AltaBird, UT 4/14-15/12

[Tony Crocker]

take out the lake affect snow such as this year and it's gonna be tuff reaching the average

I've read lake effect is ~10-15% of LCC's snowfall, most of the difference between BCC and LCC. Perfect perpendicular orographic uplift of the optimal ~7,000 feet , box canyons to trap storms is most of it. The Great Salt Lake isn't that big. Maximum over water fetch is 80 miles on a NW-SE line, which aims directly at the mouth of LCC. If the storm track isn't NW-SE, shorter fetch, not much lake effect. Otherwise Snowbasin, which sits directly east of the lake but over a much shorter fetch, would get most of the benefit.

This year lake effect was likely more since a higher proportion of the storm tracks were probably from the NW.

Days 60-61

Once again (Feb. 12 at 37 days) admin and I are tied in day count. The final result will be a close call. Only in a subpar Utah season would this be possible.

 

[Admin]

take out the lake affect snow such as this year and it's gonna be tuff reaching the average

I've read lake effect is ~10-15% of LCC's snowfall, most of the difference between BCC and LCC. Perfect perpendicular orographic uplift of the optimal ~7,000 feet , box canyons to trap storms is most of it. The Great Salt Lake isn't that big. Maximum over water fetch is 80 miles on a NW-SE line, which aims directly at the mouth of LCC. If the storm track isn't NW-SE, shorter fetch, not much lake effect. Otherwise Snowbasin, which sits directly east of the lake but over a much shorter fetch, would get most of the benefit.

I asked the esteemed Dr. Jim Steenburgh to comment on this. This is what he wrote:

Marc:

It just so happens that we just submitted a paper where we quantify how much precipitation is produced during lake-effect periods. Anyone who wants to totally geek out can access the paper at http://www.inscc.utah.edu/~steenburgh/p ... Eclimo.pdf.

During the 12-year study period, lake-effect periods accounted for 5.1% of the snow-water equivalent that fell at Snowbird from 16 Sep to 15 May. Note that some of the precipitation that falls during these periods is not lake effect (sometimes lake-effect occurs in conjunction with other precipitation features). The months with the most lake effect (on average) are October and November. I'll probably do a write up on this on the weenies soon.

Those wishing to understand the deep powder climate of Alta compared to other areas can read this paper:
http://journals.ametsoc.org/doi/abs/10. ... BAMS2576.1. The deep powder skiing in the Cottonwoods is superior to that in Colorado because the Cottonwoods get more snow, more frequent "deep powder days" (defined to be 10" or more), and a large number of storms that produce right-side up snowfalls. Storms that start out high density and go low density produces better powder skiing than storms that are all low density.

There is some discussion of the snow climate of the Cottonwoods, PCMR, Snowbasin, and Oquirrh and Stansbury Mountains in the last few posts on http://wasatchweatherweenies.blogspot.com. It is so snowy in the Cottonwoods (compared to elsewhere in the Wasatch) is that they are a very high, broad, island of high topography that is exposed to a wide variety of storms and flow directions. That being said, questions remained that are unanswered...

Jim

 

[Tony Crocker]

Jim Steenburgh is an excellent resource. I've added that to my snow reports link page.

 

[Bobby Danger]

excellent information !! o.k. i think f.t.o. would be a better place with more of his input.

 

[Evren]

After last year's runoff, I was hoping for an enhanced lake effect this year. The lake is 6 feet higher and more importantly, has 40% larger surface area (paging Marc_c for any corrections) compared to last year.
Well, we know how that turned out.

 

[Tony Crocker]

A higher proportion of lake effect would likely result in LCC running a higher percent of normal than elsewhere in the Wasatch. Based upon what I've seen so far all of the Wasatch areas are in the 75% of normal range in 2011-12.

But someone could ask Jim Steenburgh.

 

[Admin]

A higher proportion of lake effect would likely result in LCC running a higher percent of normal than elsewhere in the Wasatch. Based upon what I've seen so far all of the Wasatch areas are in the 75% of normal range in 2011-12.

There was a lot of speculation prior to the start of this winter that the increased lake surface area would result in above normal snowfall. Clearly that didn't happen.

But someone could ask Jim Steenburgh.

He's already addressed it:
http://wasatchweatherweenies.blogspot.c ... -more.html

 

[Tony Crocker]

With lake effect driving no more than 10% of average Wasatch snowfall, it's obvious that weather factors are more important. Perhaps the question BobbyD would ask is whether that 8-10% being lake effect was higher this year. Would Wasatch snowfall have been 65% with average lake effect vs. the actual 75% it was? My guess is no as all of the Wasatch areas were down a similar percent so "lake effect" snowfall was likely close to its average proportion.

 

[Admin]

Would Wasatch snowfall have been 65% with average lake effect vs. the actual 75% it was? My guess is no as all of the Wasatch areas were down a similar percent so "lake effect" snowfall was likely close to its average proportion.

Which is exactly what you describe it as: a guess. That's nothing but pure speculation without any evidence provided to support or refute it.