Wasatch Cache National Forest

In partnership with: The Friends of the Utah Avalanche Center, Utah Department of Public Safety Division of Comprehensive Emergency Management, Salt Lake County, and Utah State Parks

The Utah Avalanche Center Home page is: http://www.avalanche.org/~uac/

Avalanche advisory

Saturday, April 26, 2003

Good afternoon. This is Bruce Tremper with the Forest Service Utah Avalanche Center with your backcountry avalanche and mountain weather advisory for the Wasatch Range near Salt Lake City. Today is Saturday, April 26, 2003, and it’s about 2:30 pm.

Current Conditions:

Well, this is it. This is our last avalanche advisory for the season. I will put an end of season message out on Monday. Tell you the truth, it feels great to be pulling the plug on a season like this—one with so little snow yet a record-setting number of unintentional human triggered avalanches in the backcountry. I’ll have more statistics on Monday.

This season is ending with a whimper as none of our recent spring storm have come through with much more than wind and clouds. Today, wandering around in the fog, I found the snow surface frozen on all slopes but a little breakable on all aspects except straight south facing slopes. There’s still a few patches of dry snow on very upper elevation north facing slopes, but you need a good imagination. Temperatures have cooled off significantly and it’s about 15 degrees colder than yesterday at this time. Temperatures are supposed to be in the mid 20’s tonight at 8,000’ and in the mid teens at 11,000’.

Avalanche Conditions:

Yesterday with the very warm dust storm, someone from Mt Olympus watched a couple avalanches release naturally high in Stairs Gulch, which is a very steep, north facing area between 10,000 and 11,000’ and they ran about 300 feet wide and 1500 vertical feet. One of the avalanches kicked up a dust cloud, so it was probably a dry avalanche released from the warm conditions. This is also an area famous for glide avalanches, meaning wet slabs which come off the steep rock slabs, and one of the avalanches reported fit this description. The colder conditions have probably locked up whatever wet avalanche activity we’ve had lately. I’m guessing that Sunday will be a fairly uneventful avalanche day, as most of the week has been very quiet with the exception of the Stairs Gulch slides yesterday. If we get sun on Sunday, there will be the usual localized wet sluffs on steep, sun exposed slopes in the heat of the afternoon. As usual, get off of and out from underneath steep slopes when they get wet and mushy.

Although it probably won’t be much of a problem on Sunday, another concern is that for the past week, we have been noticing large collapses of the surface frozen crusts into wet and occasionally dry underlying layers. These collapses are just in the top inch or two of snow and so far they have not initiated any avalanches. We’re not sure what to make of them. We suspect that on steep slopes, they may slide, but so far they have just been collapsing and staying in place. They are quite rare around her and I have seen them only occasionally in the past. I’ve never had an avalanche release on me when they collapse into wet snow, but it sure is unnerving. Here’s a photo taken yesterday of one of these large collapses (CLICK HERE). Occasionally, we see what we call “corn slab” avalanches this time of year, where a wet avalanche occurs despite the fact that the surface snow is frozen hard and is supportable. They are quite rare, but they do happen. Anyway, this is probably a sign that the corn snow conditions are not entirely bombproof yet and you should use the usual caution.

Bottom Line:

For tonight and Sunday, the avalanche danger is generally LOW. With daytime heating, the danger may rise to MODERATE on steep slopes.

Mountain Weather:

Looks like a partly cloudy day on Sunday with overnight lows at 8,000’ tonight near 25 and getting up to 45 on Sunday. At 11,000’ the overnight low tonight should be in the mid teens and get up to the low 40’s on Sunday. After that, we have another spring storm on about Monday and Tuesday, but actually, I really don’t care because we’re not forecasting any more. After that, I won’t be glued to the weather radio and the Internet like usual. I love it this time of year when I quit paying attention to the weather. I wake up in the morning and look outside and say, “Hey, look at that, it’s raining.”

General Information:

To report backcountry snow and avalanche conditions, especially if you observe or trigger an avalanche, call (801) 524-5304 or 1-800-662-4140, or email to [email protected] or fax to 801-524-6301. The information in this advisory is from the U.S. Forest Service, which is solely responsible for its content. This advisory describes general avalanche conditions and local variations always occur.

I will put an end of season message out on Monday.

Thanks for calling!

________________________________________________________________________

National Weather Service - Salt Lake City - Snow.

For an explanation of avalanche danger ratings:

http://www.avalanche.org/usdanger.htm