The general avalanche hazard will rise from Moderate this morning to Considerable this afternoon above 7500'. Significant snowfall and strong west winds will form new winds slabs that will increase in size and sensitivity today. Skiers and riders have the potential to trigger these slabs as well as older slabs that lie in the snowpack. Below 7500' the hazard will increase from Low this morning to Moderate this afternoon. In lower elevation avalanche terrain, loose snow sluffs and pockets of surface slabs could be triggered this afternoon in steep shaded terrain where weak faceted snow lies.
New slabs formed by wind and snowfall today will build in steep leeward terrain. These slabs will increase in sensitivity today and are expected to be easily triggered by skiers and riders this afternoon with depths to eighteen inches.
Weak layers of faceted snow persist in the snowpack. Slabs laying on these layers vary from one foot to as much as four feet in depth. These slabs could be triggered by a single person hitting a weak spot, following the initiation of a wind slab or by larger loads such as snow machines.
( Discussion is generated from the previous day's afternoon forecast. )A stronger upper level storm system will move into the northern Rockies tonight and bring snow to western Wyoming on Thursday. This may be the first of several storms to impact the area through the weekend.Snowfall is likely to develop overnight with several inches of accumulation possible by day break and another five to nine inches likely in the mountains during the day. Up to four inches of accumulation is possible at the lower elevations. Temperatures will be in the teens in the mountains and in the 20s in the valleys. Winds will be southwest at 10 to 20 miles per hour and are forecast to veer towards the west and increase during the afternoon hours.The general avalanche hazard is expected to be MODERATE in the morning and increase as the day progresses. The hazard at the higher elevations could increase to CONSIDERABLE in the afternoon. Loose snow sluffs are likely to release frequently on very steep slopes during this storm and could attain sizable volumes in areas that overhang confined chutes and couloirs. New soft slabs will begin to form and increase in size and volume. Existing persistent slabs will be loaded and could become unstable and increasingly sensitive to human triggers. Monitor conditions and adjust your travel plan accordingly. There have been five avalanche fatalities in the Rocky Mountain area during the past two weeks.
