Alert archive / Illinois / River Flood Advisories in 2021

River Flood Advisory 18, NWS Chicago, IL

May 11, 2021Bureau County, LaSalle County, Putnam County, Illinois

NWS Chicago, IL issued this river flood advisory at May 11, 2021, 8:12 AM CDT for Bureau County, LaSalle County, Putnam County, Illinois. It was in force for 35 hr.

The area

The counties it named.

The facts

Issued: May 11, 2021, 8:12 AM CDT (13:12 UTC)
Expired: May 12, 2021, 7:02 PM CDT
In force: 35 hr
Issued by: NWS Chicago, IL
Area: Storm-based polygon

Counties Bureau County, IL, LaSalle County, IL, Putnam County, IL

The radar

The Chicago radar (KLOT), 101 km from the middle of the area, began a volume at 13:17 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

The river

Written for the forecast point Illinois River near La Salle (LSLI2).

Action stage: 19 ft
Minor stage: 20 ft
Moderate stage: 27 ft
Major stage: 31 ft

This gauge today: stage, forecast and historic crests

Stage from the USGS instantaneous record for site 411925089063901, one reading an hour, from a day before the product to a day after it ended. Flood stages are today's.

What forecasters said that day

The local office's own words before this river flood advisory went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Chicago, IL wrote its last area forecast discussion before this river flood advisory went out at May 11, 6:40 AM CDT, 1 hour 32 minutes earlier.

Area forecast discussion, May 11, 6:40 AM CDT, 1 hour 32 minutes before

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Hazardous weather outlook, May 11, 3:30 AM CDT, 4 hours 42 minutes before

Hazardous Weather Outlook
National Weather Service Chicago/Romeoville IL
330 AM CDT Tue May 11 2021

ILZ003>006-008-010>013-019>021-023-032-033-039-103>108-INZ001-002-
010-011-019-120830-
Winnebago-Boone-McHenry-Lake IL-Ogle-Lee-De Kalb-Kane-DuPage-
La Salle-Kendall-Grundy-Kankakee-Livingston-Iroquois-Ford-
Northern Cook-Central Cook-Southern Cook-Northern Will-
Southern Will-Eastern Will-Lake IN-Porter-Newton-Jasper-Benton-
330 AM CDT Tue May 11 2021 /430 AM EDT Tue May 11 2021/

This Hazardous Weather Outlook is for portions of North Central
Illinois...Northeast Illinois and Northwest Indiana.

.DAY ONE...Today and Tonight.

Weather hazards expected...

  Elevated Frost Risk

DISCUSSION...

Temperatures will once again fall into the low to mid 30s away
from Chicago leading to the development of frost tonight into
Wednesday morning.

.DAYS TWO THROUGH SEVEN...Wednesday through Monday.

Wednesday Night...
  Limited Frost Risk.
Sunday and Monday...
  Limited Thunderstorm Risk.

.SPOTTER INFORMATION STATEMENT...

  Spotter activation will not be necessary through tonight.

LMZ740>745-120830-
Winthrop Harbor to Wilmette Harbor IL-
Wilmette Harbor to Northerly Island IL-
Northerly Island to Calumet Harbor IL-
Calumet Harbor IL to Gary IN-Gary to Burns Harbor IN-
Burns Harbor to Michigan City IN-
330 AM CDT Tue May 11 2021

This Hazardous Weather Outlook is for portions of the Illinois
nearshore waters of Lake Michigan and the Indiana nearshore
waters of Lake Michigan.

.DAY ONE...Today and Tonight.

  No hazardous weather is expected at this time.

.DAYS TWO THROUGH SEVEN...Wednesday through Monday.

Monday...
  Limited Thunderstorm Risk.

Carlaw

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The office that day

Everything else NWS Chicago, IL issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
May 10, 7:28 PM CDT	River Flood Warning	LOT	Bureau, LaSalle, Putnam	13 hr
May 11, 2:11 PM CDT	Frost Advisory	LOT	Boone, Cook, DeKalb, DuPage, Ford, Grundy and 12 more	17 hr

Nearby

River Flood Advisories in Illinois, 2021 Every river flood advisory in 2021

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; radar from the NEXRAD Level II archive; the gauge from the NWS water service and the USGS.