Alert archive / Arizona / Pima County / Flash Flood Warnings

Flash Flood Warnings in Pima County, Arizona, 2012

49 flash flood warnings in 2012. An alert counts here when it covered this county. The archive of flash flood warnings reaches back to 1986.

Pima County and its neighbors

Each county as a circle sized by its count in 2012. Tap one for its archive.

Flash Flood Warnings
49
Busiest month
September19 flash flood warnings
Busiest day
September 6, 20128 flash flood warnings

Over time

By month

Warning verification

How often warnings here had a storm report inside them, and how much warning the reports had.

12 of 49 flash flood warnings covering Pima County in 2012 had a flash flood report inside them; 17 of 19 flash flood reports fell inside a warning, on average 53 minutes after it went out.

Pima County, 2012

WarningsWith a reportFalse alarm ratioReportsInside a warningMean lead time
Flash flood warnings491276%1989%53 min

Each office's whole area, 2012

WarningsWith a reportFalse alarm ratioReportsInside a warningMean lead time
NWS Tucson, AZ: flash flood warnings802075%3382%49 min

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.

The alerts

Every alert, in the order issued. Times are local, Mountain Time. Each opens its own page with the text, the map, the radar and the sounding.

IssuedProductOfficeLasted
Jul 4, 12:59 PM MSTFlash Flood WarningTWC2 hr
Jul 4, 1:32 PM MSTFlash Flood WarningTWC118 min
Jul 4, 1:45 PM MSTFlash Flood WarningTWC111 min
Jul 12, 4:30 PM MSTFlash Flood WarningTWC2 hr
Jul 14, 1:42 PM MSTFlash Flood WarningTWC2 hr
Jul 14, 2:47 PM MSTFlash Flood WarningTWC118 min
Jul 15, 4:15 PM MSTFlash Flood WarningTWC2 hr
Jul 15, 5:00 PM MSTFlash Flood WarningTWC2 hr
Jul 15, 7:02 PM MSTFlash Flood WarningTWC118 min
Jul 16, 8:09 PM MSTFlash Flood WarningTWC111 min
Jul 21, 1:53 PM MSTFlash Flood WarningTWC112 min
Jul 22, 1:56 PM MSTFlash Flood WarningTWC92 min
Jul 28, 3:15 PM MSTFlash Flood WarningTWC2 hr
Jul 28, 3:54 PM MSTFlash Flood WarningTWC2 hr
Jul 29, 2:16 PM MSTFlash Flood WarningTWC119 min
Jul 29, 2:44 PM MSTFlash Flood WarningTWC91 min
Jul 29, 4:13 PM MSTFlash Flood WarningTWC2 hr
Aug 17, 11:02 AM MSTFlash Flood WarningTWC118 min
Aug 17, 12:39 PM MSTFlash Flood WarningTWC117 min
Aug 17, 2:05 PM MSTFlash Flood WarningTWC115 min
Aug 19, 7:19 PM MSTFlash Flood WarningTWC86 min
Aug 19, 8:47 PM MSTFlash Flood WarningTWC103 min
Aug 19, 8:58 PM MSTFlash Flood WarningTWC2 hr
Aug 19, 10:56 PM MSTFlash Flood WarningTWC64 min
Aug 20, 5:59 PM MSTFlash Flood WarningTWC2 hr
Aug 21, 2:49 PM MSTFlash Flood WarningTWC86 min
Aug 21, 5:39 PM MSTFlash Flood WarningTWC85 min
Aug 21, 5:45 PM MSTFlash Flood WarningTWC2 hr
Aug 21, 6:38 PM MSTFlash Flood WarningTWC112 min
Aug 21, 7:51 PM MSTFlash Flood WarningTWC114 min
Sep 2, 5:02 PM MSTFlash Flood WarningTWC118 min
Sep 2, 5:10 PM MSTFlash Flood WarningTWC80 min
Sep 2, 6:59 PM MSTFlash Flood WarningTWC2 hr
Sep 2, 8:40 PM MSTFlash Flood WarningTWC80 min
Sep 3, 4:46 PM MSTFlash Flood WarningTWC119 min
Sep 6, 12:55 PM MSTFlash Flood WarningTWC3 hr
Sep 6, 1:39 PM MSTFlash Flood WarningTWC2 hr
Sep 6, 1:48 PM MSTFlash Flood WarningTWC3 hr
Sep 6, 2:06 PM MSTFlash Flood WarningTWC84 min
Sep 6, 2:30 PM MSTFlash Flood WarningTWC2 hr
Sep 6, 2:48 PM MSTFlash Flood WarningTWC117 min
Sep 6, 2:50 PM MSTFlash Flood WarningTWC3 hr
Sep 6, 3:36 PM MSTFlash Flood WarningTWC114 min
Sep 8, 1:41 PM MSTFlash Flood WarningTWC3 hr
Sep 8, 3:56 PM MSTFlash Flood WarningTWC2 hr
Sep 10, 2:41 PM MSTFlash Flood WarningTWC94 min
Sep 10, 3:54 PM MSTFlash Flood WarningTWC2 hr
Sep 10, 4:13 PM MSTFlash Flood WarningTWC2 hr
Sep 10, 5:03 PM MSTFlash Flood WarningTWC5 hr

The busiest days

Days with the most alerts issued, by UTC date.

Nearby

Alerts in force nowTornadoes on recordForecastThe radar archive20112013

Sources

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.