Flash Flood Warnings in Maryland, 2015

By month

32 of 52 flash flood warnings covering Maryland in 2015 had a flash flood report inside them; 58 of 77 flash flood reports fell inside a warning, on average 68 minutes after it went out.

Maryland, 2015

Each office's whole area, 2015

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 County25
• Harford County17
• City of Baltimore15
• Anne Arundel County10
• Prince George's County9
• Howard County8
• Montgomery County7
• Frederick County6
• Carroll County5
• Cecil County4
• Saint Mary's County2
• Kent County2
• Washington County2
• Garrett County1
• Allegany County1
• Charles County1
• Queen Anne's County1

1. June 27, 20158flash flood warnings
2. June 1, 20154flash flood warnings
3. June 23, 20154flash flood warnings
4. June 21, 20153flash flood warnings
5. July 7, 20153flash flood warnings
6. September 10, 20153flash flood warnings
7. May 19, 20152flash flood warnings
8. July 1, 20152flash flood warnings
9. July 6, 20152flash flood warnings
10. July 14, 20152flash flood warnings
11. July 15, 20152flash flood warnings
12. August 20, 20152flash flood warnings

Alerts in force nowTornadoes on recordThe radar archive20142016

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.