What Does a Strong October Mean for the Rest of the Snow Season?
Updated: Apr 26, 2020
The snow season in the Southern San Juan Mountains is off to a strong start! Wolf Creek Ski Area opened on October 13, only 5 days later than their record (October 8, 2011). What can a strong October tell us about the rest of the snow season?
The South San Juans on 11/1/18 (Photo by Chris Rapp)
To answer that question, I compiled October precipitation totals between 1979-2018 and plotted them against annual snow accumulation at the Upper San Juan SNOTEL site, located at 10,200 feet on the west side of Wolf Creek Pass.
As you can see from the graph, there is no relationship between October precipitation and annual snow accumulation. The best phrase to describe our snowpack is "highly variable", but I still enjoy comparing the past to the present.
The median October precipitation is 3.8 inches, and we received 6.3 inches this October. 1986, 1987, 1990, and 1998 all had around 6 inches of precipitation at the end of October, and all but 1990 finished above the median.
Ironically, 2011 (2012 water year) holds the record for October precipitation (and the earliest opening date for Wolf Creek), but it was a lousy snow season, finishing well below the median of 32 inches of water. The best year in the data set is 1979, which started out with only 3 inches of October precipitation.
As far as predicting the 2019 snow season, October precipitation is not reliable. Hopefully the stubborn ridge of high pressure that diverted the jet stream around us nearly all last winter will be replaced by endless atmospheric river events as well as closed lows. Those are the weather systems that bring us the famed powder dumps at Wolf Creek.