January 18, 2011

Huge Intense Storm in the Pacific

Sometimes you have to stand back and be amazed by what goes on in the Pacific. Take a look at the Pacific surface analysis for earlier today:

See the HUGE low pressure system over the eastern Pacific with a central (lowest) pressure of 933 millibars. That is simply amazing. And a 1038 mb high is just to the north, and an incredible pressure difference between them.

This pressure is the equivalent of a category 4 hurricane, as shown in the Saffir-Simpson hurricane scale shown below:

A huge, deep, slow moving storm like this produces very large waves, since waves depend on wind speed, fetch (length of area where winds are influencing the sea surface), and wind duration--all very large in this case.

Here is a prediction of wave height for tomorrow at 10 AM our time based on the National Weather Service WaveWatch3 model:

We are talking about 40 ft waves! Hawaii is going to get hit hard tomorrow--some of the expert surfers on the north side of Oahu are probably licking their chops tonight! In fact, the NWS has put out a high surface warning already for waves reaching 30-40 feet.An interesting aside--because of improvements of weather prediction we have less surface observations in such storms than we used to. When weather predictions were bad commercial and fishing vessels would find themselves in the middle of such behemoths. If they survived they provided some interesting data. Today's vessels generally avoid these storms--not good for weather prediction but that is ok--today we have other assets, many based on satellites.

In contrast we will be having lamb-like weather here with sunny skies, light winds, and temperatures in the 40s tomorrow. With all the rain and warm temperatures the snowpack in the central Cascades is now below normal...not the usual story for La Nina year...and nothing interesting is expected for days.


  1. I flew through this storm last night coming back from Maui. I am a United pilot, and we crossed a huge line of weather that was along the edge of the trough. Lot's of turbulence, lightning, and a 180 degree wind shift in less than 50 miles.

  2. I haven't seen the Coast Guard in Alaska publicize shipping seeking shelter in the Aleutians before.


    Glad I'm safe ashore.

  3. I find a nice sunny day in January can be very interesting!

  4. I just visited the pacific storm surf site, discussing this same low. I've always wondered what was meant by the wind gaining "traction" on the sea surface. Forecasters there use this term to predict if gales will produce significant swell for surfers. What factors in the atmosphere are needed for this to happen on the sea surface?

    I attended your discussion in Bellingham and a mention that the jet stream doesn't travel in a linear fashion was stated. Does the wind travel similar to a set of waves, with a crest and a trough? I wanted to ask this question when you visited, but didn't get called on. I really enjoy visiting your blog, and learning more with each visit.

  5. I was a bit disappointing to see no wave height forecast for our beaches. Searching for that, I stumbled upon a really neat animated world wide wave height forecast. It shows the expected effects of this storm and where they move.

  6. The GFS really had that storm lined up nicely for what seemed like a good 7 days previous. It was interesting to see it in the models again and again and then finally bloom into being.
    I'm glad you find it interesting, Michael. As a skier, I'm not in agreement. This La Nina winter has been producing some amazing weather all around the world, but the PNW is not getting much of it. Week after week of Nor'easters for NY, New England, mammoth snow at Mammoth Mtn, ridiculous rains in Australia.. La Nina, you are bumming me out!

  7. Will we see any effects from this storm in Seattle?

  8. I was curious what surf forecasters mean when they say, the wind is gaining "traction" on the sea surface. What has to happen in the atmosphere when a gale is present for this to happen.

    I recall from your talk in Bellingham recently, that the jet stream doesn't travel in a linear fashion. Does the jet stream act in a similar fashion as a set of waves with troughs and crests?

    I enjoy visiting your blog frequently.

  9. Cliff, what is your opinion on how this deep mid Pacific low will affect our local weather in the next week or two? I would think that it will cause the pesky west coast high to amplifly.With some offshore flow and good mixing, a string of relatively weak 57-58 degree record maximums next week at Sea-Tac could be in jeopardy of falling.

  10. I noticed it a couple days ago and actually couldn't believe seeing a 936MB center. I've been following it on the satelite the last couple of days. Anyone think this could change the pattern before the models pick up on it?

  11. HI Cliff,

    Excellent article by Robert Reich tonight that plugs right into your thoughts about math education standards here and why it is failing. See


  12. Peter, I don't take the weather personally (well maybe a few times a year). However when I was a professional sled dog racer in Alaska I very much did! It's all relative. Good luck with the skiing but I called the rain on snow event here in this blog in November and it won't be the last so you might want to check out cheap airfares. Cheers!

  13. I was wondering if you might do a post on why the La Nina forecast (over-hyped by the media this fall) has basically not panned out and we are having a fairly mild winter - does this have to do with the very negative NAO patterns? Just a random thing?

  14. Cliff, I know that regular-old rain is really boring, but I'm surprised that you say "nothing" is going to happen when Probcast is calling for Bellevue to have rain Thursday night... yeah, so? Well, there's a 10% chance of having more than 1.23" overnight (after a 10% chance of having more than 0.93" during the day). That doesn't seem like nothing to me.

    P.S. The sun was great... I've gotten in several great 4 mph walks... so much more fun than walking in front of the TV with a Wii game! :-)

  15. Jumping off of Ben's comment, I've been wondering if that "big snowstorm" that the models began suggesting for western WA about two weeks ago, but which failed to materialize, was our last best chance for significant snow this winter. Since being aware of the La Nina thing, I've noticed that it does not always translate (much to this snow lover's disappointment) to very much lowland snow west of the Cascades.

    But I am buoyed a little by the latest NWS Feb and Feb/March/April Outlooks, just released today, which can be found at http://www.cpc.ncep.noaa.gov/ -- though I'm not sure I'd really want much colder and wetter conditions so much in March, and definitely not April, as I suspect that would mostly be represented as cold rain in the lowlands.


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