With high humidity, Atlanta will again will feel like 100 degrees Friday

Atlanta will spend yet another afternoon in the 90s today, but with the humidity, it will feel more like triple digits outside.

For all but three days this month, the city has recorded highs in the 90s, according to data from the National Weather Service. That trend continues today with a projected high of 94, which won’t break any records but could verge on dangerous heat once the ever-present sticky air factors into play. Added into the summertime mix today is a 40% chance of a thunderstorm.

The oppressive heat is part of a wave that has smothered the southern half of the United States for weeks. As many as 80 million people across the country will experience heat indices above 105 degrees through the weekend, and dozens of daily high-temperature records are expected to be set, according to the NWS.

High-pressure atmospheric conditions have created a dome effect, trapping vast areas of sweltering heat and sometimes preventing rain and clouds that could bring relief. The heat dome has already led to record-breaking triple-digit temperatures from Texas to California, Channel 2 Action News chief meteorologist Brad Nitz said.

“We’re on the eastern edge of the high-pressure ridge, which has pushed our temperatures into the mid-90s,” he said. “The high pressure ‘heat dome’ features light wind and sinking air, which tends to trap the hot air in place.”

Credit: HYOSUB SHIN / AJC

Credit: HYOSUB SHIN / AJC

Temperatures on Thursday failed to set any records, leaving July 1 and its 96-degree high as the hottest day so far this year. That is still well below the all-time hottest temperature recorded in Atlanta, which was 106 degrees on June 30, 2012.

ExploreHow to stay safe in a heat wave

But at 91% humidity, Thursday’s heat index — an accurate measure of how hot it really feels taking both air temperature and relative humidity into account — was expected to reach 104 degrees in the city. With lower humidity expected today, a heat index of 102 is on tap this afternoon.

Heat advisories take effect when heat index values top 105 degrees. Under those conditions, the body can’t cool itself efficiently because perspiration doesn’t easily evaporate in high humidity. Heatstroke sets in when your body temperature exceeds 103 degrees, which can cause damage to the brain, kidneys, muscles, and even death.

It’s important to take the heat seriously and quickly seek shade and hydration when you feel symptoms of heat exhaustion, which include experiencing heavy sweating, dizziness, a rapid pulse, nausea, headaches and cool, moist skin.

ExploreHow to avoid heatstroke this summer in Atlanta

Atlanta has opened a cooling center at the Old Martin Luther King Jr. Natatorium to help residents fight the heat. Located at 90 Boulevard, it’ll be open Friday from 11 a.m. to 6 p.m.

Rain in the forecast could spell relief from the heat. Forecasters predict storms may become more widespread in the state this afternoon into Saturday, then the greatest coverage of storms is expected over central and southern Georgia at the start of next week.

Isolated severe storms, particularly with damaging downburst winds, could occur through Saturday, the NWS warns.