Springtime conditions exist: avalanche danger increases with daytime warming and solar radiation.
Above 2,500ft Considerable
1,800 to 2,500ft Moderate
Below 1,800ft Moderate
Degrees of Avalanche Danger ?
|MONDAY||TUESDAY||WEDNESDAY & THURSDAY|
Elevation: Below 6000′
Aspect: All steep terrain, especially aspects that have direct sun
Terrain: Slopes >35 degrees near rocks and vegetation.
Sensitivity: Touchy when warmed.
Likelihood (Human Triggered): Likely when warmed.
Danger Trend: Increasing quickly each day with warming temperatures, falling with freezing at night
Forecaster Confidence: Good
Terrain: corniced ridgelines
Likelihood (Human Triggered): Possible
Size: Small to 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>
Maritime (Coastal) Specific:
The spring shed is in progress. Over the past week, daytime temperatures have reached into the 50s in the valley bottoms. Most of our remaining Chugach snow has been freezing at night and thawing during the day. This means crusts and lots of isothermal snow below 3000′.
Having just finished a 19-day dry spell, the bit of rain and snow this week will freshen our snow world. If the 1/4″ of precipitation comes our way, we can expect rain to about 4000′ with snow above. With warm temps the new snow should bond quickly. An exception will be upper elevations with a sun crust come bed surface. When the sun pops out again toward the weekend, expect fresh loose avalanches and the possibility of new wet slab.
A tour of the Woodworth and Deserted Glaciers Sunday April 23 showed increased flow in the creeks, lots of cornice failure, and some new wet slabs in the upper elevations on sunny aspects.
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Recent Avalanche Activity
Maritime (Coastal) Specific:
- April 23 Natural wet slab D2.5 above Deserted Glacier, west aspect, 5800′. Lots of south and west cornice failure and wet loose activity into the Woodworth and Deserted Glaciers.
- April 17 The Wall/Tomahawk rockfall resulting in D3+ avalanche.
- April 13-16 More wet loose activity in the afternoon on steep solar affected slopes
- April 18th “Things are coming unglued out there” Photo: Jeremy Martin
- Large avalanche on, “The Wall/Tomahawk” caused by rockfall Photo: Jed Workman
|WEATHER FORECAST for NEXT 24 HRS at 3,000 ft:|
|Temperature Forecast (Min/Max *F):||33 / 34|
|Ridgetop Wind Forecast (direction/mph):||East / 0-10|
|Snowfall (in/water equivalent):||0.23″ / 0.06″|
|WIND & TEMPERATURE
PAST 24 hours
|Ferry Terminal||Thompson Pass|
|Average Wind Speed (mph) / Direction||10 / W||14 / NE|
|Max Wind Gust (mph) / Direction||14 / WSW||23 / ENE|
|Temperature Min / Max (*F)||40 / 50||34 / 44|
Weather Forecast: Mostly cloudy skies with sputters of rain through Thursday. Precip accumulation of 0.25″. Freezing line 1700′, which means a bit of fresh white stuff in the upper elevations. Light variable wind.
Additional Info & Media
|SNOW HISTORY:||Valdez 4/24 AM||Thompson Pass 4/24 AM|
|24 Hour Snow / Water Equiv.||0”/0.0″||0″ /0″|
|Storm Snow /Water Equiv. (3/26-4/9)||16.9″ /4.1″||24″ /2.4″|
|Current Snow Depth||8″||39″|
|April Snow / Water Equiv.||trace″ /1.82″ rain||8″ / 0.8″|
|Total Winter Snowfall / Water Equiv.||239.8″ /24.47”||327″ / 31.4″|
|Snowload in Valdez||65.0 lbs/sq. ft.|
|SNOWFALL at OTHER STATIONS:
LAST 24 HRS (4/24 AM)/STORM TOTAL (3/27-4/6)/STORM WATER EQUIV.:
|Nicks Valley at 4200 ft (in):||0″ / ~16″ / ?”|
|Upper Tsaina at 1750 ft (in):||0″ / ?” / 1.2+”|
|Sugarloaf at 550 ft (in):||0″/ 20+rain” / 2.8″|
|SNOW DEPTH & WATER SURVEY (4/2/2017)||Depth||Snow Water Equivalent|
|Milepost 2.5 Valdez||41.9″||11.9″|
|Milepost 29 Worthington Flats||62.2″||19.6″|
|Milepost 37 Tsaina River bridge||46.3″||12.5″|
|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.