Tuesday-Friday 1/16-1/19
Issued: Tue, Jan 16, 2018 at 8AM
Expires: Fri, Jan 19, 2018
Valdez, Thompson Pass, and the Copper Basin have received 2-4 feet of new snow since January 14. Give this new snow 2-3 days to settle before approaching avalanche terrain (30-45 degree slopes). Be on the lookout for natural avalanches. If you see natural avalanches, stay far away from slopes of similar aspect/elevation. The danger will increase with wind transport.
Above 2,500ft Considerable
1,800 to 2,500ft Moderate
Below 1,800ft Moderate
Problem Details
| TUESDAY | WEDNESDAY | THURSDA Y& FRIDAY |
|---|---|---|
 |
|
|
DANGER SCALE |
LOOSE SNOW:
Elevation: Above 1800′
Aspect: All
Terrain: 35+ degrees steepness
Sensitivity: Responsive
Distribution: Widespread
Likelihood (Human Triggered): Likely
Size: Small – Large
Danger Trend: Steady
Forecaster Confidence: Good
WIND SLAB:
Elevation: Above 2000′
Aspect: Lee of ridges, gullies, ridgetops
Terrain: All terrain exposed to wind
Sensitivity: Responsive
Distribution: Specific
Likelihood (Human Triggered): Likely
Size: Small – Large
Danger Trend: Steady
Forecaster Confidence: Fair
PERSISTENT SLAB:
Elevation: Above 2500′
Aspect: All
Terrain: 35+ degrees steepness
Sensitivity: Stubborn
Distribution: Specific
Likelihood (Human Triggered): Possible
Size: Small – Large
Danger Trend: Decreasing
Forecaster Confidence: Poor
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: A good Ol’ Copper Whopper ran its course on the Eastern Chugach this weekend. Storm totals range from 18’’ in Kenny Lake/Chitina to 36’’ at 46 mile/Thompson Pass. This snow came in fairly “blower” but peaked out with heavier characteristics during the brunt of the storm. As with any big storm expect wind slabs and storm snow to be major concern. Give this new snow 2-3 days to settle before exposing your self to avalanche terrain. Previous to this storm there were concerns of a persistent weak layer about 1-2’ under the snow surface. This persistent weak layer is now buried 3-4’ down, be on the look out for natural avalanche activity on this old layer. If you see natural avalanches on this layer, use extreme caution on slopes of similar aspect/elevation.
Recent Avalanche Activity
A few natural avalanches to size D2 where observed from town to elevations up to 4000′. No additional reports of natural or human triggered avalanches further interior.
Recent Weather
| WEATHER FORECAST for NEXT 24 HRS at 3,000 ft: | ||||
| Temperature Forecast (Min/Max *F): | 21/ 31 | |||
| Ridgetop Wind Forecast (direction/mph): | E / 7-31 | |||
| Snowfall (in): | 0-4 | |||
| WIND & TEMPERATURE PAST 24 hours |
Ferry Terminal | Thompson Pass |
| Average Wind Speed (mph) / Direction | 2 / N | 22 / ENE |
| Max Wind Gust (mph) / Direction | 12 / N | 30 / ENE |
| Temperature Min / Max (*F) | 34 / 43 | 27 / 35 |
Weather Forecast: Early this week temperatures near the coast will remain above freezing. As one travels towards Thompson Pass and the Interior Region expect temperatures to remain below freezing. Snowfall will be spotty throughout the week, but there is a chance of northerly air prevailing and sunnier skies this Thursday/Friday. The Jet Stream seems to be changing directions towards Washington State, but as always mother nature will keep us on our toes.
Additional Info & Media
| SNOW HISTORY: | Valdez 1/14 AM | Thompson Pass 1/14 AM |
| 24 Hour Snow / Water Equiv. | ~”/ ~” | ~″ / ~″ |
| Storm Snow /Water Equiv. (1/13-present) | rain” / 0.45″ | 12″ / 0.45″ |
| Current Snow Depth | 25″ | 78″ |
| January Snow / Water Equiv. | 13.25″ / 4.19 ″ | 44″ / 3.55″ |
| Total Winter Snowfall / Water Equiv. | 77.1″ / 20.49” | 252″ / 27.75″ |
| Snowload in Valdez | 45 lbs/sq. ft. |
| SNOWFALL at OTHER STATIONS: LAST 24 HRS / STORM TOTAL / STORM WATER EQUIV.: |
||||
| Nicks Valley at 4200 ft (in): | ~” / ~” / ~” | |||
| Upper Tsaina at 1750 ft (in): | ~” / ~” / ~” | |||
| Sugarloaf at 550 ft (in): | rain” /rain” / 0.4″ | |||
| SNOW DEPTH & WATER SURVEY (2/1/2017) | Depth | Snow Water Equivalent |
| Milepost 2.5 Valdez | ″ | ″ |
| Milepost 18 | ″ | ″ |
| Milepost 29 Worthington Flats | ″ | ″ |
| Milepost 37 Tsaina River bridge | ″ | ″ |
| This survey is done the first week of each month. | ||
Weather Quicklinks:
- 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
- Windy
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)
Run Map of Thompson Pass Area (Sean Wisner) (2MB download)
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.
