Alert archive / Washington / Thurston County

Weather alerts in Thurston County, Washington, 2021

16 weather alerts in 2021, from the National Weather Service and the Storm Prediction Center. An alert counts here when it covered this county.

Thurston County and its neighbors

Each county as a circle sized by its count in 2021. Tap one for its archive.

Alerts
16
Warnings
8
Watches
5
Advisories
3
Busiest month
January9 alerts
Busiest day
January 3, 20214 alerts

Over time

By month

Warning verification

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

Thurston County, 2021

WarningsWith a reportFalse alarm ratioReportsInside a warningMean lead time
Tornado warnings00
Severe thunderstorm warnings10100%0
Flash flood warnings00

Each office's whole area, 2021

WarningsWith a reportFalse alarm ratioReportsInside a warningMean lead time
NWS Seattle, WA: tornado warnings50100%0
NWS Seattle, WA: severe thunderstorm warnings5260%540%21 min
NWS Seattle, WA: flash flood warnings040%

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 1, 11:58 AM PSTFlood WatchSEW50 hr
Jan 2, 8:48 PM PSTAreal Flood WarningSEW56 min
Jan 2, 11:41 PM PSTAreal Flood AdvisorySEW2 hr
Jan 3, 4:31 AM PSTRiver Flood WarningSEW35 hr
Jan 3, 6:16 AM PSTRiver Flood WarningSEW4 days
Jan 10, 2:52 PM PSTFlood WatchSEW4 days
Jan 12, 8:02 AM PSTAreal Flood AdvisorySEW7 hr
Jan 12, 1:59 PM PSTRiver Flood WarningSEW3 days
Jan 12, 4:32 PM PSTRiver Flood WarningSEW43 hr
Feb 22, 8:57 AM PSTFlood WatchSEW17 hr
Feb 23, 1:37 AM PSTRiver Flood WarningSEW20 hr
Feb 23, 8:17 AM PSTFlood WatchSEW44 hr
Oct 28, 5:53 PM PDTAreal Flood AdvisorySEW15 hr
Nov 9, 2:27 PM PSTSevere Thunderstorm WarningSEW33 min
Nov 10, 12:56 PM PSTFlood WatchSEW6 days
Nov 12, 11:56 AM PSTRiver Flood WarningSEW40 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 archive20202022

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.