Expires:202405121200;Remove:202405121200;047276
WWUS86 KSEW 112314
SPSSEW

Special Weather Statement
National Weather Service Seattle WA
414 PM PDT Sat May 11 2024


WAZ001-503-504-506-507-509>517-555-556-558-559-567>569-121200-
San Juan County-Western Whatcom County-Southwest Interior-
Western Skagit County-Everett and Vicinity-Tacoma Area-
Admiralty Inlet Area-Hood Canal Area-Lower Chehalis Valley Area-
Olympics-Eastern Strait of Juan de Fuca-
Western Strait of Juan De Fuca-North Coast-Central Coast-
East Puget Sound Lowlands-Bellevue and Vicinity-
Seattle and Vicinity-Bremerton and Vicinity-
West Slopes North Cascades and Passes-
West Slopes North Central Cascades and Passes-
West Slopes South Central Cascades and Passes-
414 PM PDT Sat May 11 2024

...EXTREME GEOMAGNETIC CONDITIONS OBSERVED AND CONTINUED SEVERE 
GEOMAGNETIC STORMS EXPECTED TO CONTINUE THROUGH THE WEEKEND...

The NOAA Space Weather Prediction Center has observed extreme (G5)
geomagnetic conditions early Saturday morning and expects severe 
(G4) conditions to continue through the weekend.

A geomagnetic storm of this strength can cause multiple and
widespread issues with various power and communications systems. 
Widespread voltage control problems may occur, and some power grid
systems may experience component failures, disruption of service,
and protective device trips. This could result in blackouts.

GPS and other satellite navigation may be degraded for days.

HF/VHF/UHF radio propagation may be impossible in many areas for 
one to two days. 

Low-frequency radio navigation can be out for hours.

Aurora may be visible at much lower latitudes. 

For space weather information...visit www.swpc.noaa.gov
For weather information...visit www.weather.gov

$$

www.weather.gov/seattle