Excellent Example of Frontagenical Forcing/Banding & Its Effects On SnowfallJanuary 23rd, 2013 at 4:12 pm by Chad Evans under Chad's WLFI Weather Blog
Very good example of frontagenic banding is present today with weak clipper. This is a front at surface & in 850-700 mb layer. There, in the SGZ, sharp temp contrast exists. Very efficient dendrite/snowflake production occurs in these situations. You can squeeze out 3″ of snow from 0.11″ of liquid. Ratios in Illinois in that band have been as high as 22:1 today, when typical ratio is 10:1 (1″ of snow is 0.10″ of liquid or 10″ snow is 1″ of liquid). Ideal frontagenic snowfall banding occurs when strong upper jet exists over the banding.
These band are often intense & slow-moving. Such has been the case in Illinois with a 7.5-mile wide band of +4″ on Doppler radar. In our area, a band has developed over Tipton County with up to 0.5″ snow per hour. Otherwise, up to 1″ of snowfall has occurred in some places today. I have had just a trace at WLFI.