Update 8:50 p.m.: A string of severe thunderstorms continues to move across the area. Most lines are capable of generating wind gusts of up to 60 miles per hour. If you're in the path of these storms, take shelter (preferably on high ground)!
Update 8:41 p.m.: A tornado warning has been issued for parts of Carroll and Whiteside counties until 9:15 p.m. The storm is moving east at 30 mph. If in the path of this storm, take shelter!
Update 8:40 p.m.: Flash flood warnings for Winnebago County have been classified as “severe”: Here's the wording of the latest warning: Up to 2 inches of rain has fallen in the warning area, with an additional 2 inches possible quantity. The severity of flash flooding is about to worsen.
Update 8:15 p.m.: A new severe thunderstorm warning has been issued for southern Boone County until 9 p.m. The severe storm is located near Belvedere and is moving northeast at 10 mph. The storm was capable of producing wind gusts of 60 mph and quarter-sized hail.
Update 8:10 p.m.: A new severe thunderstorm warning has been issued for northwest Ogle County until 8:45 p.m. The storm is located near Forreston and is moving east at 20 mph.
An additional severe thunderstorm warning has been issued for northeastern Whiteside County and southeastern Carroll County until 9 p.m. The storm is located near Chadwich and is moving east at 25 mph. Both storms can produce wind gusts up to 60 mph. If you are in the path of this storm, seek shelter immediately.
Update 8:00 p.m.: A tornado warning has been canceled for north-central Joe Davis and Carroll counties, but a severe thunderstorm warning remains in place for parts of northwestern Illinois. Currently, the biggest threats are wind gusts up to 60 mph and hail.
Even more worrisome is the continued heavy rain, which currently has a flash flood warning in effect for southern Winnebago County until 1 a.m. Monday. Up to 2 inches of rain per hour will soon move into the area, which will cause flash flooding.
Update 7:30 p.m.: A tornado warning has been issued for Joe Davis County and north-central Carroll County until 8:15 p.m. There is a storm with possible tornadoes near Masbach, moving east at 25 mph. This is a radar-indicated spin, but if you're in the path of this storm, make sure to seek shelter immediately.
Update 7:03 p.m.: A new severe thunderstorm warning has been issued for north-central Whiteside County and central Carroll County until 7:45 p.m. A severe storm over Andover, Iowa (north of Clinton) is moving east at 25 mph. Wind gusts up to 60 mph and quarter-size hail are possible.
Joe Davis County has just issued another severe thunderstorm warning until 8 p.m. This storm is located southeast of Galena and is moving east at 20 mph. Wind gusts up to 60 mph are possible.
Update 7:00 p.m.: Keep an eye on storms in Joe Davis County near Galena. The storm was capable of producing wind gusts of 50-55 mph and half-inch hail. The storm is moving east at 15 mph. Heavy rainfall also occurred.
Update 6:00 PM: A new severe thunderstorm warning has just been issued for all of northern Illinois and southern Wisconsin until 1 a.m. Monday.
Thunderstorms are now becoming more scattered across southwestern Wisconsin and northeastern Iowa. Coverage from these storms is expected to increase over the next few hours.
Update 5:25 p.m.: Isolated thunderstorms are beginning to develop in southwestern Wisconsin and northeastern Iowa. Coverage from these storms will continue to increase over the next few hours into northwestern Illinois. There remains a serious threat from the storm, with the threat of damaging winds and heavy rain throughout the evening.
Active weather will continue again Sunday night, with another round of strong to severe storms still possible across southern Wisconsin and northern Illinois. Sunday morning, after a moderate storm, skies cleared and temperatures climbed back into the mid-to-upper 80s. Dew point temperatures have risen into the mid-to-upper 70s and closer to 80 degrees, which pushes heat index values into the mid-to-upper 90s.
A few showers and isolated thunderstorms developed in mid to late morning and moved across the area throughout the afternoon. These have now been moved closer to Chicago and across Lake Michigan.
Our focus turns to the west, with an upper-level disturbance currently over Iowa, the legacy of a thunderstorm complex over the Plains on Saturday night. This disruption will enter an environment that has built up quite a bit of instability over the past few hours. Therefore, it is likely that we will see some kind of watch release within the next hour. The entire region remains within a “slight risk” of severe storms.
Thunderstorms are expected to develop over northwestern Illinois and northeastern Iowa over the next few hours and will move east/southeast with upper-level airflow. The storm will move a little faster than Saturday night's storm, but the threat of additional flash flooding remains given the amount of rainfall in northern Illinois. As a result, a flood watch is in effect for Winnebago, Boone, Ogle, Lee, DeKalb and McHenry counties as of late tonight.
In addition to the risk of flooding, strong to severe storms are possible, with damaging wind gusts and hail being the main concerns, followed by the risk of isolated tornadoes within single storm cells that may form. These individual storm cells are expected to then form into another storm cell that moves across other areas of northern Illinois and southern Wisconsin at sunset.
The storm threat will end around midnight, and skies are expected to become dry Monday morning. Unfortunately, another severe weather threat will emerge Monday afternoon and evening, with the potential for damaging winds, heavy rain, and isolated tornadoes across much of northern Illinois and southern Wisconsin.
