Alert archive / Illinois / Severe Thunderstorm Warnings in 2020

Severe Thunderstorm Warning 1, NWS Chicago, IL

March 28, 2020Boone County, Ogle County, Winnebago County, Illinois

NWS Chicago, IL issued this severe thunderstorm warning at Mar 28, 2020, 7:01 PM CDT for Boone County, Ogle County, Winnebago County, Illinois. It was in force for 29 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
Mar 28, 2020, 7:01 PM CDT (00:01 UTC)
Expired
Mar 28, 2020, 7:30 PM CDT
In force
29 min
Issued by
NWS Chicago, IL
Area
Storm-based polygon
Hail
1.0 in
Wind
50.0 mph

Counties Boone County, IL, Ogle County, IL, Winnebago County, IL

The radar

The Milwaukee radar (KMKX), 93 km from the middle of the area, began a volume at 00:02 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, 0.0 hours before the alert went out and 134 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 2020-03-29Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 504 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 2020-03-29The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 480 square meters per square second.1939587897117136156Sfc1 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
504 J/kg
Mixed-layer CIN
-27 J/kg
Mixed-layer LCL
963 m above ground
0-6 km bulk shear
88 kt
0-1 km storm-relative helicity
480 m²/s²
0-3 km storm-relative helicity
520 m²/s²
Significant tornado parameter
1.7
Supercell composite
9.3

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 Mar 28, 6:43 PM CDT, 18 minutes earlier.

Area forecast discussion, Mar 28, 6:43 PM CDT, 18 minutes before
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Hazardous weather outlook, Mar 28, 2:56 PM CDT, 4 hours 5 minutes before
Hazardous Weather Outlook
National Weather Service Chicago/Romeoville IL
256 PM CDT Sat Mar 28 2020

ILZ003>006-008-010>013-019>021-023-032-033-039-103>108-INZ001-002-
010-011-019-292000-
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-
256 PM CDT Sat Mar 28 2020 /356 PM EDT Sat Mar 28 2020/

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

.DAY ONE...Tonight.

Weather hazards expected...

  Significant Thunderstorm Risk...with an associated:
     Significant Tornado risk.
     Significant hail risk...up to tennis ball size.
     Elevated damaging wind risk...up to 60 mph.
  Limited Flooding Risk.

DISCUSSION...

An outbreak of severe thunderstorms remains possible this afternoon
and evening, with the potential for very large hail and tornadoes,
including some threat of significant tornadoes. While the threat
of severe weather will exist across the entire outlook area, the
greatest threat for tornadoes will be around and southwest of a
line from Dixon to Dwight to Watseka. Thunderstorm movement will
be rapidly to the northeast.

Late tonight, strong southwest to west winds will develop, with
gusts to 45 mph expected by morning.

.DAYS TWO THROUGH SEVEN...Sunday through Friday.

Sunday...
  Elevated Non Thunderstorm Wind Risk.

DISCUSSION:

Strong west to southwest winds gusting up to 45 mph are expected
Sunday.

.SPOTTER INFORMATION STATEMENT...

Any reports of severe weather will be greatly appreciated this
afternoon and evening.

GENERAL STORM MOTION OF THE DAY:

  Moving toward the northeast at 50 to 60 mph.

LMZ740>745-292000-
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-
256 PM CDT Sat Mar 28 2020

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...

  Gale force winds and or very hazardous waves.
  Significant Thunderstorm Risk...with an associated:
     Significant hail risk...up to half dollar size.
     Elevated thunderstorm wind gust risk...up to 60 mph.
  Elevated Fog Risk.

.DAYS TWO THROUGH SEVEN...Sunday through Friday.

Sunday...
  Gale force winds and or very hazardous waves are likely.
Friday...
  Hazardous conditions for small craft are likely.

Kluber

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In the hours before

Special weather statement, Mar 28, 4:29 PM CDT, 2 hours 32 minutes before
SPECIAL WEATHER STATEMENT
National Weather Service Chicago/Romeoville IL
429 PM CDT Sat Mar 28 2020

ILZ006-103-104-290030-
Lake IL-Northern Cook-Central Cook-
Including the cities of Waukegan, Buffalo Grove, North Chicago,
Highland Park, Mundelein, Gurnee, Round Lake Beach, Evanston,
Des Plaines, Schaumburg, Palatine, Northbrook, Chicago, Cicero,
Oak Lawn, Oak Park, and La Grange
429 PM CDT Sat Mar 28 2020

...Dense Fog near the lake...

Dense fog with visiblity to one quarter mile or less is possible
at times through mid evening. Fog will occasionally lift with
periods of showers or storms, so visibility may vary frequently
and over short distances. Use caution if traveling near the
lakefront in Lake and Cook Counties.

KMD
Special weather statement, Mar 28, 6:49 PM CDT, 12 minutes before
Special Weather Statement
National Weather Service Chicago/Romeoville
649 PM CDT Sat Mar 28 2020

ILZ003-008-290015-
Winnebago IL-Ogle IL-
649 PM CDT Sat Mar 28 2020

...SIGNIFICANT WEATHER ADVISORY FOR NORTHEASTERN OGLE AND
SOUTHEASTERN WINNEBAGO COUNTIES UNTIL 715 PM CDT...

At 649 PM CDT, Doppler radar was tracking a strong thunderstorm over
Oregon, moving northeast at 65 mph.

Up to nickel size hail will be possible with this storm.

Locations impacted include...
Rockford, Loves Park, Machesney Park, Oregon, Rockford Airport,
Roscoe, Byron, Cherry Valley, Stillman Valley, Davis Junction and New
Millford.

Including the following interstates...
 I-39 between mile markers 111 and 123.
 I-90 between mile markers 11 and 18.

This includes...  Lowden State Park, Rock Cut State Park, Rock Valley
College, Rockford Rivets Baseball, and Rockford Speedway.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

This storm may intensify, so be certain to monitor local radio
stations and available television stations for additional information
and possible warnings from the National Weather Service.

&&

LAT...LON 4241 8906 4233 8894 4214 8894 4197 8926
      4198 8934 4204 8936
TIME...MOT...LOC 2349Z 222DEG 56KT 4202 8929

Borchardt

The office that day

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

IssuedProductOfficeCountiesLasted
Mar 28, 8:53 PM CDTTornado WarningLOTLee, Ogle37 min
Mar 28, 9:19 PM CDTTornado WarningLOTOgle, Winnebago26 min
Mar 28, 11:37 PM CDTSpecial Marine WarningLOT53 min
Mar 28, 11:41 PM CDTSpecial Weather StatementLOTCook19 min
Mar 29, 12:36 AM CDTRiver Flood WarningLOTBureau, LaSalle, Putnam5 days
Mar 29, 4:58 AM CDTRiver Flood WarningLOTLake30 hr
Mar 29, 4:58 AM CDTRiver Flood WarningLOTCook30 hr
Mar 29, 8:25 AM CDTRiver Flood AdvisoryLOTLaSalle47 hr
Mar 29, 10:17 AM CDTRiver Flood AdvisoryLOTWinnebago6 days

Nearby

Severe Thunderstorm Warnings in Illinois, 2020Every severe thunderstorm warning in 2020

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.