textproduct: Morristown

KEY MESSAGES

Updated at 241 AM EDT Sat Mar 21 2026

- Scattered showers and storms are possible late this afternoon and evening. The main threat with these storms will be hail.

- Warm and breezy on Sunday with a low chance of rain returning Sunday night/Monday morning.

- Dry and seasonally cooler conditions are expected Monday until a warming trend and returning rain chances late in the week.

DISCUSSION

Issued at 241 AM EDT Sat Mar 21 2026

A surface front will be pushing southward across the OH Valley today, while a weak shortwave trough will approach in the NW flow aloft. The front is expected to be positioned near the TN/KY border by the afternoon when the trough crosses the MS River. CAMS are coming into better agreement on the development of convection south of the front in the Cumberland Plateau area, mainly around 4-6 PM. The convection tracks SE into the central TN Valley through the evening. Given the midlevel lapse rates of around 7-8 C/km, low WBZ height below 10k ft, and MLCAPE around 1000-1200 J/kg, hail appears to be the main threat from storms. Winds aloft are not particularly strong (20-30 kt up to 500 mb) for damaging winds, but an inverted V profile in NAM soundings suggest evaporative cooling could enhance wind gusts. Most of this activity should be over by 10 PM.

The front lifts northward on Sunday as a low pressure system tracks across the central Plains. This will keep our area in a warm SW flow through the low levels, and highs on Sunday will be well above normal - in the lower to mid 80s in most spots. This will be within a few degrees of record highs - the TRI record of 81 could be tied or broken. That low pressure system and its associated cold front will cross our area on Monday, with a low chance of showers/storms ahead of it late Sunday night/Monday morning. Instability in the morning appears too limited for any strong/severe storms, and the chance of showers will mainly be north of I-40.

Daily Record High Maximum Temperatures Date Chattanooga Knoxville Tri-Cities Oak Ridge 03-22 89(1907) 87(1907) 81(1938) 83(2011)

A colder air mass will build into the area on Monday behind the cold frontal passage. High pressure over the Great Lakes and OH Valley region will promote drier and seasonally cooler conditions through Tuesday. By Wednesday, broad ridging will expand from the southwest with high pressure shifting eastward, leading to a return of southerly flow and increasing moisture and WAA. Low-end rain chances return late in the week as a front settles somewhere in the TN/OH Valley region. The position of a large high pressure ridge across the Gulf Coast region will mean moisture will be limited, but we could have several days with rain chances late in the week as the front remains nearly stationary and parallel to the midlevel flow.

AVIATION

(06Z TAFS) Issued at 140 AM EDT Sat Mar 21 2026

VFR can generally be expected outside of any precipitation. CHA likely to stay dry. LLWS kept at TRI during the overnight hours. Possible leftover precipitation from the north will reach TRI later this morning. PROB added at TYS for the later afternoon and evening with possible development of storms later tonight. The near-storm environment doesn't appear that damaging winds will be much of a threat, mainly hail.

PRELIMINARY POINT TEMPS/POPS

Chattanooga Airport, TN 85 58 86 62 / 10 10 0 10 Knoxville McGhee Tyson Airport, TN 80 60 84 58 / 40 40 0 20 Oak Ridge, TN 80 58 84 58 / 30 40 0 30 Tri Cities Airport, TN 73 55 80 54 / 20 20 0 50

MRX WATCHES/WARNINGS/ADVISORIES

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