THEWEATHERMOGIL:: Snowfall gradients

Yesterday’s winter-spring storm produced lots of severe weather on its eastern flank, but it also generated a band of heavy snow to its west. Just to the east of Chicago, IL, the infamous “rain-snow” line helped to create a rather large snowfall gradient. That gradient (0.44 inches of snow per mile, across a 34-mile distance) gave the National Weather Service (NWS) office in Chicago an opportunity to play up such gradients (Fig. 1). Bravo!


Yet, much larger gradients came into play for the Jan. 26-28, 2015 snowstorm in the mid-Atlantic and Northeast U.S. I refer readers of this blog site to an article I wrote after that event – THEWEATHERMOGIL:: Looking back at an almost perfect winter storm forecast (1/26-1/28/15). Gradients in that storm were some two to three times larger than the one near Chicago yesterday (Fig. 2).


What’s important is that people realize that weather-related gradients (e.g., snow, rain, temperature, wind, cloudiness) can be large and affect the viability of current, highly localized forecasts. They can also play a role in how weather is treated in legal and insurance matters.

© 2016 H. Michael Mogil

Originally posted 2/25/16