textproduct: Morristown

KEY MESSAGES

Updated at 134 AM EDT Fri Sep 4 2026 - Very hot conditions will continue again today with highs reaching well into the 90s and heat index values approaching or exceeding 100 for most places outside the higher elevations. Take frequent breaks and drink plenty of water when outdoors.

- Temperatures will gradually moderate some through the weekend with a return of isolated to scattered showers and storms.

- A few storms this afternoon/evening mainly in the northeast and then including most of the remainder of the area Saturday may become strong to severe, with damaging wind gusts the primary threat.

DISCUSSION

Issued at 134 AM EDT Fri Sep 4 2026

In the upper levels, a ridge is centered overhead extending through the Central U.S. The ridge will weaken overhead slightly by this evening and shift a bit west. Troughing over the Northeast will dip a bit southward into the Mid-Atlantic. This puts our counties in northeast Tennessee and southwest Virginia closer to the northwest flow action zone of storms riding the ridge. However, it looks like those more organized storm clusters will stay to the north over Ohio and West Virginia today and tonight. CAMs confirm that and also that showers and storms will be isolated in the Tennessee Valley today and more scattered in the higher elevations. Since the northeast counties are on the fringe of the northwest flow action zone, some strong storms cannot be ruled out late this evening. SPC has extreme Northeast Tennessee and Southwest Virginia in a marginal risk for the uncertainty.

Another very hot day is expected today due to the ridge overhead. A Heat Advisory is in effect for this afternoon and evening throughout most of the Tennessee counties, the only exception is the far east Tennessee mountains and extreme northeast Tennessee counties. The Virginia and North Carolina counties are not included but even areas outside of the advisory will be unseasonably hot with heat indices in the 100-104 range in the lower elevations. Within the advisory heat indices will be in the 105 to 108 degree range.

On Saturday, the trough dips into the Ohio Valley as the ridge narrows to the west centered over the Great Plains. At the surface, a weak cold front will move through the region Saturday, bringing a better chance showers and storms especially in the northeast. With better synoptic lift in place on Saturday, there is also a higher chance for strong to severe storms especially in extreme northeast Tennessee and southwest Virginia (SPC Slight risk), closer to the trough. Most of the rest of the region is under a marginal risk for severe, the exception is Chattanooga and surrounding counties since coverage will likely be less that far south. With good instability but weak deep layer shear and high freezing levels, the primary threat will be damaging straight-line winds. Saturday will be slightly cooler, maybe even significantly cooler if storms form earlier in the day which seems like a possibility. The southern Tennessee Valley south of Knoxville still may need a Heat Advisory for Saturday afternoon since storm coverage will be more isolated that far south.

Slightly cooler temps expected by Sunday after frontal passage. Although, not so much near Chattanooga despite what appears to be a clean frontal passage. There will still be some showers and storms mainly in the easternmost counties Sunday and Monday as the region stays sandwiched between a ridge to the west and a trough to the east. Monday will have cooler temps (although still very warm), with Chattanooga likely the only place to break 90.

By midweek, the ridge is likely to wander back into the Southeast. Perhaps, bringing more hot, dry conditions.

Daily Record High Maximum Temperatures

Date Chattanooga Knoxville Tri-Cities Oak Ridge 09-04 102(1954) 101(1954) 99(1954) 100(1954) 09-05 104(1925) 103(1954) 99(1954) 102(1954) 09-06 103(1925) 101(1954) 100(1954) 102(1954) 09-07 104(1925) 102(1925) 100(1954) 99(1954) 09-08 100(1925) 96(1941) 92(2002) 95(1999) 09-09 102(1925) 100(1925) 95(1954) 97(1954)

AVIATION

(06Z TAFS) Issued at 134 AM EDT Fri Sep 4 2026

High pressure centered over the Southern Appalachians this morning, will support clear and calm through the rest of the nighttime hours. Nearby lake fog could again be possible at TRI just before sunrise. Once we mix out, winds will be light and variable with mid and high clouds later this afternoon. Chances of showers and storms around, but a fairly low chance/low confidence of occurrence at the terminals themselves.

PRELIMINARY POINT TEMPS/POPS

Chattanooga Airport, TN 99 76 98 74 / 10 0 30 10 Knoxville McGhee Tyson Airport, TN 97 75 96 71 / 10 0 20 20 Oak Ridge, TN 98 74 96 71 / 10 10 30 10 Tri Cities Airport, TN 95 70 91 67 / 10 10 50 40

MRX WATCHES/WARNINGS/ADVISORIES

NC...NONE. TN...Heat Advisory until 8 PM EDT /7 PM CDT/ this evening for Anderson-Bledsoe-Bradley-Campbell-Claiborne-Grainger- Hamblen-Hamilton-Hancock-Hawkins-Jefferson-Knox-Loudon- Marion-McMinn-Meigs-Morgan-North Sevier-Northwest Blount- Northwest Cocke-Northwest Greene-Northwest Monroe-Rhea- Roane-Scott TN-Sequatchie-Union-West Polk.

VA...NONE.