Tuesday, March 12, 2013

Where is Spring?

A lot of Minnesotans are wondering where spring-like weather is now that we are into the month of March.  So far this month, we have seen a few snow events across the state, dumping a half-foot or more at one time to some parts.  The Twin Cities saw heavy snow on March 4th and 5th, and northern and southeastern Minnesota were on the receiving end March 8th and 9th, and 10th and 11th, respectively.


As for temperatures, high temperatures in the Twin Cities are generally below average.  We have yet to see 40 degrees for the month.  Contrast this to this time last year, where the mercury was in the 50s once, and three days saw temperatures in excess of 60 degrees.



2011-12 was also a very abnormal year when it came to winter.  We were spoiled, and that is part of the reason we are clamoring for spring to arrive.  Only 22.3 inches of snow fell the entire season.  Area lakes were already ice-free by the end of February as average high temperatures were well above normal for the month.  As a result, our perception of “normal” changed.


As of March 11, 2013, we have seen twice as much snow with 44.8 inches in the Twin Cities. This is 1.4 inches below normal, so this is pretty close to a typical winter for the metro.  The 2012-2013 meteorological winter (December 1, 2012 to March 1, 2013) for St. Cloud and Twin Cities saw near normal temperatures and precipitation.  It was a different story for the western central and far northern Minnesota as average temperatures were slightly below normal, and precipitation was well above normal.  Some locations saw double the amount of water in a typical meteorological winter.



So how do we really feel about winter?  The Minnesota State Climatology Office attempted to quantify the severity of winter by creating an index, known as the Winter Misery Index.

Here is a little information on how it works:

The Winter Misery Index (WMI) is an attempt to weigh the relative severity of winters. The index assigns points for daily counts of maximum temperatures 10 degrees or colder and daily minimums of 0 or colder. If the minimum temperature is -20 or colder greater weight is assigned to the value times 8. For snowfall, one inch is assigned a point per calendar day. A four inch snowfall is times 4, and an 8 inch snowfall is times 8. The duration of a winter is noted by the number of days the snow depth is 12 inches or greater. All current measurements are at the Twin Cities International Airport.

As of March 1, 2013 the WMI in Twin Cities is 53 points, or three points away from the "moderate winter" category.  This roughly parallels snow totals and average temperatures against normal in a given season.  The lowest WMI score was the winter of 2011-2012 with 16 points, a very mild, or comfortable winter. The most severe winter is 1916-1917 with 305 WMI points.


The common theme from the information above is that we are going through a normal winter.  We have not one of these in a couple years, so this is more of a reminder of what winter is supposed to be like for the Twin Cities and surrounding area.  With that said, March daytime temperatures are starting off eight degrees below normal.  Temperatures should be running in the upper 30s by now.  Most days in the month so far have been a struggle to hit 30 degrees.  March snowfall averages just over 10 inches, and we are 9.3 inches for the month, so we are near average not even halfway through the month.  It is not so much the winter that people are asking for spring, but rather due to March not starting off the way it should based on averages.  Only time will tell how the rest of the month plays out, and how much of a spring we have this year.


No comments:

Post a Comment