Historic And Record BreakIng Last Season Snowstorm, Sat April 27th Update #4

(12:00AM - 4/27/19) Confidence continues to grow in now what looks likely to be a historic, record breaking, late season snowstorm for portions of Northern Illinois Saturday...

Model guidance from this afternoon and tonight continues to be in fairly good agreement regarding track of the storm system and placement of the main snowfall axis. Will keep going forecast from this afternoon, with minimal changes to the TAM snowfall forecast.

Previous forecast...
​Precipitation will start as rain, spreading across Northern Illinois early to mid morning Saturday. As dynamic and evaporative cooling occurs, rain will mix with and change to snow for portions of Northern Illinois during the mid morning to early afternoon. From that point, snow will continue into Saturday night, before ending from west to east by midnight. Model soundings show conditions highly favorable for banding of heavier snow, very heavy snowfall rates and thundersnow. At this time we expect an axis of 6-9" snowfall totals across far Northern Illinois, with locally higher amounts possible. From there, amounts will quickly taper as you had south towards I-88 and I-80.

This will be a very heavy and wet snow, due to marginal temperatures and the time of year. Given temperatures have been overall warm and trees/bushes have leafed out, some damage is possible...in additional to power lines/poles potentially being affected. The heavy and wet nature of the snow could also lead to damage to flowers and plants that have recently grown or been planted. Caution should be taken when shoveling this type of snow as well.

As mentioned earlier in this article, this will likely be a historic and record breaking late season snowstorm for portions of Northern Illinois. To put this in perspective... Chicago has NEVER on record seen a 6"+ snowfall after April 6th...And has never seen a 3"+ snowfall beyond today's date.

​Below is our updated TAM snowfall forecast for this event.

JP

​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 ​​​​​​​​​​​​​