Thursday, March 9, 2017

Spring Break Ain't What It Used to Be

Next week is spring break at the University of Utah.  The timing is perfect.  The terrain and climate of Utah lend itself to March adventuring, with the possibility of good skiing in the mountains if it is cold and snowy, or treks to southern Utah if it is sunny and warm.

Over the past couple of decades, however, the dice have become increasingly loaded to favor the latter.  There have been only four Marches since 1989 with a statewide average temperature below the 20th century (1901-2000) mean, and those months were barely below the average.


In fact, the average March temperature for the past 30 years (1987-2016) is 40.2ºF, 3.3ºF warmer than the previous 30 year period (1957-1986).  Given that the mean temperature from March 1st to April 1st increases about 8ºF, that's about the equivalent of moving Spring Break almost 2 weeks later into the year.  Basically, the weather of a mid-March Spring Break today is more like a late-March spring Break for your older professors when they were in college.  Basically, the odds of good powder skiing for spring break are declining and the odds of spring conditions are increasing.

Next week's Spring Break looks to be consistent with recent trends.  The GFS forecast below is valid for 6 PM MDT Monday and shows a high-amplitude ridge and associated warm weather parked firmly over the western U.S.  It certainly looks like Spring Break will get off to a warm start.


The latter part of spring break is far enough out that we'll have to see what happens, but my money is on the week ending up well above average for temperature and below average for precipitation.

If this continues, snow-loving students should lobby the University to move Spring Break to the last week of February or first week of March.  Those who want warmth can go to Ft. Lauderdale or Arizona like other college students!

11 comments:

  1. You did a post awhile (a year or two?) back where you listed data sources for your charts. I'd particularly like the data source for this chart of March average temp since 1900. Could you point me to that post, and the data source for this chart if its not in the post. Did you make this chart in Excel, or is it an auto-chart from one of your data sites.

    Thx

    Pray for Snow, even if it is March

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    1. Ah, I must have missed adding that. Those are from NCEI: https://www.ncdc.noaa.gov/cag/. Adjust the options to what you want. There is an option to download to a comma separated file, which can be imported into various software packages. I did that particular chart in Excel.

      Jim

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  2. Thanks, great data.

    I notice it is from a NOAA server.

    No doubt you've read the Washington Post piece on OMB's first whack at NOAA
    https://www.washingtonpost.com/news/energy-environment/wp/2017/03/03/white-house-proposes-steep-budget-cut-to-leading-climate-science-agency/?utm_term=.53000d4e4ab4

    Skimmed Honest Broker. I've been slightly aware of Wilbur Ross, Sec of Commerce, who oversees NOAA, for a decade or two. Sharp guy, data driven. I do think if a group of professors wrote a letter to Utah's Congressional delegation, or, better yet, met w staff to explain what the cuts would do to weather prediction, that would be acting as an honest broker.

    Hopefully, the the budget Ross negotiate's w OMB won't impede the public's ability to access weather data.

    Weather is probably a better word than climate, in this context.

    We could quibble about whether (pun unavoidable) 120 years of data is a climate signal or weather data, but we should really put our hearts into praying for MORE SNOW

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  3. Do you take requests, Jim?
    My wife and I are SLC natives, and we concur in our recollections that it wasn't so windy here in the valley back in the 80s and 90s as it has been in recent years, say the past decade or so. You're in you're in a unique position to confirm or, uh, disconfirm that suspicion. (https://youtu.be/puMPxcJmsWk?t=2m45s) And no, I don't think it's the carpet pissers did this. Thanks.

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    1. That one will need to be left to others, at least for now, as I lack the time to investigate.

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  4. While I agree that rising temperatures will move the onset of spring conditions earlier, there is zero evidence that March snowfall in Utah is any lower than 40 years ago. Thus the incidence of powder days should be unchanged.

    The interesting part of this post is that the Utah March temperature increase of 3.3F is about twice as larger as the overall world temperature increase over a similar time frame of 0.94C.

    Is "one month in Utah" too small a sample size given weather variability? How many other months show similar temperature increases? Is there a meteorological reason why Utah temperatures would rise more than worldwide temperatures, as we know is the case in the Arctic for example?
    I missed my mid-March timeshare week last year, but came to Utah the last week of March. It was full on winter for a week with two major storms of 18+ inches.

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    1. I agree on the snowfall statement (for upper elevations), but keep in mind that snowfall is the *last* snow measure measure to show clear trends related to global warming (http://wasatchweatherweenies.blogspot.com/2013/08/western-snow-trends-and-global-warming.html) and that it is not the only factor in skiing quality. Even if snowfall is unchanged, a warmer march means increases in snow density, melt-freeze cycles, etc. March can still bring it, but the statistics are changing in a way that spring skiing conditions are becoming more frequent in March.

      Utah has been warming faster than the global average and over the long-term of many decades, this is expected to continue. Details and attribution at http://journals.ametsoc.org/doi/abs/10.1175/2008JCLI2397.1 and more recent papers that cite it.

      Jim

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  5. Jim,

    Can you comment as to how much variability there is in temperature for march? For example In the chart above some months average almost 8 degrees below the average where some months were 8 degrees above. Do all months have this type of variability?

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    1. I suspect July has the least variability from year to year, but haven't ever done a comparison across the various months to explore this myself. Dig into the data yourself at https://www.ncdc.noaa.gov/cag/.

      Jim

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  6. Snow loving students, March is the perfect time for a ski trip to the Tetons.

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  7. Actually it's not, because Jackson has terrible exposure, steep and predominantly SE facing. The inversions which keep Jackson's lower snow dry mid-winter are long gone by March, same as in SLC. Even Targhee is mostly west facing.

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