Archived Information - Not Current This is archived in relation to a fatal incident which occurred on this day Forecast for the Salt Lake Area Mountains Issued by Dave Kelly on Saturday morning, December 28, 2024 Today, the avalanche danger is HIGH in upper-elevation terrain, and on mid-elevation northerly facing terrain. Avalanches may break 1'-3' deep and over 600' wide. Natural and human-triggered avalanches are likely. There is a CONSIDERABLE avalanche danger on mid elevation west and southerly-facing slopes, and there is a moderate danger on low elevation slopes. Avoid traveling in avalanche terrain on any slope steeper than, connected to, or below a slope that is greater than 30° in steepness. -- Avalanche Warning -- What: The avalanche danger for the warning area is HIGH today Where: For the mountains of Northern and Central Utah, and Southeastern Idaho, including the Wasatch Plateau (Skyline)...Wasatch Range...Bear River Range...Wellsville Mountains Impacts: Heavy snow combined with strong wind is creating widespread areas of unstable snow. Both human-triggered and natural avalanches are likely What to do: Avoid all avalanche terrain. Stay off of and out from under slopes steeper than 30°. Carry and know how to use avalanche rescue equipment. Find safer riding conditions on slopes less than 30° with no overhead hazard Warning Times: Saturday, December 28, 2024 - 6:00am to Sunday, December 29, 2024 - 6:00am Weather and Snow Currently it is snowing lightly. Temperatures are in the mid-teens to low 20's °F. Winds are blowing from the west in the teens gusting to the high 20's MPH. Overnight gusts at the highest ridgelines were pushing into the 80's MPH with a few gusts close to 100 MPH. Overnight there was another 2"-6" of new snow and .30"-1.00"water reported which brings our storm totals to 8"-20" of snow and 1"-2.25" of water. For today, continued snowfall with 8"-16" of snow and 1"-1.5" of water forecasted. The snow densities could be quite high and increasing through the day as temperatures warm up. Temperatures will be 31-36 °F and the freezing level may rise to 8,000'. There is a chance we could see rain at lower elevations later this afternoon. Winds will blow primarily from a westerly direction 20 gusting to 25 MPH at the lower ridgelines and 45 gusting to 55 MPH at the higher and more exposed ridgelines. For Salt Lake there will be increased periods of precipitation with the northwest flow. Recent Avalanches Yesterday, there was a report of natural avalanche on South Monitor. This was a wind drifted snow avalanche failing on facets that was 18" deep x 600' wide x 600' vertical (photo below). In our field day yesterday Nikki and I saw some small wind drifted snow avalanches on leeward aspects with the deepest being on a northeast aspect at 10,100'. Ski area and highway operations reported natural avalanche activity during increased snowfall rates in the early evening on south and west facing aspects. Ad to help fund the USFS Avalanche Problem #1 Persistent Weak Layer Location: E-N-W mid and upper elevations Likelihood: Likely to Certain Size: Medium Description: There is a weak layer of faceted snow now buried under the new storm snow. This weak snow has now been and will continue to be overloaded creating dangerous avalanche conditions. Avoid being on, underneath, or adjacent to slopes steeper than 30° in steepness. Avalanches involving PWLs can be triggered remotely (from a distance). Cracking slopes are sure signs that you would see avalanches on steeper slopes. Avalanche Problem #2 Wind Drifted Snow Location: All aspects at mid and upper elevations Likelihood: Likely to Certain Size: Medium Description Continued strong winds blowing from the west have now overloaded a weak snowpack. These wind drifted snow avalanches could be enough to catch and carry a rider, however combined with the buried persistent weak layers this could make for much larger avalanches breaking 1'-3' deep and up to 600' wide. The very nature of strong winds is that they will load slopes on all aspects regardless of wind direction. Avalanche Problem #3 New Snow Location: All aspects, all elevations Likelihood: Unlikely to Likely Size: Small to Medium Description Watch for sensitive soft slabs of new snow, especially during periods of increased precipitation. Today's snowfall may have density inversions which can create sensitive soft slabs of new snow. These by themselves may not be an issue to riders, but combined with the buried persistent weak layer (PWL) and some wind could create bigger avalanches. There is also a chance of rain on snow at elevations below 8,000' later this afternoon. You could see wet loose roller balls in lower elevation terrain.