DOT will be doing avalanche control work from MP 37-42 today! Expect delays.
Another 5 inches of snow tallies up to 23 total at Thompson Pass for this storm cycle.
Limited visibility and unstable snow slabs will complicate travel and terrain selection.
Evaluate the new snow to old snow bonding and mid-storm weaknesses as temperatures have been quite variable throughout the storm.
Friday April 14: VAC Spring Full Moon FUNraiser with Acoustic Avalanche @ Tsaina Lodge
Above 2,500ft Considerable
1,800 to 2,500ft Considerable
Below 1,800ft Moderate
Degrees of Avalanche Danger ?
|THURSDAY||FRIDAY||SATURDAY & SUNDAY|
Likelihood (Human Triggered): Likely
Size: Small – Large
Danger Trend: Increasing
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
AVALANCHE PROBLEM TOOLBOX <here>
Maritime (Coastal) Specific:
An upside down snowpack has developed since temperatures warmed Wednesday, peaking in the high 30s down near the port and mid to high 20s near 3000′. 2 feet of snow has been measured in the port and on Thompson Pass, with more likely in the upper elevations which is colder and dryer. Human triggered avalanches were reported on the road run the last couple of days and slab and wet loose snow was moving on very steep slopes around the port on Wednesday. Maintain vigilance in evaluating the bonding of new snow to old and mid-storm weaknesses that have been failing with a top heavy load.
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
Maritime (Coastal) Specific:
Poor visibility have limited observations: please share if you have seen anything!!!
- March 29: 0-1000′ elev. below Comstock: up to 18″ of heavy storm snow was shifting and sliding under foot in steeps with friction: propagation limited
- March 28: human triggered avalanches on the road run
- March 25: reports of upper elevation (>4500′ elevation) human triggered windslabs to a foot thick releasing off steep slopes.
|WEATHER FORECAST for NEXT 24 HRS at 3,000 ft:|
|Temperature Forecast (Min/Max *F):||26 / 29|
|Ridgetop Wind Forecast (direction/mph):||SE / 10-25|
|Snowfall (in/water equivalent):||5-10″ / 0.7″|
|WIND & TEMPERATURE
PAST 24 hours
|Ferry Terminal||Thompson Pass|
|Average Wind Speed (mph) / Direction||4 / Var||17 / SE|
|Max Wind Gust (mph) / Direction||21 / W||25 / ESE|
|Temperature Min / Max (*F)||32 / 37||20 / 28|
Weather Forecast: With slightly cooler temps this morning (high teen on the pass and just below freezing at lower elevations) and a few snowflakes are falling in town, expect a continuation of light snowfall until this evening when volume could pick as the bulk of a front hits us (possible 6 inches overnight). Clouds and light precipitation will persist through the weekend, but temperatures will warm Friday, transitioning the moisture to rain up to 2500′. Not much precipitation will make it interior until Friday when more gusto can push over the range. Winds will remain moderate with the back and forth battle of onshore and offshore flow at mountain passes.
Additional Info & Media
|SNOW HISTORY:||Valdez 3/30 AM||Thompson Pass 3/30 AM|
|24 Hour Snow / Water Equiv.||0.6”/.44″||5″ /0.5″|
|Storm Snow /Water Equiv. (3/27-30)||13.6″ /?”||23″ /2.3″|
|Current Snow Depth||42.9″||42″|
|March Snow / Water Equiv.||14.6″ /1.6″||34″ / 2.7″|
|Total Winter Snowfall / Water Equiv.||237.5″ /22.5”||317″ / 30.4″|
|Snowload in Valdez||52.0 lbs/sq. ft.|
|SNOWFALL at OTHER STATIONS:
LAST 24 HRS (3/30 AM)/STORM TOTAL (3/27-30)/STORM WATER EQUIV.:
|Nicks Valley at 4200 ft (in):||3″ / 10″ / ?”|
|Upper Tsaina at 1750 ft (in):||1″ / 6″ / 0.8″|
|Sugarloaf at 550 ft (in):||0.01″/ 15″ / 1.6″|
|SNOW DEPTH & WATER SURVEY (2/28/2017)||Depth||Snow Water Equivalent|
|Milepost 2.5 Valdez||41.8″||12″|
|Milepost 29 Worthington Flats||63.6″||18.6″|
|Milepost 37 Tsaina River bridge||49.3″||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.