Flash Flood Warnings in Maryland, 2023

By month

19 of 36 flash flood warnings covering Maryland in 2023 had a flash flood report inside them; 33 of 34 flash flood reports fell inside a warning, on average 51 minutes after it went out.

Maryland, 2023

Each office's whole area, 2023

An office's figures cover every county it serves, including across state lines.

Verified by the Iowa Environmental Mesonet's Cow, which matches each storm-based warning with the local storm reports inside its polygon while it was in force, within 15 km of its edge: a tornado warning counts as verified on a tornado report, a severe thunderstorm warning on hail of 1 inch or more, a gust of 58 mph or more, or wind damage, a flash flood warning on a flash flood report. The false alarm ratio is the share of warnings with no such report; "inside a warning" is the probability of detection, the share of reports that fell inside one; lead time runs from the warning's issue to each report inside it, counting zero for a report that came first. A warning with no report is not proof nothing happened: reports come from spotters, the public and damage surveys, and are thin where few people live.

• Baltimore County9
• Prince George's County8
• Wicomico County7
• Harford County5
• City of Baltimore5
• Montgomery County5
• Dorchester County4
• Anne Arundel County3
• Caroline County2
• Calvert County2
• Saint Mary's County2
• Somerset County2
• Cecil County1
• Charles County1
• Worcester County1

1. September 13, 20236flash flood warnings
2. July 16, 20235flash flood warnings
3. August 8, 20234flash flood warnings
4. July 9, 20233flash flood warnings
5. August 14, 20233flash flood warnings
6. September 9, 20233flash flood warnings
7. June 27, 20232flash flood warnings
8. July 4, 20232flash flood warnings
9. July 25, 20232flash flood warnings
10. July 1, 20231flash flood warnings
11. July 7, 20231flash flood warnings
12. July 14, 20231flash flood warnings

Alerts in force nowTornadoes on recordThe radar archive20222024

National Weather Service watches, warnings, advisories and statements from the Iowa Environmental Mesonet's VTEC archive, which reconstructs tornado, severe thunderstorm, flash flood and marine warnings back to 1986 from the NWS text archive. Storm Prediction Center watches and mesoscale discussions from SPC's archive through the Mesonet. County centers from the US Census Bureau. Warning verification from the Mesonet's Cow. Rebuilt daily.