Alert archive / Illinois / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 60, NWS Quad Cities, IA

July 15, 2021Carroll County, Whiteside County, Illinois

NWS Quad Cities, IA issued this severe thunderstorm warning at Jul 15, 2021, 12:07 AM CDT for Carroll County, Whiteside County, Illinois. It was in force for 23 min. 1 report came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued
Jul 15, 2021, 12:07 AM CDT (05:07 UTC)
Expired
Jul 15, 2021, 12:30 AM CDT
In force
23 min
Issued by
NWS Quad Cities, IA
Area
Storm-based polygon
Tornado
Possible
Hail
0.75 in
Wind
60.0 mph

Counties Carroll County, IL, Whiteside County, IL

The radar

The Quad Cities radar (KDVN), 73 km from the middle of the area, began a volume at 05:11 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.

What was reported inside it

TimeReportWhereRemark
Jul 15, 12:10 AM CDTTSTM WND DMGLanark, ILLARGE TREE BRANCH REPORTED DOWN JUST OUTSIDE OF TOWN.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Davenport, (KDVN), launched 00:00Z, 5.1 hours before the alert went out and 67 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 2021-07-15Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2569 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 2021-07-15The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 253 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
2569 J/kg
Mixed-layer CIN
-10 J/kg
Mixed-layer LCL
832 m above ground
0-6 km bulk shear
38 kt
0-1 km storm-relative helicity
253 m²/s²
0-3 km storm-relative helicity
346 m²/s²
Significant tornado parameter
3.2
Supercell composite
23.4

Open this sounding in Storm Lab

The text

As transmitted.

734 
WUUS53 KDVN 150507
SVRDVN
ILC015-195-150530-
/O.NEW.KDVN.SV.W.0060.210715T0507Z-210715T0530Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Quad Cities IA/IL
1207 AM CDT Thu Jul 15 2021

The National Weather Service in the Quad Cities has issued a

* Severe Thunderstorm Warning for...
  Northeastern Whiteside County in northwestern Illinois...
  Southeastern Carroll County in northwestern Illinois...

* Until 1230 AM CDT.

* At 1207 AM CDT, a severe thunderstorm was located over Fairhaven,
  or 9 miles south of Mount Carroll, moving east at 45 mph.

  HAZARD...60 mph wind gusts.

  SOURCE...Radar indicated.

  IMPACT...Expect damage to roofs, siding, and trees.

* This severe thunderstorm will be near...
  Chadwick and Coleta around 1215 AM CDT.
  Lanark and Milledgeville around 1220 AM CDT.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

Large hail and damaging winds and continuous cloud to ground
lightning is occurring with this storm. Move indoors immediately.
Lightning is one of nature's leading killers. Remember, if you can
hear thunder, you are close enough to be struck by lightning.

Torrential rainfall is occurring with this storm, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.

&&

LAT...LON 4182 9000 4201 9011 4219 8969 4193 8969
      4193 8963 4188 8963
TIME...MOT...LOC 0507Z 250DEG 38KT 4195 8996 

TORNADO...POSSIBLE
HAIL...<.75IN
WIND...60MPH
 
$$

Gibbs
1 follow-up statement
520 
WWUS53 KDVN 150519 RRA
SVSDVN

Severe Weather Statement
National Weather Service Quad Cities IA/IL
1219 AM CDT Thu Jul 15 2021

ILC015-195-150530-
/O.CON.KDVN.SV.W.0060.000000T0000Z-210715T0530Z/
Whiteside IL-Carroll IL-
1219 AM CDT Thu Jul 15 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 1230 AM CDT
FOR NORTHEASTERN WHITESIDE AND SOUTHEASTERN CARROLL COUNTIES...

At 1219 AM CDT, a severe thunderstorm was located over Milledgeville,
or 11 miles southeast of Mount Carroll, moving east at 45 mph.

HAZARD...60 mph wind gusts.

SOURCE...Radar indicated.

IMPACT...Expect damage to roofs, siding, and trees.

This severe thunderstorm will remain over mainly rural areas of
northeastern Whiteside and southeastern Carroll Counties, including
the following locations... Hitt, Malvern, Franklin Corners, White
Pigeon, Carroll County Fairgrounds and Penrose.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
sturdy building.

Continuous cloud to ground lightning is occurring with this storm.
Move indoors immediately. Lightning is one of nature's leading
killers. Remember, if you can hear thunder, you are close enough to
be struck by lightning.

Torrential rainfall is occurring with this storm, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.

&&

LAT...LON 4183 8997 4196 8990 4207 8996 4219 8969
      4193 8969 4193 8963 4188 8963
TIME...MOT...LOC 0519Z 250DEG 38KT 4199 8980 

TORNADO...POSSIBLE
HAIL...<.75IN
WIND...60MPH
 
$$

Gibbs

The office that day

Everything else NWS Quad Cities, IA issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jul 14, 11:10 PM CDTSevere Thunderstorm WarningDVNCarroll, Jo Daviess50 min
Jul 14, 11:41 PM CDTSevere Thunderstorm WarningDVNCarroll, Jo Daviess, Stephenson34 min
Jul 15, 12:05 AM CDTSevere Thunderstorm WarningDVNStephenson25 min
Jul 15, 1:01 AM CDTSpecial Weather StatementDVNRock Island89 min
Jul 15, 1:51 PM CDTSpecial Weather StatementDVNMcDonough39 min
Jul 15, 2:31 PM CDTSpecial Weather StatementDVNMcDonough29 min
Jul 15, 5:23 PM CDTSpecial Weather StatementDVNWhiteside37 min

Nearby

Severe Thunderstorm Warnings in Illinois, 2021Every severe thunderstorm warning 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.