textproduct: Morristown

KEY MESSAGES

Updated at 123 AM EDT Mon Jul 20 2026

- Isolated to scattered showers and storms to continue this afternoon and evening. A few strong to marginally severe storms are possible and could produce gusty winds and localized flooding.

- Possible strong cold frontal passage tomorrow evening into Wednesday bears watching for severe weather potential.

- Below normal temperatures and drier air will follow beyond Wednesday. Precipitation returns next weekend.

DISCUSSION

Issued at 123 AM EDT Mon Jul 20 2026

The large scale pattern can be classified by ridging generally centered over the Four Corners region and Intermountain West the next couple of days, followed by weak NWly flow over us with troughing to the north and subsequent shortwaves cycling through. A Tropical Depression by the Florida Peninsula will become almost stationary until it gets picked up and eventually drifts westward. A stout shortwave expected to dive SE across the northern Great Lakes before curving up around the U.S. border late tomorrow into Wednesday, will bring our next frontal system across the area. Following that, we'll still be situated east of upper ridge into the latter part of the week and into the weekend.

Diurnal thunderstorm activity continues today much like the past couple of days, except the mountainous terrain will likely see the best chance during the afternoon and evening. The west to east boundary that was draped near the TN and VA border yesterday, will be situated a bit further north today. A few strong strong to severe storms are possible due to moderate cape, but shear will continue to be weak. The main threat with any stronger storm will be localized gusty winds. Heavy rain is also expected as PWATS are around 2 inches and this may lead to isolated flooding for some. Any area that sees repeat heavy showers through this evening will be most at risk for flooding. Again, gusty wind threat and flood threat will be isolated. The stronger storm and flooding threat will likely be for areas east of I-75.

Attention turns to tomorrow into Wednesday with a potential strong cold frontal passage. SPC introduced a slight risk for severe weather for the northern part of the CWA as of this discussion. The main threats are damaging winds and heavy rain that may lead to flash flooding. Secondary threats that cannot be ruled out are a couple of tornados and possible small hail. The tornado threat will ultimately depend on whether storms remain surface-based during the overnight hours or become elevated. Timing will definitely play a role as to when the main line arrives and what it means for our area, so there's still some uncertainty. One factor that models have consistently shown the past couple of nights is increased shear.

Following the mid-week cold front, Thursday will be very nice with low to mid 80s highs and dew points in the 60s under high pressure. Temperatures rise a couple of degrees into the weekend, but for the most part remain below normal. A shortwave cycling the top of the upper ridge Friday into Saturday, may bring precipitation chances back to the area and unfortunately increased dew points yet again. A possible boundary that could get hung up to our south may complicate things.

AVIATION

(06Z TAFS) Issued at 123 AM EDT Mon Jul 20 2026

Patchy fog early this morning, with most likely impact at KTRI which is already at dewpoint. All VFR skies by or shortly after 12z. Scattered TS again today, though low confidence at terminals, with much of the initial SHRA or TS anchored over the higher terrain features across the region, though some encroachment later into the valley is still possible. Light winds generally less than 10 knots.

PRELIMINARY POINT TEMPS/POPS

Chattanooga Airport, TN 92 75 93 76 / 40 10 30 30 Knoxville McGhee Tyson Airport, TN 90 74 90 75 / 20 10 30 60 Oak Ridge, TN 90 73 90 74 / 20 20 40 70 Tri Cities Airport, TN 88 69 88 70 / 20 50 70 90

MRX WATCHES/WARNINGS/ADVISORIES

NC...NONE. TN...NONE. VA...NONE.