Alert archive / Illinois / Severe Thunderstorm Warnings in 2018

Severe Thunderstorm Warning 43, NWS Chicago, IL

July 13, 2018Ogle County, Winnebago County, Illinois

NWS Chicago, IL issued this severe thunderstorm warning at Jul 13, 2018, 7:04 PM CDT for Ogle County, Winnebago County, Illinois. It was in force for 56 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 13, 2018, 7:04 PM CDT (00:04 UTC)
Expired
Jul 13, 2018, 8:00 PM CDT
In force
56 min
Issued by
NWS Chicago, IL
Area
Storm-based polygon
Hail
0.75 in
Wind
60.0 mph

Counties Ogle County, IL, Winnebago County, IL

The radar

The Milwaukee radar (KMKX), 103 km from the middle of the area, began a volume at 00:07 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, 0.1 hours before the alert went out and 122 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-pSkew-T log-p diagram, Davenport, at 00:00Z on 2018-07-14Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1696 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Davenport, at 00:00Z on 2018-07-14The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 49 square meters per square second.193958Sfc1 km3 km6 km9 kmRMLM
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
1696 J/kg
Mixed-layer CIN
-52 J/kg
Mixed-layer LCL
1134 m above ground
0-6 km bulk shear
28 kt
0-1 km storm-relative helicity
49 m²/s²
0-3 km storm-relative helicity
-44 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 13, 7:03 PM CDT, 1 minute earlier.

Area forecast discussion, Jul 13, 7:03 PM CDT, 1 minute before
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Hazardous weather outlook, Jul 13, 3:30 PM CDT, 3 hours 34 minutes before
Hazardous Weather Outlook
National Weather Service Chicago/Romeoville IL
330 PM CDT Fri Jul 13 2018

ILZ003>006-008-010>014-019>023-032-033-039-INZ001-002-010-011-019-
142030-
Winnebago-Boone-McHenry-Lake IL-Ogle-Lee-DeKalb-Kane-DuPage-Cook-
La Salle-Kendall-Grundy-Will-Kankakee-Livingston-Iroquois-Ford-
Lake IN-Porter-Newton-Jasper-Benton-
330 PM CDT Fri Jul 13 2018 /430 PM EDT Fri Jul 13 2018/

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.

DISCUSSION...

Thunderstorms are likely to spread into portions of far northern
Illinois this evening, including the Rockford metropolitan area.
Depending on how organized the thunderstorms become and how
quickly they move into the area, isolated marginally severe wind
gusts will be possible. Outside of any severe wind risk, all
thunderstorms can be expected to produce occasional to frequent
cloud to ground lightning and very heavy downpours, with a
localized flooding risk.

In addition, heat indices will be around 100 degrees this
afternoon from the far western suburbs of Chicago south to Pontiac
and then west to the Mississippi River.

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

Saturday...
  Elevated Thunderstorm Risk.
  Limited Flooding Risk.
  Limited Excessive Heat Risk.
Sunday...
  Limited Thunderstorm Risk.
  Limited Excessive Heat Risk.
Monday...
  Elevated Thunderstorm Risk.
  Limited Excessive Heat Risk.
  Limited Coastal Flood Risk
Tuesday...
  Limited Coastal Flood Risk
Wednesday and Thursday...
  Limited Thunderstorm Risk.

.SPOTTER INFORMATION STATEMENT...

  Spotters may be needed this evening in northwest and north central
  Illinois.

GENERAL STORM MOTION OF THE DAY:

  Moving toward the east at around 30 mph.

LMZ740>745-142030-
Winthrop Harbor to Wilmette Harbor-
Wilmette Harbor to Northerly Island-
Northerly Island to Calumet Harbor-Calumet Harbor to Gary-
Gary to Burns Harbor-Burns Harbor to Michigan City-
330 PM CDT Fri Jul 13 2018

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 34 to 50 knots.

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

Saturday through Monday...
  Limited Thunderstorm Risk.
Thursday...
  Limited Thunderstorm Risk.

LMZ080-261-362-364-366-563-565-567-669-671-673-675-777-779-868-
870-872-874-876-878-142030-
Lake Michigan from Michigan City IN to St. Joseph MI 5 NM
offshore to Mid Lake-
Lake Michigan from Seul Choix Point to Rock Island Passage 5 NM
offshore to Mid Lake-
Lake Michigan South of a line from Seul Choix Point to the
Mackinac Bridge and north of a line from Charlevoix MI to South
Fox Island 5 NM offshore-
Lake Michigan from Charlevoix to Point Betsie MI 5 NM offshore to
Mid Lake-
Lake Michigan from Point Betsie to Manistee MI 5 NM offshore to
Mid Lake-
Lake Michigan from Rock Island Passage to Sturgeon Bay WI-
Lake Michigan from Sturgeon Bay to Two Rivers WI 5 NM offshore to
Mid Lake-
Lake Michigan from Two Rivers to Sheboygan WI 5 NM offshore to
Mid Lake-
Lake Michigan from Sheboygan to Port Washington WI 5 NM offshore
to Mid Lake-
Lake Michigan from Port Washington to North Point Light WI 5 NM
offshore to Mid Lake-
Lake Michigan from North Point Light to Wind Point WI 5 NM
offshore to Mid Lake-
Lake Michigan from Wind Point WI to Winthrop Harbor IL 5 NM
offshore to Mid Lake-
Lake Michigan from Winthrop Harbor to Wilmette Harbor IL 5 NM
offshore to Mid Lake-
Lake Michigan from Wilmette Harbor IL to Michigan City IN 5 NM
offshore to Mid Lake-
Lake Michigan Holland to Whitehall MI 5 nm off shore to mid-
line of lake-
Lake Michigan from Whitehall to Pentwater MI 5 NM offshore to Mid
Lake-
Lake Michigan from Grand Haven to Whitehall MI 5 NM offshore to
Mid Lake-
Lake Michigan from Holland to Grand Haven MI 5 NM offshore to Mid
Lake-
Lake Michigan from South Haven to Holland MI 5 NM offshore to Mid
Lake-
Lake Michigan from St. Joseph to South Haven MI 5 NM offshore to
Mid Lake-
330 PM CDT Fri Jul 13 2018

This Hazardous Weather Outlook is for portions of the open waters
of Lake Michigan.

.DAY ONE...Tonight.

Weather hazards expected...

  Elevated Thunderstorm Risk...with an associated:
     Limited thunderstorm wind gust risk...up to 34 to 50 knots.

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

Saturday through Tuesday...
  Limited Thunderstorm Risk.
Thursday...
  Limited Thunderstorm Risk.

MTF

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The office that day

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

IssuedProductOfficeCountiesLasted
Jul 13, 7:46 PM CDTSpecial Weather StatementLOTWinnebago29 min
Jul 13, 8:05 PM CDTSpecial Weather StatementLOTOgle40 min
Jul 13, 8:47 PM CDTSpecial Weather StatementLOTLee28 min
Jul 13, 9:18 PM CDTSpecial Weather StatementLOTLee27 min
Jul 13, 9:49 PM CDTSpecial Weather StatementLOTDeKalb26 min
Jul 14, 9:02 AM CDTSpecial Weather StatementLOTFord43 min
Jul 14, 9:17 AM CDTSevere Thunderstorm WarningLOTFord, Iroquois43 min
Jul 14, 9:51 AM CDTSevere Thunderstorm WarningLOTIroquois39 min
Jul 14, 10:20 AM CDTSevere Thunderstorm WarningLOTBenton31 min

Nearby

Severe Thunderstorm Warnings in Illinois, 2018Every severe thunderstorm warning in 2018

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.