9:40pm Update: New Severe Thunderstorm Watch issued for parts of southeast Minnesota and north-central Iowa until 3am. Thunderstorms over Minnesota continues to develop Sunday evening, but may take more of a south/southeast track versus southeast track overnight. The reason for that is because of where higher moisture and instability are located in the atmosphere currently. Now as we head through the night the higher moisture and instability may be pulled a little further to the east thanks to the arrival of the low level jet. Storms are still expected over northern Illinois and southern Wisconsin, but could actually be arriving in more of a weakening trend. I still do believe isolated hail and localized strong wind gusts will still be a threat, but the highest risk for severe weather may be more centered over to our northwest. Arrival time for storms still appear to be roughly between 2am and 5am. Pushed back slightly due to slower storm development over Minnesota.
8:00pm Update: Enhanced Risk for severe weather has been shifted further northwest, while a Slight Risk covers all of northern Illinois and southern Wisconsin. Not too much has changed with the forecast for the night, however, the strongest storms may occur closer tied to where the highest instability is located. This, right now, appears to be over southeast Minnesota and northeast Iowa.
The quiet weather from the weekend will be coming to an end Sunday night as northern Illinois and southern Wisconsin return to a very active weather pattern for the next several days. The first round of thunderstorms will arrive late Sunday night - after Midnight - into very early Monday morning.
08Z - 3am Monday Morning
0830Z - 3:30am Monday Morning
Damaging winds will be the biggest concern, followed by hail and heavy rain. The two images on the left are from our short-term weather forecast models the RPM and HRRR. Both show somewhat similar scenarios between 2am and 3am Monday morning - a line of thunderstorms with a few stronger embedded bows. Most of the activity should be moving east between 8am and 9am, with the rain wrapping up after 10am Monday.
Before going to be Sunday night, make sure you have a way to receive watches and warnings should they be issued. Bring in any loose objects that could fly around outside and make sure you know where your safe place is should you need to take shelter.