Subj : Area Forecast Discussion For Tri Cities, TN/VA To : All From : Sean Dennis Date : Sat Jun 27 2026 19:00:02 398 FXUS64 KMRX 271904 AFDMRX Area Forecast Discussion National Weather Service Morristown TN 304 PM EDT Sat Jun 27 2026 ....New DISCUSSION... ..KEY MESSAGES... Updated at 302 PM EDT Sat Jun 27 2026 - Showers and storms continue through Sunday morning. A few strong to severe storms are possible. Isolated flooding is likely wherever training occurs. Although low probability, an isolated tornado can't be ruled out with an overnight MCS. - Hot temperatures well into the 90s are likely next week. Heat indices may climb above 100 degrees in the Tennessee Valley especially by mid week. && ..DISCUSSION... Issued at 302 PM EDT Sat Jun 27 2026 Widespread to scattered showers and storms are ongoing at the current hour. This activity will continue through late afternoon and into early evening. A few strong storms are possible during this timeframe, with isolated damaging wind gusts up to 60 mph as the main threat. The flood potential remains low during this time, but isn't zero, as some areas have already seen close to 1 inch of rainfall. The current environment is quite unstable and very moist, with PW values approaching 2 inches. With weak/mod shear in place, long lived clusters of storms will remain possible. Last few runs of the HRRR are in good agreement that we see a decrease in activity as we approach sunset and then remain fairly quiet until around midnight. This is when our next cluster of storms arrives from out of middle TN/KY. This next cluster of storms, potential MCS, will bring additional widespread showers and storms into our area. The environment will remain conducive for heavy rainfall as well as strong and damaging wind gusts. This overnight activity is what will elevate our flooding risk and is the main timeframe of concern. CAMS are in good agreement that there will be a swath of 2 to 4 inches of rainfall somewhere within our area. So while the probability of at least some flooding is high, the exact locations are still very uncertain. A locations flood risk is directly tied to how much rainfall they receive this afternoon and evening and then where the overnight storms track/train. The Flood Watch goes into effect at 8 PM EDT and remains in place through Sunday at 11 AM EDT. In addition to the flood threat, a low end tornado threat was introduced by SPC for portions of our area. This risk is associated with the MCS that will be tracking across the area. So while the main threat is still damaging straight line winds, an isolated tornado can't be ruled out. Showers and storms will slowly taper off late Sunday afternoon or evening. A strong ridge will be building into the region from the Southeast up to the Great Lakes Sunday afternoon/evening. Monday through Friday will be hot and mostly dry as a strong ridge stays anchored over the Eastern U.S. There will be low rain chances mainly in the higher terrain of the East Tennessee Mountains. Monday and Tuesday highs will be mainly in the lower to mid 90s in the Tennessee Valley. Wednesday through Friday will be even hotter with highs in the mid to upper 90s. Heat index around 100 degrees is likely in the Southern and Central Tennessee Valley Monday and Tuesday. Heat index will be climbing into the 100 to 105 range on Wednesday through Friday. && ..AVIATION... (18Z TAFS) Issued at 113 PM EDT Sat Jun 27 2026 Messy TAFs and flying conditions for the next 12-18 hours. Multiplerounds of thunderstorms expected with conditions dropping down to IFR or lower. Afternoon storms are capable of wind gusts in excess of 40 knots, while overnight storms will be capable of heavy downpours. Moderate to high confidence on the impacts, but low confidence on the locations of storms. && ..PRELIMINARY POINT TEMPS/POPS... Chattanooga Airport, TN 73 91 74 95 / 40 40 10 10 Knoxville McGhee Tyson Airport, TN 71 87 72 91 / 90 80 30 20 Oak Ridge, TN 70 88 72 92 / 90 80 30 30 Tri Cities Airport, TN 67 84 68 90 / 90 80 30 30 && ..MRX WATCHES/WARNINGS/ADVISORIES... NC...NONE. TN...Flood Watch from 8 PM EDT /7 PM CDT/ this evening through Sunday morning for Anderson-Bledsoe-Blount Smoky Mountains- Campbell-Claiborne-Cocke Smoky Mountains-Grainger-Hamblen- Hancock-Hawkins-Jefferson-Johnson-Knox-Loudon-McMinn-Meigs- Morgan-North Sevier-Northwest Blount-Northwest Carter- Northwest Cocke-Northwest Greene-Northwest Monroe-Rhea- Roane-Scott TN-Sevier Smoky Mountains-Southeast Carter- Southeast Greene-Southeast Monroe-Sullivan-Unicoi-Union- Washington TN. VA...Flood Watch from 8 PM EDT this evening through Sunday morning for Lee-Russell-Scott VA-Washington VA-Wise. && $$ DISCUSSION...99 AVIATION...99 --- MBSE BBS v1.1.7.2 (Linux-x86_64) * Origin: Outpost BBS * Johnson City, TN (618:618/1) .