January 23, 2021
January 24, 2021
Zone or Region:
Airplane Observations North and Central Cascades
Did you observe any avalanches? Yes
Size 3: Could bury and destroy a car, damage a truck, destroy a wood frame house, or break a few trees
Surprisingly few large slabs post 1/12. Saw just 5. Many smaller slabs to 2-3', mostly filled in, some with wide propagation and sympathetic triggering downslope. Large full depth glide avalanches esp. on Green Mountain, perhaps a dozen. Most avalanches that were large initiated with small slabs or spalling off mid-elevation cliffs, and gradually entrained significant wet snow. Little furrowing north of Snoqualmie Pass; most slopes smooth above 5500-6000' but with wind texturing in some areas. No snow to speak of on trees anywhere - evidently wind.
Slopes most likely to have very deep slabs were upper NW to N facing steep and somewhat rocky summit slopes. No real evidence of slabs having been historic with valley floor runouts. Presumably, there were a number of smaller avalanche cycles as the moist period persisted. The last huge final storms evidently deposited very dense and fast settling snow that was strong enough to resist the final rains with warm front. Rain in these higher starting zones was not significant to penetrate the snowpack except for the aforementioned rocky summit slopes.