Flash Flood Warnings in Arizona, 2010

By month

58 of 174 flash flood warnings covering Arizona in 2010 had a flash flood report inside them; 80 of 124 flash flood reports fell inside a warning, on average 602 minutes after it went out.

Arizona, 2010

Each office's whole area, 2010

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.

• Pima County39
• Mohave County34
• Maricopa County24
• Pinal County22
• Coconino County18
• Cochise County18
• Gila County16
• Navajo County11
• La Paz County9
• Yavapai County9
• Santa Cruz County8
• Yuma County6
• Apache County6
• Graham County4
• Greenlee County3

1. July 30, 201014flash flood warnings
2. July 31, 201012flash flood warnings
3. January 21, 201010flash flood warnings
4. August 17, 201010flash flood warnings
5. January 22, 20109flash flood warnings
6. July 29, 20109flash flood warnings
7. July 20, 20107flash flood warnings
8. July 21, 20107flash flood warnings
9. August 27, 20107flash flood warnings
10. August 16, 20106flash flood warnings
11. February 7, 20105flash flood warnings
12. August 28, 20105flash flood warnings

Alerts in force nowTornadoes on recordThe radar archive20092011

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.