APRIL-MAY: CHILLY AND STORMY IN CANADA AND US
June 3 2012 preliminary followup: Early April was warm, and runners in the Boston Marathon faced such a hot day they were permitted to drop out. By a day or two later, Boston and the rest of the US were into a month of frost, snow, hail, and as Accuweather put it, thousands of miles of storms. Wave after wave of chill and severe storms crossed the country from northwest to southeast. At about mid-May, things warmed up.
February 2013. Time to be more systematic.
