Another Snowy Spring

We live in a climate where you probably never should say never, but the odds are extremely low that this area will record any more snowfall this season.  So unless something unforeseen occurs, our current spring (March through May) will end up ranking as the 2nd snowiest on record.  In total, 31.3 inches of snow was measured by our official observer in north Moorhead since March 1.

Only one spring, 1997, was more snow recorded when 33.6 inches was measured.  Our spring snow total of 31.3 inches was nearly one-half of the total snow recorded this cold season.  This past winter, 68.4 inches of snow fell in Fargo Moorhead which will rank as the 11th snowiest on record.

Other recent springs with abundant snow include, 2009 with 28.3 inches (4th highest) and 2008 when 28.1 inches fell (5th highest).  Therefore, three out of the five snowiest springs on record have all occurred in the past five years.

Top 5 For Snow

Last month finished as the 5th coldest April on record.  Not only did we finish in the Top 5 for cold temperatures, but also for snowfall.  The official observer in north Moorhead measured 16.7 inches of snow last month which ranked as the 4th snowiest April on record.  A couple of days ago in a previous blog I mentioned that although April ranked as the 5th coldest on record, we came within 1 degree of breaking the monthly record. 

It was also a similar scenario for snowfall last month.The 16.7 inches that was measured barely missed the April snow record of 17.4 inches set in 1904.  The other two years with a higher snow totals in the month of April were in 2008 with 16.9 inches and 16.8 inches recorded in 1937.   In total, 2.11 inches of liquid equivalency of recorded last month.

 It was a rare April in the sense that almost all of that moisture came from snowfall as only 0.05 inches of rain was recorded with 2.06 inches coming from melted snow. 

Full of Snow

As the month of April comes to a close, most individuals in the Midwest will likely not forget this month for a very long time.  The residents of one city in particular definitely had a month to remember.  Duluth, Minnesota recorded 50.8 inches of snow this month. 

That total surpassed the 31.6 inches of snow that fell in April, 1950 the previous snowiest April on record by an astounding 19.2 inches.  This month also surpassed the 50.1 inches that fell during November, 1991 to become the overall snowiest month in the city since records have been kept.   The 50.8 inches that fell this month brought the seasonal total in Duluth to 129.4 inches which is currently the 3rd snowiest cold season on record for the city. 

Although the seasonal total so far has fallen short of the record, 95.7 inches of that total has fallen since February 1, making the period from February 1 through April 30 the snowiest such period on record by 27.2 inches.    

150 and counting

Today marks the 150th day with at least 1 inch of snow on the ground this cold season.  This is only the 5th time on record that Fargo Moorhead has recorded at least 150 days of snow cover.  As a reference, the winter of 1996-1997 recorded 147 days with snow covering the ground.  Including this cold season, that ranks as the 5th highest such total on record. 

The years with the highest total number of days with snow cover occurred during the winters of 1935-1936 and 1978-1979.  Both of those cold seasons recorded 155 total days with at least 1 inch of snow depth.  Last year, the winter of 2012-2013 recorded only 65 such days.  Because of the warmer temperatures expected beginning tomorrow it is likely we will not be breaking the record for the most snow covered days in a season, but we did break the record for the most such days in the month of April by at least 7 days and counting

The Norm not the Exception

Accumulating snow in April is the norm, rather than an exception in Fargo Moorhead. In the 127 years with snow data, at least 0.1 inch of snow was recorded in 102 of them.  Or put another way, accumulating snow has occurred in 80% of Aprils. 

Our current April was not included in those statistics, but of course, we have recorded an accumulating snow event this month as well.  Several recent years have been snow free in locally with no accumulating snow measured in 1999, 2005, 2006, 2010 and 2012.  Yet, intermixed with those years was one of the snowiest Aprils on record. 

Just five year ago, 16.9 inches of snow was recorded in Fargo Moorhead.  That nearly broke the record for the month that was set in 1904 when 17.4 inches was measured.  That nearly 17 inches including a nine inch event on April 25 and 26.  That was the heaviest snow event so late in the season on record for the metro.

Extra Snow

The snowfall on Monday in Fargo Moorhead pushed the snow depth up to 7 inches, the highest of the season so far.  Last winter, like this year, the snow depth was generally minimal, although, it did peak at 9 inches in early March.

Since snow depth records have been kept during the winter of 1892-1893 the average maximum snow depth locally has been 13 inches.  The record snow depth was recorded during the infamous winter of 1996-1997 when 32 inches was recorded in March.  In more recent winters, the snow seasons of 2008-9, 2009-10, 2010-11 all recorded a maximum depth around 20 inches which has likely attributed to the sense of so little snow in these past two years.

Lack of snow cover was particularly noticeable in the late 1950s.  The six winters from 1954-55 to 1959-1960 all never had a snow depth above 8 inches and those were also years with very little total snowfall as well.

Snow is Lacking in the States

A few weeks ago I noted in this space that the amount of snow over Siberia was well above average at the end of October.  That trend continued for the first half of November not only in central Asia, but over the entire Northern Hemisphere.

As recently as 10 days ago, the amount of ground covered by snow in the Northern Hemisphere was about 2 million square kilometers (750,000 square miles) above average.  That would be more than three times greater than North Dakota, South Dakota and Minnesota combined.  But during the last week, although the amount of snow over the hemisphere has remained about the same, the average snow cover slowly rises this time of year, so as of Monday, the total snow cover was running right at the average for the time of year.

The one part of the hemisphere that is currently lacking snow cover is in the lower 48 states and that will likely not be changing too much in the next week.

Snowy Somewhere

Although Fargo Moorhead has not recorded much snowfall this season, we are only running a couple of inches below average.  Grand Forks has also observed only a few light snow events this season.  But much of the northern tier of North Dakota have recorded above average snow fall this month and parts of north central and northwestern North Dakota well above.  Williston has received 16 inches this month, twice their November average.

Yet, just north of there, the snow totals have been even higher.  Both Regina and Estevan, Saskatchewan have both had record breaking November snowfalls.  Regina has recorded 23 inches of snow besting the old record for the month of 21.1 inches.  That also happens to be more snow than they received all of last winter when just 20.5 inches fell.  Estevan has recorded even more snow with 25.7 inches being measured this month which also exceeds their total from last winter by 1.1 inches.

Snow Matters

The winter of 2011-2012 was the warmest on record in Fargo Moorhead.  It was nearly 10 degrees above the current 30 year average.

There is no doubt that the overall pattern last winter was a mild one. The upper level wind pattern was consistently from the west allowing mild Pacific air to dominate the season with only a couple of intrusions of Arctic air disrupting that pattern.  But another very important element to the warmth was our lack of snow cover. This past week has been a prime example.

Fargo Moorhead missed the big storm earlier this month that left a significant snow cover over central and northern North Dakota.  The eight days following the storm the average high in Fargo was 40 degrees, but in usually warmer Bismarck with a snow cover the average high was just 32 degrees.  Even Grand Forks with minimum snow from the storm (like Fargo), the nearby snow pack lowered their average to just 33 degrees.

Because the sun angle is so low this time of year making it difficult to melt much snow, an early season snow storm can in turn, influence the average temperature for the entire cold season.

Current snow cover over the area.

Siberian Drivers

After a slow start, the second half of October recorded several snow events that greatly expanded the snow cover over Siberia.  Some studies have suggested that October snow cover has some correlation with winter temperatures in the United States, especially areas east of the Rocky Mountains.  In October the snow cover can increase anywhere from between 4 to 6 million square miles, an area larger than the United States.

Last year Siberia recorded below average snow cover during the month of October.  This year, there has been a significant increase in snow cover and last month ranked as the 11th highest total in the past 45 years.  The theory is that the larger the build up of snow in Siberia early in the season, the higher the likelihood that large Arctic air masses will form and eventually move into North America, especially in January and February bringing a colder than average winter.

Of course, this is just one of many possible drivers that could influence the weather patterns during our cold season