Forecasts call for a Monday high of 91 to 92 degrees, with the heat index approaching 99, before thunderstorms become possible after 2 p.m. The National Weather Service says some storms could produce damaging winds and brief heavy rain, while repeated downpours may create localized flooding through Wednesday. The severe-weather threat is not expected to be high, but outdoor plans and the evening commute may need flexibility.
The hottest part of the pattern arrives before the wettest one. Monday morning should remain partly cloudy to mostly sunny, with temperatures rising from the low 70s into the 90s. Rain chances increase during the afternoon and evening, and the overnight low should fall to about 69 degrees, according to the forecast reported by WATE 6.
Why the storm risk matters
The National Weather Service outlook for the Knoxville area calls for a few afternoon and evening storms that may bring damaging wind gusts and heavy downpours. Slow-moving cells are the main concern for localized flooding, especially if rain falls repeatedly over the same locations, though the current forecast does not establish the rainfall totals or damage that could occur. Residents should move indoors when thunder is heard and never drive through water covering a roadway, according to the National Weather Service.
Knox County says residents can register for its Everbridge emergency notification system to receive public-safety alerts, including severe-weather warnings, by text message, email or voice call. That service can provide updates if conditions lead to warnings or other local emergency notices, but it does not predict which specific roads or neighborhoods will flood.
A forecast concern, not a repeat of past floods
Knoxville has experienced more disruptive flooding in past weather events, but those incidents should not be treated as predictions for this week. The National Weather Service documented flash flooding around Knoxville on Sept. 23, 2006. During the remnants of Hurricane Ida from Aug. 30 through Sept. 1, 2021, the agency reported 2 to 4 inches of rain across much of the Valley, locally 4 to 6 inches in parts of the central and northern Valley, along with localized flooding in urban Knoxville and on low-lying rural roads near creeks and streams. Those observed totals and impacts were substantially greater than anything established by the current outlook, according to the National Weather Service Morristown.
For people working outdoors Monday, the Occupational Safety and Health Administration recommends water, rest and shade to help prevent and treat heat-related illness. The advice is especially relevant before storms arrive, when the combination of high temperatures and humidity is expected to make conditions feel hotter than the air temperature alone, according to OSHA.
Storm chances continue before a cooldown
Tuesday remains warm, with a high near 89, with an 80% chance of precipitation during the day and broader shower and thunderstorm chances, followed by a 70% chance Tuesday night. Wednesday is expected to bring showers and thunderstorms. The possibility of additional localized flooding remains part of the outlook, but the timing, placement and severity of any flooding are still unknown.
Showers may linger Thursday morning before tapering to scattered showers and thunderstorms. Temperatures should remain in the 70s, with conditions trending clearer Thursday night. Friday through Sunday are forecast to be mostly sunny to sunny, with highs in the mid-to-upper 70s and overnight lows in the low-to-mid 50s—a marked change from Monday's heat.
