Weather
Chicago-Area Weather: Rainfall Rates Over 1 Inch Per Hour, Flash Flooding Possible
Suburban towns already affected by flooding could see more issues in the coming days as heavy rain is in the forecast.
For those hoping for some relief from the rain, it may not come for a couple days. A flash flood watch has been issued for counties throughout the Chicago area for 4 p.m. Friday through Saturday morning as multiple rounds of thunderstorms are expected to roll through north central and northeast Illinois. Those storms, which are expected to start late this afternoon and continue through early Saturday, could produce heavy rainfall and rainfall rates well over 1 inch per hour, according to the National Weather Service.
The storms could pose a threat specifically for far northern Illinois where the ground is already saturated in many areas from recent flooding. In addition, rises in already brimming rivers and creeks should be expected.
"Heavy rainfall will likely quickly produce runoff and produce flash flooding," according to the Flash Flood Watch from the National Weather Service.
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In McHenry County, a flash flood warning remains in effect for the Fox River in Algonquin. On Thursday, the river reached record high levels, rising past the former record of 12.7 feet. As of 7 p.m., the river was at 12.9 feet, well above its flood stage of 9.5 feet. The spike in the river's waters Thursday came after heavy rains on Wednesday night and early Thursday forced the already high river level to rise further.
The river is expected to rise to 13 or 13.5 feet, which means a flood that has already gone on for eight days could continue through July 27 at the earliest, McHenry County Emergency Management Agency Director David Christensen told the Chicago Tribune. And all of that could be even worse if the county is hit hard by rain in coming days.
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The heavy rains this past week also caused the Des Plaines River, which is also under a flood warning in Gurnee, Riverside Des Plaines and Lincolnshire, to rise. But it has not again hit record highs that it did in the past week, Stormwater Management Commission Chief Engineer Kurt Woolford told the Chicago Tribune. In Kane County, towns along the Fox River are preparing as the river level continues to rise there as well.
The highest likelihood of storms on Friday will be north of Interstate 80 during the late afternoon and early evening hours. There is also a lower chance for storms on Saturday and Sunday, according to the National Weather Service. In addition, the heat and humidity is expected through Friday and Saturday, and Sunday should be warm as well.
Area residents, especially those in flood-prone areas, should keep an eye on the weather forecast in the coming hours and days and have multiple ways of receiving flood alerts if they are issued for your area. In addition, it is good to know which roads are prone to flooding in your area and along your commute and identify alternate routes. If you do come upon a flooded road, turn around.
As of Friday morning, no evacuations have been issued in flooded towns, but officials are urging residents to know where they will need to go and to be prepared if they need to head to higher ground.
The Chicago area is expected to get a break from the heat and the rain next week.
Here is a more detailed look at the forecast for the coming days:
FRIDAY: Mostly cloudy. Chance of showers and thunderstorms in the afternoon. Some thunderstorms may produce heavy rainfall in the afternoon. Highs in the upper 80s inland...but only in the mid 80s near the lake. Southeast winds 5 to 10 mph. Chance of precipitation 30 percent.
FRIDAY NIGHT: Mostly cloudy. Chance of showers and thunderstorms in the evening, then showers and thunderstorms likely after midnight. Some thunderstorms may produce heavy rainfall. Lows in the mid 70s. South winds 5 to 10 mph. Chance of precipitation 70 percent.
SATURDAY: Partly sunny. Chance of showers and thunderstorms in the morning, then a slight chance of showers and thunderstorms in the afternoon. Some thunderstorms may produce heavy rainfall in the morning. Highs in the upper 80s. Highest heat index readings 96 to 101 in the afternoon. West winds 10 to 15 mph. Chance of precipitation 40 percent.
SATURDAY NIGHT: Partly cloudy. A 20 percent chance of showers and thunderstorms in the evening. Lows in the lower 70s. Northwest winds 10 to 15 mph.
SUNDAY: Partly cloudy. A 20 percent chance of showers and thunderstorms in the afternoon. Highs in the mid 80s. West winds 5 to 10 mph.
SUNDAY NIGHT: Mostly clear. A 20 percent chance of showers in the evening. Lows in the mid 60s.
MONDAY: Partly cloudy. Highs in the upper 70s.
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