Timing the Rain Tuesday

An upper level, amplified ridge has been in place over the Midwest for the past week or so, which have brought a string of days that made it into the 90's. Since Wednesday, September 20th through Sunday September 24th, four of those five days made it to 90° or above. The only day that didn't was Thursday, but it will still a hot afternoon with the high temperature in Rockford at 89°.

Now, a developing low pressure out west will ride along the ridge and help to break it down late Tuesday into Wednesday. This will bring a more zonal flow (from west to east) aloft in the atmosphere, while at the surface a cold front will pass. This will bring a big drop in temperatures by the end of the week. But it will also bring a chance for some much needed rain, unfortunately not as much as we need.

The cold front will only have minimal lift when it passes, and there isn't much instability to work with either. This brings mainly just a threat for widely scattered showers and a rumble of thunder. Timing of the front as of now will be Tuesday afternoon into the early evening, before drier air moves in Wednesday. Right now, only .10" of an inch is in the forecast for rain on Tuesday. The rest of the week remains dry, and into Sunday.