This is going to be interesting. The weather this winter has been strange enough especially “back East,” and we have certainly benefited from relatively benign conditions out here. Certainly the dominant weather pattern has been the strange oscillations of the polar vortex which continues plaster the Midwest with way cold temperatures and more snow.
The 24 Hour forecast chart from the NWS shows an absolutely awesome area of high pressure centered over eastern BC and Alberta with a reading of 1052 millibars (nowhere close to the record of 1083mb set in Siberia). With its clockwise rotation it is sending very cold air into the Midwest with some spilling back through the Rockies, the gaps in the Cascades, and down the Fraser River Valley into our area. Offshore of the mouth of the Columbia River we have a relatively weak low pressure system of 995 mb and as we know, wind flows from areas of higher pressure to areas of lower pressure.
The other feature to be cognizant of is the shapes of these system. When pressure systems are irregularly shaped they can be pushed around much easier by the jet stream or frontal systems. The rounder pressure systems are the more stable they are. As you can see from the chart both of these systems are projected to move putting more distance between the centers which will cause an easing in the pressure gradient and a drop in the wind speed.
This is where things will become interesting. As we watched the models converge and diverge over the course of the week it really hasn’t become any clearer what sort of conditions we’ll have during the race. This will become even more interesting for the Race Committee as our normal topographically forced wind will not likely be in play for Saturday. For the last two mornings we’ve had a pronounced easterly breeze which has been lighter on the east side of Sound and slowly builds as it reaches the west side of the Sound. As the day progresses and the land masses begin to warm, the breeze backs around to the NNW. As the sun drops into the western sky the breeze clocks back around to the east northeast as the very cold drainage easterly begins to come back down through the passes and the Fraser River Valley.
So which way will the Race Committee send us in an easterly? The sprit boats and those with code zeros should love this race. Both the UW MM5 and the PredictWind high resolution models show some type of easterly with Shilshole being roughly centered between the wind coming down from Fraser River Valley and the wind coming up through Enumclaw. So it could be east northeasterly or east southeasterly. Wind strengths will probably be in the 10-12 knot range at the start and then dropping to the 5-10 knot range as the day progresses with slightly more wind on the west side of the Sound and more wind south of Shilshole as the day goes on.
Tides and Tactics
I like the reverse start however it really means to have to watch for clear lanes in which to sail and in a reaching race that could be tough. The first start will be roughly at the end of the ebb with slack at 1110. As a result of the rain earlier this week there has been a fair amount of freshwater coming out from the Ship Canal and the Duwamish River. This could prolong the ebb at West Point by some 10-15 minutes. As the flood develops remember this is not the big flood of the day so what advantage there is to current will be very small and it will pay to watch the tide lines for short gains. The end of the flood will occur after about 1630 hours.
Tactics are going to be tough as this will probably be pretty much straight line sailing so you will need to make extensive use of barber haulers moving the headsail lead outboard to the rail and slightly forward and then have your best trimmer working his or her tail off.
As always, keep your head out of the boat and pick out the usually well-sailed boats that have started ahead of you and keep track of their gains and losses.
Before you leave the house in the morning be sure to check the Washington State Ferry weather reports from Elliott Bay and Edmonds-Kingston. Then check the plot from West Point on the NBDC site.
Good luck and we’ll see you out there.