It's the hottest day of the year, as the heat index is already flirting with 100 degrees as of 10:30AM. A Heat Advisory is valid for nearly the entire Tennessee Valley through 8PM tonight. The heat index will reach dangerous levels this afternoon, reaching 104 to 109. Here is a list provided from the National Weather Service, noaa.gov, that shows the impacts of the heat index verses the impacts on the body. Notice, these levels are in the shade! In the sunshine, the temperature and heat index is up to 15 degrees higher!

Caution 80°F - 90°F Fatigue possible with prolonged exposure and/or physical activity
Extreme Caution 90°F - 103°F Heat stroke, heat cramps, or heat exhaustion possible with prolonged exposure and/or physical activity
Danger 103°F - 124°F Heat cramps or heat exhaustion likely, and heat stroke possible with prolonged exposure and/or physical activity
Extreme Danger 125°F or higher Heat stroke highly likely

The heat index is so dangerous, because the higher the humidity, the more it slows down the evaporation process, and sweating along isn't enough to cool the body. There must be some evaporation. 

Now, we're talking storms.

Newest info from the storm prediction center has placed Chattanooga and all Tennessee counties in a Slight Risk of severe weather tonight, mainly from 9PM through 3AM Wednesday morning. There is a chance we'll get hit and miss showers this afternoon east of I-75, but the bulk of this system holds off until overnight. The biggest threat with storms overnight will be strong 60 mph wind gusts. I expect some power outages overnight. Storms will end by 2AM-3AM on Wednesday morning, leaving a mostly dry commute tomorrow. There's a chance debris and clean up will be ongoing where the strongest storms hit.

The biggest take away from this, have a plan of action as storms increase tonight. Do you have a weather radio? How are you getting your weather alerts? If you have a smart phone, you can add the WRCB Weather App, and make sure notifications are turned on in settings.

 

The National Weather Service warns that there are several factors that increase the impact of heat. They include:

  • Alcoholic consumption
  • Certain medications
  • Certain medical conditions
  • Elderly or infants (age)
  • Physical exertion
  • Exposure to sun

A few storms look possible east of I-75 this afternoon, but these will be very hit and miss. There is a Slight Risk of severe weather tonight for Chattanooga, Cleveland, and our folks in Tennessee. While there is a Marginal (low) risk of severe weather for our folks in Georgia. Timing for organized storms tonight, 9PM tonight-3AM Wednesday morning. The biggest threat with storms overnight will be strong 60 mph wind gusts. Downed power lines, and trees are possible late tonight. Expect power outages where the strongest storms develop. Storms will also bring heavy rainfall. Therefore, localized flooding, and cloud to ground lightning will be possible.

TODAY:

  • 12PM: P. Cloudy and Hot, 91 (Heat Index 97) Slight Rain Chance east of I-75
  • 3PM: P. Cloudy and Hot, 97 (Heat Index 105)
  • 6PM: P. Cloudy and Hot, 98 (Heat Index 107)

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