How Tonga volcano eruption pushed out Seattle fog from nearly 6,000 miles away

The eruption of the Hunga Tonga Hunga Ha’apai volcano had the entire West Coast of the United States under a tsunami warning for most of Saturday. But the volcano’s effect on the Seattle area manifested in a different, more peculiar way.

The volcano’s eruption sent thick plumes of ash and smoke into the skies above the Pacific Ocean. What it also did was send an 820-mile-an-hour shockwave straight toward the United States, which was then detected by the University of Washington’s atmospheric sciences department. It’s estimated that the shockwave covered over 5,700 miles in a matter of hours before arriving in the Seattle area.

For the early hours of Saturday morning, thick fog had socked in much of the city and its surrounding areas. The shockwave from the volcano arrived with such force, though, that the fog was temporarily cleared from the skies above SeaTac. Once it passed, the fog returned.

That shockwave was also prominent enough to show up on a 50-year-old consumer-grade analog barograph owned by KIRO Newsradio’s resident historian, Feliks Banel.

“Fascinating stuff,” the National Weather Service noted.

mynorthwest.com