Thursday, December 28, 2017

Skiing, Inversions, Pollution, and All That

It's been an interesting break.  After hemming and hawing about whether or not to get out of Dodge, we decided that there was enough snow and decent enough air quality that we'd gut out Christmas week at home.  By and large, I think it was a wise decision.

The cross country skiing has been pretty decent and has provided a good cleansing of my aorta.  Back country skiing?  We got in a tour the day after Christmas.  I can't say the skiing was good, but it was an education for my son who had never been out on such a hair-trigger, high-hazard day before.  I made him suffer too, with a 2000 vertical foot climb through heavily brushed slopes to start the day.  It's important that youngsters recognize it's not all fun and games out there. 

We went up for a couple of high-speed laps at Alta this morning.  It was only my 2nd day of lift served this year.  Conditions were surprisingly good for carving.  I'm always amazed that when conditions here are about as bad as they can get, it's still far better than most of the good days I had when I lived in upstate NY.  That being said, it's incredible to think that Mineral Basin is still closed and probably will be through the 1st of the year, unless Snowbird has some real tricks up its sleeve.

Despite the poor off piste coverage, the coverage on the groomers was adequate and by 11, the corrals were full and there was stiff competition for Jerry of the Day honors.  After a few laps of human-breakaway-slalom, we decided to return home and get something done.

Which brings us to the weather.

Here's your pearl of wisdom for the day.  Don't count on a pattern change until you see the whites of its eyes.  Stop looking at the 10-day forecast and buy yourself a fat bike.  Alternatively, go to Jackson.

Now maybe you can provide me with some pearls of wisdom.  Is it just me or is this the weirdest inversion ever?  Remember all that fog, stratus, and pollution on Christmas Day and Boxing Day?  Well, the fog has dissipated, we just hit 44˚F at the airport, and the PM2.5 concentrations have been up and down like a yo-yo the past few days.

Source: DAQ
I'm sure there's still plenty of gunk behind the lake breeze where the cool air over the lake won't release the goods to the free atmosphere, but this situation is far better than I could have hoped a couple of days ago.  More time at the office is needed to decipher this riddle.  Comments on what's going on appreciated.


  1. Jim thanks so much for your blog and comments. I really like your comment that you can’t trust a pattern change until you see the whites of its eyes. By the way the free Euro maps created by Ryan Maue are paywalled as of today! I was really enjoying doing some forecasting myself!

    1. More info at Dig through the thread.

      Forecast using No Euro, but everything else is better :-).

  2. Looking at the past day's time lapse at:

    For both WBB cams is helpful. You can see the Lake Slug fliw back to the south and refill the Valley.

    I'd still love to see a Purple Air monitor installed out in the Lake somewhere and maybe one at Salt Air. The trick is that it needs wifi.

  3. I enjoy the contrast between you NOAA and Wasatch snow forecast. It's nice to peak ahead sometimes even if it's taken with a huge grain of salt. I'm sure you do it even if you don't write about it.

    1. There's not a lot of useful skill in extended weather forecasts over northern Utah, especially specific forecasts. Start verifying the 7-day forecasts presented on the nightly news and you'll see this immediately. At best, we can talk about generalities, and even then there are problems. Remember how cold it was supposed to be on Christmas? I saw one forecast around December 17 of a high of 18 at Salt Lake City. How'd that work out?


    2. In relation to the forecasted extreme cold snap it seems those are relatively common in the winter extended forecasts but very rarely verify. Nothing I've checked empirically but a sense I get.

  4. From reading your blog and seeing extended forecasts rarely verify I have to try to mostly block out forecasts past 5 days. I guess I do still think of a good (wet) forecast 7 days out as something that pushes the odds to the wetter end of probabilities relative to climatology, just not that much.