012 FXUS64 KMRX 051354 AFDMRXArea Forecast Discussion National Weather Service Morristown TN 954 AM EDT Fri Sep 5 2025
...New UPDATE...
.UPDATE... Issued at 951 AM EDT Fri Sep 5 2025
Currently a few ongoing showers around the TN/KY/VA border counties this morning. These weak showers will likely linger in the vicinity through the rest of the morning before we get a brief break in precipitation chances before ramping back up this evening. With the dense fog and cloud from the morning precipitation temperatures are running several degrees cooler than previously forecasted as the sun hasn`t had much time to make it to the surface. Am still expecting a good warm up today into the 80`s and even 90`s but some places are going to be slower than others. Have updated hourly temperatures for the remainder of the day to come better in line with surface observations.
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.DISCUSSION... Issued at 121 AM EDT Fri Sep 5 2025
Key Messages:
1. Scattered storms are likely late Friday evening into Saturday with a few strong to marginally severe storms possible.
3. Drier and cooler weather will move in Sunday into Monday with no rain expected during the next week.
Discussion:
Late tonight through the morning hours, isolated to scattered showers and possibly isolated storms will develop and linger across the region. Rain amounts will likely be light but isolated flooding issues cannot be ruled out with some areas still soaked from recent rains.
This afternoon will be dry and hot with increasing POPs this evening through tomorrow afternoon as a cold front approaches. A trough will be digging into the Midwest, Ohio and Tennessee River Valleys this evening, giving the stalled cold front over Central Kentucky and Middle Tennessee some upper level support. CAMs indicate a line of strong storms developing to our northwest in Central Kentucky and Middle Tennessee this evening and moving into our region late in the evening. Most of the CAMs have this line weakening as it moves through our region, with instability decreasing into the nighttime hours. SPC has outlined a marginal risk for severe for most of the region with a Slight risk upstream to the northwest. Flooding potential will have to be monitored with repeated rounds of heavy rain possible especially in places that have received high rain amounts the past few days.
There may be a lull in activity late tonight or in the morning hours before another round of showers and storms develops in the early afternoon hours Saturday as the cold front moves closer. A few strong storms seem possible during max heating when ML CAPE gets around 600 to 1000 J/KG in the southern half of the region. This will be a clean frontal passage Saturday evening bringing cooler temps and lower dew points. Also, a noticeable wind shift to northerly winds.
Sunday through early next week looks dry with high pressure over the Eastern U.S. and below normal temps Sunday and Monday. Mid week will see a warming trend with temps returning to near normal.
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.AVIATION... (12Z TAFS) Issued at 653 AM EDT Fri Sep 5 2025
Dense fog is already starting to improve. VFR conditions will return within an hour or two after sunrise. Showers are more isolated this morning. There is increasing confidence in a line of showers and storms moving into the region this evening. Some storms may be strong to severe.
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.PRELIMINARY POINT TEMPS/POPS... Chattanooga Airport, TN 93 70 83 60 / 20 40 50 10 Knoxville McGhee Tyson Airport, TN 90 68 79 59 / 20 50 60 20 Oak Ridge, TN 88 66 77 56 / 20 60 60 10 Tri Cities Airport, TN 85 63 77 57 / 20 30 80 30
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.MRX WATCHES/WARNINGS/ADVISORIES... NC...NONE. TN...NONE. VA...NONE. &&
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DISCUSSION... AVIATION...McD
NWS MRX Office Area Forecast Discussion