Alert archive / Washington / Snohomish County

Weather alerts in Snohomish County, Washington, 2022

51 weather alerts in 2022, from the National Weather Service and the Storm Prediction Center. An alert counts here when it covered this county.

Snohomish County and its neighbors

Each county as a circle sized by its count in 2022. Tap one for its archive.

Alerts
51
Warnings
31
Watches
10
Advisories
3
Busiest month
January11 alerts
Busiest day
March 1, 20226 alerts

Over time

By month

Warning verification

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

Snohomish County, 2022

WarningsWith a reportFalse alarm ratioReportsInside a warningMean lead time
Tornado warnings00
Severe thunderstorm warnings00
Flash flood warnings20100%0

Each office's whole area, 2022

WarningsWith a reportFalse alarm ratioReportsInside a warningMean lead time
NWS Seattle, WA: severe thunderstorm warnings010%
NWS Seattle, WA: flash flood warnings30100%40%

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
Jan 2, 8:25 PM PSTAreal Flood AdvisorySEW3 hr
Jan 2, 11:53 PM PSTAreal Flood AdvisorySEW6 hr
Jan 4, 2:00 PM PSTFlood WatchSEW4 days
Jan 6, 3:25 PM PSTAreal Flood AdvisorySEW23 hr
Jan 7, 12:46 AM PSTRiver Flood WarningSEW29 hr
Jan 7, 12:50 AM PSTRiver Flood WarningSEW5 hr
Jan 10, 4:37 AM PSTFlood WatchSEW62 hr
Jan 12, 2:03 AM PSTRiver Flood WarningSEW28 hr
Jan 12, 6:34 AM PSTRiver Flood WarningSEW22 hr
Jan 12, 7:43 AM PSTRiver Flood WarningSEW22 hr
Jan 12, 7:48 AM PSTRiver Flood WarningSEW38 hr
Feb 27, 12:41 PM PSTFlood WatchSEW70 hr
Feb 28, 9:04 AM PSTAreal Flood WarningSEW22 hr
Feb 28, 4:13 PM PSTRiver Flood WarningSEW30 hr
Feb 28, 5:49 PM PSTRiver Flood WarningSEW28 hr
Feb 28, 9:08 PM PSTRiver Flood WarningSEW51 hr
Feb 28, 9:08 PM PSTRiver Flood WarningSEW51 hr
Feb 28, 10:55 PM PSTRiver Flood WarningSEW16 hr
Feb 28, 10:55 PM PSTRiver Flood WarningSEW8 hr
Apr 12, 3:09 PM PDTSpecial Weather StatementSEW36 min
May 21, 6:59 PM PDTSpecial Weather StatementSEW31 min
May 21, 7:16 PM PDTSpecial Weather StatementSEW29 min
May 21, 7:32 PM PDTSpecial Weather StatementSEW28 min
May 21, 8:09 PM PDTSpecial Weather StatementSEW36 min
May 26, 6:52 PM PDTSpecial Weather StatementSEW23 min
Aug 9, 2:17 PM PDTRed Flag WarningSEW36 hr
Aug 16, 3:01 PM PDTRed Flag WarningSEW46 hr
Sep 2, 8:35 AM PDTRed Flag WarningSEW14 hr
Sep 4, 2:28 PM PDTFire Weather WatchSEW24 hr
Sep 5, 2:23 PM PDTRed Flag WarningSEW33 hr
Sep 6, 3:50 PM PDTFire Weather WatchSEW23 hr
Sep 7, 2:40 PM PDTRed Flag WarningSEW4 days
Sep 20, 11:25 AM PDTRed Flag WarningSEW9 hr
Sep 25, 3:40 AM PDTFire Weather WatchSEW11 hr
Sep 25, 2:31 PM PDTRed Flag WarningSEW28 hr
Oct 13, 2:39 PM PDTFire Weather WatchSEW21 hr
Oct 14, 11:47 AM PDTRed Flag WarningSEW53 hr
Oct 25, 3:20 AM PDTFlash Flood Warning Considerable damage threatSEW115 min
Nov 1, 3:23 PM PDTFlood WatchSEW4 days
Nov 4, 10:27 AM PDTRiver Flood WarningSEW24 hr
Nov 4, 10:27 AM PDTRiver Flood WarningSEW25 hr
Nov 4, 1:43 PM PDTRiver Flood WarningSEW15 hr
Nov 4, 11:32 PM PDTRiver Flood WarningSEW17 hr
Nov 5, 12:39 AM PDTRiver Flood WarningSEW18 hr
Nov 5, 3:20 AM PDTRiver Flood WarningSEW75 min
Nov 22, 3:36 PM PSTFlash Flood Warning Considerable damage threatSEW2 hr
Dec 20, 5:34 AM PSTMesoscale DiscussionSPC4 hr
Dec 23, 3:25 PM PSTFlood WatchSEW37 hr
Dec 24, 7:05 PM PSTRiver Flood WarningSEW17 hr
Dec 26, 10:33 AM PSTFlood WatchSEW38 hr
Dec 26, 12:04 PM PSTRiver Flood WarningSEW19 hr

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 archive20212023

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.