Afternoon storms pack heavy rain, trigger tornado warning in Howard Co., Md.

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Storms bringing heavy rain popped up around the D.C. area Friday afternoon, which could help improve the region’s poor air quality stemming from Canadian wildfire smoke drifting to the national capital region.

WTOP meteorologist Mike Stinneford said storms should end before sunset, but could pack heavy rain, gusty winds and hail.

Just before 4:30 p.m., Stinneford said a band of heavy rainfall stretched from D.C. northward to the Pennsylvania line and was moving northeast. The system triggered a tornado warning for part of Howard County until 4:45 p.m.

The National Weather Service said just before 4:30 p.m., a severe thunderstorm capable of producing a tornado was spotted over Columbia. The system was moving northeast at 15 mph and also brought the possibility of baseball-sized hail.

Shortly after the tornado warning, the NWS issued a severe thunderstorm warning for parts of Baltimore, Anne Arundel County, Howard County and Baltimore County until 5:30 p.m.

A flood warning is in effect in parts of North Central and Northern Maryland until 8:30 p.m. Friday.

WTOP’s Dave Dildine reported the conditions made for traffic backups on major thoroughfares between Silver Spring and Baltimore during rush hour and the Fourth of July holiday weekend getaway.

The good news is the storms should help push out the unhealthy air that triggered a “Code Red” alert Thursday and a “Code Orange” Friday.

According to the Environmental Protection Agency’s AirNow rating system, Code Red means the air is unhealthy for everyone. Code Orange triggers an advisory for sensitive groups to take extra caution during outdoor activities.

The air quality was still at Code Orange levels as of 6:10 p.m. Friday.

“You’ll still want to take it a bit easy out there if you’re doing anything strenuous — the long run, that can hold off until maybe the weekend,” 7News First Alert Chief Meteorologist Veronica Johnson said.

Air pollution is measured by the air quality index. Code Red falls between an index value of 151 and 200, while Code Orange falls between 101 and 150. Earlier this month, the D.C. area was under a rare “Code Purple” alert, meaning the air was very unhealthy for everyone.

The Metropolitan Washington Council of Governments forecasted a Code Yellow for Saturday, meaning the air will be healthy for most people.

The poor air quality has been a result of out-of-control Canadian wildfires and the weather patterns throughout the United States.


FRIDAY NIGHT: Chance of a shower or thunderstorm before midnight. Partly to mostly cloudy overnight. Lows in the 60s to around 70.

SATURDAY: Partly to mostly cloudy with afternoon and evening thunderstorms. Storms may be severe. Highs in the mid to upper 80s.

SUNDAY: Muggy with afternoon and evening thunderstorms. Storms strong to severe. Highs in the upper 80s to around 90.

MONDAY: Hot and humid with afternoon thunderstorms. Highs in the lower 90s.

FOURTH OF JULY/TUESDAY: Partly cloudy with only isolated afternoon storms. Highs upper 80s to lower 90s.

Current weather

WTOP’s Tadiwos Abedje and Jack Moore contributed to this report. 

Thomas Robertson

Thomas Robertson is an Associate Producer and Web Writer/Editor at WTOP. After graduating in 2019 from James Madison University, Thomas moved away from Virginia for the first time in his life to cover the local government beat for a small daily newspaper in Zanesville, Ohio.

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