Alert archive / Illinois / Flash Flood Warnings in 2023

Flash Flood Warning 2, NWS Chicago, IL

March 31, 2023Cook County, DuPage County, Lake County, Illinois

NWS Chicago, IL issued this flash flood warning at Mar 31, 2023, 7:09 PM CDT for Cook County, DuPage County, Lake County, Illinois. It was in force for 4 hr. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued: Mar 31, 2023, 7:09 PM CDT (00:09 UTC)
Expired: Mar 31, 2023, 11:00 PM CDT
In force: 4 hr
Issued by: NWS Chicago, IL
Area: Storm-based polygon
Damage threat: Considerable
Flood severity: None

Counties Cook County, IL, DuPage County, IL, Lake County, IL

The radar

The Chicago radar (KLOT), 51 km from the middle of the area, began a volume at 00:11 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 nearest sounding before it

Lincoln, IL (KILX), launched 00:00Z, 0.2 hours before the alert went out and 218 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.

Mixed-layer CAPE: 638 J/kg
Mixed-layer CIN: -39 J/kg
Mixed-layer LCL: 921 m above ground
0-6 km bulk shear: 63 kt
0-1 km storm-relative helicity: 347 m²/s²
0-3 km storm-relative helicity: 369 m²/s²
Significant tornado parameter: 1.4
Supercell composite: 7.1

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this flash flood warning 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 flash flood warning went out at Mar 31, 7:03 PM CDT, 6 minutes earlier.

Area forecast discussion, Mar 31, 7:03 PM CDT, 6 minutes before

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Hazardous weather outlook, Mar 31, 12:15 PM CDT, 6 hours 54 minutes before

Hazardous Weather Outlook
National Weather Service Chicago/Romeoville IL
1215 PM CDT Fri Mar 31 2023

ILZ003>006-008-010>013-019>021-023-032-033-039-103>108-INZ001-002-
010-011-019-011715-
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-
1215 PM CDT Fri Mar 31 2023 /115 PM EDT Fri Mar 31 2023/

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

.DAY ONE...This Afternoon and Tonight.

Weather hazards expected...

  Significant Thunderstorm Risk...with an associated:
     Elevated Tornado Risk.
     Elevated Hail Risk...up to golf ball size.
     Significant Damaging Wind Risk...up to 80 mph.
  Limited Flooding Risk.
  Elevated Non Thunderstorm Wind Risk.

DISCUSSION...

A robust early spring storm system will track across the
Midwest and into the Great Lakes region today. A significant
severe threat exists across the area this afternoon through mid
evening. All severe weather hazards are possible, including
significant damaging winds and strong tornadoes. Stay up to date
with the latest forecast information.

A period of strong non-thunderstorm winds to around 50 mph is
expected late this afternoon and into Saturday morning. At this
time, the strongest winds are favored to be south of I-80 this
afternoon and near the Wisconsin line late tonight.

.DAYS TWO THROUGH SEVEN...Saturday through Thursday.

Saturday...
  Elevated Non Thunderstorm Wind Risk in the morning south of I-80.
  Elevated Lakeshore Flood Risk for northwest Indiana.
Monday...
  Limited Thunderstorm Risk.
Tuesday...
  Limited Severe Thunderstorm Risk.
  Limited Non Thunderstorm Wind Risk.
Wednesday...
  Limited Non Thunderstorm Wind Risk.

.SPOTTER INFORMATION STATEMENT...

  Spotters will likely be needed this afternoon and evening.

GENERAL STORM MOTION OF THE DAY:

  Moving toward the northeast at 50 mph this afternoon, and to
  the east at 65 mph this evening.

LMZ740>745-011715-
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-
1215 PM CDT Fri Mar 31 2023

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...This Afternoon and Tonight.

Weather hazards expected...

  Gale force winds and or very hazardous waves.
  Significant Thunderstorm Risk...with an associated:
     Limited waterspout risk.
     Limited hail risk...up to half dollar size.
     Elevated thunderstorm wind gust risk...up to 70 knots.

.DAYS TWO THROUGH SEVEN...Saturday through Thursday.

Saturday...
  Gale force winds and very hazardous waves are likely.
Sunday...
  Hazardous conditions for small craft are likely.
Tuesday...
  Hazardous conditions for small craft are likely.
  Limited Severe Thunderstorm Risk.
Wednesday...
  Gale force winds and very hazardous waves are likely.
Thursday...
  Hazardous conditions for small craft are likely.

Yack

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In the hours before

Local storm report, Mar 31, 5:04 PM CDT, 2 hours 5 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE CHICAGO IL
504 PM CDT FRI MAR 31 2023

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0503 PM     HAIL             6 ENE VALPARAISO        41.52N 86.95W
03/31/2023  M0.70 INCH       PORTER             IN   PUBLIC

&&

Local storm report, Mar 31, 5:06 PM CDT, 2 hours 3 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE CHICAGO IL
506 PM CDT FRI MAR 31 2023

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0454 PM     HAIL             LAKES OF THE FOUR SEASO 41.41N 87.22W
03/31/2023  M1.00 INCH       LAKE               IN   TRAINED SPOTTER

&&

Local storm report, Mar 31, 5:43 PM CDT, 1 hour 26 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE CHICAGO IL
543 PM CDT FRI MAR 31 2023

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0536 PM     HAIL             SUBLETTE                41.64N 89.23W
03/31/2023  M0.88 INCH       LEE                IL   LAW ENFORCEMENT

&&

Local storm report, Mar 31, 5:54 PM CDT, 1 hour 15 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE CHICAGO IL
554 PM CDT FRI MAR 31 2023

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0408 PM     FUNNEL CLOUD     5 ESE CORNELL           40.96N 88.65W
03/31/2023                   LIVINGSTON         IL   AMATEUR RADIO

            1 MILE NORTH OF I-55 ON IL-23. UNSURE
            WHETHER THE FUNNEL TOUCHED DOWN.

&&

Local storm report, Mar 31, 6:38 PM CDT, 31 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE CHICAGO IL
638 PM CDT FRI MAR 31 2023

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0549 PM     FLOOD            1 NE OAK FOREST         41.61N 87.74W
03/31/2023                   COOK               IL   PUBLIC

            1 FT OF STANDING WATER AT THE CICERO AND
            159TH ST. UNDERPASS.

&&

KMD

Local storm report, Mar 31, 6:41 PM CDT, 28 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE CHICAGO IL
641 PM CDT FRI MAR 31 2023

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0616 PM     FLOOD            WOOD DALE               41.96N 87.98W
03/31/2023                   DUPAGE             IL   PUBLIC

            SOCIAL MEDIA PHOTO SHOWS AT LEAST 1 FOOT OF
            STANDING WATER ON RESIDENTIAL STREETS IN
            WOOD DALE.

&&

The office that day

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

Issued	Product	Office	Counties	Lasted
Mar 31, 7:01 PM CDT	Flood Watch	LOT	Cook, DuPage, Kane, Lake, Will	2 hr
Mar 31, 7:10 PM CDT	Severe Thunderstorm Warning Considerable damage threat	LOT	LaSalle	50 min
Mar 31, 7:18 PM CDT	Tornado Warning	LOT	DeKalb, Lee, Ogle	42 min
Mar 31, 7:23 PM CDT	Tornado Warning	LOT	Boone, DeKalb, McHenry, Ogle, Winnebago	43 min
Mar 31, 7:35 PM CDT	Severe Thunderstorm Warning Destructive damage threat	LOT	Kane, Kendall	40 min
Mar 31, 7:38 PM CDT	Severe Thunderstorm Warning	LOT	Ford, Iroquois	22 min
Mar 31, 7:42 PM CDT	Tornado Warning	LOT	Ford, Iroquois	48 min
Mar 31, 7:43 PM CDT	Severe Thunderstorm Warning Destructive damage threat	LOT	Grundy, LaSalle	47 min
Mar 31, 7:47 PM CDT	Special Marine Warning	LOT		95 min
Mar 31, 7:52 PM CDT	Severe Thunderstorm Warning Destructive damage threat	LOT	Cook, DuPage, Lake, McHenry, Will	68 min
Mar 31, 8:34 PM CDT	Tornado Warning	LOT	Cook	11 min
Mar 31, 11:04 PM CDT	River Flood Warning	LOT	Cook	22 hr
Apr 1, 11:30 AM CDT	River Flood Warning	LOT	Bureau, LaSalle, Putnam	3 days
Apr 1, 6:34 PM CDT	Small Craft Advisory	LOT		9 hr
Mar 31, 8:15 PM CDT	Tornado Warning	LOT	Benton	32 min
Mar 31, 8:16 PM CDT	Severe Thunderstorm Warning	LOT	Lake	14 min
Mar 31, 8:22 PM CDT	Severe Thunderstorm Warning	LOT	Lake, Porter	23 min
Mar 31, 8:39 PM CDT	Severe Thunderstorm Warning Considerable damage threat	LOT	Lake, Porter	46 min
Mar 31, 8:42 PM CDT	Tornado Warning	LOT	Jasper	25 min
Mar 31, 8:57 PM CDT	Tornado Warning	LOT	Lake, Porter	18 min
Mar 31, 9:07 PM CDT	Severe Thunderstorm Warning	LOT	Jasper, Lake, Newton, Porter	42 min

Nearby

Flash Flood Warnings in Illinois, 2023 Every flash flood warning in 2023

Sources

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