January 22, 2012

Southeast Olympic Snowstorm

It is snowing right now at fairly low elevations to the southeast of the Olympics--something that happens a few times every winter.    For example, here is an image from Dale Ireland's home above Hood Canal

At the same time it is raining and in the upper 30s and lower 40s in much of the rest of the area.  How can this be?  The National Weather Service has been spotlighting this possibility for a while and the local high resolution models were going for this snow for days (see forecast from yesterday below-24h snowfall ending 4 PM) for forecast initialized 4 PM yesterday.

The key to this is southeasterly flow and the cooling influence of melting.  A strong low is approaching the coast (see graphic) and that has forced strong southeasterly flow over

western Washington.  To prove this, here are the profiler winds above Seattle for the past day (see graphic).  Strong SE flow through depth (latest observations on the left).

 When strong flow approaches the Olympics it is forced to rise, producing enhanced precipitation rates.  To see this, here is the latest Camano Island radar image (it can't see southern side of the Olympics well, but you get the idea).  You can see the impact of the Olympics, with heavier precip on the eastern side of the barrier.

Our precipitation aloft in winter is nearly always in the form of snow, as the snow falls into an initially warmer layer below (a layer above freezing) melting occurs.  Melting causes cooling.  That allows the snow level to move downward and potentially to the surface.

So southeasterly flow causes upslope on the mountains, which causes a heavier precipitation rate, which causes more melting and cooling, which results in the snow level coming down to the surface.   This effect can also happen in other areas of enhanced precipitation, such as the Puget Sound convergence zone.

You pull the tail of a tiger and it is going to snap at you!  On Tuesday, my blog noted that a ST writer was making fun of forecasters for changing their predictions in time. And on Wednesday, I complained about the big headline of MEGASTORM in the ST that day, when the latest forecasts were only for 3-6 inches over Seattle. 

Well, the ST began with reporter Nick Provenza in an article "Forecasts Change, Right?  Professor Mass"  in which he pointed at my earlier speculation that a heavy snow was possible (my forecast subsequently changed with new model output).  Sort of like suggesting that I was the meteorological version of Newt Gingrich, calling for moral purity while he was playing around with multiple women.  But I only gave one forecast at a time!  Monographical prediction.

And today they brought out the heavy artillery:  ST humorist Ron Judd, who suggested an "about-face forecasting retreat on Tuesday."   As if holding to a failing forecast is the route to victory! 

Now a bit of good-natured ribbing is fine, but this correspondence shows that many, including some ST folks, don't appreciate the essential nature of forecasting, and particularly that forecasts change in time, and generally improve as you get closer.  My profession needs to find a way to communicate the evolving forecast without losing the confidence of the media and the public.  Polls change in time and people don't seem to get upset and make fun of pollsters.  We need the same for meteorologists!

By the way, there is a pretty good story today in the ST on the ice-storm forecast by reporters who took the time to understand the problem.

Finally, a fun parody of the local snowstorm coverage is now available:



  1. you're dealing with J-school grads in a dying media. Please, Cliff, you should delight in this.
    Just remember: people don't remember good/bad, they just remember your name. So, the Seattle Times is promoting you better than if you took out a full page ad.
    Good work! Now piss them off some more.

  2. What the Seattle Times response actually demonstrates is that their journalistic standards are very, very low.

    I vowed to never spend another quarter on the Times in the late 1980s, and am proud to have held to that vow.

  3. Part of the problem lies in that there are several sources that are "compeating" to provide the forecasts, and they provide differening updates at different times. There is a bit of information overload.... the NWs may be cited in some places, you are cited elsewhere, my cell phone provides updates froma different sources, KOMO provides....

    Some stick to forecasts for a longer period before updating, others do not. Then the NEWS people grab whatever one seems convenient and may hype it ad naseum.

    That is where the real problem lies, in my opinion. There are too many sources of weather REPORTS (the news related to forecasts, not the FORECASTS themselves). That leads to confusion and some disconnect along with the already chaning weather itself.

  4. All they need to do is follow some of tbe models themselves. Then they would see that they change, not only day to day, but sometimes within hours. I appreciate your forcast updates as these weather events get closer, cliff. Thank you!

  5. And then there's this:


    Big difference between science and "The News."

  6. You and the NWS guys were pretty much spot-in this week, Cliff. Some minor problems with the ice, I suppose, but that is hard to call. The carping in the media and by ST commenters reveals nothing but know-nothingness.

  7. I dont care what the Seattle Times says and the newspaper information always seems woefully out of date by the time it hits the presses.
    I trust you Dr. Mass and will turn to your site for information I trust, even if it is ultimately disappointing (like when you back off high snow totals). Also, I like the forecast discussion on the NWS site for current situation status even if I dont understand most of what they say. I imagine that many of these guys are former students of yours :) Anyway, you have made meteorology fun and exciting even when its only rain in the forecast!

  8. I don't think that the Seattle Times are technically considered news media.

  9. "meteorological version of Newt Gingrich" lol! Best line for the day!

  10. I appreciate your work Cliff. Please continue to make your forecasts and update them as the situation unfolds. I would not like it if you left a forcast unchanged under changing circumstances.

    Port Townsend

  11. I wouldn't worry too much about the lashings of cranky snide remarks from underpaid workers at a second-rate paper that mostly just reprints wire service stores as they fade into irrelevance.

  12. I think it's a bit silly for Proffessor Mass to be mocking the Times headline when he himself claimed that the storm was probably going to be huge. Yes the paper has to sell, but I'm not seeing that big of a difference in what the paper printed the morning of the 17th vs what was in the blog the night of the 16th. Mass has the benefit of only being on the web instead of having to print something on physical paper. The forecast changed. The Times is probably thinkin that they are damned wither way so they will go the exciting route. I don't think the people at the paper would insist he stick to the original forecast, that's dumb. I also think its ironic for Mass to mock the paper's headlines, then say two days later that the missed forcasting of the ice storm was not his professions finest hour. Seems to me like both Mass and the Times want it both ways. Having said that, I love this blog and appreciate the outreach and knowledge sharing by by him.

  13. I think the explanation is simple enough. As Brad Colman said in today's Seattle Times of the NWS "Our mandate from Congress is the protection of life and property." The Seattle Times is there to sell papers/news to sell eyeballs to advertisers and make money. Two dramatically different business models as I see it. And our American culture wants certainty 99% of the time when life is really only certain 1% (or less) of the time. I love learning about NW weather and why it's so darn difficult and interesting in these parts. Thanks for your personal efforts and for teaching others.

  14. Actually we do make fun of pollsters!

  15. I very much enjoy reading your weather discussions here. I hope you find Leah this weekend!

  16. Perhaps what they're looking for is the same thing Steven Colbert liked about George W. Bush at the correspondents dinner. "..the kind of guy who believes the same thing on Wednesday as he believed on Monday. No matter what happens on Tuesday.." It's time to bring some idealism to science! Or it's not.

  17. The ink stained wretches had to drink office coffee that day...they were too snow miserable to hike to Starbucks or Peets... it's understandable that they would look for a target for their rhetorical fire...

  18. Another argument for focusing on the sorry state of science education.

    I found your hyperbole a bit intense (sicking their dogs on me; and the Gingrich comparision). It takes away from your professionalism, IMHO.

  19. I liked Ron Judd's column. I thought it was spot on quite a few points. What are we if we can't laugh at ourselves?

  20. Cliff... You missed the whole point!....Could it be that the ST reporters had a lot of money resting on a wager based on your forecast? How would you like it if the odds kept moving underneath you on a committed wager? ..... :)

  21. Cliff, I am a newcomer to your blog. I'm fascinated with the weather due to the fact that I'm a skier and I always want to know when the temps are dropping and the precip is on the way. I would appreciate it if you could explain the graphics that you post a little bit better. For example, what do the colors indicate? Precip, temp, cloud cover? Also, can you help me read the wind charts that you post. The recent wind chart where you talk about "Southeast flow" has red lines throughout as well as little blue flags. Can you decipher what the graphics mean? In addtion, there are numbers on the axes of your graphs without units. It would be nice to know what those numbers mean. Thanks for your diligent, updated posts.

  22. Weather is weather - can't see what politics has to do with what Dr Mass is doing in his role as a forecaster. Drop the political commentary and stick to the weather. It affects us all.

  23. From my observation of the local media, nobody working for the local paper nor the television news departments has any training in journalism, science, math, social sciences or any other topic save how to yammer and give opinions.

  24. I'm not siding with anyone, but a few comments are correct. The ST took the forecast, NWS, and I bet this blog, on what would occur at a specific time to beat their deadline.

    So how would you feel, trying to be report the closest thing to truth, only to have it change before the ink has dried.

    You can hit a couple backspaces and correct it a day later. This has nothing to do with profit or trying to sell papers.

    Its called humility and accountabilty, on both sides. An over hyped, over predicted storm on Wednesday and a underpredicted storm and late reporting on Thursday.

  25. Oh come on. I've been reading this blog and several newspapers and you all got the timing wrong. Headlines don't contain disclaimers, in the Times or in my RSS reader.

  26. I have a sense that beyond the science of meteorology there is an emotional component to individual interpretation of the data and a financial component to the publishing/broadcasting of the weather.

    The financial aspect is no secret -- big news sells papers and brings viewers back. Fear sells news, unfortunately.

    But beyond that I have the impression that meteorologists, given a range of interpretations will dwell on the more exciting meteorological events. Sounds like human nature to me. When the chance to experience an out-of-the-ordinary meteorological event, with the opportunity to show how cool and complicated the science really is, meteorologists emotionally gravitate toward the most interesting possible outcome.

    Combine that with the financial interests of corporate news, and the formula seems to optimize for prediction of more extreme events than are actually the most probable.

    To the public, the two motives are hard to disambiguate, and can be simply seen as "crying wolf." Good natured ribbing follows.

  27. Hahaha, that Newt Gingrich line was spot on.

  28. Forecasters are in a bubble if they don't realize that nobody wants to depend on a forecast, especially about snow, then to have it change. As far as I'm concerned, every forecast should be accompanied by a percent chance that the forecast can be trusted. "80% chance of snow in downtown seattle Wednesday, 75% chance that forecast is dependable". Because after all, some of the forecasts are rock solid, some aren't, and why should the public be expected to know the difference?

  29. Like the local TV news, the Seattle Times is a joke and has been for several years now. As you know Cliff, no good deeds go unpunished. Hopefully you're able to laugh at all this and continue to provide the excellent info myself and numerous others very much appreciate.

  30. Terrible black ice this morning. Would have been nice if we'd had more of a heads up. (Not directed at this blog, which is a blog and not an up to the minute weather forecast.)

  31. Mr. Mass, honestly until last week I'd never heard of you then I caught you sounding like Nostradamus about the weather and thought there is a man for whom weather is a true passion. I came up from California and was so appreciative of the data that you provided. Probably the clearest most concise description of the impending disaster. I heard it on NPR. I don't think you mentioned ice at the time but the snowfall how and where it landed was dead on. I'll say this. I haven't read the articles that I imagine are disparaging of you but people at the bottom routinely try to shoot down the person on top. Thanks again sincerely.

    Francisco Cruz

  32. Hey Cliff,

    I enjoy your blog, as well, and as an outdoors person, find it very useful.

    To expound on my column quips: Nothing I wrote is intended to deny the difficulty in making pinpoint forecasts in the NW -- or the relative merit of sticing to one once made. In fact, it was an acknowledgment of that very difficult. Nobody I know expects you or anyone else to nail a snow forecast to the inch, 48 hours out. Some of us have lived here long enough to know that's impossible.

    My comments were mocking the fact that you were, albeit with the usual, (appreciated) caveats, doing exactly that: citing specific snow depths and warning of "record" snowfall -- then turning around, once things changed, and decrying as ignorant hype news accounts that, in fact, were pretty faithful reporting of your own original forecast. Do you honestly expect to put out those kinds of red-alert warnings and not have them reported as predictions -- ones that, given your own status as an expert -- bear significant weight?

    A quote from baseballer Pedro Guerrero comes to mind: "You guys always quote what I say and not what I mean."

    BTW, believe it or not, the Times has no daily mandatory meeting to set an agenda, and doesn't expect columnists to conform to one. No one has ever suggested I pursue a particular column subject. For better or worse, I alone make those choices.

    Cheers and sunny skies,
    Ron Judd

  33. Journalists are easy targets just like weather forecasters, and often for reasons just as specious.

    Cliff, you keep saying that forecasts change. Of course they do. *Nobody* that I've read here or elsewhere is saying that you should have held on to an outdated and erroneous forecast. Well, maybe some people did, but those people don't understand science or the nature of predictions.

    The issue here is that the Seattle Times reported on the best information it had available, just as you did - and that forecast agreed with yours. Because they're a print publication and had to lock their copy in early and can't edit it online, their prediction for huge snow looked outdated when it printed. Unlike you, they weren't able to modify their forecast. (except online, where they did modify it)

    What bothers some of us is that you then ridiculed them for their headline and reporting, when *they were reporting exactly what you had reported!* It was unfair and intellectually dishonest. In effect you were guilty of doing something very similar to what you're accusing others of doing, armchair quarterbacking somebody who had to make a decision of what to tell people based on the best information they have. They just don't have the same flexibility to update by-the-minute that you do.

    That is the issue - you were unfair about it. You continue to be unfair about it, and that has *nothing* to do with the fact that forecasts change.

    And some of your behavior just makes it worse:
    - going back and editing caveats into your older posts without making a note that they had been edited, which is frowned upon in web etiquette and makes it looks like you're trying to cover your tracks
    - removing your initial swipe at the Times, not because you realized it was unfair or wrong, but because you "guessed it was a distraction," as if it's our fault that we identified it as unfair and called you on it
    - and now tagging this additional swipe at the Times at the bottom of an unrelated post

    You are a great weather forecaster and personality, and we all read this blog because we love you. But this is amateur and bush-league, and unworthy of who you are and what you do.

  34. Cliff,
    Can you comment on the "?localized" icy roads we had this morning south of Seattle. For example, West Marginal and 509 south were like skating rinks. Car temps showed 37-38º F without Fog.

  35. Bright, BRIGHT, sun in Lacey right now...if I didn't know better, it looks like a summer day. Oddities of nature abound.........

  36. One thing I was disappointed with all around was the lack of any warning of a potential for massive power outages...I should have deduced that on my own accord, but not once did I hear a warning that widespread power outages were likely. It would have given folks the chance to prepare and hunker down. This is not the job of a weather forcaster, per se, but some media source should have sounded the warning alarm. NE Thurston County...near Nisqually Reach...no power since Thursday 11am. Not harping or anything...it just would have been helpful from -some-source (including my own brain...LOL) Thanks Prof. Maas

  37. Cliff,
    Could you give us your explanation for the extensive icing this morning? Temps in my car were 37º, no fog, yet points south (West Marginal, 509, which they closed) were like a skating rink.

  38. I'm a little worried about Dale. If he doesn't clear that snow off his railing he is likely to spill his cocktail.

  39. Ron and Stackhouse,
    You guys are not understanding me! On Tuesday night, the NWS forecast (and mine) was for a very modest snow event over Seattle (3-5 inches). Annual event. The ST then put up the megastorm headline. This was quite irresponsible of the paper. The fact that a few days before I mentioned the possibility of a big event is absolutely irrelevant. My forecast had been changed due to the shift of the model solutions over the past several days.


  40. Not the way I remember it, Cliff, and if it's true that your earlier posts have been edited without being so indicated, it's sort of a moot point to discuss the precise timing of it now.

    By the way, sorry for a couple typos in my post. It should have read "difficulty" and "sticking."


  41. Cliff,
    It seems that meteorologists (especially those on tv) need to scale back such specific forecasts so far in advance especially when it's based almost solely on imperfect numerical models. For example, 5,10 ore even 15-day forecasts predicting highs and lows to the nearest degree and precipitation to the nearest hundredth of an inch? No way anyone is that good! Their experience in the weather field should tell them that there is a large uncertainty with models so far out trying to predict such a complicated storm.

    Perhaps the best forecast that could have been made several days out was that a big snow storm is likely but the location is uncertain. Or we will get snow, but the amounts have a high uncertainty ranging from 2-20 inches. Btw...I remember you blogging that it all depended on where the low would come in and that +/- 50 miles would make a big difference. They should tell people that that's the best that can be done until the storm gets closer. A good example is with hurricane forecasts when the cone of the storm's probable path and intensity is shown.

    It is more beneficial to the public to know the uncertainty in the forecast as what may be a conservative forecast to one person may be unconservative to another. If the uncertainty is low, Great!. If not, let it be known. This is the approach that engineers who are held personally responsible for their forecasts take. It is the engineers job to estimate a systems response and to inform their clients of how accurate they think they are. Then the client can make an informed decision going forward. Meteorologists should treat the public the same way.

    By the way...can you explain the difference between the temperature and bias corrected temperature plots? As I followed the storm it seemed that the bias corrected temp indicated the cold might stick around a little longer.

  42. Ron,
    This does not have to do with your or others memory...or my blog. The NWS forecasts on Tuesday night are public record and are on the web. They were NOT going for a big storm when the ST created that headline. The NWS forecast is what the ST should be communicating and the paper instead chose to hype the storm...cliff


Please make sure your comments are civil. Name calling and personal attacks are not appropriate.

New Podcast: Memorial Day Weekend Forecast and More on Western Washington Wildfires

This weekend will be a mixed bag west of the Cascade Crest but warm over eastern Washington.  The predicted high temperatures for the next f...