Dangerous heat expected this week

TALLAHASSEE, Fla. (WCTV) - Much of the eastern United States will experience higher moisture and temperatures that will create unbearable and dangerous heat for most of the work week.

Most of the viewing area was placed under a Heat Advisory by the National Weather Service Forecast Office in Tallahassee for Tuesday. Heat index values of 105 to 110 are anticipated, according to a statement from their office.

High temperatures will likely hit the mid to upper 90s inland for the work week and extend into the weekend. Tuesday’s normal high for Tallahassee is 91. With dewpoints in the lower to mid-70s anticipated (except for some inland locations during the late afternoon where it can be drier), the higher moisture levels will likely bring heat index values approaching the 110-degree beyond Tuesday.

The heat index uses the temperature and relative humidity as the variables in a long mathematical equation that carries many assumptions. Those assumptions are fixed parameters such as a person’s clothing coverage is at 84%, the person’s body temperature is 98.6 degrees, the wind speed is around 6 mph, and the person is walking at around 3 mph according to a technical document from the National Weather Service.

A ridge of high pressure in the mid-and upper-levels of the atmosphere will continue to nudge east and be centered over the Southeast U.S. by Tuesday morning. This will increase the temperature throughout the atmospheric profile and will be warmer than normal for mid-June. The ridge will not only act to keep large-scale storm systems away from the eastern U.S. but also place a “cap” on rain and thunderstorm chances.

The nearly-stacked ridge pattern will begin to slide west by Thursday and be centered over the South-Central U.S. by Friday. Heat indices will likely remain in the lower 100s at the highest in the Big Bend and South Georgia Friday thanks to drier conditions inland, but will be lower than earlier in the work week. If the air remains drier Friday, the actual high temperature could approach 100 degrees.

The ridge’s anticipated westward movement would bring a trough of low pressure to the northeastern U.S. late week. The pattern will allow a cold front at the surface to move toward the Southeast U.S. during the weekend. So far, it’s likely the front’s movement will slow and stay to the north of the area during the weekend. So far, rain chances look low.

Meteorologist Josh Green laid out some hot weather safety suggestions that include drinking plenty of water, taking frequent breaks indoors, and checking on those who are vulnerable to the heat.

The First Alert Weather Team will continue to monitor the forecast trends and provide updates online and on air.

This story was updated to include information about the heat index and how it is determined.

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