Bomb cyclone brewing off coast. What does that mean for Tacoma and Olympia

Bomb cyclone. Explosive cyclogenesis. A beast. Those are some of the terms weather forecasters are using Wednesday to describe the witch’s cauldron of a storm simmering off the Washington coast. Puget Sound should feel its effects Thursday and Friday. If you’re reading this in a small boat, you might need a bigger boat. But what does a bomb cyclone mean for the South Sound. A week-long period of windy wetness, forecasters say.

WHAT IS A BOMB CYCLONE

$2 for 2 months Subscribe for unlimited access to our website, app, eEdition and more CLAIM OFFER A cyclone is kind of a South Pacific version of a hurricane. Energized by tropical waters, this one is supposed to appear out of nowhere on Thursday after it collides with another system already parked in its destination. But forecasters know it’s coming. “As the storm comes together a few hundred miles off the coasts of Washington and British Columbia, its intensification could easily surpass the criteria for bombogenesis,” said AccuWeather meteorologist Alex Sosnowski. “From a weather standpoint, it’s impressive,” National Weather Service meteorologist Jacob DeFlitch said Wednesday morning. The “bomb” aspect of the storm occurs when pressure at the center of the system drops rapidly within a short period of time, DeFlitch said. That’s called explosive cyclogenesis or bombogenesis and will occur Thursday. While unusual for Washington, “It likely is only going to bring breezy winds and heavy rains” to the area. The overall effects in Washington are not unusual for a fall system, DeFlitch said. Indigenous Affairs Weekly roundup of news affecting Native American communities in the Northwest. SIGN UP This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.

HOW LONG WILL IT LAST

The bomb cyclone event will last Thursday through Friday. After Friday, a series of fronts every 24-36 hours will sweep across western Washington with rain and wind at least through Tuesday. “We’re in a very active weather pattern over the next week or so,” DeFlitch said.

HOW WINDY WILL IT GET

In Tacoma, winds could reach gusts of 20 miles per hour Wednesday and the same for Olympia on Thursday. Winds could reach close to 30 miles per hour later Thursday and Friday. The coast will get “breezy” or “windy” weather daily for the next week, according to the Weather Service. The windiest weather will occur Thursday with gusts as high as 36 miles per hour in Long Beach.

WHAT ABOUT RAIN AND SNOW

The heaviest rain will fall from Northern California up through western Oregon, western Washington and Vancouver Island. Rain will only toy with Tacoma and Olympia through Thursday afternoon. Then things get serious. Up to 3/4-inch of rain is possible, the Weather Service said. The rain will taper off and then return in earnest on Saturday with no exit strategy in sight through as least Tuesday. Snow will fall from the Sierra Nevada in California, through the Cascades and along the coastal British Columbia mainland. By next week, AccuWeather said, “several yards of snow could pile up across the high country of the Sierra Nevada, Cascades and the Olympics.

” HOW COLD WILL IT GET

“We’re not seeing cold air pouring down into western Washington,” DeFlitch said. While the cyclone’s aftermath will send out wave after wave of cold fronts for the next week, lows will remain in the mid-40s in Puget Sound. Highs will be in the high-50s. Thursday could see a high of 67 degrees.

WHAT ABOUT THE DROUGHT

AccuWeather meteorologist Alex Sosnowski said the storm has the potential to “be a tremendous shot in the arm” for water-starved California. Western Washington is mostly normal to moderately dry going into the storm, according to the U.S. Drought Monitor. But eastern Washington is still listed as being in extreme and exceptional drought conditions.