Wednesday morning update: looks certain we will get major cold in western WA Monday-Wed next week and a real chance for light snow in the lowlands from Seattle south on Monday. And snow over the weekend on the N. Olympic Peninsula...more tonight!
We had quite a blow last night, although for most it wasn't more than the kind of windstorms we get a few times a winter. However, as I will mention to below, there were some subtleties here....for example, as I will explain there really was two distinct wind events going on. Also, later in the season there would have been far less damage and power outages. This was the first storm of the season and there was plenty of decayed and vulnerable branches ready to to...and the leaves still on many trees makes it worse! And there were plenty of careful construction folks who did not prepare for strong winds or forgot to finish their work (like a portion of the new departmental bicycle shelter that blew away!)
200,000 lost power last night and there were some impressive wind reports:
North Bend, WA--sustained 36 gusts to 60 mph
Port Townsend-50 mph
Sea Tac-49 mph
Eastern Strait (buoy 46088): 56 mph
Wenatchee 63 mph
Mission Ridge 105 mph
Stevens Pass 117 mph
Whidbey Is NAS 61 mph
As I describe in my book, one of the most entertaining aspects of this and other windstorms is the firework show that occurs when the winds start blowing. Lightning? Nope. The multicolor displays are caused by transformer fuses or cutouts (see picture) When a circuit get grounded by a branch or some other object, these fuses can blow--cutting off the circuit with a bright flash. Then the associated neighborhood goes dark.
Want to watch a video of the fun? Check this out:
Now the winds of yesterday were really concentrated in several areas:
1. A surge of strong westerly winds in the Strait as the low center moved by and the winds aloft aligned with the Strait. I call this a westerly Strait surge and they can get much stronger than Monday's event. One took out Ivar's Mukilteo Landing Restaurant in 2003.
2. Strong southerly and southwesterly winds in the southern to central Sound. This had associated with two things...the strong low passing to the north and strong lee troughing off the Olympics (more on this in another blog)
3. Very strong NW wind aloft associated with the passing low and its associated upper trough. This provided the strong winds at mountain stations.
4. Strong downslope winds hitting the lower portions of the eastern slopes.
Our high resolution models did get most of this right. To prove to doubters--here is the wind forecast (sustained winds) for 10 PM on Monday made more than 36 hr before (multiply by 1.5 to get gusts).
What about snow?
First, there will be heavy snow in the mountains. Feet of it. Be prepared if you are driving over it...you may need chains.
Over the lowlands, the big threat over the weekend will be NW Washington and the northern parts of the Olympic Peninsula. The latest runs will bring cool, air from the BC interior through the Fraser and other gaps in the Cascades...starting later on Friday. Vancouver, Blaine, the San Juans,Vancouver Is., and northern Olympics could get some snow very late Friday into the weekend. Serves those smug folks in the Sequim rainshadow right!...this time they will be on the windward side as strong NE wind head right towards them.
You are now reading the articleWindstorm Factoids with the link address http://www.outsiderla.me/2010/11/windstorm-factoids.html