Problems I Want to Work On

Last night's storm period was one that I really enjoyed simply because it shows how remarkably variable snowfall can be in the central Wasatch.  As suggested in the prior post, the low-level ESE flow favored Deer Valley, which received more snow than Alta-Collins.  

Deer Valley/Ontario: 1.41"/14+" (snow depth sensor got flaky at 7:35 AM; 14 was the total at that time)
Alta-Collins: 1.02"/10"

It seems that a lot of data is not flowing into MesoWest from there resorts right now so I couldn't dig much deeper than that, but the Utah Avalanche Center report included storm totals as of 5 am also showing the decrease in snowfall from east to west. 

Source: https://utahavalanchecenter.org/

This is not something that is unusual for such a flow pattern or that experienced meteorologists wouldn't anticipate, as illustrated by yesterday's blog post.  However, we don't have a good understanding of the physical processes operating during such storm periods, nor do we have models that reliably anticipate such fine-scale snowfall variations.  By reliable, I mean not getting it right every now and then but instead being able to do it consistently. 

This has been the most challenging academic year of my career.  I'm not getting any younger and it has me thinking about what I want to do in my last few years as a researcher.  During my career, I have always been interested in snow and I'm especially interested in understanding and predicting microscale variations of snowfall in areas of complex terrain.  

Last night's case is a good example.  What I wouldn't give to have had a portable radar in the Heber Valley to see what is happening to the cloud and precipitation system on the south side of the Deer Valley Ridgeline and over the Snake Creek area southeast of Brighton.  It would have been so exciting.  More importantly, I'd like to compare this storms to others, as we all like to generalize, but the reality is that there are a lot of variations that we can't anticipate.  

Additionally, what I wouldn't give to have the time and horsepower to improve fine-scale forecasts of these storms using traditional numerical weather prediction or newer Artificial Intelligence/Machine Learning prediction systems.  

The reality is that we do not currently have a high-resolution ensemble that can reliably predict these fine-scale snowfall variations.  If you think the HRRR can do it, think again.  Here's the forecast from yesterday morning's HRR through 1200 UTC 6 March (5 AM today).  The numbers for Deer Valley and Alta-Collins aren't bad, but note how the snowfall maximizes not on the Deer Valley ridgeline but instead on the Alpine Ridgeline near Lone Peak.  We don't have observations up there, but I think that's an unrealistic spatial pattern.  

In part, this may be due to the resolution, or the grid spacing of the HRRR, which is about 3 km, or possibly due to how it deals with cloud processes, including the growth and transport of snow in storms.  The swiss aren't running models at 3 km grid spacing.  They are running them at 1 km grid spacing and trying to get even finer.  That might help.  However, one also has to be able to handle the snow growth, transport, and fallout processes right and this is where observations and clever minds are needed to incorporate such effects into our modeling systems.  

AI/ML is pretty exciting and is going to become increasingly important moving forward, but it's unclear how to do it for such fine scale precipitation patterns in which training datasets are limited.  There are some proposed approaches, but it's going to take careful testing and evaluation to advance AI/ML capabilities for situations like this.  

I guess in the end things haven't changed much throughout my career.  I love snow and winter storms in complex terrain and these are the kinds of problems that I want to work on.  Beyond my own personal interests, advances in these areas would likely help with forecasting for the 2034 Olympic Winter Games, road weather and avalanche mitigation in Little Cottonwood Canyon, and other weather and climate applicatios over northenr Utah.