Flash Flood Warnings in New Hampshire, 2013

By month

21 of 36 flash flood warnings covering New Hampshire in 2013 had a flash flood report inside them; 53 of 58 flash flood reports fell inside a warning, on average 68 minutes after it went out.

New Hampshire, 2013

Each office's whole area, 2013

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.

• Cheshire County11
• Grafton County9
• Merrimack County7
• Hillsborough County6
• Coos County5
• Sullivan County5
• Rockingham County5
• Belknap County4
• Carroll County3
• Strafford County1

1. June 30, 20135flash flood warnings
2. September 2, 20135flash flood warnings
3. September 12, 20134flash flood warnings
4. July 18, 20133flash flood warnings
5. July 1, 20132flash flood warnings
6. July 2, 20132flash flood warnings
7. July 3, 20132flash flood warnings
8. August 29, 20132flash flood warnings
9. August 31, 20132flash flood warnings
10. June 2, 20131flash flood warnings
11. June 23, 20131flash flood warnings
12. June 28, 20131flash flood warnings

Alerts in force nowTornadoes on recordThe radar archive20122014

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.