textproduct: Morristown

KEY MESSAGES

Updated at 115 PM EDT Sat May 2 2026

- A Freeze Warning and Frost Advisory have been issued for portions of the NWS Morristown forecast area for tonight.

- Cooler temperatures continue on Sunday, but a warming trend then begins heading into next week.

- Some isolated showers may occur over the plateau this afternoon and evening. Otherwise the next chance for widespread showers and storms will be the middle of next week.

DISCUSSION

Issued at 115 PM EDT Sat May 2 2026

An anomalously deep trough will swing through the region later today, with upper heights and H85 temps some 2-3 standard deviations below normal for this time of year. Regional radar imagery shows some showers associated with this trough over southern IL and western KY this afternoon. With dry air in place across the MRX forecast area, and the trough axis arriving well after peak heating, the odds of rainfall in our area seem low. However, I would not be surprised to see some spotty showers over parts of the plateau later this afternoon and evening. Surface high pressure then builds in from the west tonight, leading to light winds and good radiational conditions. This should allow for some freezing temperatures in sheltered areas of our Virginia counties, as well as some near- freezing temperatures and areas of frost in parts of the northern plateau, far northeast TN counties, and even our east TN mountain zones and the valley areas of our NC counties. Freeze warnings and frost advisories have been hoisted to account for this. Temperatures will be a touch warmer on Sun and Sun night, though still cooler than normal. Frost doesn't appear to be a concern for Sunday night.

Broad cyclonic upper flow continues into early next week, but low level flow becomes increasingly southwesterly with time. As such, we should see temperatures rebound back into the 70s to near 80 by Mon and Tue. A weak impulse embedded in the WNW upper flow looks to spark off some nocturnal convection over southern Illinois late Sunday night into Monday. Looking at deterministic guidance, there's a mixed bag of rain chances. Current NBM places some 20-40% rain chances north of the I-40 corridor during the daytime hours on Mon, favoring our VA counties and some of our northern TN mountain areas for the highest odds of seeing rainfall. Given the pattern and orientation of the low level jet and associated isentropic ascent, it is certainly plausible that our northern areas could see some rainfall Monday. Am inclined to leave this as-is primarily because I don't have enough confidence in exactly where this rainfall will occur. It could be displaced further north or south than currently advertised, but it seems reasonable to have some rain chances in there.

A stronger shortwave is expected to reinforce the Great Lakes region troughing mid-week. NBM currently ramps up pops during the day Wednesday but ensemble guidance really suggests it will be more of a Wednesday evening/overnight rainfall event. Nevertheless, the latest NBM probabilities for 24 hour rainfall of 1.0" or greater have increased since yesterday and now stand at around 60-70% for a large chunk of our CWA - highest over the most drought stricken areas in the south. Other ensemble guidance has similar odds, and even some deterministic guidance like the ECMWF- AIFS shows over 0.70" of QPF across a large swath of the CWA. In other words, it looks like a good rain event is on the horizon. Will also be worth keeping an eye on this system for strong/severe storm chances. Strong shear is all but certain, but instability may be a limiting factor, especially in the event of a nocturnal passage. There will also be potential for some late season mtn/foothill gusty winds with a southwesterly LLJ and tightening pressure gradient. Cooler and drier conditions end the week post FROPA.

AVIATION

(18Z TAFS) Issued at 115 PM EDT Sat May 2 2026

VFR conditions are expected through the period. An incoming disturbance aloft will likely spread some ISOLD SHRA into the plateau region this afternoon and evening, but they should not persist long enough or be widespread enough to impact any terminals. Gusty north winds at KTYS and KCHA will give way to near calm conditions overnight as high pressure builds in.

PRELIMINARY POINT TEMPS/POPS

Chattanooga Airport, TN 44 71 47 80 / 0 0 0 0 Knoxville McGhee Tyson Airport, TN 42 68 47 79 / 10 0 10 10 Oak Ridge, TN 40 68 45 79 / 10 0 20 20 Tri Cities Airport, TN 35 64 42 75 / 0 0 10 30

MRX WATCHES/WARNINGS/ADVISORIES

NC...Frost Advisory from midnight tonight to 9 AM EDT Sunday for Cherokee-Clay.

TN...Frost Advisory from midnight tonight to 9 AM EDT Sunday for Blount Smoky Mountains-Campbell-Claiborne-Cocke Smoky Mountains-Hancock-Hawkins-Morgan-Northwest Carter-Scott TN- Sevier Smoky Mountains-Southeast Greene-Southeast Monroe- Sullivan-Unicoi-Washington TN.

Freeze Warning from midnight tonight to 9 AM EDT Sunday for Johnson-Southeast Carter.

VA...Freeze Warning from midnight tonight to 9 AM EDT Sunday for Lee- Russell-Scott VA-Washington VA-Wise.