Warm temperatures and abundant sunshine will cause the hazard to increase throughout the day. Slab avalanches lie upon persistent weak layers and will become increasingly sensitive to human triggers as the day progresses. Yesterday, a skier in Grand Teton National Park triggered a slab avalanche in the South Fork of Granite Canyon on a lower angle slope. Similar events are possible today, especially after snow surfaces soften.
Dense, surface slabs, up to two feet in depth will become increasingly sensitive to human triggers as the day warms. The potential exist for these slabs to step down to deeper layers of faceted snow with depths to three feet.
( Discussion is generated from the previous day's afternoon forecast. )The region will experience dry and very warm temperatures under a building high pressure ridge. Temperatures will become inverted overnight. On Monday skies will be mostly sunny above areas of morning valley fog. Temperatures at dawn are forecast to be in the teens in the valleys and in the mid-20s at the higher elevations. Daytime highs will approach 40 degrees in the mountains and rise into the low to mid 30s in the valleys. Winds will decrease to around 5 miles per hour and back to the south.Warm temperatures and sunshine will cause the hazard to increase during the day. Surface slabs up to 18 inches in depth will become increasingly sensitive to human triggers in steep terrain and cliff areas as the day progresses. Some potential may exist, in isolated areas, for these slabs to step down to deeper layers of faceted snow. The general hazard is expected to be MODERATE.
