Alert archive / Illinois / Special Weather Statements in 2021

Special Weather Statement, NWS Chicago, IL

August 6, 2021Lake County, Illinois

NWS Chicago, IL issued this special weather statement at Aug 6, 2021, 8:49 PM CDT for Lake 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 outline as issued.

The facts

Issued
Aug 6, 2021, 8:49 PM CDT (01:49 UTC)
Expired
Aug 6, 2021, 9:45 PM CDT
In force
56 min
Issued by
NWS Chicago, IL
Hail
0.00 in
Wind
40

County Lake County, IL

The radar

The Chicago radar (KLOT), 81 km from the middle of the area, began a volume at 01:50 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, 1.8 hours before the alert went out and 228 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 2021-08-07Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2016 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Davenport, at 00:00Z on 2021-08-07The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 27 square meters per square second.1939Sfc1 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
2016 J/kg
Mixed-layer CIN
-22 J/kg
Mixed-layer LCL
1080 m above ground
0-6 km bulk shear
21 kt
0-1 km storm-relative helicity
27 m²/s²
0-3 km storm-relative helicity
113 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.2

Open this sounding in Storm Lab

The text

As transmitted.

884 
WWUS83 KLOT 070149
SPSLOT

Special Weather Statement
National Weather Service Chicago/Romeoville
849 PM CDT Fri Aug 6 2021
 
ILZ006-070245-
Lake IL-
849 PM CDT Fri Aug 6 2021

...Strong thunderstorms will impact portions of Lake County through
945 PM CDT...

At 848 PM CDT, Doppler radar was tracking strong thunderstorms along
a line extending from Wheatland to Grandwood Park to near Lake Bluff.
Movement was southeast at 25 mph.

HAZARD...Winds in excess of 40 mph.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around 
         unsecured objects.

Locations impacted include...
Waukegan, Arlington Heights, Palatine, Buffalo Grove, Wheeling,
Northbrook, North Chicago, Gurnee, Mundelein, Highland Park, Round
Lake Beach, Vernon Hills, Zion, Grayslake, Libertyville, Lake Zurich,
Lake Forest, Round Lake, Antioch and Wauconda.

Including the following interstates...
 I-94 between mile markers 1 and 26.
 I-294 between mile markers 1 and 26.

This includes...  Chain O Lakes State Park, College of Lake County,
Great Lakes Naval Training Center, Lake County IL Fairgrounds, Lake
Forest College, Ravinia Music Festival, and Six Flags Great America.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building. 

&&

LAT...LON 4249 8780 4229 8783 4221 8780 4215 8776
      4215 8820 4250 8820
TIME...MOT...LOC 0148Z 333DEG 20KT 4258 8818 4241 8798 4228 8781 

MAX HAIL SIZE...0.00 IN
MAX WIND GUST...40 MPH

$$

Petr

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 6, 7:56 PM CDTSpecial Marine WarningLOT94 min
Aug 6, 8:27 PM CDTSpecial Marine WarningLOT2 hr
Aug 7, 12:20 AM CDTSpecial Weather StatementLOTJasper40 min
Aug 7, 1:32 AM CDTAreal Flood AdvisoryLOTJasper118 min
Aug 7, 2:05 AM CDTSpecial Weather StatementLOTJasper55 min

Nearby

Special Weather Statements in Illinois, 2021Every special weather statement 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.