(7:15AM - 1/21/20) What seems to be a never ending pattern we are stuck in recently, yet another late week/weekend winter storm will affect the state, from Wednesday through Saturday. This storm system will be of long duration, bringing with it a wide range of precipitation types across the state...Including snow, sleet, ice and rain. Light to moderate accumulations of wintry precipitation are likely across at least portions of the state.
A complex setup is expected to unfold across the region this later this week on into the weekend. Several upper air disturbances entering the region will interact with each other during this time. The result will be the development of a storm system, which will push northeastward across the region. During this period, an extended period of precipitation is likely across the state from Wednesday through Saturday. Wintry precipitation will be favored for most areas during most of this period. Even with the complex nature of this period, model guidance is in decent agreement regarding the period. However, it should be noted that temperature profiles will be marginal most of this time period, and is of concern. Thus, for now we will hold of the side of caution, and go on the lower end of guidance regarding wintry precipitation amounts.
Snow, perhaps with some mixed precipitation, will first push into Northwest and Western Illinois by Wednesday afternoon. This activity will then slowly expand across the rest of the state by Thursday morning. Precipitation will then continue across much of the state from this point right on into Saturday, before slowly ending. Much of Northern and Central Illinois has a good shot at seeing most of the precipitation during this period fall as snow, with only small periods of mix/rain being possible. Across Southern Illinois, much of the precipitation will fall as rain and a mix of precipitation.
Final snowfall totals are expected to be widespread in the 1-3" range across much of Northern and Central Illinois, with higher amounts in excess of 3" expected towards the Illinois/Iowa border. Again, will stress for now that we are holding on the side of caution, and going on the lower end of model guidance on snowfall amounts.
Below is our TAM snowfall forecast for this event.
To receive updates from us via the in-telligent app, text ISC to 833-369-3800