Forecast for the Logan Area Mountains
Issued by Toby Weed on
Sunday morning, February 9, 2020
Sunday morning, February 9, 2020
Heightened avalanche conditions and MODERATE danger exist on many slopes in the backcountry today. People could trigger 1 to 3 foot deep avalanches of wind drifted snow on upper and mid elevation slopes.
- Evaluate snow and terrain carefully.
Low
Moderate
Considerable
High
Extreme
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Weather and Snow
It's 12°F at the 8400' Tony Grove Snotel, and there is an inch or two of graupel with 0.2" of Snow Water Equivalent in the last 24 hours. The station recorded almost 5"of SWE with the windy and warm late week storm. There is now 88 inches of total snow, containing 137% of normal SWE. The winds veered from the northeast overnight, and are currently blowing around 15 mph at the CSI Logan Peak weather station, and it's 8°F at 9700'.
Accumulations of very heavy snow, rain at lower elevations, and sustained strong westerly winds created heightened avalanche conditions in the backcountry this weekend. Much cooler temperatures last night have set up the mushy and wet snow at lower elevations, and the snow is now harder and much more stable. A thick rain-crust, translucent and brittle in places, exists in many areas even at high elevations. It is capping a soft and moist layer of graupel and heavily rimed snow. A fast moving squall dropped another inch or two of graupel in the Central Bear River Range yesterday.
A thick and supportable rain-crust caps Thursday's moist layer of fresh graupel and rimed snow.
Graupel fell during yesterday's squall
There's a chance of snow showers this morning, then expect partly sunny conditions, with high temperatures at 8500' around 21°F, and 13 to 15 mph east winds. Tonight will be mostly clear, with low temperatures around 5°F, 9 to 14 mph northeast winds, and wind chill values as low as -12°F. Snow showers are possible tomorrow afternoon. It'll be mostly cloudy, with a high temperature near 20°F, 20 to 25 mph north winds, and wind chill values as low as -11°F.
Recent Avalanches
Clearing yesterday morning allowed us to get views of fairly widespread natural avalanche activity in the Wellsville Mountain Wilderness, including this nice fresh avalanche of wind drifted snow in Old Logway Canyon. The avalanche appears to be two to three feet deep and 300' to 400' wide, running well over 2000 vrt', but stopping just short of the flats on Maple Bench.
Natural wet avalanches hit highway 89 in the Dugway Area of Logan Canyon and forced it's closure around 3:00 Friday afternoon. The highway was closed for a couple hours so crews could clear the debris.
We easily and intentionally triggered a good sized avalanche Thursday in Hatties Bowl above Rick Springs in Logan Canyon. The 1' deep and 100' wide avalanche cracked released after we dropped a very small chunk of cornice on it.
Avalanche Problem #1
Wind Drifted Snow
Type
Location
Likelihood
Size
Description
This morning's northeast winds could form drifts in unusual or unexpected places at upper elevations. Heightened avalanche conditions exist on upper and mid elevation slopes today, and people could trigger avalanches of wind drifted snow. Sustained and strong west winds Thursday and Friday moved tons of heavy snow into deep drifts on the lee sides of the major ridges and avalanche starting zones. The fresh drifts were quite sensitive when they first formed, and people easily and remote triggered soft slab avalanches. Natural avalanches occurred on many drifted slopes Thursday night and Friday. The drifts gained significant stability yesterday, and will probably be fairly hard and stubborn today. Hard wind drifts sometimes allow people to get out on them before releasing, kind of like a mouse trap.
- Watch for and avoid fresh drifts near ridge lines and in and around terrain features like cliff bands, scoops, gully walls, and sub-ridges.
- Avoid ridge top cornices, which can break much further back than expected and start avalanches on slopes below.
Shooting cracks like this from Thursday are a sure sign of instability.
Additional Information
Here's what we saw in the Wellsville Mountain Wilderness last week.
General Announcements
Are you looking to improve your avalanche skills? We are offering a Backcountry 101: Introduction to Avalanches class at Powder Mountain February 14-15. Info and sign up HERE
Thanks to the generous support of our Utah ski resorts and Ski Utah, we have discount lift tickets available. All proceeds from these go towards paying for avalanche forecasting and education! Get your tickets HERE.
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Remember your information can save lives. If you see anything we should know about, please help us out by submitting snow and avalanche observations....HERE. You can also call us at 801-524-5304, email by clicking HERE, or include #utavy in your tweet or Instagram.
This forecast is from the USDA Forest Service, which is solely responsible for its content. The forecast describes general avalanche conditions and local variations always occur.
I will update this forecast before about 7:30 tomorrow morning.