Turnagain Pass Avalanche Forecast

2023 is crashing in with heavy rain, snow, and wind – Happy New Year!

A strong storm system is over the Eastern Turnagain Arm and already there has been around 1″ of rain at sea level and 10-14″ of snow in the higher elevations. The storm will peak today and taper off tomorrow. Today’s precip could bring 1-2″ of additional rain and up to 2 feet of snow to favored areas above 2,000′ (check out the graphic below). Turnagain Pass itself has seen 14″ of snow as of 6am with up to 18 more inches forecast today. The rain/snow line was around 500′ last night but expected to rise to 1,500′ by this afternoon and into tomorrow. Ridgetop winds are easterly and strong; hourly averages have been 30-40mph with gusts in the 70’s and should remain strong through the day.

Natural Avalanche Cycle:  Avalanches are likely occurring now in the mid and upper elevations due to the strong wind and heavy snowfall. It’s a textbook case of strong storms = avalanches. With 2-3 feet of new snow and wind in the Alpine, avalanches composed of just the new snow could be 2-4′ deep. These are the typical storm slab and wind slab avalanche types. As the rain/snow line rises and temperatures warm, this only adds to the instability by heavier snow/rain falling on lighter snow. Wet or moist snow storm slab avalanches could start releasing in the mid elevations with this ‘upside down‘ setup. Rain on snow at the lower elevations may or may not be creating wet snow avalanches as the prior snowpack was mainly crusts from the rain that occurred during the Christmas Storm. However, debris from avalanches above could run to the bottom of paths into the lower terrain.

If you are planning on braving the roads and getting outside today, be aware that travel in avalanche terrain is NOT recommended. This is the kind of day for sleeping in, and letting the mountains do their thing.

As of 6am 10-14″ of snow has already fallen above 1,500′. Another 12 to even 24″ of snow could fall today above 2,000′. Graphic courtesy of NWS Anchorage.

This storm is the second large loading event for the snowpack. It will again test those buried weak layers that sit around the Thanksgiving crust, or even any weak layer that may be left from the Christmas Storm a week ago. Again, we will do our best at seeing if any storm snow avalanches are able to break into buried weak layers. This will be an indicator of how those layers are healing and if they will continue to be a problem in our future or not. For now however, this deeper problem is just one more reason why avoiding avalanche terrain is a good call.