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The avalanche danger is MODERATE for WET LOOSE avalanches at all elevations, on SE to SW aspects, on slopes steeper than 35º.
A LOW hazard exists for PERSISTENT SLABS on northerly aspects, NW to NE, on slopes steeper than 30º.
5-6″ of new snow this week combined with high humidity and significant cloud cover have dramatically moistened snow surfaces on all aspects.
Expect stability to remain good with few avalanche problems until we see a rapid warm-up, significant loading event, and/or it ceases to freeze at night. May your Easter egg hunt include finding good riding conditions!
Saturday, April 15th will be the last forecast of the season. We will continue to post observations throughout the spring. If you haven’t gotten a chance to donate to your favorite grassroots community avalanche center, it’s not too late. Thank you for all your support this season. Donate here.
Travel Advice | Generally safe avalanche conditions. Watch for unstable snow on isolated terrain features. | Heightened avalanche conditions on specific terrain features. Evaluate snow and terrain carefully; identify features of concern. | Dangerous avalanche conditions. Careful snowpack evaluation, cautious route-finding, and conservative decision-making essential. | Very dangerous avalanche conditions. Travel in avalanche terrain not recommended. | Extraordinarily dangerous avalanche conditions. Avoid all avalanche terrain. |
Likelihood of Avalanches | Natural and human-triggered avalanches unlikely. | Natural avalanches unlikely; human-triggered avalanches possible. | Natural avalanches possible; human-triggered avalanches likely. | Natural avalanches likely; human-triggered avalanches very likely. | Natural and human-triggered avalanches certain. |
Avalanche Size and Distribution | Small avalanches in isolated areas or extreme terrain. | Small avalanches in specific areas; or large avalanches in isolated areas. | Small avalanches in many areas; or large avalanches in specific areas; or very large avalanches in isolated areas. | Large avalanches in many areas; or very large avalanches in specific areas. | Very large avalanches in many areas. |
One human triggered persistent slab was reported on April 4 on a NE aspect at 3600′ on Wimp Bowl. See obs here. No pictures were taken.
Numerous natural small to large loose dry avalanches (sluffs) were observed on Wednesday after 5-6″ of new snow in steep terrain on all aspects.
On 4/5 a loose-wet avalanche (sluff) was human triggered on the south face of Microdot and ran approximately 600 ft. See obs here.
Signal Word | Size (D scale) | Simple Descriptor |
Small | 1 | Unlikely to bury a person |
Large | 2 | Can bury a person |
Very Large | 3 | Can destroy a house |
Historic | 4 & 5 | Can destroy part or all of a village |
Loose Wet avalanches aka wet sluffs will be likely to trigger on southerly aspects SE to SW, at all elevations, on slopes steeper than 35º. Significant cloud cover and high humidity over the past two days has had a major greenhousing effect on all snow surfaces. 5-6″ of new snow from 4/4-4/5 above 3500′ has already become shockingly moist on all aspects including north. Expect to find 5″+ of new moist snow on firm crusts on south aspects that will be easy to trigger and initiate a wet sluff. We observed moist snow in the morning and our party triggered a slow-to-start wet loose that gained significant momentum and ran approximately 600-800 ft.
Although temperatures at 3500′ have remained in the low twenties this week, it felt like 50ºF on Wednesday. Don’t forget your t-shirt, skin wax and glopper stopper and leave the long underwear at home!
Wet loose sluffs can entrain a significant amount of snow as they gain momentum. They can start out as a small rollerball and easily become large enough to bury, injure, or kill. Avoid sunny or moist slopes during the heat of the day which might be most of the day with significant cloud cover. If the slope you’re on is getting warm, sticky, or unsupportable consider moving to cooler aspects or going to the lodge for a beer.
It’s hard to believe it’s April already. As spring temperatures continue to warm up keep an eye out for these avalanche problems in the next several weeks:
Signal Word | Size (D scale) | Simple Descriptor |
Small | 1 | Unlikely to bury a person |
Large | 2 | Can bury a person |
Very Large | 3 | Can destroy a house |
Historic | 4 & 5 | Can destroy part or all of a village |
6″ to 12″ thick persistent slabs will be mostly unlikely but still possible to trigger in isolated and extreme terrain, on northerly aspects, NW to NE, at mid and upper elevations, on slopes 30º and steeper.
Numerous people were out recreating during the good weather spell Saturday-Monday. Most sought after fine northerly lines and no avalanches were observed or reported. However, some evidence exists which points towards the possibility of triggering a slab avalanche where persistent grains have been preserved and are sitting on firm bed surfaces. However, due to the lack of a continuous weak layer/bed surface combo, finding a spot to trigger a slab will be challenging but not impossible.
On Tuesday, a slab was human triggered on a NE aspect at 3600′ that was approximately 70′ wide, ran 80′, with a crown depth ranging from 6-12″ thick. To avoid this problem we recommend doing hand shears and pole tests to identify whether a cohesive slab exists that is sitting on a persistent grain or graupel on a firm crust.
On 4/4-4/5 HP received 5-6″ of new snow with 0.4″ SWE at above 3550′.
NWS AVG Forecast here.
NWS point forecast here.
Marmot Weather Station here.
Independence Mine Snotel here.
Frostbite Bottom Snotel here.
State Parks Snow Report and Motorized Access information here.
XC trail grooming report for Mat-Su, Anchorage, and Kenai here.