textproduct: Morristown

KEY MESSAGES

Updated at 230 PM EDT Tue Apr 21 2026

- Unseasonably warm and dry conditions will continue through Friday. Highs will be around 10 degrees above normal. Low afternoon relative humidity each day with 20s and 30s expected.

- Increasing moisture and instability this weekend with likely chances of showers and possibly storms, especially Saturday.

- Another round of storms anticipated for Monday and Tuesday. There is a threat for strong to severe storms.

DISCUSSION

Issued at 230 PM EDT Tue Apr 21 2026

For Tonight and Wednesday, a short-wave will move across the upper Ohio valley into the central Appalachians. This wave will produce an area of showers and thunderstorms that will approach southwest Virginia toward Wednesday morning. At this time, the dynamics and moisture will stay north of the region with surface ridging, so dry conditions are anticipated. Low afternoon relative humidity will with values in the 20s.

For Thursday and Friday, upper ridge builds over the area producing mostly dry and unseasonably warm conditions. Highs will be around 10 degrees above normal. Low afternoon relative humidity will continue with values in the 20s/30s.

For Friday night through Saturday, a northern stream (Great Lakes/Ohio Valley) and southern stream waves (central Gulf coast states) produce an area of showers and possibly a thunderstorm. Since limited phasing is expected with these waves, and instability and dynamics are limited, confidence is low on QPF amounts. Currently expecting from 0.25 to 0.50 inch but ensemble probabilities suggest lesser amounts.

Another system moves into the Tennessee valley and southern Appalachians early next week. The short-wave and jet dynamics will this wave is stronger and taps into Gulf moisture. Joint ensemble probability of CAPE/SHEAR suggest a great threat of strong to severe storms possible. Will need to watch the evolution of this system close as we move into the weekend for possible messaging of severe storms. CIPS Analog also suggest the potential of severe storms.

AVIATION

(18Z TAFS) Issued at 141 PM EDT Tue Apr 21 2026

VFR conditions will prevail through the next 24 hours at all TAF sites. Increasing low level jet overnight with 850mb winds of 30-35 knots will produce a chance of LLWS at TRI but confidence is not high enough to include. Westerly winds will increase at TRI tomorrow morning to 12-14 knots and gusty.

PRELIMINARY POINT TEMPS/POPS

Chattanooga Airport, TN 53 83 54 84 / 0 0 0 0 Knoxville McGhee Tyson Airport, TN 51 81 54 82 / 0 0 0 10 Oak Ridge, TN 50 82 52 83 / 0 0 0 10 Tri Cities Airport, TN 44 78 49 79 / 0 0 0 10

MRX WATCHES/WARNINGS/ADVISORIES

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