Localized flooding from rainfall Thursday morning; More heavy rain on the way

 

Heavy rain came down Thursday morning with some locations picking up over two inches of rainfall! A brief flash flood warning was issued for southern Lee and DeKalb counties where radar estimated amounts of 3-5 inches occurred. Thankfully, the heaviest rain came to an end mid-morning with only drizzle and light showers continuing near and north of the state line into the afternoon.

A stalled boundary near Highway 20 allowed afternoon temperatures to warm into the low 80s along the I-88 corridor, while the 60s and 70s were found to the north. Drizzle and fog continued in southern Wisconsin but there have been some improvements over the last couple of hours. High pressure to the north will continue to sink down across the northern Great Lakes pushing the stalled boundary further south Thursday night. This will lead to mostly dry skies but could also lead to a little patchy fog through Friday morning. Temperatures will drop on either side of 60 degrees.

Friday morning will be dry, but mostly cloudy. We may see a few peeks of sunshine before clouds take over once again. This will be ahead of a northward advancing warm front that'll lift into northern Illinois late Friday night. Along the front a few showers cannot entirely be ruled out, developing from the west and southwest and moving to the east. These would move in during the late morning and early afternoon hours. By mid-afternoon the rain should be coming to an end with mostly dry skies through late afternoon and perhaps into early evening.

The next round of heavy rain is then expected overnight Friday into Saturday morning where another 1-3 inches area wide could come down. Following some of the recent heavy rainfall the last few days it's possible that localized flooding may occur in some spots. Most of the rain will be wrapping up mid-morning Saturday, but scattered showers with a few isolated thunderstorms can't entirely be ruled out through the afternoon. The coverage of any afternoon thunderstorms will depend on where the warm front ends up, which may be pushed further south with the rain in the morning. This would significantly limit the amount of warmth we would experience during the afternoon, resulting in temperatures staying in the 70s - and possibly 60s.

Another round of heavy rain can be expected once again Saturday evening into Sunday with the cold front moving through. An additional inch of rain will be possible during that time. In all, rainfall totals of 2-5 inches will be possible through the weekend. Rain chances become a little less into next week, but temperatures will be quite a bit cooler for the last few days of summer.

Showers and storms early, drying out this afternoon

Rainy Morning:

A stationary boundary positioned to the south of the Stateline has helped ignite a large area of showers and storms across eastern Iowa this morning, with that activity working its way into the Stateline. As a result, expect a wet start to the day and a rainy morning commute for anyone heading out. Rain will likely be steady, possibly heavy at times, especially underneath any thunderstorm. Overall, the severe weather threat remains low. However, some of the stronger thunderstorms could still produce heavy downpours, frequent lightning, and brief reductions in visibility. Allow for extra travel time and keep the windshield wipers working. 

Drying Out This Afternoon: 

Chances will be at their highest during the morning hours along the boundary. Conditions should then gradually improve this afternoon, with showers tapering off and drier weather beginning to work its way back into the Stateline. 

  

While an isolated shower can't be completely ruled out into the evening, most locations should remain dry under a mostly cloudy sky. Additional breaks in the cloud cover are expected overnight into early Friday as drier air filters in ahead of Friday's storm system. This setup will lead to an increase in chances for showers, thunderstorms, and periods of heavy rain late Friday evening, with these unsettled conditions lingering into the first half of Saturday. 

Light showers/drizzle move through northern Illinois Wednesday afternoon

 Temperatures have been running on the cooler side thanks to an abundance of cloud cover and a few light showers that have spiraled their way across northern Illinois. Rainfall amounts haven't added up to much, but our visibility has fallen in some locations where there is more drizzle/mist rather than light showers.

The showers have been the result of a few upper-level disturbances that have been moving overtop a strong ridge of high pressure to the south, which has brought significant heat to the south the last several days. That ridge will hold strong through the end of the week as it shifts a little further towards the southern Plains this weekend. We will remain to the north which will limit our overall warm-up during that time.

For the rest of Wednesday evening skies will remain cloudy with a little drizzle from time to time. Temperatures won't move much through the evening, holding steady into the mid-60s. We may even see some fog try to develop through sunset. A stronger push of moisture late Wednesday night will lead to widespread showers and thunderstorms developing after Midnight. This activity will move close to northern Illinois during the overnight, with the heaviest rain arriving after between 3am and 9am Thursday.

Flood Watches have been issued for Carroll and Whiteside counties beginning at 10pm Wednesday and lasting through Thursday morning. It does look like the heaviest rain may remain just to our south. This is where rainfall totals between 1-3 inches will be possible. To the north, and for most of northern Illinois, rainfall amounts between half an inch to an inch will be possible.

Rain chances remain following Tuesday's beneficial rainfall

Beneficial Rain:

Beneficial rainfall made its way across much of the Stateline on Tuesday, providing a welcome boost to an area that has seen its fair share of warm and dry conditions during the summer months. Some locales picked up more than 1.25" of rain. In Rockford, the rain gauge saw a steady climb throughout the day, ultimately finishing with 0.77".  

Shower Chances Remain:

Rain chances do not completely disappear behind Tuesday's rainfall, though they will be more limited moving forward. The best opportunity for showers today will be south of I-88, where the front boundary responsible for yesterday rain resides. Areas closer to the Illinois/Wisconsin border may see little to no rain, though an isolated shower can't be ruled out. With clouds sticking around and a cool easterly wind in place, expect highs in the low 70s. 

Rain chances tick up slightly once again overnight, bringing the potential for scattered showers and an isolated thunderstorm or two. Even then, the more favorable setup for rain will remain tied to the front parked to the south of the area. Overnight lows will be a touch warmer in the low 60s.
  

Light rain continues through Tuesday evening

 

Steady and heavy rain came down late Monday night, into most of Tuesday morning. This resulted in rainfall totals ranging anywhere from a half an inch all the way up to two inches in some spots.

The steady rain came to an end by late morning with a few breaks in the clouds occurring during the afternoon. This allowed temperatures to reach the low 80s in a few spots south of Rockford, with Rockford's high reaching 80 degrees. But a cold front passing through northern Illinois this evening has brought with it another round of steady rain, although not as heavy or widespread as this morning.

The additional rainfall will add another quarter to few tenths of an inch, wrapping up around sunset Tuesday evening. As the cold front shifts and settles to the south the majority of the accumulating rainfall Tuesday night will remain just outside the viewing area, but a few showers could move across Whiteside, Lee, and DeKalb counties overnight. 

Wednesday won't start off quite as rainy as Tuesday did but with a little weak low-pressure system sliding through during the afternoon we could see some scattered shower activity into the early afternoon. Temperatures Wednesday will warm into the low to mid-70s.   

Rainy start across northern Illinois, scattered shower chances continue

Rainy Tuesday Morning:

The batch of rain and thunderstorms that developed Monday evening is finally making its way through the Stateline this morning, bringing periods of showers and a few rumbles of thunder. 

The good news is that these storms are expected to remain under severe limits, though they are and will be capable of producing beneficial rain. Since the midnight hour, several Stateline locales have already picked up impressive totals, with areas in southern Wisconsin and Galena seeing amounts up to or even above the half-inch mark. 

Chances Continue:

Keep the umbrella handy and the windshield wipers on as rain will remain likely through the start of the day. Periods of rain and a few thunderstorms will continue through the morning becoming scattered by this afternoon as a cold front pushes through northern Illinois. With this frontal passage will also come a change in wind as winds turn to the northwest later today, limiting highs to the upper 70s. 

Severe potential is rather low and better off to the south as the Storm Prediction Center left the entire area out of today's Marginal Risk. 

 

 

  

Rain chances don't completely disappear behind the cold front that passes through today. Both Wednesday and Thursday continue to feature opportunities for scattered showers, but there has been a noticeable downward trend in overall coverage. The key will be how far south the frontal boundary settles. The further south it ends up, the lower our rain chances become across the Stateline. Even so, it will be worth keeping an eye on over the next couple of days. 
 

Foggy start, potential soaking rain ahead this week

What's Ahead:

Patchy dense fog is on the table across the Stateline this morning as excess moisture from recent rainfall combines with clear skies and light winds. Visibility may drop quickly in some locations, especially in low-lying areas and near rivers. If you encounter any dense fog this morning, slow down, allow for extra distance between you and other vehicles, and travel with your low-beam headlights.  

Once the fog lifts, our attention then turns to a much wetter weather pattern developing into the middle of the week. While there may be an isolated shower in the works for this afternoon, rain and thunderstorm chances will go up overnight into Tuesday as the stuff that forms in eastern Nebraska and western Iowa pushes in. Additional rounds of scattered showers will also be on the table Wednesday into Thursday as a ridge sets up well to our south.   

Severe Potential:

Thankfully, with whatever pushes in overnight will remain under severe limits. The Storm Prediction Center has the highest potential for severe storms across western Iowa. The Stateline remains under a "non-severe" risk at the moment. Severe potential for tomorrow also dodges the Stateline, with the highest potential south of Interstate 88.   

Potential Rainfall:

Some locations may finally wind up with a good rain from the multiple chances this week. Current forecast models suggest the potential for widespread rainfall totals exceeding 1", with some painting pockets of 2"+ rainfall across portions of the area. 

However, a lot will depend on where the frontal boundary ultimately sets up and where the strongest portion of the upper-level jet becomes established. Even small shifts in either feature could have a significant impact on where repeated rounds of showers and thunderstorms develop. Regardless, the overall pattern favors an extended period of unsettled weather. I would plan on having the rain gear in hand Tuesday morning, then again late Wednesday into Wednesday night.