'Tis the season ... for king tides around Puget Sound

‘Tis the season for king tides: The highest tides of the year. Extreme high tides are headed to Puget Sound Saturday, Sunday, and Monday morning of the last week of December.

King tides last January washed up nearly two feet higher than expected, breaking records and flooding some coastal buildings and roads.

University of Washington climate researcher Guillaume Mauger said this month’s king tides are unlikely to be so extreme.

“The king tides for next week are over a foot and a half higher than a typical high tide in Seattle,” Mauger said. “Most of our protections on the coast are designed for a 100-year event, and this wouldn't get close to that.”

“There could be some flooding Friday and Saturday, especially on south facing shores in Puget Sound and North Sound,” Washington Sea Grant oceanographer Ian Miller said by email. “The marine forecast suggests strong winds from the south.”

Tides are influenced by wind and weather, as well as gravitational pulls from the moon and sun.

Last January’s record-breaking tides got a boost from exceptionally low air pressure that allowed Puget Sound to bulge upwards. The National Weather Service expects the atmospheric river system in the Washington forecast will have low pressure, but not exceptionally low. The agency is not forecasting major flooding from these king tides, but heavy precipitation could bring flooding along streams and rivers.

King County officials say flooding is the most frequent natural disaster in the county.

On Puget Sound, king tides come in about nine inches higher than they did a century ago to, thanks to global warming.

Scientists say these tides offer a glimpse of normal conditions in future decades as the planet keeps heating up.

King tides naturally go together with extra-low tides as water sloshes around our rotating planet.

But if you’re thinking about going Christmas tidepooling, bring your headlamp. This time of year, the lowest tides come in the dead of night.