More king tides coming to Puget Sound, but flooding unlikely

With more king tides expected to start up Tuesday, communities across the Puget Sound region are preparing for the possibility of flooding.

The tides will not be near as large as they were in the last round of flooding at the end of December, according to Dustin Guy, National Weather Service meteorologist, and there is currently no Coastal Flood Advisory in effect.

“They aren’t going to be anything like we saw back in December. In order to get things like coastal flooding, often you have to have not only astronomically high tides but also very low atmospheric pressure,” Guy said. “Other extenuating circumstances like high wind can actually make it worse. But overall, what we’re looking at today is not going to be on the same level of that.”

Nearly 50 buildings in Seattle’s South Park neighborhood were damaged from Duwamish overflows last month. Homes and businesses in other flood-risk areas, such as Olympia, Edmonds, and parts of Skagit County, also had damage.

The city of Seattle has dozens of responders ready to help if flooding does happen, though, and has placed about 90,000 sandbags and large concrete barriers throughout the South Park area. Several pumping stations have also been installed in order to pump water back into the river if flooding occurs.

In the long-term, the city is making $100 million in improvements to drainage and roads that should help prevent flood damage in the future.

NOAA: Next set of king tides not expected to cause major flooding

Several factors are involved in creating these king tides. First, the Earth’s annual rotation around the sun is not a perfect circle – it is more elliptical. During the northern hemisphere’s winter season, the earth is closer to the sun than in the summer, meaning the sun has a greater gravitational pull.

Second, king tides occur when Earth aligns itself with the moon rotating around our planet and the sun. Since the Earth is seasonally closer to the sun, combined with the moon’s greater gravitational pull on the oceans, the highest tides occur this time of the year.

King tides alone can cause minor tidal overflow in low-lying Western Washington coastal areas, including the Puget Sound. But if a storm with lower atmospheric pressure and strong winds coincides with a king tide, the tide will be even higher, and wave action can produce much greater coastal flood damage.

“We also encourage all communities to revisit their emergency preparedness plans. For some, flooding is a known hazard. Flooding preparedness includes tracking the tides and weather, waterproofing and elevating valuables, and having a “go bag” at the ready in case evacuation becomes necessary,” Seattle Public Utilities advised.

The highest predicted king tide of the season for Seattle will be 13.1 feet on Jan. 24 at 7:21 a.m.

You can remain informed of potential Puget Sound area coastal flooding by monitoring the National Weather Service, which issues coastal flooding emergency messaging.