textproduct: Morristown

KEY MESSAGES

Updated at 243 PM EDT Sat Apr 18 2026

- Showers and storms expected this evening primary threat will be damaging winds and small hail, especially along and north of Interstate 40. - Drier and much cooler conditions are expected Sunday into Monday with low RH's in the 20s and lower 30s returning.

- Dry conditions will continue through the week, along with a gradual warming trend. Low RH's continue to be of concern.

DISCUSSION

Issued at 243 PM EDT Sat Apr 18 2026

A cold front is approaching the area today with increasing southerly flow out ahead. Showers and storms, some discrete, are ongoing ahead of this front. However... the focus for strong to marginally severe storms continues to be in the northern half of the region where CAPE up to 1,000 J/kg is possible. While stronger flow is expected in the mid levels, the 850mb winds will remain generally light to moderate with limited low-level shear. CAPE hail growth zone is could grow to 400 J/kg. So there remains a low end threat for damaging winds and hail during the evening hours. The cold front will move through the area after midnight, leading to decreasing rain coverage.

Tomorrow the cold front will moved well to the east with high pressure expanding from the southwest. This will lead to cooler and drier conditions with high temperatures remaining in the 60s for most. Low relative humidities in the 20s will return, along with northwesterly winds. Tomorrow night will be cooler following the front with some places dropping into the 30s. Next week, high pressure will be centered overhead, leading to a lighter winds, but dry conditions will continue. Cold low temperatures can be expected again Monday night, potentially cold enough for frost in some areas. By Tuesday, high pressure will shift off to the east, turning winds more to southerly. This will begin another warming trend with highs rising back above normal. Ridging will lead to further strengthening pressure through the end of the week with most places rising back into the 80s. Unfortunately low relative humidities will continue next week.

AVIATION

(18Z TAFS) Issued at 243 PM EDT Sat Apr 18 2026

ISOLD SHRA will move into the TN valley in the next 2-4 hours, with VCSH possible at all terminals for a few hours thereafter. Increasing coverage in SHRA and embedded TSRA expected later tonight. FROPA should occur around or shortly after 08z tonight, with low-end VFR or possibly some MVFR CIGS lingering until daybreak or thereabouts. Post-frontal winds should be fairly gusty tomorrow so have gusts of 20-22kt at all sites to account for that.

PRELIMINARY POINT TEMPS/POPS

Chattanooga Airport, TN 48 68 44 75 / 90 0 0 0 Knoxville McGhee Tyson Airport, TN 46 64 43 68 / 100 0 0 0 Oak Ridge, TN 46 65 41 69 / 100 0 0 0 Tri Cities Airport, TN 44 61 38 62 / 100 10 0 0

MRX WATCHES/WARNINGS/ADVISORIES

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