Tuesday, March 15, 2016

A Major Forecast Bust

The good news is that as of 4 AM MDT (I'm up early), we've picked up 5 inches of snow at Alta-Collins overnight, bringing the storm total to 10 inches and the total snow depth to 100 inches.  The bad news is that the storm total of 10 inches is well below expectations.

My forecast issued on Sunday was probably my worst of the season (see Skinny Skiing Followed by the Storm Forecast).  I called for .7 to 1.4 inches of water and 7 to 14 inches of snow at Alta-Collins through 6 PM MDT Monday.  Only 0.54" of water and 5" of snow were observed.

One has to hand it to the NCAR ensemble.  While the NAM and GFS were going for big water, the NCAR ensemble was drier and the 0.54" that was observed fell within the range predicted.

This is the future folks.  Multi-member ensembles run at cloud-permitting grid spacings (i.e., 3 km or less).  The sooner we get there, the better.


  1. You were the only site I saw that urged caution on the forecast of the storm and you got closer than most, yet you apologize. I don't see a future in this weather business for you with such honesty :)

  2. The WRF-GFS out of the University of Washington provided one of the best forecasts as usual.

  3. Quite a bit more fell Tuesday afternoon thru the overnight...another 3-6 inches perhaps. Had a great afternoon on the upper slopes at Canyons off the Ninety-Nine-Ninety chair. In the complex world of convective post frontal precip and multiple weak shortwaves, perhaps not such a bad forecast by the end of the event this morning??

    1. Perhaps in a storm-relative sense, but timing errors matter.