Overnight model guidance continues to remain in relativity good agreement on a strong area of low pressure moving through portions of Illinois tomorrow and producing a swath of heavy snow on the north side of the low with sufficient low level cold air in place. This remains somewhat of a tricky forecast like our last April snow event and given we are now in late April, this is even more rare to see but the potential is definitely there for accumulations across portions of northern Illinois from this.
A brief update follows below...
As you can see in the loop below, a widespread area of precipitation will develop to our west and northwest late tonight and early tomorrow across the northern plains and portions of the Midwest, before streaking ESE into the northern portions of the state by tomorrow morning and afternoon. Precipitation will be moving into southern Wisconsin and northern Illinois tomorrow morning when temperatures are still cool/cold to start the day and could very well start as snow across those areas. There is going to be a sharp contrast in temperature from southern Wisconsin to down south of I-80, going from the low to mid 30's to near 60 degrees, as you'll see below. The best chance for heavy snow and accumulations will come Saturday afternoon and evening across northern Illinois.
Temperatures will be much colder in the heart of band of heavy precipitation/snow across southern Wisconsin/far northern Illinois but warm quickly as you head into the heart of Illinois and south of the area of low pressure. This image is valid at 7pm tomorrow evening.
Given the tricky forecast track meaning all the difference in the world on how far south accumulating snow gets, uncertainty does remain but hoping to fine tune our snowfall map later but as you can see below, it is certainly possible portions of northern Illinois get in on the snow later Saturday.
A new TAM/snowfall totals map will be out later today...
Please consider becoming a Patreon as a way to say thanks and support us for what we do! www.patreon.com/user?u=16598980
To receive text alerts via our in-telligent groups text ISC to 900900