Though temperatures Sunday are only forecast to reach the low 30s, relatively light winds belie another surge of polar air looming to the north. An energetic upper level disturbance approaching from central Canada will amplify jet stream flow once again, sending air into the Great Lakes region directly from the arctic. The leading edge of this January-level cold is due to arrive Sunday night, as winds shift to northwest, and gust as high as 30 mph.
High temperatures Monday and Tuesday will struggle to reach the low 20s, at a time of the year when upper 40s are normal. The lowest high temperature recorded on Nov. 18 in Chicago was 22 degrees in 1903. That record may be in jeopardy.
Overnight readings may dip to single digits in the suburbs. Gusty winds will accentuate the cold, lowering wind chill readings to around zero.
