Blizzards Cold air is needed to make snow.
For snow to fall to the ground, the temperature must be cold both up in the clouds where snow forms and down at ground If the air near ground level is too warm, the snow will melt on its way down, changing to rain.For a blizzard there needs to be high winds which 35 mph.you can see about 0.25 mi or less.
The Chicago Blizzard of 1967 struck northeast illinoise and northwest indina on January 26, 1967 with 23 inches of snow falling on Chicago and its suburbs before the storm abated the next morning.
Forty five years ago, on January 26 and 27, 1967, Chicago endured its worst snowstorm ever. The snow started at 502 AM on the 26th, and by 1010 AM of the 27th a record 23 inches of snow crippled the city.