Not that fall is a bad thing but cooler weather is on the way just not with the usual moisture. The reason for the heat this weekend is a thermal trough that will be developing along the coast and higher pressure inland which will cause an offshore flow. This will bring a strong easterly flow through the gaps in the Cascades and as this flow develops, the downslope flow will create compressional heating. By late Sunday it will all be gone as the trough becomes a weak (1000MB) low-pressure system off of the central Oregon Coast.
Today’s sat pic is spectacular as the new, high-resolution picture allows us to zoom in to our area and clearly show the Cedar Creek fire in central Oregon and the offshore flow driving the smoke out over the Pacific. It also shows the smoke from Eastern Washington blowing over the central Sound. Air quality is already deteriorating on the East side of Lake Washington. Then if you compare the sat pic with the surface forecast and the 500MB chart you will see that there is nothing to move this low-pressure system very far or very fast. As a result, we will have a strong southerly breeze along the coast that will travel inland to the Sound on Sunday. This will persist until Monday when this low will start to weaken and drift away from the coast.
For the inland waters, we can expect 15-20 knot northerlies in the Central Sound south to Pt. Defiance. As southerlies develop along the coast, the northerlies will ease over Central and South Sound before becoming southerly early Sunday morning. For Admiralty Inlet and the East end of the Strait of JdF conditions will remain light for the weekend.
Sunday will see the start of a downward trend in temperatures as we head towards next weekend. Rain chance will increase into the low 20% range by next Friday. So really, plenty of nice weather to continue boating into our Indian Summer.
Enjoy the weekend!
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)