Good morning. This is Kevin Wright with the Chugach National Forest Avalanche Information Center on Wednesday, April 4th at 7am. This will serve as a general backcountry avalanche advisory issued for Turnagain Arm with Turnagain Pass as the core advisory area (this advisory does not apply to highways, railroads, or operating ski areas).
Skookum drainage is now closed to motorized use for the season. All CNFAIC Staff motorized areas on the Glacier Ranger District, including Placer Valley, 20-Mile and Johnson Pass remain open.
We can expect 2 time zones in the avalanche danger today. This morning a LOW with pockets of MODERATE trend exists with a hard surface crust in most areas except Northerly upper elevation slopes. This afternoon/evening the trend moves towards overall MODERATE if the temperature increases enough to cause wet avalanching.
With the degree of freezing last night, the possibility of finding avalanches this morning is isolated to upper elevation Northerly pockets where buried surface hoar might still be reactive. If temperatures get high enough in the afternoon the possibility of wet avalanches is pretty good, but all that solar energy will have to penetrate and melt the surface crust first. Travel late in the day should be strategically planned to avoid traveling on sunny slopes and near the bottom of large runout areas.
Concern #1 – Buried Surface Hoar
This problem has shown itself to be pockety in nature. It’s not hard to find in wind loaded areas above 2000 feet on shaded aspects. It’s generally confined to the top foot of the snowpack, and the slab size seems to be in the smaller size range. The worst case scenario would be dropping into a steep North facing line where the runout takes you places you don’t want to go.
Concern #2 – Wet Avalanches
Late in the day on sunny low elevation slopes, natural activity is possible if our temperatures rise significantly. This problem didn’t happen very severely yesterday with relatively colder temperatures and a really solid crust from the previous night. If the heat melts the crust this afternoon start thinking about getting off the South facing slopes before they fall apart in the evening.
Warm temperatures during the day and a hard freeze the last 2 nights means a solid supportable crust below 2000 feet across our region. It’s been a while since any snowfall, and there is only a slight possibility of snow today. Clouds are expected to take over the sunny skies this afternoon and a chance of rain or snow is creeping into the forecast tomorrow.
CNFAIC Weather Page and the NWS forecast
Wendy will issue the next advisory Thursday morning. If you get out in the backcountry we want to know what you are seeing. Please send us your observations using the button at the top of this page or give us a call at 754-2369. Thanks and have a great day.