Alert archive / Illinois / Severe Thunderstorm Warnings in 2012

Severe Thunderstorm Warning 21, NWS Chicago, IL

May 6, 2012LaSalle County, Livingston County, Illinois

NWS Chicago, IL issued this severe thunderstorm warning at May 6, 2012, 3:43 PM CDT for LaSalle County, Livingston County, Illinois. It was in force for 52 min. 3 reports 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
May 6, 2012, 3:43 PM CDT (20:43 UTC)
Expired
May 6, 2012, 4:35 PM CDT
In force
52 min
Issued by
NWS Chicago, IL
Area
Storm-based polygon
Hail
1.5 in
Wind
60.0 mph

Counties LaSalle County, IL, Livingston County, IL

The radar

The Chicago radar (KLOT), 97 km from the middle of the area, began a volume at 20:47 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
May 6, 3:50 PM CDTFUNNEL CLOUD6 E Wenona, ILFUNNEL WAS BECOMING RAIN-WRAPPED.
May 6, 3:50 PM CDTTSTM WND GST 606 E Wenona, IL
May 6, 3:57 PM CDTFUNNEL CLOUDStreator, ILLAW ENFORCEMENT RELAYED A PUBLIC REPORT OF A POSSIBLE FUNNEL VISIBLE FROM THE 1500 BLOCK OF SOUTH JEFFERSON.

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

The watch it was issued in

The SPC watch in force over the same counties when this warning went out.

IssuedProductOfficeLasted
May 6, 1:42 PM CDTSevere Thunderstorm WatchSPC7 hr

The nearest sounding before it

Lincoln, IL (KILX), launched 12:00Z, 8.7 hours before the alert went out and 116 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, Lincoln, IL at 12:00Z on 2012-05-06Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2922 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, Lincoln, IL at 12:00Z on 2012-05-06The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 48 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
2922 J/kg
Mixed-layer CIN
-37 J/kg
Mixed-layer LCL
576 m above ground
0-6 km bulk shear
14 kt
0-1 km storm-relative helicity
48 m²/s²
0-3 km storm-relative helicity
98 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

341 
WUUS53 KLOT 062043
SVRLOT
ILC099-105-062145-
/O.NEW.KLOT.SV.W.0021.120506T2043Z-120506T2145Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
343 PM CDT SUN MAY 6 2012

THE NATIONAL WEATHER SERVICE IN CHICAGO HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  SOUTHWESTERN LA SALLE COUNTY IN NORTH CENTRAL ILLINOIS...
  NORTHWESTERN LIVINGSTON COUNTY IN CENTRAL ILLINOIS...

* UNTIL 445 PM CDT

* AT 342 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING PING PONG BALL SIZE
  HAIL...AND DAMAGING WINDS IN EXCESS OF 60 MPH.  THIS STORM WAS
  LOCATED NEAR MC NABB...OR 12 MILES SOUTHEAST OF HENNEPIN...AND
  MOVING EAST AT 25 MPH.

* THE SEVERE THUNDERSTORM WILL BE NEAR...
  TONICA AROUND 355 PM CDT.
  STREATOR AROUND 425 PM CDT.


PRECAUTIONARY/PREPAREDNESS ACTIONS...

SEVERE THUNDERSTORMS PRODUCE DAMAGING WIND IN EXCESS OF 60 MILES PER
HOUR...LARGE HAIL...DEADLY LIGHTNING...AND VERY HEAVY RAIN. FOR YOUR
PROTECTION MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR OF YOUR HOME
OR BUSINESS. HEAVY RAINS FLOOD ROADS QUICKLY SO DO NOT DRIVE INTO
AREAS WHERE WATER COVERS THE ROAD.

&&

LAT...LON 4127 8916 4119 8875 4097 8881 4102 8905
      4110 8905 4110 8906 4110 8912 4110 8916
      4111 8917 4123 8917
TIME...MOT...LOC 2043Z 275DEG 20KT 4113 8915
WIND...HAIL 60MPH 1.50IN

$$

BIRK
3 follow-up statements
308 
WWUS53 KLOT 062058 RRA
SVSLOT

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
358 PM CDT SUN MAY 6 2012

ILC099-105-062145-
/O.CON.KLOT.SV.W.0021.000000T0000Z-120506T2145Z/
LA SALLE IL-LIVINGSTON IL-
358 PM CDT SUN MAY 6 2012

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT FOR NORTHWESTERN
LIVINGSTON AND SOUTH CENTRAL LA SALLE COUNTIES UNTIL 445 PM CDT...

AT 356 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
SEVERE THUNDERSTORM CAPABLE OF PRODUCING PING PONG BALL SIZE HAIL...
AND DAMAGING WINDS IN EXCESS OF 60 MPH.  THIS STORM WAS LOCATED 5
MILES SOUTH OF STREATOR...MOVING EAST AT 45 MPH.

THIS SEVERE THUNDERSTORM WILL AFFECT MAINLY RURAL AREAS OF
NORTHWESTERN LIVINGSTON AND SOUTH CENTRAL LA SALLE COUNTIES.


PRECAUTIONARY/PREPAREDNESS ACTIONS...

SEVERE THUNDERSTORMS PRODUCE DAMAGING WIND IN EXCESS OF 60 MILES PER
HOUR...LARGE HAIL...DEADLY LIGHTNING...AND VERY HEAVY RAIN. FOR YOUR
PROTECTION MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR OF YOUR HOME
OR BUSINESS. HEAVY RAINS FLOOD ROADS QUICKLY SO DO NOT DRIVE INTO
AREAS WHERE WATER COVERS THE ROAD.

SEVERE THUNDERSTORMS PRODUCE DAMAGING WIND IN EXCESS OF 60 MILES PER
HOUR. FOR YOUR PROTECTION MOVE TO AN INTERIOR ROOM ON THE LOWEST
FLOOR OF YOUR HOME OR BUSINESS.

&&

LAT...LON 4110 8907 4120 8899 4119 8875 4097 8881
      4102 8905 4110 8905
TIME...MOT...LOC 2058Z 289DEG 40KT 4104 8882
WIND...HAIL 60MPH 1.50IN

$$

BIRK
580 
WWUS53 KLOT 062117
SVSLOT

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
417 PM CDT SUN MAY 6 2012

ILC099-105-062145-
/O.CON.KLOT.SV.W.0021.000000T0000Z-120506T2145Z/
LA SALLE IL-LIVINGSTON IL-
417 PM CDT SUN MAY 6 2012

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT FOR NORTHWESTERN
LIVINGSTON AND SOUTH CENTRAL LA SALLE COUNTIES UNTIL 445 PM CDT...

AT 415 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
LINE OF SEVERE THUNDERSTORMS CAPABLE OF PRODUCING HALF DOLLAR SIZE
HAIL...AND DESTRUCTIVE WINDS IN EXCESS OF 70 MPH. THESE STORMS WERE 
LOCATED ALONG A LINE EXTENDING FROM 8 MILES NORTHEAST OF STREATOR TO 
8 MILES NORTHWEST OF PONTIAC...MOVING EAST AT 30 MPH. THESE STORMS 
HAVE A HISTORY OF PRODUCING DAMAGING WINDS AND LARGE HAIL. 

LOCATIONS IMPACTED INCLUDE...


PRECAUTIONARY/PREPAREDNESS ACTIONS...

SEVERE THUNDERSTORMS PRODUCE DAMAGING WIND IN EXCESS OF 60 MILES PER
HOUR...LARGE HAIL...DEADLY LIGHTNING...AND VERY HEAVY RAIN. FOR YOUR
PROTECTION MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR OF YOUR HOME
OR BUSINESS. HEAVY RAINS FLOOD ROADS QUICKLY SO DO NOT DRIVE INTO
AREAS WHERE WATER COVERS THE ROAD.

SEVERE THUNDERSTORMS PRODUCE DAMAGING WIND IN EXCESS OF 60 MILES PER
HOUR. FOR YOUR PROTECTION MOVE TO AN INTERIOR ROOM ON THE LOWEST
FLOOR OF YOUR HOME OR BUSINESS.

&&

LAT...LON 4102 8902 4110 8894 4120 8888 4119 8875
      4097 8881
TIME...MOT...LOC 2116Z 275DEG 29KT 4118 8869 4097 8872
WIND...HAIL 70MPH 1.25IN

$$

BIRK
781 
WWUS53 KLOT 062135
SVSLOT

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
435 PM CDT SUN MAY 6 2012

ILC099-105-062145-
/O.CAN.KLOT.SV.W.0021.000000T0000Z-120506T2145Z/
LA SALLE IL-LIVINGSTON IL-
435 PM CDT SUN MAY 6 2012


...THE SEVERE THUNDERSTORM WARNING FOR NORTHWESTERN LIVINGSTON AND
SOUTH CENTRAL LA SALLE COUNTIES IS CANCELLED...

THE LINE OF STORMS WHICH PROMPTED THE WARNING HAVE MOVED OUT OF THE
WARNED AREA.

LAT...LON 4102 8902 4110 8894 4120 8888 4119 8875
      4097 8881
TIME...MOT...LOC 2135Z 275DEG 29KT 4117 8849 4096 8852

$$

BIRK

The office that day

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

IssuedProductOfficeCountiesLasted
May 6, 3:56 AM CDTFlash Flood WatchLOTBoone, DeKalb, DuPage, Ford, Grundy, Iroquois and 10 more27 hr
May 6, 9:39 AM CDTSpecial Weather StatementLOTDeKalb36 min
May 6, 10:02 AM CDTSpecial Weather StatementLOTGrundy28 min
May 6, 10:15 AM CDTSpecial Weather StatementLOTBoone45 min
May 6, 10:44 AM CDTSpecial Weather StatementLOTKendall31 min
May 6, 10:48 AM CDTSevere Thunderstorm WarningLOTKendall42 min
May 6, 11:24 AM CDTSpecial Weather StatementLOTWill36 min
May 6, 1:55 PM CDTSpecial Weather StatementLOTCook65 min
May 6, 1:56 PM CDTSevere Thunderstorm WarningLOTFord, Iroquois, Kankakee, Livingston64 min
May 6, 2:37 PM CDTSevere Thunderstorm WarningLOTCook38 min
May 6, 2:39 PM CDTSpecial Marine WarningLOT96 min
May 6, 2:46 PM CDTSpecial Weather StatementLOTLivingston59 min
May 6, 2:57 PM CDTSevere Thunderstorm WarningLOTFord, Iroquois, Kankakee63 min
May 6, 3:19 PM CDTFlash Flood WarningLOTFord, Grundy, Iroquois, Kankakee, Livingston6 hr
May 6, 3:26 PM CDTTornado WarningLOTIroquois64 min
May 6, 3:31 PM CDTSevere Thunderstorm WarningLOTGrundy, LaSalle, Livingston59 min
May 6, 3:39 PM CDTFlash Flood WarningLOTGrundy, LaSalle, Livingston6 hr
May 6, 3:41 PM CDTSevere Thunderstorm WarningLOTIroquois64 min
May 6, 3:42 PM CDTTornado WarningLOTLaSalle, Livingston48 min
May 6, 4:02 PM CDTSevere Thunderstorm WarningLOTFord, Iroquois, Livingston48 min
May 6, 4:03 PM CDTSevere Thunderstorm WarningLOTFord, Grundy, Kankakee, Livingston57 min
May 6, 4:28 PM CDTSevere Thunderstorm WarningLOTGrundy, LaSalle, Livingston32 min
May 6, 4:46 PM CDTTornado WarningLOTIroquois44 min
May 6, 4:56 PM CDTSevere Thunderstorm WarningLOTIroquois64 min
May 6, 5:01 PM CDTSevere Thunderstorm WarningLOTFord, Iroquois, Livingston59 min
May 6, 5:15 PM CDTFlash Flood WarningLOTFord, Iroquois6 hr
May 6, 5:25 PM CDTTornado WarningLOTFord, Iroquois50 min

Nearby

Severe Thunderstorm Warnings in Illinois, 2012Every severe thunderstorm warning in 2012

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.