Park Forest Cleans Up After Monster Derecho

SPC Day 1 Severe Thunderstorm Outlook issued at 10:57 a.m., Aug. 10.
SPC Day 1 Severe Thunderstorm Outlook issued at 10:57 a.m., Aug. 10. (National Weather Service)

Park Forest, IL-(ENEWSPF)- Better than 24 hours after severe storms in the form of a massive derecho swept through the area more than 1,100 residents in the Park Forest area remain without power. ComEd crews continue to work on downed power lines in effort to restore service to area residents.

The Village of Park Forest offered the following information in the aftermath of the storm:

Park Forest would like to make residents aware of several important things related to today’s storms and the clean-up efforts to follow:

  • Park Forest’s Public Works Department is in the process of clearing the nearly 72 miles of Park Forest roadway of debris to ensure that all streets are safe and accessible for motorists. This process could take a few days.
  • Public Works will begin debris pick-up tomorrow. Residents with debris for pick-up should bundle that debris and leave it at the curb. Bundled branches should be five feet in length or less with no branch greater than four inches in diameter.
  • Residents wishing to expedite the process of debris collection may bring collected debris to a designated drop-off location at the northeast corner of Westwood Drive and Forest Boulevard.
  • The Village of Park Forest does not trim trees or remove debris on private properties.
  • Residents in need of tree cutting or debris removal services should contact a Park Forest licensed contractor. A list of Park Forest licensed contractors can be found on the village’s website here.  
  • Residents should use extreme caution underneath trees. Some large branches may continue to fall over the next several days and pose a great danger.
  • Those still without power should remain in contact with ComEd for updates. ComEd provides power outage updates via a mobile app, via their website at Comed.com, or by phone at 800-334-7661.

What is a Derecho?

According to the National Weather Service, a derecho produces a swath of particularly damaging thunderstorm winds (specifically, wind gusts of at least 58 mph along most of its length with several well-separated 75 mph or greater gusts) over an area at least 250 miles long.

Monday’s storm was 750 miles long, according to the National Weather Service.

Derechos are primarily classified as straight-line winds rather than tornadic.

Even so, wind speeds in a derecho can exceed 100 mph which is equivalent to that of an EF1 tornado but over a vastly larger area than a tornado would impact.

Tornadoes can also be embedded within derechos and produce concentrated areas of even more intense damage.

NBC Chicago confirmed that a tornado did in fact touch down in Chicago Monday.

Derechos develop in an environment with very warm and moist air at the surface, colder air aloft, and moderate to strong winds at upper levels of the atmosphere.

Northern Illinois and northern Indiana have long been known as a corridor of enhanced derecho activity, as shown in this graphic from a published paper by Guastini & Bosart (2016) titled “Analysis of a Progressive Derecho Climatology and Associated Formation Environments.”

Derecho climatology from 1996-2013 by Guastini and Bosart (2016).
Derecho climatology from 1996-2013 by Guastini and Bosart, National Weather Service. (2016)

Despite the massive coverage and impressive intensity of the wind damage, there were a very limited number of serious injuries. This speaks to the effort of our partners including fellow meteorologists in the weather enterprise effectively communicating the threats and action needed to be taken, as well as emergency management and law enforcement for their preparedness efforts beforehand and assistance efforts immediately after.

This is content from the Village of Park Forest and the National Weather Service.