A vigorous cold front–what’s often referred to as a “pneumonia front”– is to plunge through the Chicago area this evening bringing a sharp temp drop and a vigorous wind increase.
The frontal passage should occur across the city from north to south in the 7 to 8pm time fame producing a shift from Monday’s docile and unseasonably warm daytime westerly winds to strong, temp-dropping northerly which will increase rapidly to 20+ mph, introducing a steep drop in temps as winds, which have traveled over cool waters length of Lake Michigan roar into Chicago.
Lake Michigan’s comparatively calm, wave-free state will undergo abrupt changes with waves building to as much as 5-6 ft over the waters adjoining Chicago by late Monday night. Cool north/northwest winds, along with lake-effect clouds and spotty light shoreline showers, are to circulate into the area around the southern flank of a strong Canadian high pressure to the north. It’s a development which is to limit peak Tuesday temps to the 50s or low 60s over the Chicago area before warmth floods back into the area with higher humidities later Wednesday and Wednesday night—and growing t-storm prospects Thursday. Another steep temp decline hits for the coming weekend.