Funny you should mention that. I don't have the history here that a lot of you guys do, but the last several years - 6 or so - I've noticed that it seems our snowfall cycle is often dumbbell shaped, with Jan/Feb being dry, and Nov/Dec + Mar/Apr being heavy. I thought it was an El Niño thing, but I've seen it on La Niña years too.
I believe it is a global warming thing. In my memory we almost always used to have a dry spell for about a week or ten days during February even back in the early 70's. But since about the mid-80's it has been typical to have prolonged dry spells (Rex Block usually) from sometime in January until mid-February to early March, depending on the year. I don't think that was an historical pattern prior to the 80's.
By the way, the big avalanche on the west face of Mt. Snoqualmie was I believe in the second week of February in 1990. The biggest slides were in the Baker area where nearly 500" of snow fell in about 25 days. I skied Mt. Herman on about the 15th of February and the biggest crowns I saw at the time looked to be 25'. (There was a 13' crown at the top of the old Blueberry area that I photographed.) One avalanche in the Baker area took out perhaps ten acres of old growth and left a trimline 400' above a gully that the slide ran down and then climbed the opposite wall. Another of the 1990 slides was the obvious track that crosses Highway 20 beneath Ruby Mountain with the broken snags. There were also huge slides in 1982 and in mid-January 1971 (Yodelin avalanche). In August of 1972 I hiked up Downey Creek and came through an area of downed old growth (to 4') that had fallen upslope. That avalanche had started on Green Mountain descended to Downey Creek then climbed the opposite slope through forest 400' to take out the timber on the trail. 1999 had a similar period of snowfall to 1990 and some slides were quite large that year too, including the one on Shuksan Arm that resulted in fatalities.
