This weekend will mark the official start of fall weather in the Pacific Northwest as we will have a series of frontal systems make their way through the area. The 500mb charts show a strong zonal flow (100+-knots) that will allow these systems unobstructed access to the Salish Sea. What will be interesting is the timing of the arrival of these systems as it looks like while there will be plenty of breeze to the north (small craft advisories and gale warnings in the Straits) and south of the race area, it looks like the post-frontal flow down the Straits and around the bottom of the Olympics through the Chehalis Gap will have to meet somewhere and that may be near Shilshole, at least on Saturday. The good news is that Sunday looks like a great day to be out on the water as the breeze should be southerly all day at 10-15 knots.
Today’s surface analysis shows these fronts that are attached to a series of relatively weak low-pressure systems, 1008mb and 1002mb off of the west coast. To the north, the lows are stronger at 989mb and 984mb. As the daylight hours get shorter, these stronger lows will eventually make their way further south. At least we aren’t having to deal with what Louisiana will be experiencing tonight with their fourth named storm of the season (Delta) coming ashore between the mouth of the Mississippi and Beaumont, Texas. They still haven’t recovered from Laura.
October 9 500 mb 
October 9 Surface Analysis 
October 10 Surface Forecast 
October 11 500 mb 
October 11 Surface Forecast 
October 12 Surface Forecast 
October 13 500 mb 
October 13 Surface Forecast
Current conditions in the area indicate the front is on its way, with barometric pressure dropping around the area and 30 knots of SE at Destruction Island, see the Windspeed/Baro Chart. Notice the nice correlation between dropping pressure and increasing windspeed. The Langley Hill Doppler also shows the approaching front just starting to come ashore at Neah Bay. The other interesting feature in this picture is the activity off of Westport. When you put the loop in motion it doesn’t move and it’s not raining. It is an indication of the sea state just offshore as a result of the strong ebb from the Chehalis River meeting the ocean waves coming onshore.
Today’s satellite pic also shows the front approaching but even scarier is the smoke still coming north from the fires in Northern California. You can bet those folks are hoping for these fronts to start coming in to help control these huge fires.
By tomorrow we’ll be dealing with a strong onshore flow as mentioned above with the next cold front lurking offshore. Sunday that front will have passed with more onshore flow and yet another fast-moving system lurking offshore.
We will still have tidal currents just not very strong and more likely to be influenced by wind-generated surface currents from the prevailing southerlies. The floods won’t be as strong and ebbs will start earlier and last longer than the forecasts. You should also go out the south entrance of Shilshole to gauge the amount of outflow from the Ship Canal and just how far it carries.
Tidal Currents at West Point
Saturday
0818 Max Flood .93 knots
1212 Slack
1348 Max Ebb .28 knots
1742 Slack
Sunday
0906 Max Flood .87 knots
1300 Slack
1436 Max Ebb .32 knots
1848 Slack
Have a great weekend, be safe, and stay well.
Bruce has raced and cruised the Pacific Northwest his entire life. He earned a Bachelor’s of Science from the University of Washington in Biological Oceanography and learned meteorology “to keep from getting kicked around on the race course.” Bruce spent nearly two decades as Associate Publisher for Northwest Yachting Magazine, retiring in mid-2015, and was the chairman of the board of trustees for the Northwest Marine Trade Association in 2014. (photo of Bruce driving Playstation is a bit dated, but cool)