Saturday, January 12, 2013

When it Comes to Snow Efficiency, Twin Cities a Dud


I’ve long suspected that the Twin Cities endures a tremendous amount of cold weather for a relatively paltry amount of snow. But the question always remained: how can you measure cold weather “efficiency” in producing snow?

By tossing around a few numbers and making some general assumptions, I developed an efficiency rating that measures “bang for the cold weather buck” when it comes to producing snow. The statistics confirm that when it comes to snow making and cold weather, the Twin Cities is like a souped-up car that struggles to reach 50 mph.

First, some background on my approach. I decided to measure “cold hours” as every hour of temperatures at 32 or below. That’s also the temperature at which legitimate snowmaking becomes a possibility. I divided the number of cold hours by the average annual snowfall (obtained here). This results in a snow-making efficiency factor expressed as cold hours per inch of snow produced.

I developed the numerator by reviewing daily averages for each of the cities detailed below. Here’s how I measured that. For a given day, if a city had an average high of 40 and an average low of 24 (a daily average of 32), I assumed that half the day’s hours were at or below 32. Using the same general assumption, if a city had an average high of 40 and an average low of 28 (a daily average of 34), I determined that 10 of those 24 hours were at or below 32.

I came up with a scale of cold hours per day based on the theory above. If a city’s daily average was 44 or higher, I assumed they had no “cold hours.” If the daily average was 20 or lower, I assumed that had 24 cold hours. It’s not a particularly scientific approach and I’m sure there are inherent statistical biases, but given my limited abilities and the desire to come up with a ballpark estimate, I think it works for the purpose.

The results were generally as I expected and probably won’t surprise most weather enthusiasts, yet I think it’s fun to see an actual number assigned. As you can see from the table, Erie, Pennsylvania must only endure 17.7 cold hours to receive an inch of snow. Rocky Mountain locations also score well in the snow efficiency rating. Aside from cities bordering the Great Lakes, the Midwest must endure the coldest temperatures for relatively little snow. The Twin Cities requires nearly 54 hours of sub-freezing temperatures to receive one inch of snow. For comparison, Burlington, Vermont, has almost as many cold hours as the Twin Cities, but receives 60 percent more snow. East coast cities are more “snow efficient” with cold weather than Midwestern cities, though obviously not as prolific as lake-effect locations.

Hardly surprising data to be sure, but hopefully rather entertaining for weather enthusiasts. The Twin Cities climate may produce one of the better theatre of seasons in the country, but when it comes to snow production, the long-duration winter – which consists of an estimated 2,675 hours of sub-freezing temperatures – is a relative dud.

34 comments:

  1. Very interesting, Bill! Nice work. I'm a stats geek and this is great stuff.

    Incidentally, we set our first temperature record of 2013 yesterday with a daily minimum of 34.

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  2. Interesting.. though to me I don't mind the cold at all, in fact I'd rather have Alaska type temps. What would be interesting is to see snow efficiency as it relates to how long snow actually stays on the ground once we get it.

    For example, Denver, a place I've been interested in moving for quite some time, gets dumped on... yet about 3-4 days later, the snow is gone. Its just a big wet mess really.

    Here we get snow and it stays longer.. though the last couple years we see much of it disappearing.

    I'd like to know what locations in the US get the most snow and keep the most snow. Once I determine the areas that it likes to stick around, I'm moving. I have my sights set on Alaska now with global warming ripping us off our winters.

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    1. marquette, michigan is where you want to move.
      i am considering moving there for exactly the same reasons. They are also experiencing a below average snowfall winter so far ( about 38 inches below), but as of today they have had 51 inches of snow with 10 inches on the ground.

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  3. Good work Bill,like to see the comparisons between cities,but as suspected we are way cold a lot of the winter season(temps below 32)but hardly produce enough snow to show for it,and lately like living on the east coast again storms come along and poof there goes the cold air needed for snow and you get an icy mixture of sleet/freezing/snow or me and my brothers favorite joke line was "along comes a storm and we warm up to 40 and rain".
    This week is a perfect example,after our thaw disappeared on Friday night,temps will run below freezing for the foreseeable future(2 weeks)except for a brief time on Wednesday when we may hover around 35,but besides for some flurries and snow showers that may create a dusting to an inch this week,our snow potential is pretty pathetic looking out into the foreseeable future

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  4. Once again Huttner has screenshots of the GFS predicting mega cold. The GFS from two weeks ago predicted a high of -3 for yesterday, but we got to 9. So the error was 12 degrees; pretty significant. But the real kicker is that it was predicting brutal cold for this entire week. None of the current forecasts show anything close to that. GFS of 1/2/2013 said a high of about -17 for Wednesday. The current Euro says a high of 36. The GFS will have been off by 53 degrees if that holds.

    At least Huttner does mention that the GFS is "overdoing" the cold. It makes me wonder if it's by total accident when the GFS gets something right looking two weeks out. In any case, I think Huttner should add a disclaimer that says it's for amusement purposes only.

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  5. The same Paul Huttner that this past fall every time a 'cold' front would show up on the charts would predict "last 60s of the season". He did it at least 4 times, and every time Mother Nature proved him wrong.
    I feel for these poor forecasters. They have to write a column every-day and they attach to anything that may bring attention, even the 2-week long term output if the GFS which is notoriously inaccurate more than 3 days out.
    The truth is that we have no clue about what is going to happen beyond 4-5 days and yet everybody continues to speculate about things they don't what they are talking about.
    Very sad.

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  6. I think you hit the nail on the end.

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  7. Look at this map, it's well within the GFS fantasy land.

    http://i960.photobucket.com/albums/ae84/arpetersonembaqcom/12zgfstminint168gifGFScold.gif

    And the Euro which I can't post is similar but about 18 hrs slower.

    The cold is coming. So I have a bit of advice that I followed today. If your vehicle is in need of a oil change, I would have it done now!!! While your at it have the mechanic check your antifreeze protection, hopefully it'S good to -40°. NO I AM NOT CALLING FOR -40 TEMPS, BUT MAKE SURE IT'S WELL PROTECTED.

    It looks like our 4 year streak of high temps staying above 0° is in serious jeopardy.

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  8. randyinchamplin is right, the real cold is coming and it is less than a week away. The long range models show it, and we should break the streak of high temperatures staying above 0 somewhere between Sunday-Tuesday. It's possible we could stay below 0 all of these days, but most likely Monday-Tuesday.

    As for looking at the long range models, the GFS be good for picking up large pattern shifts - large troughs/ridges in the jet stream, etc. That far out you have to look at it in a more regional sense. Hypothetically, two weeks out you can pick out if a blizzard will hit the northern plains, or when a large severe weather outbreak is possible in the southern plains. This storm may shift from MN into the Dakotas, or from MN to IA, but the GFS did pick out a significant storm happening in the northern plains two weeks out. This is a big improvement over what you could forecast even 10-15 years ago.

    If you are expecting the long range models to be accurate in forecasting highs and lows or precipitation to a point location 2 weeks out, that just won't be reality the majority of the time.

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  9. @Bill,there is something wrong with trying to access this post that I and Bemaki alluded to on the end of the previous thread.Tried to access this blog last night on the work computer and got the same thing that i get on my cell phone,my house computer is just fine....so not sure what is up,but something is up,just an fyi.

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  10. I think I know what's going on, Bill:

    Internet explorer is not properly reading the URL for some reason. I opened this with firefox and it worked fine, but when I opened with Ie8, it only gives me a title and no place to put comments. I prefer Ie8, but if I want to comment, much less see the comments, it seems I must use something other than Ie8.

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  11. I can confirm that it is IE not rendering the page correctly. It doesn't work for ie7, ie8, or ie9. Just the title and picture. Chrome, Firefox, Safari (ipad/iphone) works fine.

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  12. Weird... I'm not doing anything differently. I use Blogger. Must be something they're working on. Maybe a good reason to give up Explorer.

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  13. Interesting going back to the previous blog post about the cold.

    Sure its not going to get to -30 like the model showed and its going to be a few days later than forecasted, but these models can pick out general patterns in that 10 to 14 day range. That in itself is pretty damn impressive.

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  14. It looks like another 40+ degree day tomorrow (Friday). The temps for Saturday have now been jacked up into the mid-30's. The arctic front is scheduled to come through Saturday. It appears it will be cold through Wednesday before, you guessed it, yet another warm-up occurs. According to the NWS, it will get so warm that precipitation types will be an issue with next week's minor system...again! Heaven forbid we actually have a no doubt about it snowstorm in Minnesota in January! After all, January is our snowiest month, right? (insert sarcastic, frustrated laugh). To recap what I stated in a previous post: cold for a few days followed by a warm-up so it can rain or at least not be all snow, and then it will be clear and cold again. I have decided to hereby christen this as "The Mid-Atlantic Effect". What another waste of cold air. I am seriously beginning to wonder whether this season's snow totals will even match last season's totals. This is really starting to shape up to be "winter's" version of the Twins losing 90+ games in back to back seasons. Even though this season is colder than last season, which isn't hard to do, it still manages to continue to come up with ways to be yet another lame Minnesota "winter".

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  15. @Snow Miser

    Well at least the Twins (in theory) have control over whether they win or lose! :)

    I noticed that the Euro has moderated quite nicely. It will definitely be cold Sunday thru Tuesday, but all the predicted highs are 0+ now.

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    1. @Disco80

      Good point! I hold out more hope for our Twins than I do for our "winters".

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    2. Everything going as planned: I posted about what Snow Miser calls the "Mid-Atlantic Effect" last October, and this is what is exactly happening. General drought, and when storms come by they also bring warm air.
      I also agree with total snowfall: in October I even thought we were in the run to beat the least snowiest record (and we won't just because of that big storm that somewhat managed to materialize).
      No snow is in the forecast for the rest of January (any moisture will be rain...) in February I'd say maybe 3 inches total... which will bring us to around 20 inches. I think we all agree we should forget about March snow: we will probably be talking 70 degrees by then...
      Last year was 22.6 I think, so yes I think it will tough to match it. I said in October that we had to consider ourselves lucky if we got 20 inches. I feel more and more confident that my out of frustration forecast may actually turn out to be correct

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  16. TWITTER - Dr. Ryan Maue - Weatherbell
    Ryan Maue ‏@RyanMaue
    ECMWF 12z has a blizzard upper-Midwest has been waiting for all season. Alas, it's a 7-day forecast.

    https://twitter.com/RyanMaue/status/291986728749785088/photo/1

    =========
    save a little hope

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  17. At least some of our favorite forecasters haven't forgotten their favorite "go to" predictions. DD says a chance for a gold old fashioned snow storm late next week... Paul Douglas says no significant snow through the end of the month... and NWS says precip type issues for late next week.

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    Replies
    1. which tells you once again: nobody has a clue about what they are talking about.

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  18. I saw this today on the NWS site. It's a breakdown of the average number of days with snowfall per month in the metro for the period of 1983-2012. I don't think any of us will be surprised at the results.

    http://www.crh.noaa.gov/news/display_cmsstory.php?wfo=mpx&storyid=91761&source=0

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    1. Only those who think or try to sell the metro as a snowy place should be surprised (and this includes some of the local mets).

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    2. Interest, and like you said, not surprising.

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  19. Keep an eye on that clipper for the end of next week (Thurs-Fri time frame). It doesn't look like much now, but with favorable snow growth temps up to 600mb Thurs evening, it won't take much moisture to put down a few inches of snow. Great snow making weather if we can get the moisture up here. Maybe it will end up trending stronger in future runs. Who knows... :)

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  20. Plymouth Weather LoverJanuary 19, 2013 at 9:18 AM

    Keep talkin' Duane. Bring it!!!

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  21. I couldn't help but to notice this morning just how much bare ground there is. The 40+ degree temps yesterday and the current 38 degrees today surely haven't done our meager snow cover any favors. Despite the miniscule amounts of snow we have received this season, we would still have several inches on the ground from the December storm but for the days in the 40's and the RAIN!! Yes, I have a huge pet peeve about RAIN in the winter. It can rain anytime of the year. It doesn't have to rain during our winters! For fun I looked at the Minneapolis weather data for the decade of the 1970's. It was nothing back then to have a week or two of consecutive nights below zero along with 3-4 days with maximum temperatures below zero. Now that's Minnesota cold! I know that many of us on this site are hopeful for some snow later next week, but I'm not holding my breath. The drought beat goes on. Last season (2011-2012) on a scale of F- to A+, I gave an F- for snow and an F- for cold temperatures. At the halfway point for this season I gave an F- for snow and a D for cold temperatures. Let's see if the second half of winter can redeem itself. Come on February!!

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  22. I just wanted to add that if we did have a deep snow cover, the pending temperatures over the next few days would easily be 10 degrees or so colder than they will otherwise. Under those circumstances the metro would be looking at actual minimum air temperatures of possibly 30 degrees below zero.

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    Replies
    1. Major cold air advection has commenced, has anyone heard the winds?

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  23. Usually the official reports are taken more often during events like this. So far I'm only seeing the normal hourly reports from KMSP.

    Looks like winds are gusting a bit over 40 at 3pm. Sad thing is, we were out and about this morning and it was pretty nice around noon.

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  24. Still watching Thursday for a low QPF/high ratio snow potential, but something to watch for would be as we close out January. GFS has held on to some type of storm developing and moving into the area. The Euro and GEM look to be on board with this as well but we are talking 240 hours (10 days) away. Nice to see a consistent signal of this occurring, but right now it is still in no mans land. Stay warm all!

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