Today’s satellite photo is, as always, very interesting since there are some interesting features on display especially when you combine it with today’s surface analysis chart.
Probably the first feature that captures your eye on that chart is that large low-pressure system (985MB) off the coast of California with it’s attached frontal system. Then if you look at the sat pic you can see some very impressive cloud tops off the northern coast of California and southern coast of Oregon. This marks the front as well as an area of vertical instability which even has lightning in it, a bit strange for this time of year.
Dec. 6 500MB 
Dec. 6 Surface Analysis 
Dec. 8 500 MB 
Dec. 8 Surface Forecast 
Dec. 9 Surface Forecast 
Dec 10 500 MB 
Dec. 10 Surface Forecast
As this front comes onshore and that low moves slowly towards the coast it will weaken to a 997MB system dragging yet another wet cold front ashore in Cal. This system will move across the US this coming week and when it meets up with some VERY cold area coming out of the Arctic in the Midwest there will be more significant snowfall and we’ll all be glad we live in the Pacific NW enjoying mild temps and relatively dry conditions. While today may be beautiful just look at today’s Doppler Radar from the Langley station, it’s definitely wet out there and it’s coming our way.
For the Winter Vashon race you would think with all this activity there should be the possibility of a good old-fashioned, gear busting, sailmaker benefit race. Probably not going to happen this year as we are just out of the reach of all this activity. True, for the coast, the Strait of JdF, and the San Juan Islands, it will be breezy tonight with weak low pressure over the area for tomorrow but that will be about it for the weekend. There will be rain and some snow in the mountains but probably not enough to make up for our current almost seven-inch rainfall deficit.
The really bad news is that since the system will be moving on Saturday there will be a bit of a post-frontal southwesterly over the south Sound which will be enough to get you started however as the system moves east what breeze you have will begin to evaporate. This will lead to light and variable conditions by about mid-day with some large, very glassy areas on the racecourse. Luckily, the TYC Race Committee has an excellent record of knowing when to shorten the course at the top mark, making all the Seattle boats pretty happy about only having a short distance to power in the rain to get back to the dock.
The other charts of interest today are the 500MB charts which show a strong zonal flow over the mid-Pacific, 100+ knots. Earlier this week southeast of Sakhalin Island and the Kamchatka Peninsula this zonal flow was measured at 240-knots! Now if you were flying from the Far East to the Pacific NW that would be a great tailwind.
Have a great weekend, stay dry and have plenty of warm beverages aboard to ward off hypothermia!
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)