We??re into a fine early summer pattern which should hold for the majority of the Memorial Day weekend. Technically, it is still spring and it should get quite cool yet tonight. A better example of summer in May occurred 42 years ago. The summer preview in 1972 actually began on May 18 when the temperature soared to 87 degrees at the NWS. The next day it reached a summery 90. Then from the 23rd to 25th, record highs in the 80s were observed. At Ironwood where data goes back to the turn of the 20th century, consecutive record highs of 88 degrees occurred from May 17-19. The temperature also hit the upper 80s on the 24th and 25th.
The blast of summer was the result of a highly amplified pattern that featured a huge ridge that crested over the Great Lakes region during mid-May 1972 (Image 1 above). Five days later, the huge, hot ridge had barely drifted eastward (Image 2). In a scenario like this, very warm, dry weather can last for days. That??s exactly what happened in 1972.
This great stretch of weather was preceded by one of the coldest, most backward springs of the 20th century. Snow stayed on the ground in parts of the U.P. well into the first part of May in 1972. Then there was the sudden shift to summer after mid-month. However, the summer weather did not remain during the actual summer season. June, July and August 1972 were all considerably below average.
Our current warm spell will reach a peak on Sunday when a number of spots could hit 80 degrees. Then a cool front will sweep across the Upper Peninsula starting early Memorial Day over the western U.P. The front should exit the east by evening. Some showers and possible thundershowers will accompany the front. This looks like the only decent chance of rain over the next week.