Summary (tl;dr)

Portions of the Mid-Atlantic region, including Maryland, Washington D.C., and parts of Virginia and Delaware, are currently under a tornado watch due to an increased threat of severe thunderstorms and potential tornadoes.

Essential Background

A tornado watch is issued by the National Weather Service when conditions are favorable for tornadoes and severe thunderstorms to develop in and near the watch area. This differs from a tornado warning, which means a tornado has been sighted or indicated by radar, requiring immediate action. The current weather system follows a period of active severe weather across parts of the Midwest and Ohio Valley earlier in August 2026, which included multiple confirmed tornadoes and a derecho event.

The Full Story

On Thursday, August 20, 2026, the National Weather Service Baltimore/Washington office issued a tornado watch for Southern Maryland, including Calvert, Charles, and St. Mary's counties, in addition to other parts of Maryland, the District of Columbia, and portions of Virginia. This tornado watch, issued at 3:01 p.m. EDT, remains in effect until 10 p.m. EDT, replacing an earlier severe thunderstorm watch. Twelve counties across Maryland, including Anne Arundel, Howard, Montgomery, Prince George's, Carroll, Cecil, Baltimore, Baltimore City, and Harford, are also covered under the watch. The region is experiencing a "Slight Risk" (Level 2 of 5) for severe thunderstorms, with damaging winds being a primary concern, alongside the possibility of isolated tornadoes and heavy downpours. The Philadelphia region is also under tornado, storm, and flood watches.

Why It Matters

Tornado watches are critical alerts that inform the public of potentially life-threatening weather conditions. Residents in the affected areas need to remain vigilant and prepared to take immediate shelter if a tornado warning is issued, which signifies an imminent threat. The severe weather could lead to damaging winds, hail, localized flooding, and power outages, posing significant risks to property and personal safety. This event underscores a pattern of an active severe weather year in some regions, with Illinois, for example, experiencing a record number of tornadoes in 2026.

Geographic Location

• Calvert County, Maryland, United States (under tornado watch)
• Charles County, Maryland, United States (under tornado watch)
• St. Mary's County, Maryland, United States (under tornado watch)
• Anne Arundel County, Maryland, United States (under tornado watch)
• Howard County, Maryland, United States (under tornado watch)
• Montgomery County, Maryland, United States (under tornado watch)
• Prince George's County, Maryland, United States (under tornado watch)
• Carroll County, Maryland, United States (under tornado watch)
• Cecil County, Maryland, United States (under tornado watch)
• Baltimore County, Maryland, United States (under tornado watch)
• Baltimore City, Maryland, United States (under tornado watch)
• Harford County, Maryland, United States (under tornado watch)
• Washington, D.C., District of Columbia, United States (under tornado watch)
• Virginia, United States (portions under tornado watch)
• Delaware, United States (most of Delmarva under tornado watch)
• Philadelphia region, Pennsylvania, United States (under tornado, storm, and flood watches)