The North outflow winds are back. If you ski or high mark a slope with wind affect, it has a much greater chance of sliding than unscathed powder snow.
Above 2,500ft Considerable
1,800 to 2,500ft Moderate
Below 1,800ft Low
Degrees of Avalanche Danger ?
Elevation: Above 2500′
Aspect: Lee to northerly winds
Terrain: Near ridgelines, rollovers, and gully walls
Likelihood (Human Triggered): Possible
Size: Small – Large
Danger Trend: Increasing
Forecaster Confidence: Fair
AVALANCHE PROBLEM SCALE DESCRIPTORS:
Sensitivity: Non-reactive, Stubborn, Responsive, Touchy
Distribution: Isolated, Specific, Widespread
Likelihood: Unlikely, Possible, Likely, Nearly Certain
Size: Small, Large, Very Large (size scale <here>)
Danger Trend: Increasing, Steady, Decreasing
Forecaster Confidence: Good, Fair, Poor
AVALANCHE PROBLEM TOOLBOX <here>
Inter-Mountain (Transitional) Specific:
Last night and continuing into today winds up to 70MPH have scoured the Chugach Mountains surrounding Valdez. Every peak, ridge, and even some gullies/drainages have seen some sort of wind. Wind loaded areas are most likely to produce avalanches. These areas will have textured snow surfaces, and will be harder and punchy. The wind protected areas harboring soft snow are where you want to play speaking from an avalanche forecaster’s and a skier/snowmachiner’s perspective.
The last significant storm cycle during February 13-15 deposited more than 30″ of heavy snow, mixed with rain below ~3000′, in the Thompson Pass region. A widespread avalanche cycle occurred during this storm, flushing out many persistent weak layers deeper in the snow pack. Make a mental note of where these large avalanches occurred, for areas that didn’t slide could still harbor problems.
The clear and cold spell February 18-22 created widespread surface hoar and near surface facets (sugar snow). These weakness may be found under fresh wind transported snow from the last week.
Find more photos and observations at the bottom of the page. Sharing your observations creates an informed community that everyone benefits from at some point.
Recent Avalanche Activity
Inter-Mountain (Transitional) Specific:
Observed Feb. 18:
- Numerous large(D3+) Wet Slab avalanches ran during the storm in the Tsania Valley that hit the valley floor
- Natural Sluffs (Loose Snow) Observed on North Aspects in the Tsania Valley(before the glacier), while no natural activity was observed in the Tonsina Glacier area
Observed Feb 16:
- Many mid storm avalanches released up to D2.5 off of steep faces: Several on north face of Odyssey, School Bus, Vertigo, Snatch, 40.5 Mile Ridge/Wilburs
- Extensive shallow slab releases on mid+ elevation southerly aspects below Bald Boy to Hippy Ridge (MP 29-37): seemed to be pulling out on persistent weaknesses: likely surface hoar or near surface facets formed last week.
- Large deeper avalanche releases on basal weaknesses at the ground below Max Low and Wilbur’s on 40.5 Mile Ridge
Reported Feb.13-15 during the storm:
- Large avalanches at Milepost 38, 42, and 50
See Maritime Zone for updated weather.
Additional Info & Media
- NWS forecast for Northeast Prince William Sound <here>
- NOAA NWS spot forecast for Thompson Pass <here>
- Thompson Pass RWIS weather station <here>
- MP 30 Nicks (Happy) Valley weather station at 4200 feet <here> (scroll to Nicks Valley)
- Valdez Glacier UAF weather station at 6600 feet <data here> <map here>
- Further weather resources <here>
SNOW CLIMATE ZONES:
- Maritime (Coastal) – from the Port of Valdez to Thompson Pass, all waters flowing into Valdez Arm and everything south of Marshall Pass.
- Inter-mountain (Transitional) – between Thompson Pass and Rendezvous Lodge.
- Continental (Interior) – the dry north side of the Chugach (north of 46 Mile, including the Tonsina River).
Photo of Thompson Pass
Interactive Map of Valdez Forecast Areas w/ Many Resource Layers (Trevor Grams)
NEWS: Our region is “one of the snowiest places on earth” – Serendipity / Rendezvous snowfall record set in 1963 <here>.
Free smart phone avalanche forecasts at: http://www.