406 FXUS64 KMRX 291826 AFDMRX Area Forecast Discussion National Weather Service Morristown TN 226 PM EDT Mon Jun 29 2026 ...New DISCUSSION... .KEY MESSAGES... Updated at 214 PM EDT Mon Jun 29 2026 - Isolated to scattered showers and thunderstorms this afternoon mainly northeast, then diminishing this evening. - Very hot this week with high temperatures well into the 90s common. Afternoon heat index values will climb to around or above 100 degrees in in most valley locations multiple days. && .DISCUSSION... Issued at 214 PM EDT Mon Jun 29 2026 There have been a few showers showing up on radar over the northeast, and a few showers and possibly thunderstorms will continue over our northeastern areas through this afternoon before dissipating by early tonight. Will continue to mention the possibility of localized flooding in the HWO for any areas of heavy rain that may occur over already saturated soils. A large upper ridge over the eastern CONUS will dominate our weather this week, providing mostly dry and very hot conditions. The better chances for an afternoon shower or thunderstorm will be over the mountains Tuesday and Wednesday. By Thursday into the weekend, the ridge axis shifts to our east and isolated to scattered showers and storms will be possible even in valley areas mainly during the afternoon hours. The main story for the week looks to be the hot conditions. High temperatures are expected to be in the 90s across all but the higher elevations each day this week and through the weekend, with mid to upper 90s across portions of the valley especially Wednesday through Friday which right now look to be the hottest days. Heat index values around or above 100 will common in the afternoons, and heat index values may exceed 105 across portions of the area especially Wednesday and Thursday. While forecast heat index values are borderline for a heat advisory at this time, based on the heightened impacts of a multi-day period of very hot conditions a heat advisory will be issued starting Tuesday and continuing through Thursday. It may eventually need to be extended longer in time as it still looks very hot Friday and into at least the beginning of the weekend, but for now will start with this three day period given forecast uncertainties in the longer ranges. A short wave may bring more coverage of showers and storms along with slightly lower temperatures by Sunday or Monday, but confidence in the details is low that far out. && .AVIATION... (18Z TAFS) Issued at 1237 PM EDT Mon Jun 29 2026 May be a shower or thunderstorm around early at TRI, and will include a prob30 thunder group there. The other concern is possible fog development late tonight. TRI looks to have the highest probability of impacts from fog, and for now will include several hours of MVFR conditions there. Lower conditions with the fog are possible, but the probability of occurrence still looks too low to include at this point. && .PRELIMINARY POINT TEMPS/POPS... Chattanooga Airport, TN 76 97 77 98 / 0 0 10 20 Knoxville McGhee Tyson Airport, TN 73 93 73 94 / 0 0 0 10 Oak Ridge, TN 73 94 74 95 / 0 10 0 10 Tri Cities Airport, TN 69 93 70 95 / 10 10 0 10 && .MRX WATCHES/WARNINGS/ADVISORIES... NC...Heat Advisory from 11 AM Tuesday to 9 PM EDT Thursday for Cherokee-Clay. TN...Heat Advisory from 11 AM EDT /10 AM CDT/ Tuesday to 9 PM EDT /8 PM CDT/ Thursday for Anderson-Bledsoe-Blount Smoky Mountains-Bradley-Campbell-Claiborne-Cocke Smoky Mountains- East Polk-Grainger-Hamblen-Hamilton-Hancock-Hawkins- Jefferson-Johnson-Knox-Loudon-Marion-McMinn-Meigs-Morgan- North Sevier-Northwest Blount-Northwest Carter-Northwest Cocke-Northwest Greene-Northwest Monroe-Rhea-Roane-Scott TN- Sequatchie-Sevier Smoky Mountains-Southeast Carter- Southeast Greene-Southeast Monroe-Sullivan-Unicoi-Union- Washington TN-West Polk. VA...Heat Advisory from 11 AM Tuesday to 9 PM EDT Thursday for Lee- Russell-Scott VA-Washington VA-Wise. && $$ DISCUSSION...99 AVIATION...99