wxgeek's weather-Foothills and Denver Snowfall Climatology

As many people have begun to make statements regarding our current dry start to the season, I thought it would be interesting to do some digging and find snowfall records to determine how many dry and wet snowfall years we have had locally, as well as in Denver since they have records that go back much further and Denver snowfall has a very strong positive correlation with foothill snowfall. So I used the Conifer Mountain almanac that has records back to 1993, and the Denver NWS office snowfall statistics that go back 130 years. As I prefer to base weather statements on data versus perception or memory, which has been proven to be very unreliable. Please also note that snowfall data is only part of the overall drought equation, as rainfall records would need to be included to determine the overall moisture for a given year. However, there are 2 critical fire seasons here in CO, the first is from March into June which is highly dependent on snowfall, and the second is from September into November which is dependent on monsoon rainfall. Large fires during the monsoon season (July-August) are quite rare in the foothills. Here is what I have found.

Conifer Mountain (20 year history) - The average snowfall from 1993 to 2012 is 167 inches. There have been 9 years with below average snowfall, and 11 years with above average snowfall. There has only been one preiod with consecutive below average years, which was 1999 - 2002. There have been 3 times with consecutive above average years, 1993-1995, 1996-1999, and 2006-2008. The average snowfall since 2006 is 184 inches, so a higher average than the entire period for the past 6 seasons. Highest seasonal snowfall was in 280 inches in 2006-2007, and the lowest snowfall was 99 inches in 2005-2006, and second driest was 102 inches in 2001-2002.

Denver (130 year history) - The average snowfall in Denver is 57 inches. There have been 74 seasons below average, and 56 seasons above average. There have been 7 periods with 3 consecutive below average snow seasons, which are 1882-1890, 1899-1906, 1933-1936, 1962-1967, 1974-1978, 1998-2000, and 2003-2006. There have been 9 periods with 3 consecutive above average seasons, which are 1911-1914, 1925-1931, 1936-1939, 1946-1949, 1950-1953, 1956-1962, 1971-1974, 1985-1988, 1990-1995. Highest Denver snowfall was 118 inches in 1908-1909. Lowest snowfall was 21 inches in 1888-1889, and second driest was 23 inches in 2010-2011.

In general, the above average periods (consecutive seasons) seem more prevalent and persist longer than the below average periods. However, the most prevalent climatological condition is for seasons to be near average. Let me be clear here, we cannot make declarative assumptions from such a small data set. With only 130 years of actual weather observations, we simply do not have sufficient data to make long term climate statements. The weather 1,000 or 1,000,000 years ago likely was very different than the past 100 years. The droughts of the late 1800's and early 1900's seemed pretty bad, but not many people living out here then. n general the 1950's were pretty wet, and the late 1980's to early 1990's were pretty wet.

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"Climatology is what you expect, Weather is what you get".

"It is better to be roughly right than precisely wrong".