Monday, February 10, 2014

Welcome to Seattle!

A drippy, foggy Monday morning in Salt Lake City
This morning dawned with Seattle-like rain and fog in the Salt Lake Valley and Cascade-like conditions in the Wasatch Mountains where high-density snow continues to pile up in the upper elevations.  Water and snow storm totals reported on the Utah Avalanche Center web site this morning range from 2.87"/30" at Alta to 46"/6.94" at Sundance.  Logan and American Fork Canyons remain closed and tragically, two deaths have occurred in backcountry avalanches.  

The storm should wind down today, with a break in the action tomorrow.  Beyond that, I hope you like the Northwest weather as we're going to get more of it.  A broad, low amplitude ridge remains over the region throughout the week, with another push of moisture into the northern mountains likely late Wednesday and Thursday.  Yes, it will be another atmospheric river event, with the tongue of tropical moisture that will be coming our way beginning to surge northeastward near Hawaii (westernmost arrow), just upstream of the remnants of the atmospheric river that gave us the deluge the past few days (easternmost arrow).  

GFS Integrated Water Vapor (mm, warmer colors indicate higher values) at 1200 UTC 10 Feb 2013.
If things come together as currently projected by the models, that will mean another round of rain for the valleys and high-density snow for the mountains.  The biggest uncertainty in this forecast concerns the position of the atmospheric river as a slight shift to the north or south can make a big difference for water/snow totals.  After that, the models call for the ridge to amplify somewhat with dry conditions but very warm temperatures on Friday.  

The GFS forecast time series shown below summarizes the situation.  Note in particular the heavy precipitation late Wednesday into Thursday (bottom left panel) and then the big warmup thereafter with temperatures on Mt. Baldy (11,000 ft) going into solidly into the 30s (upper left panel).  The GFS typically overestimates snow levels so don't panic about them going to almost 10,000 feet on Wedensday (upper right), but it is going to be a warm storm, so expect snow levels to be pushing 8000 feet.
Looks like an investment in Gore-Tex or Hefty bags might be in order.  A pair of ultra-fat fully rockered skis would be nice too.  


  1. As a Seattle native I walked out the door this morning and thought the same thing to myself. I kind of miss the warmish, damp, foggy and grey weather. Better than a bad inversion and freezing cold temps.

    Hope people stop making poor choices and venture out into the back country with the extreme avalanche conditions.

  2. Definitely need as much water as we can get. Though, it's always sad to hear about avalanche fatalities.