1. What Destroyed Ivar’s Mukilteo Landing Restaurant?

2. October 28, 2003 Ivar’s Mukilteo Landing Restaurant was destroyed by large waves

3. The“rogue wave” theory

4. But what was the REAL cause? Rogue wave? Intense thunderstorm with lightning? Surge of winds down the Strait? Tsunami? Powerful Pacific Storm? Ferry wake?

5. The Answer: A surge of westerly winds down the Strait of Juan De Fuca

6. Or as some of us like to call it: A STRAIT WIND SURGE

7. Early Visitors to the Region Learned Quickly About the Dangers of the Strait

8. Strait Dangers During the winter, with higher pressure inland and a low center approaching the coast, air can accelerate to the west producing easterly powerful winds, reaching 60-80 mph near Tatoosh Island.

9. Basic idea: Air accelerates from high to low pressure in a gap between two mountain barriers

10. Some people called it “the graveyard of the Pacific”

11. During the days of sail, 1830 - 1925, 137 major shipping tragedies occurred in the immediate vicinity of the entrance to the Straits of Juan de Fuca

12. Think of the Strait As Being A Big Muzzle

13. But sometimes, under the right conditions, the muzzle can be turned around, now being aimed at the eastern Strait of Juan de Fuca and the adjacent coast Under these conditions, Whidbey Island, Everett, and Mukilteo can be hit by fierce winds of hurricane force.

15. Ground zero of such Strait Surges is Everett Harbor --the location of the newest Navy carrier base on the West Coast!

16. It has happened many times in the past

17. December 17, 1990: The Elwha Surge Washington State Ferry Elwha

18. The Elwha Surge Winds were particularly severe in Everett Harbor, where some ship anemometers measured 70-80 mph winds. The Washington State ferry Elwha was thrown against the pier by increasing wave action, destroying a wooden barrier and snapping off pilings. Subsequently, the ferry beat against a concrete pier until the vessel’s car deck crumbled.

19. December 17, 1990 Seattle Times and The Snohomish County Daily Herald

20. The event was so noteworthy (141,000 lost power!) that the local utility district even published a newspaper about it.

21. On October 28, 2003 another major Strait Surge occurred We call it “The Ivar’s Storm”

22. To get a good Westerly Strait Surge you need three ingredients A strong upper level trough of low pressure with intense northwesterly winds aligned down the Strait aloft. We had that. A strong front with a big pressure rise behind it. We had that. Pressure falls between the Olympics and Vancouver Island as the air sinks down those barriers. We had that.

23. October 28, 2003 4 PM

24. Sea Level Pressure, 4 PM October 28, 2003

25. Winds Gusted to 50-70 mph in and near the Strait for 6-9 hours

26. Computer models correctly forecast the winds. UW MM5 24-h forecast

27. The strong winds, even with a limited fetch, where able to produce the wave action that destroyed the restaurant

28. Today, newly installed weather sensors allow restaurant patrons to see when active weather is affecting the location and can head to this restaurant to experience it.

29. The End