Thanks to everyone who participated in the VAC fundraiser last night at the Tsaina Lodge!
Above 2,500ft Moderate
1,800 to 2,500ft Moderate
Below 1,800ft Moderate
Degrees of Avalanche Danger ?
|Saturday||Sunday||Monday & Tuesday|
Elevation: Below 4500′
Aspect: SE – S – SW
Terrain: Southerly facing terrain on slopes above 30 degree slope angle
Sensitivity: Non-reactive – Responsive as sun and warmer temperatures dominate
Likelihood (Human Triggered): Possible
Size: Small – Large
Danger Trend: Increasing with solar input and warmer temperatures
Forecaster Confidence: Good
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
LIST OF AVALANCHE PROBLEMS <here>
SNOWPACK DISCUSSION: The forecast region is experiencing a spring shed cycle, particularly below 4500′. Temperatures around Thompson Pass have been above freezing during the day, and barely freezing over night. This cycle can produce corn snow but is also the precursor to surface instability and an isothermic snowpack.
Snow surface conditions above ~3000′ are widely variable. Conditions on northerly facing slopes range from wind scoured pencil hard sastrugi, melt/freeze, to decomposing unconsolidated particles. Southerly faces are experiencing a range from heavy wet snow, to melt freeze crusts, to corn, to isothermal.
Snow depths generally range from 30-300cm, including on glaciated terrain.
Check out our public observations!
Recent Avalanche Activity
Numerous southerly facing slopes above 30* slope angle are experiencing natural wet avalanches from the port of Valdez up to 4500′ throughout the advisory area. Most of this wet avalanche activity has been surface snow but could step down deeper into the snowpack.
Friday 4/13 PM: Three Pigs at Milepost 39 ran to the edge of the highway.
The conditions we’re experiencing lately don’t fit well with our North American Danger Scale. We’re at a low danger in the mornings, with natural and human triggered avalanches unlikely. As the day progressively becomes warmer and solar input increases, the danger will spike. When this happens, human and natural triggered avalanches become likely.
|WEATHER FORECAST for NEXT 24 HRS at 3,000 ft:|
|Temperature Forecast (Min/Max *F):||26 / 35|
|Ridgetop Wind Forecast (direction/mph):||W / 0-8|
|WIND & TEMPERATURE
PAST 24 hours
|Ferry Terminal||Thompson Pass|
|Average Wind Speed (mph) / Direction||3 / VAR||10 / VAR|
|Max Wind Gust (mph) / Direction||11 / WSW||18 / NE|
|Temperature Min / Max (*F)||35 / 49||30 / 38|
Weather Forecast: Clear to partly cloudy skies Saturday through Tuesday. Temperatures in the Port of Valdez and at Thompson Pass into the 40’s F (4-9*C). Light to moderate winds.
Additional Info & Media
|SNOW HISTORY:||Valdez 4/15 AM||Thompson Pass 4/15 AM|
|24 Hour Snow / Water Equiv.||0”/ 0.0″||0″ / 0.0″|
|Storm Snow /Water Equiv. (3/15-19)||19” / 0.41″||40″ / 1.5″|
|Current Snow Depth||21″||64″|
|April Snow / Water Equiv.||0″ / 0″||0″ / 0″|
|Total Winter Snowfall / Water Equiv.||132.59″ / 27.2”||372″ / 36.6″|
|Snowload in Valdez||53 lbs/sq. ft.|
|SNOW DEPTH & WATER SURVEY (3/4/2018)||Depth||Snow Water Equivalent|
|Milepost 2.5 Valdez||32.2″||9″|
|Milepost 29 Worthington Flats||62.4″||21.2″|
|Milepost 37 Tsaina River bridge||58.4″||14.2″|
|This survey is done the first week of each month.|
- Northeast Prince William Sound NWS Weather Forecast
- Middleton Island Radar for Valdez area
- GOES Alaska water vapor satellite loop
- NOAA NWS Recreational spot forecast for Thompson Pass
- Thompson Pass MP 25.7 RWIS weather station 2740′ (Mesowest)
- Valdez Marine Ferry Terminal weather station sea level
- Nicks Happy Valley above MP 30 weather station 4200′ (scroll to Nicks Valley)
- Upper Tsaina River Snotel near MP 32 1750′
- Sugarloaf Snotel 551′
- Above Valdez Glacier Cryosphere program weather station 6600′ <map here>
- Valdez Blueberry Weather Plot observations (scroll to bottom: Valdez City)
- More Mountain Weather resources for Alaska
- GFS 16 Day Model for Valdez
- Model Average Meteogram for Valdez
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.