February 12, 2011

Wild Winds

Tree down in Kirkland from Justin Hurst

Today the winds really kicked up prior to and during a strong frontal passage. Over the lowlands there were gusts to 50-60 mph in exposed locations and in the mountains hurricane-force gusts were observed at many locations. As several of you have noted, Camp Muir at 10,000 ft hit 155 mph--and at this point there is no reason to discount that reading. Tens of thousands have lost power.

The models had a pretty good handle on this event, although they underplayed the extreme winds a bit. Here is the forecast surface pressures for 10 AM Saturday. The frontal trough is offshore at this time, but you can see the packing of the isobars (lines of constant pressure) and associated strong winds right in front of it.

You can get a great view of what was happening today from the Sand Point Seattle profiler , which shows the winds aloft in time. The plot has time increasing to the left and is in GMT (1303 is 7 PM Saturday) and heights are in meters. You can see the big winds descending from aloft to the surface during the early afternoon. A solid triangle is 50 kts! Long lines are 10 knots and small lines are 5 knots. Two long lines and a short one indicates 25 kts, etc.

Anyway, today is a good example what a strong front can do. It has through now and winds are rapidly relaxing. Tomorrow will be mostly dry.

And in Montana the winds hit 114 mph and the anemometer blew away.

0624 PM NON-TSTM WND GST 1 NE CHOTEAU 47.82N 112.17W


You know things are getting exciting when the anemometer blows away. Something I teach my students in the UW weather forecasting class.

And winds were very, very strong yesterday afternoon on the Oregon coast. Check out this video:


Now I don't want to get anyone excited, but the models are suggesting that later this week and next weekend we could get much colder with a chance of lowland snow.
Snow in the mountains is a certainty with this pattern.

So an alert to transportation crews in the area. Prepare you deicer fluid and get some rest. You may need it!


  1. Fascinating as always. Do you think that this week's cold snap will be a Fraser Gap/arctic outflow type event? They can be wicked here in the San Juans... thanks.

  2. Part of the weather excitement is this great little story, but for the sailing community here in Seattle, it was a biggie!
    Thanks for all you write, do, and teach us that 'use' the weather information regularly!


    ...And back story:


    And Finally, a bit more carnage:


    Thanks again!

  3. The road crews can do all they need to prepare. It usually doesn't help. As for the prospect of snow. I'll wait until a day or two before the event. I can't handle another epic fail like we had a January only to see it pound the East Coast. Time to do the snow dance!

  4. Saw just a tiny little spelling error. The photographer's last name for the fallen tree in Kirkland is Hurst, not Hirst.

    Great blog! Been reading it regularly, and I always recommend your blog to people who are new to Seattle, and a few FEMA guys.

  5. For once the Weather Service had it fairly close for the San Juan Islands. I'm trying to convince them that there shouldn't be a discrepancy between wind speeds for the islands and for the Northern Inland Waters. Typically they'll cut wind speeds by half in their island forecast. This is nonsensical and leads to very erroneous forecasts. Hopefully, I'm getting through to them.

  6. But the day temps for next weekend and forward are forecast 'warm' (nights are cold) so the snow won't stay around, or will it?

  7. It is pretty neat that the GFS has indicated this pattern change since as early as mid to late January! It kept delaying it, but it was very consistent on indicating it!

  8. I was pretty disappointed with King5's forecast Saturday morning for Saturday... let alone prior ones for the same target. I check NWS pretty frequently and didn't get the warning I expected from them either. Seemed like all were saying Bellingham (north WA) was going to gust to 50 mph while seattle only 25-35 mph.

    I've been doing lots of work outside, and at least by the morning of an event, it seems the "almost-nowcast" should be communicated clearly so people have at least a couple of hours to batten down.

    Looking at your surface map from ~0400 (Local) it's hard for me to see the model had it right either (10 knots in Seattle was way off). Maybe not enough info without a loop or series of maps showing the front transiting the region.

    Love your blog but I'm a bit down on our local forecasts of late b/c it seems like the tube is saying "washout" for the weekend then we have dry weather for both days (and rain pretty much just at night). Definitely drives your point about the need for more frequent updates and tailored interpretation. Also makes me think one should spend a lot less time paying attention to the talking heads, more time with their ear to the ground on your site/NWS (and their discussion)/looking at models), and just put the tube-ing out energy into making sure resources are protected. End of the day though we need experts to share insight into the forecast details and uncertainty and that's why I love your blog... even if it's usually looking back. Many thanks!

    Let it snow!

  9. Lowland snow I can take or leave. It's the snow in the mountains that has me excited. We skied on 6 inches of new at Crystal on Sunday and there was nothing but sun! Nowhere in the forecast was the word sun ever mentioned. What a treat! And there's nothing but snow in the forecast up there.


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