Alert archive / California / Imperial County

Weather alerts in Imperial County, California, 2009

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

Imperial County and its neighbors

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

Alerts
25
Warnings
13
Watches
7
Advisories
4
Busiest month
April6 alerts
Busiest day
September 6, 20093 alerts

Over time

By month

Warning verification

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

Imperial County, 2009

WarningsWith a reportFalse alarm ratioReportsInside a warningMean lead time
Tornado warnings00
Severe thunderstorm warnings3167%0
Flash flood warnings00

Each office's whole area, 2009

WarningsWith a reportFalse alarm ratioReportsInside a warningMean lead time
NWS Phoenix, AZ: severe thunderstorm warnings541278%3757%17 min
NWS Phoenix, AZ: flash flood warnings16381%667%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, Pacific Time. Each opens its own page with the text, the map, the radar and the sounding.

IssuedProductOfficeLasted
Mar 25, 3:04 AM PDTFire Weather WatchPSR11 hr
Mar 25, 2:00 PM PDTRed Flag WarningPSR33 hr
Mar 28, 3:26 PM PDTFire Weather WatchPSR23 hr
Mar 28, 3:26 PM PDTRed Flag WarningPSR29 hr
Mar 29, 2:23 PM PDTRed Flag WarningPSR25 hr
Apr 2, 4:10 AM PDTFire Weather WatchPSR11 hr
Apr 2, 2:55 PM PDTRed Flag WarningPSR31 hr
Apr 13, 3:49 PM PDTFire Weather WatchPSR13 hr
Apr 14, 5:10 AM PDTRed Flag WarningPSR15 hr
Apr 24, 5:43 AM PDTFire Weather WatchPSR8 hr
Apr 24, 1:51 PM PDTRed Flag WarningPSR15 hr
Jul 18, 3:40 PM PDTSevere Thunderstorm WarningPSR80 min
Jul 24, 2:49 PM PDTSevere Thunderstorm WarningPSR41 min
Aug 21, 9:25 PM PDTSpecial Weather StatementPSR65 min
Sep 5, 4:13 PM PDTAreal Flood AdvisoryPSR52 min
Sep 5, 5:46 PM PDTAreal Flood AdvisoryPSR104 min
Sep 5, 6:04 PM PDTSevere Thunderstorm WarningPSR25 min
Sep 5, 7:14 PM PDTAreal Flood AdvisoryPSR106 min
Oct 25, 1:25 PM PDTRed Flag WarningPSR6 hr
Oct 26, 12:50 AM PDTFire Weather WatchPSR13 hr
Oct 26, 2:15 PM PDTRed Flag WarningPSR30 hr
Oct 27, 2:36 AM PDTFire Weather WatchPSR11 hr
Oct 27, 1:51 PM PDTRed Flag WarningPSR27 hr
Nov 15, 5:40 AM PSTRed Flag WarningPSR6 hr
Dec 7, 4:02 PM PSTAreal Flood AdvisoryPSR118 min

By product

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

The busiest days

Days with the most alerts issued, by UTC date.

Nearby

Alerts in force nowTornadoes on recordForecastThe radar archive20082010

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.