Today’s surface analysis chart and sat pic’s don’t show what’s headed our way Sunday and into Monday. We’ve had a week of what should be considered normal weather for this time of the year. What is interesting is that we’ve already had two episodes of bombogenesis, which occurs when a low-pressure system intensifies by dropping 24MB in 24 hours. Plus, we have another one developing and it doesn’t show until the 48hr surface forecast chart when we will have 944MB just off the coast. To get a feel for just how strong this system is, note the 48hr 500MB chart which clearly shows the intrusion of this system into the upper atmosphere. This is the strongest system we’ve had this year and probably an indication of what’s to come.
October 22 Surface Analysis 
October 23 Surface Forecast 
October 24 500 MB 
October 24 Surface Forecast 
October 25 Surface Forecast 
October 26 500 MB 
October 26 Surface Forecast
How much it will affect you will, as always, depend on where you are. The coast will take the brunt of this system because as it approaches the coast it will veer to the north, weaken and head into SE Alaska, which has already this year had some wild weather. Almost all waters will see 20-25 knots at some time. Saturday will have a post-frontal westerly in the Strait of JdF with a persistent SE breeze in the eastern Strait and the San Juan Islands. The breeze will ease about mid-afternoon Saturday as the big system approaches the coast. By dawn Sunday, the pre-frontal SE breeze will be about 15-20 over the interior water with stronger breeze along the coast. Noon Sunday will have 30-35 knots in the Central Straits, 15-25 in the Central Sound and Admiralty Inlet. This will hold until early Sunday evening with possibly higher gusts.
October 22 Satellite Pic 
October 22 NorPac Satellite Pic
By Monday this storm will be weakening note the 25 Oct surface forecast chart, pressure has risen from 944MB to 960MB and will continue to do so. It is also interesting to note that the 500Mb chart shows that zonal flow has returned to the North Pacific and it is flying which will continue to bring more weather systems to the West Coast, consistent with the La Niña pattern we discussed two weeks ago. In other words, wetter and cooler than normal weather.
If you’re heading out on the water this weekend be sure to monitor conditions closely as it could change very quickly. Be safe out there.
Ed. Note. – Bombogenesis? Really, Bruce? Sounds like a good name for a boat. Oh yeah, and good luck to all those in SYC’s Grand Prix regatta. -KH
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)