Friday, April 7, 2017

Wind, Dust, Snow and All That...

I love spring storms, so I'm feeling like a kid in a candy shop today.

Winds picked up yesterday and gusted strongly overnight in advance of a developing trough and surface front over Nevada.  After midnight, peak gusts at upper-elevation locations in the northern, central, and southern Wasaatch are 82, 77, and 70 mph, respectively.  In the valleys, the Great Salt Lake Marina hit 60 mph and a sensor near the juncture of UT-201 and I-80 in the Salt Lake Valley hit 63 mph.

Winds as I write this have actually slackened just a bit.  Obs from the juncture of UT-201 and I-80 show two periods of strong winds overnight, on prior to midnight, the other from about 1:30-4:30 AM.

Source: MesoWest
With the development of the front and surface trough over Nevada today, as well as daytime surface heating, we will see strong winds today.  Given the prolonged nature of the event, dust is likely as well.  

The models are still calling for two fronts to move through northern Utah this weekend, the first late tonight or early Saturday morning:

the second late Saturday or early Saturday night:

 The NAM has backed off a bit in both instances for precipitation at Alta, especially the first front tomorrow morning, and ultimately produces a storm total by Sunday morning of 0.82" of water and 13.5" of snow.

The SREF continues to show a large spread from only 0.25" of water to over 2.5", with strong clustering based on model core (ARW or NMB - essentially, two different models are used for the SREF).  The really wet members all produce considerable precipitation early tonight, and thus get things started early.

So, here we sit, having looked at this storm for about a week, and still no guarantees!  Sunday still looks like the better ski day as snow piles up during the weekend, but how good it is will depend on whether or not we are in the upper-half of these forecasts.  Finding a smooth underlying surface or getting enough snow to fully bury the frozen coral reef will be the key to good skiing on Sunday.  One plus is that we are looking at cold temperatures Saturday night, with 700-mb tempreatures currently forecast to drop to about -14ÂșC, which should yield a right-side-up snowfall. 


  1. Any reason why 3k NAM is so overblown?

    1. The 4-km had the same problem. Excessive orographic precipitation. It hits a home run every 20 at bats, but strikes out the rest.