East Tennessee Weather: Hump Day Storms, Severe Risks, and a Sizzling Heat Wave Ahead

Happy Hump Daaaaaaaaaay, East Tennessee!
On this Wednesday, June 18, 2025, at 9:39 AM EDT, we’re halfway through the workweek, navigating morning showers, a brief dry spell, and severe storms brewing for tonight. The Storm Prediction Center has issued a Level 1 risk for severe weather today, Thursday, and Friday, so stay vigilant! From the bustling streets of Knoxville to the misty trails of the Great Smoky Mountains and the rugged charm of the Cumberland Plateau, the EastTNweather platform, led by meteorologist Mike Witcher, delivers hyper-local updates via its app, website, YouTube, Roku, Amazon Fire, and Apple TV to keep you weather-savvy. 

Wednesday: Showers, Dry Spell, and Nighttime Severe Storms
This Hump Day starts muggy, with scattered showers and patchy fog in low-lying areas like Sevierville, Cleveland, and along the Tennessee River near Chattanooga. Morning temperatures hover in the 60s, with dew points in the low 70s creating a sticky feel. Late morning into early afternoon dries out, with partial sunshine pushing lunchtime temperatures to the upper 70s. Highs reach the mid-80s, slightly above the seasonal average of 81°F, with a heat index in the low 90s in valley locations like Knoxville, Chattanooga, and Athens. The Cumberland Plateau and Smoky Mountains see milder heat indices, around the upper 80s.

After sundown, a new wave rolls in, sparking showers and storms that could turn strong to severe, particularly between 9 PM and 3 AM. The Storm Prediction Center’s Level 1 risk highlights potential for damaging winds (50-60 mph), heavy rain (0.5-1.5 inches), and isolated hail, with the greatest threat south of I-40 (Chattanooga, Cleveland, Athens) and in Knoxville. North of I-40, including Morristown and the Tri-Cities, faces lower severe risks but still expects heavy rain. The EastTNweather app is your go-to for tracking these storms, with its Interactive Radar offering past, current, and two-hour future projections. Plan morning hikes in Cades Cove or markets in Jonesborough, but shift to indoor activities like the Tennessee Aquarium in Chattanooga or the East Tennessee History Center in Knoxville for tonight. Check the app for severe weather alerts and stay safe during overnight storms!

Thursday-Friday: Severe Storms and a Cold Front
Thursday and Friday bring another wave of stormy weather, with a cold front sweeping through, amplifying severe storm risks. Highs hold in the mid to upper 80s, with dew points in the low 70s pushing the heat index to the low to mid-90s, creating a muggy summer vibe. Storms are most likely Thursday afternoon through evening and Friday morning through afternoon, with the Storm Prediction Center maintaining a Level 1 risk. Expect damaging winds (50-65 mph), heavy rain (1-2 inches per day), and breezy southwesterly winds (15-25 mph), with south of I-40 (Chattanooga, Cleveland, Athens) and Knoxville at highest risk. North of I-40, including Morristown and Johnson City, sees spottier severe threats but still faces heavy rain.

Locally heavy rain raises flood concerns, particularly in urban areas like Knoxville’s Market Square, Chattanooga’s North Shore, or low-lying regions near the Little Pigeon River in Sevierville or the Hiwassee River in Cleveland, where totals could reach 2-3 inches by Friday. The EastTNweather app’s Interactive Radar is essential for tracking these storms, with push notifications for severe weather or flood risks. Plan indoor tasks like visiting the Knoxville Zoo or the Tennessee Aquarium in Chattanooga for storm-prone hours. Use the app to find dry windows for morning commutes in Morristown or short hikes in the Smoky Mountains, especially north of I-40. The platform’s streaming updates on YouTube, Roku, Amazon Fire, and Apple TV, led by Mike Witcher, provide daily context, so check regularly for updates. Always “Turn Around, Don’t Drown” near flooded roads. These stormy days keep summer lively, but the app keeps you prepared!

Saturday-Sunday: Season’s First Heat Wave
Behind Friday’s cold front, a ridge of high pressure builds, bringing the season’s first heat wave starting Saturday, June 21, 2025. Highs soar to the low to mid-90s Saturday and Sunday, with dew points dropping briefly to the mid to upper 60s on Saturday, keeping the heat index around 95-100°F. By Sunday, dew points climb back to the low 70s, pushing the heat index near 105°F, meeting heat advisory criteria across East Tennessee, including the Cumberland Plateau and Smoky Mountains. Rain chances drop significantly, with only isolated afternoon showers possible, producing less than 0.25 inches, making this a hot, mostly sunny weekend perfect for summer fun.

The EastTNweather app’s long-range forecasts will confirm this scorching weekend, with alerts for heat advisories. Plan barbecues in Knoxville, festivals in Pigeon Forge, or kayaking on the Tennessee River in Chattanooga, but practice heat safety: stay hydrated, apply sunscreen, and take shade breaks. Check on neighbors, especially the elderly, in Chattanooga or Cleveland, where the heat index peaks. North of I-40, like Morristown and the Tri-Cities, may feel slightly less humid on Saturday, while south of I-40 faces stickier conditions by Sunday. The platform’s streaming updates provide heat safety tips, ensuring flexibility for plans in Sevierville or the Cumberland Plateau. This heat wave signals summer’s bold arrival, so stay cool and check the app!

Next Week: Heat Wave Persists, Drier Conditions
The heat wave extends through next week, with highs in the low to mid-90s and lows in the 60s to 70s, as dew points remain in the low 70s, keeping the heat index near 100-105°F. Drier weather prevails, with only isolated afternoon showers possible, producing under 0.5 inches per day. This hot, humid weather is ideal for water-based activities like swimming in the Smoky Mountains’ streams or visiting splash pads in Chattanooga, but heat safety is critical—listen to your body, drink plenty of water, and avoid strenuous activity during peak heat hours. The EastTNweather app’s extended forecasts will track this heat wave, with alerts for heat advisories or renewed storm risks by midweek.

The platform’s streaming updates on YouTube and Roku help plan for the heat, ensuring you stay cool during outdoor events in Athens or Cleveland. The low to mid-90s offer a vibrant summer vibe, with the app’s precision helping you dodge showers for hikes in the Cumberland Plateau or festivals in Knoxville. Stay tuned to the app for updates as the week evolves, keeping your summer plans safe and thriving.

Rainfall Outlook: 1″ Inch This Week
Over the next seven days, rainfall totals will range from 1-2 inches across East Tennessee, with Wednesday through Friday contributing the most. Areas hit by repeated storms, particularly south of I-40 in Chattanooga, Cleveland, or Athens, could see 2-3 inches, raising flood risks in urban areas or near rivers like the Little Pigeon in Sevierville or the Clinch in Kingston. North of I-40, including Knoxville and the Tri-Cities, expects 0.75-1.5 inches. The EastTNweather app’s Interactive Radar and flood alerts are vital for monitoring heavy rain, especially in flood-prone areas. Check the app daily to stay ahead of potential flooding and plan accordingly.