Severe Thunderstorm Warning for Calvert and St. Marys Counties, MD

Source: NOAA · Southern Maryland

This alert is no longer in effect.

NOAA issued it on August 18, 2026, 6 days ago. Warnings of this kind stay in effect for hours to a few days, so this page is a historical record of what was issued, not a current warning. For conditions where you are right now, check weather.gov (US), weather.gc.ca (Canada), the Met Office (UK), or the Bureau of Meteorology (Australia).

Areazine synthesizes this NWS weather alert directly from NOAA's official public data feed. See our methodology for full source attribution and refresh cadence.

A Severe Thunderstorm Warning is in effect for southeastern St. Marys and Calvert counties in southern Maryland until 9:45 PM EDT August 17.

Read this weather record in 30 seconds

Record type
Severe Thunderstorm Warning
Affected area
Southern Maryland
Issued
August 18, 2026
Issuing authority
NWS Baltimore MD/Washington DC

Storm notices can cover different combinations of wind, hail, lightning, and rainfall. Use the original notice for the hazards and boundaries attached to this specific record.

Record status: historical. It was issued 6 days ago; use the issuing agency's live warning service for current conditions in Southern Maryland.

Alert Details

The National Weather Service in Sterling, Virginia has issued a Severe Thunderstorm Warning for southeastern St. Marys County and southeastern Calvert County in southern Maryland. The alert was issued by NWS Baltimore MD/Washington DC at 9:03 PM EDT on August 17, 2026.

Affected Areas

The warning covers Calvert County, MD and St. Marys County, MD. Impacted locations include Lexington Park, Chesapeake Ranch Estates, Leonardtown, Piney Point, Tall Timbers, Saint Inigoes Creek, Cuckold Creek, Saint Marys City, Greenwell State Park, Saint Leonard Creek, Town Creek, Saint Marys River, White Point Beach, California, Lusby, Patuxent River Naval Air Station, Hollywood, Drum Point, Valley Lee, and Sandgates.

What You Should Do

Move to an interior room on the lowest floor of a building. Move indoors immediately due to large hail, damaging wind, and continuous cloud-to-ground lightning. Do not drive through flooded roadways.

Expected Conditions

At 9:02 PM EDT, a severe thunderstorm was located near Leonardtown moving east at 30 mph. Hazards include 60 mph wind gusts and hail up to 0.75 inches. Damaging winds may cause trees and large branches to fall, potentially injuring people outdoors and damaging homes, vehicles, and roadways. Localized power outages are possible.

Timeline

The warning is effective from 9:03 PM EDT August 17, 2026 until 9:45 PM EDT August 17, 2026.

Original source: NOAA Official Notice ↗

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Nationwide notices with similar length or severity timing 8

Two Areazine-derived peer sets for this NWS weather alert: nearest notices by body length and by same severity near the same agency date. Peers come from other categories so they are not the same-feed Related list above.

Frequently Asked Questions

Common questions about this NWS weather alert.

What is this NWS weather alert about?
A Severe Thunderstorm Warning is in effect for southeastern St. Marys and Calvert counties in southern Maryland until 9:45 PM EDT August 17.
Which agency issued this alert?
This alert was issued by NOAA. The original notice is available at the source link at the bottom of this article.
How severe is this alert?
This alert is classified as "high" severity. Take precautions and monitor for updates.
What area is affected?
This alert affects Southern Maryland. Check with NOAA for the most current geographic scope.
Where can I find more Weather Alerts updates?
Browse the full Weather Alerts feed on Areazine at areazine.com/weather/ for the latest updates from NOAA and other agencies.