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How bad has the winter been this year?

My friend John Feldt of Blue Water Outlook has an interesting post (shown below) discussing the severity of the winter this year using the AWSSI index.  He explains it below and provides a link to the Midwestern Regional Climate Center’s web page describing winter severity across the US.  You can go to the MRCC’s page and check out the interactive map at http://mrcc.isws.illinois.edu/research/awssi/indexAwssi.jsp#info.  For us in the Southeast?  No big surprise that we have been in a mild winter, with every month in the last year above normal in temperature.

Winter seasons have significant societal impacts across all sectors ranging from direct human health and mortality to commerce, transportation, and education. The question “How severe was this winter?” does not have a simple answer. At the very least, the severity of a winter is related to the intensity and persistence of cold weather, the frequency and amount of snow, and the amount and persistence of snow on the ground. The Accumulated Winter Season Severity Index (AWSSI) was developed to objectively quantify and describe the relative severity of the winter season.

The AWSSI is not limited to meteorological winter (December ‐ February) but is intended to capture winter weather from its earliest occurrence to its last. The winter season begins when the first of any one of the following instances occurs:

First measurable snowfall (>= 0.1 inch)
• Maximum temperature at or below 32°F
• December 1

The winter season ends at the last occurrence of any of the following:
• Last measurable snowfall (>= 0.1 inch)
• Last day with 1 inch of snow on the ground
• Last day with a maximum temperature of 32°F or lower
• February 28/29

Daily scores are calculated based on scores assigned to temperature, snowfall, and snow depth thresholds. The daily scores are accumulated through the winter season, allowing a running total of winter severity in the midst of a season as well as a final, cumulative value characterizing the full season. Accumulations of the temperature and snow components of the index are computed separately and then added together for the total index. This allows comparison of the relative contribution of each to the total score.

Current Accumulated Winter Season Severity Index