid- Atlantic upper low will produce isolated to scattered showers. SPC meso-analysis shows MLCAPES of 500-1000 so enough instability to produce embedded thunder.
This convective activity will effect the TAF sites through early evening. Otherwise VFR conditions are expected with a good deal of mid and high level clouds.
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.PRELIMINARY POINT TEMPS/POPS... Chattanooga Airport, TN 64 87 62 89 / 10 10 0 0 Knoxville McGhee Tyson Airport, TN 62 84 60 86 / 20 10 0 0 Oak Ridge, TN 61 84 59 86 / 10 10 0 0 Tri Cities Airport, TN 57 80 56 83 / 10 10 0 0
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.MRX WATCHES/WARNINGS/ADVISORIES... NC...NONE. TN...NONE. VA...NONE. &&
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DISCUSSION...DH AVIATION...DH
NWS MRX Office Area Forecast Discussion