February 17 is a big day in recent weather history. The highest temperature and the lowest temperature in the month of February occurred on this date at the National Weather Service (NWS) near Negaunee.
In 1979, at the peak of a long, cold snowy winter the temperature plummeted to 34 degrees below zero as arctic high pressure settled over the region. Then two years later in 1981, a mild westerly flow forced the temperature up to a record-shattering 61 degrees. The warmest temperature during the last four decades in February happened at the climax of a wild temperature swing that saw a record low of 32 below zero five days earlier!
This winter harkens back to the big winter of 1978-79. We just broke the record for consecutive days of freezing or below set back in 78-79. The old record was 72 days. Today the new record stands at 74. The streak will likely end Tuesday as mild Pacific air floods the Upper Midwest.
One more thing; yesterday, high pressure over the area gave us the clearest day since winter began. The satellite image of Lake Superior revealed an almost completely frozen lake (Image above). That hasn??t happened since the winter of 1993-94. Before that, the last winter to have a completely frozen lake was 1978-79. This is truly an amazing winter.