textproduct: Morristown

KEY MESSAGES

Updated at 743 PM EDT Tue May 5 2026

- Widespread showers and storms tonight through Thursday morning.

- Periods of heavy rain are likely. Some flooding concerns are possible given the potential for training showers and storms on Wednesday. Widespread flooding seems unlikely though.

- A conditional severe weather threat exists on Wednesday if surface-based instability can develop. If it does, damaging winds will be possible, and even a tornado risk will be present.

- Southwesterly winds will be gusty today through Wednesday especially in the East Tennessee mountains and foothills.

DISCUSSION

Issued at 151 PM EDT Tue May 5 2026

Northern and southern stream jet energy will phase over the central CONUS over the next 24 hours as a closed low over Southern California opens up in response to a synoptic scale dropping south from Canada into the northern plains and upper midwest. Surface low pressure develops over the southern plains and will shift northeast through the Ozarks and into Kentucky, with the associated front pushing through our forecast area tomorrow. Ahead of the front, showers and possibly some elevated thunderstorms will spread into the region tonight, then increase in coverage tomorrow, with widespread showers and thunderstorms expected during the afternoon and evening.

Mountain winds:

Ahead of the front, low level flow ramps up tonight with most guidance showing at least 30-40 kt of H85 flow, and some showing slightly more. Given the lack of CAD setup east of the mountains and associated pressure and temperature gradients across the Appalachians, this seems like a lower end Advisory event. However, there is enough signal for 40-50mph wind gusts in the Smokies to warrant issuing a Wind Advisory there. Elsewhere, in our typical mountain wave wind spots it looks mostly like a breezy night that will fall short of advisory levels.

Severe storms:

There remains a conditional severe weather threat tomorrow, one that largely hinges on how early morning convection will affect instability later in the day I believe. Shear won't be in question, with guidance showing effective shear north of 50kt across much of the CWA tomorrow afternoon and evening. Instability on the other hand, is uncertain. Probabilistic guidance continues to show respectable (40-60 percent) chances of seeing deep layer sheer of greater than 40kt and surface-based CAPE exceeding 500 or even 750 J/kg tomorrow afternoon in the southern parts of the CWA. Thus I believe there will be a limited window ahead of the front tomorrow afternoon and evening where some severe storms could develop. If that occurs, damaging winds will be the most likely hazard, but severe-sized hail and even a tornado risk will be on the table as well. Again though, this is a conditional situation and it's possible that cloud cover and rain during the day could keep a surface inversion in place and limit the outcome to just elevated showers with heavy rains. And I don't have high confidence in which scenario becomes a reality.

Flooding rains:

PWATs are forecast to increase to around 1.7-1.8" tomorrow, mainly south of the I-40 corridor, which is greater than the 90th percentile for this time of year. Training storms will be a possibility with steering flow largely parallel to the incoming front. Given the multiple rounds of rain expected between tonight and Wednesday night, it's possible that some flooding concerns could arise. I don't know that the threat is widespread enough to warrant issuing a watch at this time however, so will just continue to advertise in the AFD and the HWO.

Wednesday night onward:

At the moment, it looks like the cold front moves through the region overnight Wednesday night. The threat for severe storms and flash flooding may linger into the first half of the overnight hours but late in the night the threat will decrease as the front passes.

Much drier air moves in behind the front with dew points dropping into the 50s on Thursday. Showers linger on Thursday morning, with more possible again in the north Thu afternoon and evening as a weak impulse passes by. High pressure will be centered over the region Thursday night.

Friday through Monday:

Another system is possible Sun/Mon, but looks like it will move through much faster. Highs will be mainly in the 70s.

AVIATION

(00Z TAFS) Issued at 743 PM EDT Tue May 5 2026

VFR can generally be expected the first 6 hours or so, with SW gusts at times at TYS through the period. Cold front expected to move through overnight. VSBY and CIG decline to MVFR, at best from approximately 08Z until end of TAF. IFR possible. CHA possesses the best chance of TS overnight and then again for the afternoon. Afternoon activity at TYS and TRI most likely to stay rain.

PRELIMINARY POINT TEMPS/POPS

Chattanooga Airport, TN 64 77 61 72 / 60 90 100 50 Knoxville McGhee Tyson Airport, TN 62 74 58 68 / 70 100 100 60 Oak Ridge, TN 60 73 56 69 / 80 100 90 50 Tri Cities Airport, TN 58 73 56 65 / 70 100 100 70

MRX WATCHES/WARNINGS/ADVISORIES

NC...NONE. TN...Wind Advisory from 11 PM this evening to 8 AM EDT Wednesday for Blount Smoky Mountains-Sevier Smoky Mountains.

VA...NONE.