textproduct: Morristown

KEY MESSAGES

Updated at 223 AM EDT Mon Jul 13 2026

- Scattered showers and storms continue today, lessening tomorrow. A Flood Watch remains in effect into this evening.

- Though chances are very low, cannot rule out a strong gusty wind or two in any stronger thunderstorm.

- More typical summer weather Wednesday onwards with near normal temperatures and only a low PM chance of scattered thunderstorms.

DISCUSSION

Issued at 223 AM EDT Mon Jul 13 2026

Most rain has either dissipated for the night or steadily weakened, though a few showers may linger or re- develop into the morning. Additional flooding early this morning is unlikely.

HREF/REFS guidance has been consistently depicting a LPMM (a type of probability matching mean) bulls-eye of heavy rainfall from Maryville down through Polk County later today into this evening. Now, CAMs have not been nailing locations well the last couple of days, so spatial uncertainty is still quite high. My concern though is with our increasingly saturated grounds and one more day of scattered to numerous convection, it makes more sense to keep the Flood Watch around for 1 more day and see how the storms play out. Rather have the watch out and cancel later on then to cancel now only to have additional issues tomorrow. A couple days ago it was Cocke and Greene counties that saw significant flooding, then Knoxville had a round of urban flooding a few hours ago, and meanwhile other counties have seen flooding to a lesser extent.

If the storms do set up over the southern counties, those counties have seen less rain the last few days than elsewhere. Contrast Monroe and McMinn counties to portions of Meigs, Loudon, on over to Blount and north. Flash flood guidance (aka the amount of rain needed in a certain amount of time to produce flash flooding) is quite low along the northern foothills and even Meigs (1 to 2 inches in 3 hours), but still quite high in Monroe and McMinn (2.5 to 3 inches needed in 3 hours). So, depending on where storms set up will determine how quick flooding can occur. Ultimately in this environment if it rains hard enough long enough then even the drier counties will flood. Because of this I have opted to extend the Flood Watch into this evening and see how it all plays out.

The cutoff low responsible for our rainy misery the last couple of days won't cross the Mississippi River heading west until Wednesday. But at least tomorrow it will be a little further away, and thus its influence over East Tennessee will be increasingly lesser. Still likely won't be an entirely dry day, but any flood impacts would be incredibly isolated, if they occur at all. I would expect the bulk of the coverage to be south of Knoxville, and ideally any storms that do form north will have better storm motions.

As we progress through the week upper heights build slightly and between that and the departure of the closed low and associated widespread cloud cover, we'll see temperatures tick back upwards a tad. Not a heat wave, but it'll certainly get us back into the regular hot and muggy period for this time of year. Since we're maintaining a fairly moist airmass, there'll be daily storm chances, primarily in the afternoon and early evening hours, as is fairly typical for summer.

AVIATION

(12Z TAFS) Issued at 704 AM EDT Mon Jul 13 2026

Will see MVFR conditions early mainly CHA/TYS before improvement to VFR. May see MVFR conditions again in fog and/or low cigs late in the period but right now the probability looks too low to include in the terminals. There will be showers around in the morning, then an increase in the chance for thunder this afternoon. Will include prob30 thunder groups all sites during the afternoon to account for this.

PRELIMINARY POINT TEMPS/POPS

Chattanooga Airport, TN 83 70 84 70 / 70 50 60 20 Knoxville McGhee Tyson Airport, TN 83 68 86 69 / 80 20 50 0 Oak Ridge, TN 84 68 86 68 / 90 20 40 0 Tri Cities Airport, TN 81 64 86 62 / 50 10 0 0

MRX WATCHES/WARNINGS/ADVISORIES

NC...Flood Watch through this evening for Cherokee-Clay.

TN...Flood Watch through this evening for Anderson-Bledsoe-Blount Smoky Mountains-Bradley-Campbell-Claiborne-Cocke Smoky Mountains-East Polk-Grainger-Hamblen-Hamilton-Hancock- Hawkins-Jefferson-Johnson-Knox-Loudon-Marion-McMinn-Meigs- Morgan-North Sevier-Northwest Blount-Northwest Carter- Northwest Cocke-Northwest Greene-Northwest Monroe-Rhea- Roane-Scott TN-Sequatchie-Sevier Smoky Mountains-Southeast Carter-Southeast Greene-Southeast Monroe-Sullivan-Unicoi- Union-Washington TN-West Polk.

VA...Flood Watch through this evening for Lee-Russell-Scott VA- Washington VA-Wise.