March so far started cold, moderated and then a major snowstorm hit a good portion of Upper Michigan. Last year, a snowstorm hit early in the month, but thatâ??s where the similarity stops. March 2012 brought historic warmth to the U.P. and a good share of the eastern U.S. (Image 1 above). The weather over the U.S. was dominated by a huge ridge that covered much of eastern North America. It helped pump up warmth that never really quit.
This year, the pattern configuration is much different. Hereâ??s a case in point: on March 11, 2012, a record high of 63 was set at the National Weather Service (NWS) near Negaunee. This year, a record 14.4 inches of snow fell on the 11th at the NWS. Last year, the pattern was dominated by that building ridge (Image 2). This year, a deep trough was forming right where the ridge was strongest last year (Image 3). Last year the ridge kept building, reaching a high mark about St. Pattyâ??s Day. That day, the high reached a record-shattering 75 degrees. The next three days it was 78 and on March 20, 2012, a historic high of 81 degrees was observed.
Iâ??m not predicting a record cold March 2013, but it does look like the cold will hold for a good share of the month. Hereâ??s a 15-day forecast valid on March 26 (Image 4). It shows essentially the same pattern thatâ??s been dominating the last couple of weeks; a deep, cold trough nearby with high latitude blocking. To say spring will be delayed a bit is an understatementâ??especially compared to last year.