National Weather Service United States Department of Commerce

The National Weather Service (NWS) has the responsibility of issuing forecasts, watches, and warnings for weather hazards across the United States with the goal of protecting life and property. Among weather hazards that occur across the U.S., flooding has been among the most life-threatening and costly over the last several decades. The purpose of the hydrology program at the National Weather Service (NWS) Chicago Weather Forecast Office is to provide life-saving warnings and decision support for river basins across northeast Illinois and northwest Indiana. NWS Chicago works with numerous other federal, state, and local agencies, including the US Geological Survey (USGS) and the US Army Corps of Engineers (USACE), to continually monitor water levels.

Learn more about the NWS Chicago hydrology program and some general hydrology topics below.

The NWS Chicago Hydrologic Service Area

NWS Chicago is responsible for water-related hazards in the hydrologic service area which covers portions of northeast Illinois and northwest Indiana. River forecasts are provided at over 40 locations across the area and water level observations are monitored at over 100 locations. Major rivers in the area include:

  • The Illinois River and tributaries such as the Fox River, DuPage River, Des Plaines River, Chicago River, Kankakee River, Iroquois River, Mazon River, and the Vermilion River.
  • The Rock River and tributaries such as the Pecatonica River, Sugar River, and Kishwaukee River.
  • The Calumet River and tributaries such as the Grand Calumet River and Little Calumet River.

A map showing counties and rivers covered by the NWS Chicago office. This includes the counties of Winnebago, Boone, McHenry, Lake, Ogle, Lee, De Kalb, Kane, DuPage, Cook, La Salle, Kendall, Grundy, Will, Livingston, Kankakee, Ford, and Iroquois in Illinois, Lake, Porter, Newton, Jasper, and Benton in Indiana.

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Hydrology Personnel


Most NWS weather forecast offices are staffed with a hydrologist who leads the hydrology program for the area. The hydrology program leader is the office's subject matter expert on hydrology. The hydrologist helps train the forecast staff, assists in issuing watches and warnings for potential flooding, is the liason between the NWS and other agencies, including local communites, and helps perform some IT functions for hydrology-related software.

River forecasts are provided by specially-focused regional offices called river forecast centers. These centers are staffed by numerous hydrologists and meteorologists who focus on developing and running hydrology forecast models. All river forecasts for the NWS Chicago area are provided by the North Central River Forecast Center in Chanhassen, MN.

NWS Chicago contact:
W. Scott Lincoln, GISP
Senior Service Hydrologist


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Hydrology Education


Curious how hydrologists track rainfall patterns or monitor river levels? Want to learn more about what goes into river forecasts?

Hydrology is a complex science overlapping with many other sciences such as meteorology, geology, agronomy, and geography. Accurate river forecasts can't be made without accurate weather forecasts, for example. Learn more about the basics of hydrology such as the water cycle, monitoring current conditions, forecasting, and human impacts on hydrology, below.

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