Alert archive / Illinois / Severe Thunderstorm Warnings in 2019

Severe Thunderstorm Warning 89, NWS Chicago, IL

July 2, 2019DeKalb County, Kendall County, LaSalle County, Illinois

NWS Chicago, IL issued this severe thunderstorm warning at Jul 2, 2019, 9:29 PM CDT for DeKalb County, Kendall County, LaSalle County, Illinois. It was in force for 46 min. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued: Jul 2, 2019, 9:29 PM CDT (02:29 UTC)
Expired: Jul 2, 2019, 10:15 PM CDT
In force: 46 min
Issued by: NWS Chicago, IL
Area: Storm-based polygon
Hail: 0.75 in
Wind: 60.0 mph

Counties DeKalb County, IL, Kendall County, IL, LaSalle County, IL

The radar

The Chicago radar (KLOT), 51 km from the middle of the area, began a volume at 02:31 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

Davenport, (KDVN), launched 00:00Z, 2.5 hours before the alert went out and 150 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: 1722 J/kg
Mixed-layer CIN: -3 J/kg
Mixed-layer LCL: 1561 m above ground
0-6 km bulk shear: 13 kt
0-1 km storm-relative helicity: 38 m²/s²
0-3 km storm-relative helicity: 89 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this severe thunderstorm 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 severe thunderstorm warning went out at Jul 2, 8:56 PM CDT, 33 minutes earlier.

Area forecast discussion, Jul 2, 8:56 PM CDT, 33 minutes before

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Hazardous weather outlook, Jul 2, 2:47 PM CDT, 6 hours 42 minutes before

Hazardous Weather Outlook
National Weather Service Chicago/Romeoville IL
247 PM CDT Tue Jul 2 2019

ILZ003>006-008-010>014-019>023-032-033-039-INZ001-002-010-011-019-
032000-
Winnebago-Boone-McHenry-Lake-Ogle-Lee-De Kalb-Kane-DuPage-Cook-
La Salle-Kendall-Grundy-Will-Kankakee-Livingston-Iroquois-Ford-
Porter-Newton-Jasper-Benton-
247 PM CDT Tue Jul 2 2019 /347 PM EDT Tue Jul 2 2019/

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

.DAY ONE...Tonight.

Weather hazards expected...

  Elevated Thunderstorm Risk...with an associated:
     Limited damaging wind risk...up to 60 mph.
  Limited Flooding Risk.
  Limited Excessive heat Risk.

DISCUSSION...

Heat indices in the 90s to low 100s will continue this afternoon.
The heat and humidity will help fuel additional scattered thunderstorms
through this evening. Some of these may produce isolated very
heavy rainfall. Also, an isolated storm or two may
become severe with damaging winds the primary threat.

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

Wednesday...
  Limited Severe Thunderstorm Risk.
  Limited Flooding Risk.
  Limited Excessive Heat Risk.
Thursday...
  Limited Flooding Risk.
  Elevated Thunderstorm Risk.
  Limited Excessive Heat Risk.
Friday...
  Elevated Thunderstorm Risk.
  Limited Excessive Heat Risk.
Saturday through Monday...
  Limited Thunderstorm Risk.

DISCUSSION:

Expect occasional periods of thunderstorms through the holiday
and remainder of the week. Widespread severe weather is not
expected, but occasional heavy rain and damaging winds will
accompany the storms along with dangerous lightning. Stay
tuned to the weather during outdoor activities as the weather
may change quickly.

.SPOTTER INFORMATION STATEMENT...

  Due to the isolated nature of any severe weather, spotters
  activation is not anticipated. However, spotters are encouraged
  to relay any reports of damaging winds or flooding.

GENERAL STORM MOTION OF THE DAY:

  Moving toward the east at around 20 mph.

LMZ740>745-032000-
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-
247 PM CDT Tue Jul 2 2019

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...Tonight.

Weather hazards expected...

  Elevated Thunderstorm Risk...with an associated:
     Limited thunderstorm wind gust risk...up to 50 knots.

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

Wednesday...
  Limited Severe Thunderstorm Risk.
Thursday...
  Limited Thunderstorm Risk.
Friday...
  Elevated Thunderstorm Risk.
Saturday through Monday...
  Limited Thunderstorm Risk.

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In the hours before

Local storm report, Jul 2, 8:45 PM CDT, 44 minutes before

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Local storm report, Jul 2, 8:50 PM CDT, 39 minutes before

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Local storm report, Jul 2, 8:55 PM CDT, 34 minutes before

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Special weather statement, Jul 2, 9:04 PM CDT, 25 minutes before

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Local storm report, Jul 2, 9:20 PM CDT, 9 minutes before

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Local storm report, Jul 2, 9:25 PM CDT, 4 minutes before

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The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 2, 7:00 PM CDT	Severe Thunderstorm Warning	LOT	Cook, Kane	45 min
Jul 2, 7:22 PM CDT	Severe Thunderstorm Warning	LOT	Cook, Lake	32 min
Jul 2, 7:28 PM CDT	Severe Thunderstorm Warning	LOT	DuPage	35 min
Jul 2, 7:41 PM CDT	Areal Flood Advisory	LOT	Cook, DuPage	3 hr
Jul 2, 7:48 PM CDT	Flash Flood Warning	LOT	Winnebago	4 hr
Jul 2, 8:17 PM CDT	Severe Thunderstorm Warning	LOT	DuPage, Kane, Kendall, Will	43 min
Jul 2, 8:30 PM CDT	Flash Flood Warning	LOT	Cook, DuPage, Kane, Kendall, Will	4 hr
Jul 2, 8:39 PM CDT	Special Marine Warning	LOT		66 min
Jul 2, 9:51 PM CDT	River Flood Advisory	LOT	Will	33 hr
Jul 2, 10:12 PM CDT	River Flood Warning	LOT	Kane, Kendall	15 hr
Jul 2, 11:15 PM CDT	Severe Thunderstorm Warning	LOT	LaSalle	30 min
Jul 3, 6:41 AM CDT	River Flood Warning	LOT	LaSalle	8 hr
Jul 3, 6:51 AM CDT	River Flood Advisory	LOT	LaSalle	59 hr
Jul 3, 6:59 PM CDT	Areal Flood Advisory	LOT	Boone, DeKalb, Kane, McHenry	3 hr

Nearby

Severe Thunderstorm Warnings in Illinois, 2019 Every severe thunderstorm warning in 2019

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.