'Dangerous' Temps Put MD Under Excessive Heat Warning

MARYLAND — Record-high temperatures are possible from Baltimore to Washington, D.C., Friday with 100 degrees in the forecast, the National Weather Service said. Across much of Maryland, the dangerous heat and humidity will make it feel like 110 degrees outdoors.

The summer blast-furnace has prompted several advisories: An excessive heat warning, a Code Orange air quality alert and a hazardous weather outlook for parts of Maryland.

The Friday excessive heating warning is in effect from 11 a.m. until 8 p.m., while the Saturday warning will be in effect from noon to 8 p.m.

"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. "Dangerously hot conditions with heat index values up to 111 expected."

High temperatures are expected to reach 100 degrees Friday, which is the record high temperature for the day at Reagan National Airport. The record high for July 28 at Washington Dulles Airport is 99 degrees.

The record high for July 28 at Baltimore-Washington Airport is 103 degrees, and the record temp for July 29 is 101 degrees, the NWS said.

In its hazardous weather outlook, the NWS said that isolated severe thunderstorms producing damaging winds are possible Friday afternoon. On Saturday afternoon, chances for severe thunderstorms are greater as a cool front moves into the area.

The Maryland Department of the Environment has issued a Code Orange Air Quality Alert Friday for the Baltimore City metro and Annapolis region. Air pollution concentrations in the region may become unhealthy for sensitive groups, including children, people with asthma, heart disease or other lung diseases and the elderly.

Storms on Saturday will bring an end to the heat wave, with highs on Sunday expected in the mid-80s, followed by cooler and less humid air early next week.

For Friday and Saturday, residents are urged to drink plenty of fluids, stay in an air-conditioned room and stay out of the sun. Young children and pets should not be left unattended in vehicles under any circumstances.

For workers, the Occupational Safety and Health Administration recommends scheduling frequent rest breaks in shaded or air-conditioned environments.

Here's the National Weather Service weather forecast for Maryland:

Friday: Isolated showers and thunderstorms after 3pm. Mostly sunny and hot, with a high near 100. Heat index values as high as 110. Light and variable wind becoming southwest 5 to 8 mph in the morning. Chance of precipitation is 20%.

Friday Night: Scattered showers and thunderstorms, mainly before midnight. Partly cloudy, with a low around 79. Southwest wind 7 to 9 mph. Chance of precipitation is 30%.

Saturday: Showers and thunderstorms likely after 3pm. Mostly sunny and hot, with a high near 99. Heat index values as high as 108. Southwest wind 6 to 10 mph. Chance of precipitation is 60%. New rainfall amounts of less than a tenth of an inch, except higher amounts possible in thunderstorms.

Saturday Night: Showers and thunderstorms likely, mainly before 9pm. Mostly cloudy, with a low around 74. West wind 7 to 9 mph. Chance of precipitation is 60%. New rainfall amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.

Sunday: A slight chance of showers and thunderstorms before 9am, then a slight chance of showers between 9am and 3pm. Mostly sunny, with a high near 88. North wind around 8 mph. Chance of precipitation is 20%.

Sunday Night: Partly cloudy, with a low around 69.

Monday: Sunny, with a high near 87.