Bruce’s Weather Brief for May 27-29 and Swiftsure Classic!

What a week it has been in the Straits of Juan de Fuca. Tuesday saw a steady 40 at Race Rocks and Smith Island had a gust to 59. Yikes. That is not fun sailing, that is survival or better yet, just stay at the dock and don’t put yourself or your vessel in harms way. How things can change. Yesterday, for the delivery up to Victoria, it was for the most part a mill pond across the Straits with even a light, warm easterly in places.

As usual, the most predictable part of this weekend will be the tidal currents in Race Passage and they won’t be insignificant.

Tidal Current Race Passage

Saturday

0749    Max Ebb         6.7 knots

1151    Slack

1436    Max Flood       6.1 knots

1818    Slack

2146    Max Ebb         4.9 knots

Sunday

0110    Slack

0253    Max Flood       1.8 knots

0433    Slack

0843    Max Ebb         6.6 knots

1237    Slack

1527    Max Flood       5.9 knots

1912    Slack

2042    Max Ebb         5.0 knots

Kudos to the Race Committee for changing the start order because the JdF and Flattery fleets are going to need all the help they can get to make it to the Race before the flood starts. As you can see from the surface charts there is simply no gradient over the Pacific Northwest, nor will there be until later this coming week. We are caught between two relatively weak high pressure systems and with the jet stream (see 500MB charts) well north of us, there’s nothing to move this situation along.

This is also reflected in the fact that the models used for forecasting are not very much in agreement especially after tomorrow afternoon. This is where being your own weather forecaster will be helpful and that’s going to start by logging the pressure readings, wind direction and wind strength over the race course. This mornings readings showed the pressure at Forks at 1015.1 with the pressure at Bellingham at 1015.5 which tells us a couple of things. 1. The wind will be light in the Straits and from the east, never a very stable situation. And 2, sure enough 2 knots from the East at Race Rocks, 2 knots from WNW at Sheringham, and 4 knots from ESE at the JA Buoy at the mouth of the Straits. As the land masses heat up over the course of the day, this will draw a westerly down the Straits with the most wind (15-20 knots) being in the eastern part of the Straits, Race Rocks to Smith Island. This pattern may repeat itself tomorrow. Generally speaking, the first day of this pattern is the best chance of good breeze. Each day in succession, the breeze will fill later and not be as strong.

Most models show light air over the starting area tomorrow morning which will make getting through the Race before the flood starts at 1130-1200hrs a challenge. The flood starts first on the Vancouver Island side so if you get through the Race with the last of the ebb, get to the US side as fast as you can. If the pattern holds, we’ll start in a drainage or downslope ENE which will probably be less than 5 knots. Clearly with all that ebb tide you will not want to swept over the start line early as getting back might be next to impossible.

The other part about getting to the US side of the Straits is that when the westerly does fill, it comes down the US side first, with Canadian side staying light. Two of the models show the westerly filling between 1500-1800 hrs. This will make this a long race.

How long you might ask? If we run the GFS model for Crossfire, certainly one of the fastest boats out there, it shows them completing the Hein Bank course in 42 hours. Don’t kill the messenger……

Around the rest of the Northwest it will simply be a great weekend to be on the water so load the family, the BBQ, and enjoy yourselves.

Ed. Note: Bruce is giving a weather presentation at 16:30 this afternoon. We’re trying to find the location right now, when we do we’ll update this post. UPDATE: The in-person brief at 16:30 is at the Strathcona Hotel!

 

 

 

 

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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)

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