Fall catches up with Chicago

While Hurricane Wilma swamped northeastern Yucatan with two days of torrential downpours (Isla Mujeres just off the northeast tip had unconfirmed reports of an incredible 64.47 inches and it was still raining Late Sunday afternoon), a strong jet stream steered this season’s coldest air into the western Great Lakes. A persistent jet stream pattern flowing across Canada’s Northwest territory and sweeping Hudson Bay before turning south across Lake Superior establishes itself with the resulting air mass tapping some of the coldest source regions to the north and then modifying as it makes the journey south. North winds and very cold air aloft will create unstable atmospheric conditions the next couple days, the most intense being today with a forecast of extensive cloudiness and an almost continual threat of showers.
Meanwhile in the Caribbean, the record 22nd named storm of the season, Tropical Storm “Alpha” crossed Hispaniola.