Posted at 8:59 AM on May 22, 2009
by Mark Seeley
Late Tuesday night, 10:00 pm to midnight, some freezing rain was reported inland from the north shore in Cook County. Temperatures were in the low 30s F. Nobody would have guessed what a remarkable change was in store on Wednesday, May 20th. Across northeast Minnesota , overnight and early morning winds were from the east where Lake Superior's water temperatures were registering 37-38 degrees F. Consequently morning low temperatures were quite nippy. By late afternoon the winds had shifted around to come from the southwest and the high sun was producing a lot of surface heating. The list of climate stations below shows the Wednesday morning lows (mostly 4 am to 5 am readings) and the afternoon highs (mostly between 5 pm and 6 pm).
Devil Track Lake 33 F and 85 F
Seagull Lake 36 F and 88 F
Grand Portage 32 F and 80 F
Isabella 34 F and 88 F
Cook County Airport 34 F and 82 F
Ely 37 F and 86 F
Crane Lake 37 F and 86 F
Kabetogama 40 F and 86 F
In a period of roughly 12 hours the temperature rose at these stations by 46-54 degrees F, a remarkable rise and probably near record pace. Not unlike jumping from March to July on the calendar.
In a broader context, the temperature spread across the state on Tuesday afternoon (May 19) was even more remarkable. At 4:00 pm Granite Falls reported 100 degree F, while Grand Marais coastal station reported 34 degrees F, a temperature spread of 66 degrees F. For any moment in time, I would argue that this is probably a record temperature disparity in the state of Minnesota. If you can report a larger one that occurred during a single moment in time historically I will send you an associated gift pack of Minnesota cheeses from our University of Minnesota Dairy Store.