textproduct: Morristown

KEY MESSAGES

Updated at 140 PM EDT Sat Jul 11 2026

- Multiple rounds of showers and thunderstorms remain possible through Sunday night. Any areas impacted by repeated storms could see significant rainfall and experience flash flooding. As such, a Flood watch remains in effect through Sunday night.

- A few strong to severe storms could occur today and Sunday. The primary threat would be gusty winds.

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

DISCUSSION

Issued at 140 PM EDT Sat Jul 11 2026

Synoptically speaking, a semi-closed upper trough situated from the Ohio valley westward to the Ozarks of Missouri, will continue to drift southward over the next 48 hours or so. Meanwhile, upper ridging will expand from the Rockies northeastward into the northern plains during that same period, ultimately creating a quasi-rex block type pattern over the Great Lakes and Ohio valley areas as the aforementioned trough continues to meander south and gets trapped beneath the expanding ridge. Locally, this means continued chances for shower and thunderstorm activity as impulses emanate eastward from that upper trough/semi-closed low to our WNW, until this feature finally pushes south of the region by Tuesday. Given the high PWAT air mass in place and storm motions being largely parallel to upper flow, training convection will and the risk of flash flooding will continue to be a risk for much of the forecast area through Sunday night. As we get into Monday and Tuesday, the upper trough axis becomes increasingly situated overhead, meaning the focus for stronger convection and heavier rains will shift increasingly south of us. For these reasons, I don't see a need to extend the Flash Flood Watch beyond Sunday night, but I did change the expiration time to 06z Monday to account for one last batch of late evening/nocturnal storms that might move through tomorrow.

With regards to severe storms potential this afternoon and evening, I think our chances are fairly limited. SPC mesoanalysis page indicates there is somewhere in the neighborhood of 1,500 J/kg of MLCAPE in the southern valley. This seems reasonable given the current radar mosaic and strong storms along the TN/GA border area this afternoon. Those storms also have a light southward motion to them which should carry them out of our CWA by 3-4pm. Further north, the atmosphere was really worked overnight and earlier today, and cloud cover through the day has limited instability. All in all, I think the severe chances are low through this evening. CAM guidance indicates little in the way of additional convection developing later on too which lends confidence to my thoughts here. However, it's not as optimistic on the flooding side. Another round of nocturnal convection is expected in our CWA tonight and then again Sunday night. It's difficult to say exactly where storms may align, but rainfall amounts have exceeded 3-5" in a few spots over the last 24 hours that have been affected by training storms. It's not out of the question to say something similar could happen tonight or Sunday, and thus the risk of flooding continues. There is just low confidence in where exactly the greatest threat resides.

As mentioned, by Tuesday the upper low shifts south of us and we lose the focus for repeated storms and heavy rains. Rain chances remain in the forecast though, primarily for diurnally driven afternoon showers and thunderstorms. With the ridge building to our north these will be more scattered in nature. We'll also warm up moving into the mid/late week time frame, with highs climbing back into the upper 80s.

AVIATION

(18Z TAFS) Issued at 140 PM EDT Sat Jul 11 2026

Expect a mix of VFR and MVFR conditions through the period, with MVFR or lower expected in SHRA/TSRA. Expect the most likely time for convection to affect terminals after 06z tonight as another round of nocturnal storms move into East Tennessee from the WNW. Have attempted to time that in with PROB30 groups to limit how much SHRA/TSRA are mentioned in the TAFs.

PRELIMINARY POINT TEMPS/POPS

Chattanooga Airport, TN 72 86 70 83 / 50 70 70 90 Knoxville McGhee Tyson Airport, TN 70 84 69 83 / 60 80 80 90 Oak Ridge, TN 70 83 68 83 / 60 70 80 90 Tri Cities Airport, TN 66 81 66 82 / 70 70 60 80

MRX WATCHES/WARNINGS/ADVISORIES

NC...Flood Watch through late Sunday night for Cherokee-Clay.

TN...Flood Watch through late Sunday night 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 late Sunday night for Lee-Russell-Scott VA- Washington VA-Wise.