Alert archive / Washington / Snohomish County
Weather alerts in Snohomish County, Washington, 2013
16 weather alerts in 2013, 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 2013. Tap one for its archive.
- Alerts
- 16
- Warnings
- 3
- Watches
- 7
- Advisories
- 2
- Busiest month
- August5 alerts
- Busiest day
- January 7, 20131 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, 2013
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| Tornado warnings | 0 | 0 | ||||
| Severe thunderstorm warnings | 0 | 1 | 0% | |||
| Flash flood warnings | 0 | 0 |
Each office's whole area, 2013
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| NWS Portland, OR: tornado warnings | 0 | 5 | 0% | |||
| NWS Portland, OR: severe thunderstorm warnings | 12 | 4 | 67% | 12 | 67% | 13 min |
| NWS Pendleton, OR: tornado warnings | 1 | 0 | 100% | 0 | ||
| NWS Pendleton, OR: severe thunderstorm warnings | 45 | 34 | 24% | 126 | 79% | 25 min |
| NWS Pendleton, OR: flash flood warnings | 12 | 4 | 67% | 13 | 54% | 44 min |
| NWS Seattle, WA: tornado warnings | 0 | 1 | 0% | |||
| NWS Seattle, WA: severe thunderstorm warnings | 2 | 0 | 100% | 4 | 0% | |
| NWS Spokane, WA: severe thunderstorm warnings | 41 | 24 | 41% | 103 | 71% | 30 min |
| NWS Spokane, WA: flash flood warnings | 24 | 9 | 63% | 34 | 68% | 36 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.
| Issued | Product | Office | Lasted |
|---|---|---|---|
| Jan 7, 12:58 PM PST | Flood Watch | SEW | 46 hr |
| Jan 9, 7:33 AM PST | River Flood Warning | SEW | 8 hr |
| Jan 28, 1:42 PM PST | Mesoscale Discussion | SPC | 6 hr |
| Mar 11, 3:53 PM PDT | Flood Watch | SEW | 44 hr |
| May 13, 1:35 PM PDT | Mesoscale Discussion | SPC | 115 min |
| Jul 31, 8:22 AM PDT | Red Flag Warning | SEW | 15 hr |
| Aug 8, 2:58 PM PDT | Fire Weather Watch | SEW | 18 hr |
| Aug 9, 8:34 AM PDT | Red Flag Warning | SEW | 48 hr |
| Aug 10, 5:08 PM PDT | Mesoscale Discussion | SPC | 97 min |
| Aug 29, 4:21 PM PDT | Mesoscale Discussion | SPC | 84 min |
| Aug 29, 5:32 PM PDT | Areal Flood Advisory | SEW | 3 hr |
| Sep 4, 2:27 PM PDT | Flood Watch | SEW | 46 hr |
| Sep 6, 1:33 AM PDT | Areal Flood Advisory | SEW | 8 hr |
| Sep 27, 2:56 PM PDT | Flood Watch | SEW | 4 days |
| Nov 19, 8:27 AM PST | Flood Watch | SEW | 7 hr |
| Nov 29, 1:49 PM PST | Flood Watch | SEW | 62 hr |
By product
Every kind of product issued here, grouped by hazard. Each opens the same place narrowed to that product.
| Product | Alerts |
|---|---|
| Severe storms | |
| Mesoscale Discussion | 4 |
| Flooding | |
| River Flood Warning | 1 |
| Flood Watch | 6 |
| Areal Flood Advisory | 2 |
| Fire | |
| Red Flag Warning | 2 |
| Fire Weather Watch | 1 |
The busiest days
Days with the most alerts issued, by UTC date.
Nearby
Alerts in force nowTornadoes on recordForecastThe radar archive20122014
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.