The National Weather Service is urging Chicagoans and suburbanites to stay inside as strong to severe thunderstorms roll into the area from 2 to 7 p.m. Tuesday. The main weather threats will be wind damage, rainfall that may cause ponding and hail.
“If thunder roars, go indoors,” their Chicago office told followers on Twitter.
Late Tuesday night, heavy rains might turn into “torrential rainfall” with a threat of flash floods after midnight and until Wednesday afternoon. Yet the weather service noted a “good deal of uncertainty remains” in regards to the severe threats overnight and throughout Wednesday.
“(We’re) probably going to see showers redevelop late tonight into early Wednesday morning, probably around the 3 or 4 a.m. timeframe, lasting into the morning commute,” said weather service meteorologist Scott Baker. “And then we’re expecting additional storms to move into the area, with a storm system tomorrow midday, kind of late morning. Starting around 11 a.m. and then lasting into the early afternoon, about 2 or 3 p.m.”
The Tuesday forecast prompted the Metropolitan Water Reclamation District to issue an Overflow Action Day alert and encourage residents to reduce water use. It suggested delaying showers and baths, flushing toilets less frequently and waiting to do laundry or wash dishes. More tips can be found on the MWRD’s website.
According to the MWRD, when there is a potential for combined sewer overflow — when heavy rain overwhelms local sewers and reclamation plants — conserving water allows the sewer system more capacity to handle increased volumes of water. When there is overflow during extremely heavy rainfall and the Chicago River’s level exceeds the elevation of Lake Michigan, the MWRD will reverse the flow of the river. Opening the gates for this reversal allows sewage and runoff into the lake.
Most recently, the MWRD had to open the gates for overflow to spill into Lake Michigan when heavy rains hit the city July 2. After experiencing some extended periods of dry weather, northeastern Illinois was showered with several inches of rainfall in the span of four days. In two separate instances between July 2 and 5, Chicago and its outskirts experienced thunderstorms and heavy rain that flooded countless streets and basements.
“With the amount of rainfall that we’ve seen in the Chicago area over the last two weeks and these repeated rounds of rainfall over and over, we definitely do have the issue with saturated soil,” Baker said. When the ground is waterlogged from recent storms, new rain cannot be absorbed and can thus develop into flooding.
“And the McCook Reservoir is definitely filling up, so that’s another thing that we watch, because that’s where all the water that runs off the city of Chicago is stored,” Baker added. The flood-control reservoir, located in southwest suburban McCook, is over 20 times bigger than Soldier Field and is part of the $3 billion Deep Tunnel sewer system built to collect and store sewage and runoff from Chicago and Cook County suburbs.
In some of the hardest-hit Chicago neighborhoods and suburban towns, residents and community leaders have rallied since recent floods to appeal for help from neighbors, as well as to demand financial support and better infrastructural planning from city leaders.
Cook County Board President Toni Preckwinkle issued a disaster proclamation Tuesday afternoon in suburban Cook County for the July 2 storms and floods, which dumped up to 9 inches of rain in certain parts of the county. Berwyn, Cicero and Stickney were the most affected municipalities. The mayor’s office in Berwyn and the president of the town of Cicero called for disaster declarations last week.
Preckwinkle said the proclamation is the “latest step” in her administration’s process of safeguarding suburban communities and assisting in the aftermath of the storms at the beginning of July, as county municipalities have received more than 3,400 reports of property damage.
At a news conference Tuesday morning, Cicero residents asked for state, county and local agencies to invest and come up with long-term solutions to improve the city’s “crumbling” infrastructure and better manage wastewater.
The group is demanding more resilient, green infrastructure: the creation of green spaces or parks, the planting of trees and the use native species in rain gardens, all of which absorb and filter runoff stormwater and help prevent flooding.
As climate change worsens and causes more frequent and disastrous weather events, these will disproportionately affect working-class Black and brown neighborhoods, Cicero community members said in a news release.
Unfortunately, weather for the rest of the week will likely remain damp and grim in the Chicago and its suburbs.
“Best chance for a drier time would be Thursday. However, we can’t rule out potential for some shower, maybe thunderstorm activity on Thursday,” Baker said. “But it does look like again on Friday, we will have another round of showers and storms in the area.”
