Alert archive / Oregon / Multnomah County / Severe Thunderstorm Warnings

Severe Thunderstorm Warnings in Multnomah County, Oregon, 2023

2 severe thunderstorm warnings in 2023. An alert counts here when it covered this county. The archive of severe thunderstorm warnings reaches back to 1986.

Multnomah County and its neighbors

Each county as a circle sized by its count in 2023. Tap one for its archive.

Severe Thunderstorm Warnings
2
Busiest month
June1 severe thunderstorm warnings
Busiest day
June 18, 20231 severe thunderstorm warnings

Over time

By month

Warning verification

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

0 of 2 severe thunderstorm warnings covering Multnomah County in 2023 had a qualifying storm report inside them.

Multnomah County, 2023

WarningsWith a reportFalse alarm ratioReportsInside a warningMean lead time
Severe thunderstorm warnings20100%0

Each office's whole area, 2023

WarningsWith a reportFalse alarm ratioReportsInside a warningMean lead time
NWS Portland, OR: severe thunderstorm warnings8188%250%20 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
Jun 18, 4:39 PM PDTSevere Thunderstorm WarningPQR21 min
Oct 16, 4:07 PM PDTSevere Thunderstorm WarningPQR11 min

The busiest days

Days with the most alerts issued, by UTC date.

Nearby

Alerts in force nowTornadoes on recordForecastThe radar archive20222024

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.