Alert archive / Arizona / Maricopa County

Weather alerts in Maricopa County, Arizona, 2009

103 weather alerts in 2009, from the National Weather Service and the Storm Prediction Center. An alert counts here when it covered this county.

Maricopa County and its neighbors

Each county as a circle sized by its count in 2009. Tap one for its archive.

Alerts: 103
Warnings: 48
Watches: 7
Advisories: 36
Busiest month: July47 alerts
Busiest day: July 20, 200911 alerts

Over time

By month

Warning verification

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

Maricopa County, 2009

	Warnings	With a report	False alarm ratio	Reports	Inside a warning	Mean lead time
Tornado warnings	0			0
Severe thunderstorm warnings	31	8	74%	28	54%	14 min
Flash flood warnings	6	1	83%	2	50%	9 min

Each office's whole area, 2009

	Warnings	With a report	False alarm ratio	Reports	Inside a warning	Mean lead time
NWS Phoenix, AZ: severe thunderstorm warnings	54	12	78%	37	57%	17 min
NWS Phoenix, AZ: flash flood warnings	16	3	81%	6	67%	28 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.

Issued	Product	Office	Lasted
Feb 9, 11:47 AM MST	Severe Thunderstorm Warning	PSR	28 min
Feb 9, 7:36 PM MST	Areal Flood Advisory	PSR	9 hr
Mar 21, 5:51 AM MST	Fire Weather Watch	PSR	21 hr
Mar 22, 2:28 AM MST	Red Flag Warning	PSR	17 hr
Mar 25, 3:04 AM MST	Fire Weather Watch	PSR	11 hr
Mar 25, 2:00 PM MST	Red Flag Warning	PSR	33 hr
Mar 28, 3:26 PM MST	Red Flag Warning	PSR	29 hr
Mar 29, 2:23 PM MST	Red Flag Warning	PSR	25 hr
Apr 2, 4:10 AM MST	Fire Weather Watch	PSR	11 hr
Apr 2, 2:55 PM MST	Red Flag Warning	PSR	31 hr
Apr 10, 2:51 PM MST	Red Flag Warning	PSR	4 hr
Apr 13, 3:49 PM MST	Fire Weather Watch	PSR	13 hr
Apr 14, 5:10 AM MST	Red Flag Warning	PSR	15 hr
Apr 24, 5:43 AM MST	Fire Weather Watch	PSR	8 hr
Apr 24, 1:51 PM MST	Red Flag Warning	PSR	15 hr
May 17, 7:13 PM MST	Severe Thunderstorm Warning	PSR	38 min
May 18, 9:50 PM MST	Severe Thunderstorm Warning	PSR	44 min
Jun 5, 7:53 PM MST	Red Flag Warning	PSR	24 hr
Jun 29, 4:41 PM MST	Mesoscale Discussion	SPC	2 hr
Jun 30, 5:10 PM MST	Mesoscale Discussion	SPC	65 min
Jul 2, 3:20 PM MST	Areal Flood Advisory	PSR	3 hr
Jul 3, 6:44 PM MST	Severe Thunderstorm Warning	PSR	61 min
Jul 3, 7:05 PM MST	Areal Flood Advisory	PSR	115 min
Jul 3, 7:38 PM MST	Severe Thunderstorm Warning	PSR	52 min
Jul 3, 7:44 PM MST	Areal Flood Advisory	PSR	2 hr
Jul 3, 8:07 PM MST	Areal Flood Advisory	PSR	113 min
Jul 3, 9:59 PM MST	Areal Flood Advisory	PSR	106 min
Jul 3, 10:35 PM MST	Flash Flood Warning	PSR	115 min
Jul 3, 11:41 PM MST	Areal Flood Advisory	PSR	3 hr
Jul 15, 10:07 PM MST	Severe Thunderstorm Warning	PSR	30 min
Jul 16, 6:04 PM MST	Severe Thunderstorm Warning	PSR	26 min
Jul 17, 4:06 PM MST	Severe Thunderstorm Warning	PSR	39 min
Jul 17, 5:12 PM MST	Severe Thunderstorm Warning	PSR	48 min
Jul 17, 7:08 PM MST	Severe Thunderstorm Warning	PSR	31 min
Jul 19, 6:06 PM MST	Severe Thunderstorm Warning	PSR	54 min
Jul 19, 7:09 PM MST	Severe Thunderstorm Warning	PSR	66 min
Jul 19, 7:39 PM MST	Areal Flood Advisory	PSR	111 min
Jul 19, 8:04 PM MST	Severe Thunderstorm Warning	PSR	56 min
Jul 19, 8:48 PM MST	Areal Flood Advisory	PSR	117 min
Jul 19, 10:03 PM MST	Severe Thunderstorm Warning	PSR	57 min
Jul 19, 10:49 PM MST	Areal Flood Advisory	PSR	116 min
Jul 19, 11:25 PM MST	Severe Thunderstorm Warning	PSR	65 min
Jul 20, 12:31 AM MST	Areal Flood Advisory	PSR	119 min
Jul 20, 2:10 AM MST	Areal Flood Advisory	PSR	3 hr
Jul 20, 4:48 PM MST	Severe Thunderstorm Warning	PSR	42 min
Jul 20, 5:31 PM MST	Severe Thunderstorm Warning	PSR	44 min
Jul 20, 6:16 PM MST	Severe Thunderstorm Warning	PSR	44 min
Jul 20, 6:17 PM MST	Special Weather Statement	PSR	43 min
Jul 20, 6:29 PM MST	Severe Thunderstorm Warning	PSR	31 min
Jul 20, 6:57 PM MST	Severe Thunderstorm Warning	PSR	20 min
Jul 21, 3:31 AM MST	Areal Flood Advisory	PSR	85 min
Jul 21, 4:31 AM MST	Special Weather Statement	PSR	89 min
Jul 21, 5:42 AM MST	Special Weather Statement	PSR	93 min
Jul 21, 7:52 AM MST	Areal Flood Advisory	PSR	113 min
Jul 21, 8:19 PM MST	Severe Thunderstorm Warning	PSR	41 min
Jul 21, 9:48 PM MST	Areal Flood Advisory	PSR	117 min
Jul 21, 10:18 PM MST	Severe Thunderstorm Warning	PSR	42 min
Jul 21, 10:20 PM MST	Severe Thunderstorm Warning	PSR	40 min
Jul 25, 11:54 AM MST	Areal Flood Advisory	PSR	111 min
Jul 25, 3:21 PM MST	Flash Flood Warning	PSR	114 min
Jul 25, 6:34 PM MST	Areal Flood Advisory	PSR	116 min
Jul 25, 6:46 PM MST	Areal Flood Advisory	PSR	119 min
Jul 25, 7:00 PM MST	Areal Flood Advisory	PSR	2 hr
Jul 25, 7:15 PM MST	Flash Flood Warning	PSR	2 hr
Jul 25, 8:00 PM MST	Areal Flood Advisory	PSR	105 min
Jul 25, 8:33 PM MST	Special Weather Statement	PSR	57 min
Aug 12, 11:07 PM MST	Areal Flood Advisory	PSR	113 min
Aug 12, 11:21 PM MST	Special Weather Statement	PSR	39 min
Aug 13, 5:18 AM MST	Areal Flood Advisory	PSR	3 hr
Aug 21, 3:10 PM MST	Mesoscale Discussion	SPC	65 min
Aug 21, 6:53 PM MST	Severe Thunderstorm Warning	PSR	52 min
Aug 21, 7:28 PM MST	Mesoscale Discussion	SPC	92 min
Aug 21, 7:47 PM MST	Special Weather Statement	PSR	58 min
Aug 21, 7:59 PM MST	Severe Thunderstorm Warning	PSR	61 min
Aug 21, 8:34 PM MST	Areal Flood Advisory	PSR	116 min
Aug 21, 8:41 PM MST	Severe Thunderstorm Warning	PSR	49 min
Aug 22, 4:07 PM MST	Flash Flood Warning	PSR	113 min
Aug 22, 6:07 PM MST	Flash Flood Warning	PSR	113 min
Sep 3, 3:57 PM MST	Areal Flood Advisory	PSR	108 min
Sep 3, 7:00 PM MST	Areal Flood Advisory	PSR	105 min
Sep 3, 8:28 PM MST	Areal Flood Advisory	PSR	2 hr
Sep 3, 9:11 PM MST	Areal Flood Advisory	PSR	109 min
Sep 4, 3:24 PM MST	Severe Thunderstorm Warning	PSR	24 min
Sep 4, 6:31 PM MST	Areal Flood Advisory	PSR	104 min
Sep 4, 6:41 PM MST	Severe Thunderstorm Warning	PSR	34 min
Sep 5, 7:04 AM MST	Areal Flood Advisory	PSR	116 min
Sep 5, 9:13 AM MST	Areal Flood Advisory	PSR	2 hr
Sep 5, 11:22 AM MST	Areal Flood Advisory	PSR	113 min
Sep 8, 8:54 PM MST	Areal Flood Advisory	PSR	111 min
Sep 8, 10:19 PM MST	Areal Flood Advisory	PSR	116 min
Sep 8, 10:29 PM MST	Flash Flood Warning	PSR	2 hr
Sep 10, 4:34 PM MST	Areal Flood Advisory	PSR	84 min
Sep 19, 3:29 PM MST	Areal Flood Advisory	PSR	106 min
Oct 26, 12:50 AM MST	Fire Weather Watch	PSR	13 hr
Oct 26, 2:15 PM MST	Red Flag Warning	PSR	30 hr
Oct 27, 2:36 AM MST	Fire Weather Watch	PSR	11 hr
Oct 27, 1:51 PM MST	Red Flag Warning	PSR	27 hr
Dec 7, 4:33 PM MST	Areal Flood Advisory	PSR	4 hr
Dec 7, 10:41 PM MST	Special Weather Statement	PSR	64 min
Dec 7, 10:48 PM MST	Mesoscale Discussion	SPC	117 min
Dec 7, 11:06 PM MST	Severe Thunderstorm Warning	PSR	39 min
Dec 7, 11:41 PM MST	Severe Thunderstorm Warning	PSR	64 min
Dec 7, 11:45 PM MST	Severe Thunderstorm Warning	PSR	30 min

By product

Every kind of product issued here, grouped by hazard. Each opens the same place narrowed to that product.

Product	Alerts
Severe storms
Severe Thunderstorm Warning	31
Mesoscale Discussion	5
Special Weather Statement	7
Flooding
Flash Flood Warning	6
Areal Flood Advisory	36
Fire
Red Flag Warning	11
Fire Weather Watch	7

The busiest days

Days with the most alerts issued, by UTC date.

Nearby

Alerts in force now Tornadoes on record Forecast The radar archive 2008 2010

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.