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Maryland weather radar: Baltimore, Washington DC, Columbia under flash flood warning - Here's what to know
The National Weather Service (NWS) in Sterling, Virginia on Wednesday issued Flash Flood Warnings for parts of Maryland, Washington DC, and northern Virginia
The National Weather Service (NWS) in Sterling, Virginia on Wednesday issued Flash Flood Warnings for parts of Maryland, Washington DC, and northern Virginia, including Baltimore, Columbia, and Washington DC, due to severe thunderstorms producing heavy rainfall.
Flash Flood Warning Details
Howard County and South Central Carroll County (Including Columbia):
Issued: 6:06 PM EDT, July 9, 2025, until 9:15 PM EDT.
Conditions: Doppler radar indicated thunderstorms producing 1–3 inches of rain already, with an additional 1–2 inches possible at rates of 1–2 inches per hour. Flash flooding is ongoing or imminent.
Affected Areas: Columbia, Eldersburg, Sykesville, Burtonsville, Fulton, Highland, Glenelg, West Friendship, Glenwood, Dayton, Gaither, Roxbury Mills, Henryton, Clarksville, Marriottsville, Lisbon, Woodbine, Woodstock, Poplar Springs.
Impact: Flash flooding of small creeks, streams, urban areas, highways, streets, underpasses, and other low-lying or poorly drained areas.
District of Columbia, South Central Montgomery County, Arlington County, Northeastern Fairfax County, Alexandria, Falls Church:
Issued: 5:44 PM EDT, July 9, 2025, until 8:45 PM EDT.
Conditions: Thunderstorms are expected to produce 1–3 inches of rain at rates of 1–2 inches in 20 minutes, with flash flooding ongoing or expected soon.
Affected Areas: Washington DC, Arlington, Alexandria, Bethesda, Annandale, Springfield, Fort Washington, Fort Hunt, Vienna, Groveton, Falls Church, Huntington, Coral Hills, Mantua, Fort Belvoir, Pimmit Hills, National Harbor, Rosslyn, Crystal City, McLean, Reagan National Airport.
Impact: Similar to Howard County, flash flooding will affect creeks, streams, urban infrastructure, and low-lying areas, posing risks to transportation and property.
Baltimore and Surrounding Areas:
A Flood Watch remains in effect for Baltimore City, Anne Arundel, Northern and Southern Baltimore Counties, and other areas until midnight EDT. Radar indicates heavy rain across the Baltimore/Washington metro area, with 2–3 inches per hour rainfall rates possible, increasing flash flood risks.
Why Flash Flooding Is Happening
A strong frontal system is moving through the Mid-Atlantic, bringing scattered severe thunderstorms with heavy to excessive rainfall. Rainfall rates of 1–3 inches per hour are driving flash flood risks, particularly in urban areas with poor drainage.
Doppler radar shows a convergence zone south of Baltimore, with bands of heavy rain moving west and east, enhanced by the remnants of Tropical Storm Chantal. This has led to 2–3 inches per hour rainfall rates across the I-95 corridor, including Baltimore, Washington DC, and Philadelphia.
Safety and Preparedness Actions
Avoid Flooded Areas: Do not drive through flooded roads or low-lying areas. Even shallow water can sweep vehicles away.
Prepare for Outages: Charge devices, secure outdoor items, and have emergency supplies ready in case of power disruptions.
Seek Shelter: If severe thunderstorms escalate (a Severe Thunderstorm Watch is in effect until 10 PM EDT), stay indoors away from windows due to risks of damaging winds and potential tornadoes.
