Weather outlook remains ‘uncertain’ for McHenry County heading into Independence Day

With a handful of villages and cities planning fireworks and parades Monday for the Fourth of July across McHenry County, the outlook for weather, which could potentially bring storms, is still unsettled.

“There’s quite a bit of uncertainty as to how [weather on Monday] will unfold,” Meteorologist Casey Sullivan said Sunday.

Despite the outlook, officials with the towns said Friday they weren’t concerned weather would affect plans.

Three different storm systems could take place over McHenry County and northern Illinois Monday, with each affecting the next, Sullivan said.

The first, which could come in the morning, is a system expected to develop Sunday night across Iowa and Minnesota to the west, Sullivan said. That system, if it holds together, could bring showers and storms to the northern part of the state Monday morning.

Even if this were to happen, the storm would likely be weakening once it reaches McHenry County, Sullivan said.

Though, storms Monday morning would lower the chance of storms in the afternoon and evening, Sullivan said. That system, if it’s strong enough, could keep temperatures cooler and bring cloud coverage, which would stabilize the area’s atmosphere and lower a chance of further storms.

“It would be more difficult for a storm system to develop because of the stabilized atmosphere,” he said. “But it’s too difficult to pin down.”

On the other hand, if Monday morning turns out to be dry, there’s a higher chance that a new storm system could develop in the area during the afternoon and evening, he said.

As it stands, there is about a 50% chance of storms throughout all of Monday in McHenry County, forecasts from the weather service show.

While many towns in the area are planning their festivities for either during the weekend or after Independence Day, some municipalities, including Huntley, Lakemoor, Marengo, Spring Grove and Woodstock have plans for the Fourth of July.

Those plans range from fireworks shows, to parades and gatherings.

As of Friday, officials said they weren’t worried plans would be altered because of the weather. One of the towns, Huntley, has a backup day for its festivities. None of the towns had any updates posted as of Sunday.

Further updates and details on plans can be found on each respective municipality’s website and social media sites.

The last time precipitation happened in the area was back on Independence Day was in 2018, when there was a trace amount of it, according to daily climate records for Rockford. Before that it was 2010, which registered 0.01 inch. In 2004, about a quarter-inch fell, and in 1994 and 1995, the area almost got an inch.

The last time the area got more than an inch was back in 1973, data shows.

Following any festivities Monday, a strong slate of storms could also be expected Monday night into Tuesday morning, Sullivan said.

“What each system leaves behind determines what each new system has to work with,” Sullivan said. “As you go further out in time, the uncertainty increases. We just don’t know exactly what the first wave is going to do.”