‘Tis the season – King Tide season that is. The winter months are when the North Sound gets its highest astronomical high tides of the year called King Tides.
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, earth is actually closer to the sun than during our summer, meaning the sun has a greater gravitational pull. Second, King Tides occur when earth aligns itself between the moon rotating around our planet and the sun. With earth seasonally closer to the sun combined with the moon’s greater gravitational pull on the oceans, the highest tides of the year occur.
King Tides by themselves can cause some minor tidal overflow of low lying Western Washington coastal areas including the North Sound. But if a storm with lower atmospheric pressure and strong winds coincides with a King Tide, then the tide will be even higher and wave action can produce much greater coastal flood damage.
Here are a couple of examples that highlight what stormy King Tides can do. In late October 2003, such a combined King Tide and strong wind event occurred. The most memorable damage happened at Ivar’s Restaurant next door to the former Mukilteo ferry terminal.
Another stormy King Tide event occurred on December 17th in 2012. A number of Puget Sound coastal locations suffered high water and wave action damage, including water and logs into homes – not a desired holiday gift under the tree.
During the next few months, there will be several King Tide periods noted on forecast tide charts. For Everett, greater than 12 foot tides include:
– November 24th through the 29th,
– December 22nd through the 29th,
– and again from January 20th through the 26th.
The highest predicted King Tide of the season for Everett will be 13.1 feet on Christmas Day at 720 AM.
Shoreline property owners can take action now to help avoid damage during stormy King Tides such as reinforcing seawalls and other protective structures. Also remain informed of potential North Sound coastal flooding by monitoring the everettpost.com weather page, the National Weather Service at weather.gov/seattle/, the all-hazard NOAA Weather Radio stations serving the North Sound at 162.55 MHz or 162.425 MHz, and other local media sources.