'Heat Dome' Comes To Maryland: 3 Days Of Dangerously Hot Temperatures

MARYLAND — Wednesday temperatures will be hot across large parts of Maryland, followed by dangerously hot temperatures from Thursday through Saturday.

A "heat dome" that has been bringing brutal heat into the Southwest U.S. is shifting eastward, bringing some of the hottest temperatures in years to the Mid-Atlantic region, according to AccuWeather.

For Thursday, the National Weather Service has issued a heat advisory for central, northeast and southern Maryland from 11 a.m. to 8 p.m. Heat index values around 105 degrees are expected.

“Extreme heat and humidity will significantly increase the potential for heat related illnesses, particularly for those working or participating in outdoor activities,” the NWS said, adding that car interiors can reach deadly temperatures in a matter of minutes during extreme heat.

After dry weather on Wednesday, the next three days will see highs approaching or near 100 degrees, and the potential for heat indexes near or over 105. Each day also carries a chance of thunderstorms.

"For parts of the East, temperatures will climb to their highest levels of the year so far," AccuWeather said.

From a heat index standpoint, the worst of three days is expected to be Friday, with high humidity pushing the afternoon heat index into the 105 to 110 range in parts of Maryland.

The temperature in Baltimore is predicted to top out around 100 degrees Fahrenheit, the hottest it has been in years, according to AccuWeather. The temperature could also reach triple digits in Washington, D.C.

"It has not yet reached 100 in either city this year," AccuWeather Senior Meteorologist Bill Deger said. "In fact, it has not even gotten into the upper 90s yet in Washington."

The Baltimore City Health Department could issue a Code Red Extreme Heat Alert for Thursday and Friday.

In central Maryland, the record high for July 27 is 101 degrees, set in 1940. A high of 99 is forecast for Friday, with the record at 103 degrees from 1941.

On Saturday, residents should expect temperatures in the mid-90s to near 100, with high humidity pushing the afternoon heat index to around 105.

From Thursday through Saturday, residents should drink plenty of fluids, stay in an air-conditioned room, stay out of the sun, and check up on relatives and neighbors. Also, young children and pets should never be left unattended in vehicles under any circumstances.

To reduce risk during outdoor work, the Occupational Safety and Health Administration recommends scheduling frequent rest breaks in shaded or air-conditioned environments.

In terms of air quality, the Maryland Department of the Environment has issued a Code Orange Air Quality Alert for Wednesday for the Baltimore metropolitan and Annapolis regions due to pollution and high ozone concentrations.

A Code Orange Air Quality Alert means that air pollution concentrations within the region may become unhealthy for sensitive groups. Sensitive groups include children, people suffering from asthma, heart disease or other lung diseases and the elderly.

On Thursday and Friday, the current forecast is for a Code Yellow Air Quality Alert in the region.

Here is a look at the National Weather Service forecast through the upcoming weekend in central Maryland:

Wednesday: Sunny, with a high near 91.

Wednesday night: Mostly clear, with a low around 75.

Thursday: A chance of showers and thunderstorms after 2 p.m. Mostly sunny and hot, with a high near 97. Heat index values as high as 104.

Thursday night: A chance of showers and thunderstorms, mainly before 2 a.m. Mostly cloudy, with a low around 75.

Friday: A slight chance of showers and thunderstorms before 8 a.m., then a chance of showers and thunderstorms after 2 p.m. Mostly sunny and hot, with a high near 97.

Friday night: A chance of showers and thunderstorms before 2 a.m., then a slight chance of showers.

Saturday: A chance of showers and thunderstorms after 2 p.m. Mostly sunny and hot, with a high near 97.

Saturday night: A chance of showers and thunderstorms. Mostly cloudy, with a low around 71.

Sunday: A chance of showers after 2pm. Mostly sunny, with a high near 84.