Forecast for the Ogden Area Mountains

Mark Staples
Issued by Mark Staples for
Wednesday, January 23, 2019
Today wind drifting is the main issue. With increasing winds today plus more snow this afternoon, the avalanche danger is CONSIDERABLE at mid and upper elevations. Low elevations have a MODERATE danger.
Avoid wind loaded slopes and you'll avoid most avalanches. With such a huge load of snow over the last week, the possibility remains for slides to break deeper in the snowpack on buried persistent weak layers. These layers are gaining strength and do not exist everywhere, but are lurking on some slopes.
Low
Moderate
Considerable
High
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Weather and Snow
Temperatures this morning are mostly in the low teens F.
Winds at ridgetops this morning increased some and are averaging 15 mph gusting 30-35 from the W and SW.
Today will have stronger winds and snowfall. Both should start around 11 a.m. but the strongest winds and heaviest snowfall should occur later in the afternoon. Winds at upper elevations will be gusting 40-60 mph from the W and NW. By tomorrow morning the Ogden area mountains should get about 5-7 inches.
It's been snowing a lot lately. While different areas have been favored at different times, most places in the last 7 days have received snowfall containing 4-5 inches of water.
Recent Avalanches
Yesterday ski patrols were able to trigger some fresh slabs of wind-drifted snow. These weren't too big but a good heads up that with increased winds and more snow today, more slides like these will be likely.
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Avalanche Problem #1
Wind Drifted Snow
Type
Location
Likelihood
Size
Description
The number one issue today is wind-drifted snow. Wind loaded slopes will have both old and newly formed wind slabs. As winds increase today, the loading will keep these wind slabs sensitive. I think any avalanches breaking deeper in the snowpack are mostly likely to occur on these same slopes.
Winds today will be blowing from the W and NW, but I have indicated that this problem exists on all aspects at mid and upper elevations. Winds can blow and swirl in the mountains and the best way to identify wind loading is with your eyes, not with a compass or the above aspect/elevation diagram (aka the rose). Look for and avoid wind loaded slopes. I think you'll see the winds moving snow today. Otherwise, fresh wind deposits often look smooth and rounded.
Avalanche Problem #2
Persistent Weak Layer
Type
Location
Likelihood
Size
Description
There's good news and bad news. The good news is that any persistent weak layers of facets in the snowpack have gotten buried deep in the snowpack with recent storms. This means they are healing and we are building a strong snowpack. In many places the snowpack is already quite strong overall and no persistent weak layers exist. Yesterday in the backcountry north of Snowbasin, I dug 5 snowpits between about 8000 and 7000 feet on northerly aspects and couldn't find any persistent weak layers.
However, the Ogden area mountains have seen some avalanche activity on buried layers of small facets and/or surface hoar. (one good example here). A skier near North Ogden Divide found some of these weak layers yesterday. If I were skiing or riding today, I'd be looking for these layers. Fortunately you don't need to dig to the ground, dig about 3-4 feet deep. Besides it's good rescue practice.
General Announcements
This information does not apply to developed ski areas or highways where avalanche control is normally done. This forecast is from the U.S.D.A. Forest Service, which is solely responsible for its content. This forecast describes general avalanche conditions and local variations always occur.