This is a Forecast Discussion for a heavy rain event in North Illinois tomorrow.
What we will have here are low pressure systems pumping rain and warm air into the North Illinois area. This forecast discussion is based off of the latest run of the University of Illinois WRF model.
So first, we will start off with the ensemble reflectivity, meaning what is predicted to show up on radar.
This image I chose out is to show the potential of a severe component that the National Weather Service may not be recognizing. By the looks of the initial red line, there could be a small piece of bow echo in there. Overall, this shouldn’t be a severe event, but based on this image, I wouldn’t be surprised to see some gusty winds or small hail.
This next image is definitely more organized as a multi-cell storm complex. This is a more concerning image, as the abundance of strength in this complex is startling. This looks like much more of a contender for a severe weather event, and I would expect this scenario to produce gusty winds, cloud to ground lightning and hail.
This image is more of an ending piece, as in the backside of this storm. By now, this complex appears to have weakened and coincides with the first image. I will definitely be watching for either this scenario of two areas of strong storms or one big strong multi-cell complex.
Next up, we will focus on total precipitation from University of Illinois Ensembles.
This is a total precipitation estimate. The ensembles aren’t handling the swath of heaviest precipitation well, so I will continue to monitor these. Anyways, this image puts the swath of rain through the Northern Illinois area, with totals potentially up to 2 inches in some areas.
This second image is a much more humble precipitation outcome, with not as heavy precipitation in the biggest area of rain and storms. However, there is agreement in between this image and the above image that the heaviest precipitation should be across the North Illinois area.
This has been a forecast discussion. Another one on this event may be issued later.