Salt Lake Avalanche Advisory
Sunday, April 4, 2010
Forecaster: Drew Hardesty
	
BOTTOM LINE

It's the kitchen sink out there folks - plenty of avalanche issues to be concerned with -

There is a mostly MODERATE avalanche danger for today for yesterday's lingering wind slabs. They're 
most pronounced at the steep mid and upper elevations on the north through southeast facing slopes. 
Rapid warming may conspire to keep these sensitive for the first part of the day. Pockets of 
CONSIDERABLE danger exists are in mid and upper elevation wind effected terrain where it may be still 
be possible to step down to weaknesses adjacent to last week's dust layer. They're more likely to be 
triggered on the steeper north through east facing slopes. Wet and dry sluffing in last night's cold 
smoke is certain on the steeper lines - Watch for the sun to heat up the new snow this morning and 
heat initiated wet activity will have a MODERATE danger on east through south through west aspects.

Today's advisory written mostly by Wendy Wagner and approved by Drew Hardesty

CURRENT CONDITIONS

Wind and snow from Yesterday morning scoured exposed westerly aspects depositing much of the snow 
onto the easterly slopes. Snow conditions were creamy dense powder in sheltered locations with upper 
elevations seeing more wind damage. Overnight another 6-8 inches of 5-7% density snow fell in the 
Cottonwoods with slightly less in the Provo area mountains. Ogden picked up little to no snow from 
last nights storm. Winds this morning are light at most locations from the west with the higher 
stations reporting a few short-lived gusts into the low 40s. Temperatures have dropped into the low 
to mid teens and single digits at upper locations.

RECENT ACTIVITY
	

It was like a carnival of wind slabs yesterday with nearly everyone coming home with a prize. Most 
were soft and hard slabs from the stronger westerly winds, but there were some very significant 
slides all the same. One very close call in Upper Days Fork partially buried a skier and overran 
a party of two stopped in the trees at the bottom, burying their gear while they hung onto a tree 
to keep from getting caught. The skier triggered slide was around 200' wide with the crown 2' deep 
failing just under last Tuesday's dirt later. Other significant avalanches reported was a large 
natural in the upper reaches of Broads Fork beneath O'Sullivan Peak and another in the upper reaches 
of Box Elder (perhaps feeding into White Canyon). The latter initiated by cornice fall. These 
estimated to be 2-3' deep with the Broads slide perhaps 250' wide. There were several skier triggered 
soft slabs in the Brighton backcountry and Mill Creek area. These slides seem to be running on a 
variety of weakness, mainly within the storm snow density change however, a few have been reported 
at failing just above or below the dirt layer.

THREAT #1
	
Wind slab and soft slab avalanches will again be a main concern for today. The weakness within the 
storm snow from yesterday's wind and snow event may still be sensitive. These may are buried anywhere 
from 6" to 20" deep and are most pronounced on north through southeast aspects where the westerly 
winds have transported and deposed snow.

THREAT #2

We are up to 40 - 50" of snow as of March 31st. This is sitting on a dirt layer formed Tuesday 
March 30th. The past 4 days slides have been failing just a few centimeters above this dirt layer in 
the older storm snow density change. It is possible this weakness still has not settled out. 
Yesterday reports came in of slides breaking just under the dirt layer, possibly a sign this dirt 
layer can still be active. With a number of impulses of snow since the 31st, we're seeing a variety 
of failure planes that exist within the past few days of storm snow and crust.

THREAT #3
	
With 6 to 8" of light density snow overnight expect to see dry loose snow sluffing on most aspects 
and elevations. With clearing skies this morning the intense spring sun will likely heat the easterly 
and southerly facing aspects rapidly making wet loose snow avalanches a significant concern.

MOUNTAIN WEATHER
	
We should see clearing this morning with cloud cover building back in this afternoon ahead of Monday 
and Tuesday's storm. Winds are currently light and should increase later today from the southwest, 
gusting into the 20's on ridges. Temperatures should climb into the upper 20's and low 30's with the 
warmer southerly flow. Tomorrow's cold front and lingering instability may produce 1-2' through 
Wednesday.