6 PM. Storm becoming more threatening to Seattle northward. Update at 8:15 PM
As a new service of this blog, I will indicate the areas where powerlines might be damaged by the approaching storm. You can't say you don't get cutting-edge products on this site. 😊
Perhaps the forecasts might help local utilities pre-position necessary assets.
The latest European Center sea-level pressure forecast is for a very respectable 977 hPa low with a ring of strong winds wrapping around it (shown at 4 AM Saturday, winds in knots).
No, this is not some doomsday machine and, no, it is not a BOMB CYCLONE. I will not hype this storm like some amateur sites and certain local media.
Now the serious part....where will the power outages be, if any?
My general experience is that power outages during December and January generally get started when gusts surge above 40 mph (35 knots). Definitely, some losses when gusts exceed 50 mph (43 knots), and expect lots of blackouts when winds surge above 60 mph (52 knots).
Of course, there are subtleties. Outages early in the fall require less wind to damage trees and, thus, the powerlines. Unusual directions (like the easterlies of Nov. 19) do more damage.
But with all that said, let's examine the prediction winds of the best local model around (the UW super-high resolution WRF model). I will show you some new graphics that we have developed, showing the strongest wind prediction over a period.
For the period through 4 AM Saturday, there is potential trouble on the Washington coast and northwest Washington (see below). I particularly worry about Sequim to Port Townsend to central Whidbey Island). The San Juans and Bellingham could see some flickering lights. Some modest potential for the western foothills of the Cascades but NOTHING LIKE Nov. 9.
Extending the period through early Sunday morning, we see an enhanced risk over NW Washington and along the coast. Potentially strong downslope winds on the NE slopes of the Olympics....but few people live there.
Here in Seattle, it will get blustery, but I don't expect a lot of wind damage.
A good source to check is the City of Seattle WindWatch website (a project of my group), which shows the strongest winds over the city from a variety of forecast sources (below). A max gust in the low 30s mph looks like a good bet. Those of you in Seattle who bought generators during black Friday/Monday will probably not get a chance to use them.
The strongest winds over the northwest interior of western Washington will probably be on Saturday morning around 10 AM. Below are the forecast gusts at that time.
If you are in purple or blue, charge your batteries. Red....you might have some issues.
Enjoy.
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I will hold a special online zoom session at 10 AM on Saturday for Patreon supporters. I will discuss the storm and answer your questions....assuming my power does not go out!
Does the frequency of strong winds affect the likelihood power outages?
ReplyDelete(i.e. areas exposed to more frequent strong winds might be less likely to experience power outages during run of the mill events due to removal of weaker trees and branches)
Related question.. how about the power system hardware? Do the wires, poles, and braces weaken faster when installed in frequently windy areas just from being stressed so often?
DeleteThe main issue is branches/trees falling on the powerlines...not direct wind damage...cliff
DeleteFriend... generally the first wind events of the season do the most damage...so damage does not go up linearly with wind frequency...cliff
DeleteTech feedback: I suggest dropping the new gust map colors to 50-66% saturation. The brighter colors make it hard to see the land forms.
ReplyDeleteCliff, I really like your blog, you touch on many subjects. For power outages related to high winds, there are many factors that come into play including amount of leaves on trees, ground saturation (from rain), wind direction, tree maintenance, tree type, severity of previous storms (some storms wipe out many snags), and other factors.
ReplyDeleteThe idea of having crews strategically placed sounds nice, but it is impractical due to the factors stated above. Another factor is cost, if you have a large number of crews standing by, you are paying double overtime and the costs can easily get out of control. Also, the crews may have to wait even if they are aware of an outage because the roads may need to be cleared, and it may be too dangerous to be in the areas where the wind is blowing (falling trees).
That being said, I do like the idea of predicting outage locations. If you could compare your wind location prediction with actual outage data from a utility, some interesting data could come out of it.
Yup, folks don't understand that keeping their power on is a nice goal.. but only up to a point. Beyond that point, the power company is going to take the hit and customers are going to be without power. It simply costs too much to do otherwise. Nothing new here - been that way for 100 years and will always be that way.
DeleteHardly. Snohomish County PUD staged crews on Camano Island for our last couple of windstorms. They were out and had power back very rapidly. The bomb cyclone was a little more difficult due to the high volume and lots of assets being moved East. But staging the crews has shown a benefit and has been very successful. It isn't hard to deploy assets, especially when utility companies keep track of outage statistics. You are going to lose power during a big windstorm, but keeping records has allowed the utilities to restore service quickly. Maybe your utility doesn't do it, were fortunate to have a utility that actually cares and is proactive.
DeleteTake it easy keyboard warrior PrepperMike. Probably makes sense to stage a crew on an island if you know ferry service may be interrupted or have limited schedule. A utility like SnoPUD has a lot more resources than many smaller utilities. Utilities already focus on reliability as a core function, but prudence with money is also very important.
DeleteWhen somebody keeps telling me that it will not be as bad as Nov.19 I get a creepy feeling that it will be worse. I live on Camano Island and the Nov.19 forecast quoted 24 mph winds (on Weather Underground). This one is forecasted at 28 mph, so I keep thinking... Especially because dynamic pressure and wind energy is proportional to the square of the speed it might be 30% worse.
ReplyDeleteActually, I had a question about the forecast. These windstorms usually start as a relatively small bumps on the wind speed chart a week or so ahead, but as they come closer they grow, kinda like waves approaching the shore :-) I never seen an opposite situation when high wind is forecasted a way ahead and then gets downgraded. So it looks like the forecasting model is biased towards the lighter winds somehow. Is it true?