Chicago and environs continue to dig out from the recent 10 inch snowfall. Though Saturday’s high of only 32° will not make much of a dent, successively warmer days should substantially erode, if not eradicate, the snow pack by the end of the day Wednesday, when temperatures stretch to near 50deg. Effective snow-eating features in the upcoming warm-up include rain with dew points and nighttime temperatures above freezing.
Shortly thereafter in this high amplitude pattern, the tables turn abruptly as some of the coldest air of the season sweeps through starting overnight Wednesday. The jet stream, which has been southwesterly for more than a week, turns in from the north as the polar vortex shifts to this side of the northern hemisphere. Thursday promises to be very windy with steadily falling temperatures. By the weekend, reinforcing cold air with origins in Siberia arrives in force, when high temperatures climb only into single digits after subzero lows.
