Alert archive / Illinois / Tornado Warnings in 2011

Tornado Warning 25, NWS Chicago, IL

August 12, 2011Ogle County, Illinois

NWS Chicago, IL issued this tornado warning at Aug 12, 2011, 5:29 PM CDT for Ogle County, Illinois. It was in force for 46 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 12, 2011, 5:29 PM CDT (22:29 UTC)
Expired
Aug 12, 2011, 6:15 PM CDT
In force
46 min
Issued by
NWS Chicago, IL
Area
Storm-based polygon

County Ogle County, IL

The radar

The Quad Cities radar (KDVN), 114 km from the middle of the area, began a volume at 22:30 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 12:00Z, 10.5 hours before the alert went out and 108 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 12:00Z on 2011-08-12Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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 12:00Z on 2011-08-12The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 38 square meters per square second.19395878Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1545 m above ground
0-6 km bulk shear
27 kt
0-1 km storm-relative helicity
38 m²/s²
0-3 km storm-relative helicity
60 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.

661 
WFUS53 KLOT 122229
TORLOT
ILC141-122315-
/O.NEW.KLOT.TO.W.0025.110812T2229Z-110812T2315Z/

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
529 PM CDT FRI AUG 12 2011

THE NATIONAL WEATHER SERVICE IN CHICAGO HAS ISSUED A

* TORNADO WARNING FOR...
  NORTH CENTRAL OGLE COUNTY...

* UNTIL 615 PM CDT

* AT 528 PM...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO. THIS DANGEROUS
  STORM WAS LOCATED NEAR GERMAN VALLEY...OR 10 MILES SOUTHEAST OF
  FREEPORT...AND MOVING EAST AT 15 MPH.

* LOCATIONS IMPACTED INCLUDE...
  BYRON...ADELINE AND LEAF RIVER.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW. MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR OF A
STURDY BUILDING. AVOID WINDOWS. IF IN A MOBILE HOME...A VEHICLE OR
OUTDOORS...MOVE TO THE CLOSEST SUBSTANTIAL SHELTER AND PROTECT
YOURSELF FROM FLYING DEBRIS.

&&

LAT...LON 4217 8957 4220 8955 4220 8933 4218 8922
      4206 8930
TIME...MOT...LOC 2229Z 291DEG 14KT 4219 8949

$$

BMD
3 follow-up statements
033 
WWUS53 KLOT 122238
SVSLOT

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
538 PM CDT FRI AUG 12 2011

ILC141-122315-
/O.CON.KLOT.TO.W.0025.000000T0000Z-110812T2315Z/
OGLE IL-
538 PM CDT FRI AUG 12 2011

...A TORNADO WARNING REMAINS IN EFFECT FOR NORTH CENTRAL OGLE COUNTY
UNTIL 615 PM CDT...

AT 537 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO.  THIS DANGEROUS
STORM WAS LOCATED NEAR GERMAN VALLEY...OR 9 MILES NORTH OF MOUNT
MORRIS...MOVING EAST AT 15 MPH.

LOCATIONS IMPACTED INCLUDE...
  BYRON AND LEAF RIVER.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW. MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR OF A
STURDY BUILDING. AVOID WINDOWS. IF IN A MOBILE HOME...A VEHICLE OR
OUTDOORS...MOVE TO THE CLOSEST SUBSTANTIAL SHELTER AND PROTECT
YOURSELF FROM FLYING DEBRIS.

&&

LAT...LON 4217 8957 4220 8955 4220 8933 4218 8922
      4206 8930
TIME...MOT...LOC 2238Z 291DEG 14KT 4218 8945

$$

BMD
518 
WWUS53 KLOT 122256
SVSLOT

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
556 PM CDT FRI AUG 12 2011

ILC141-122315-
/O.CON.KLOT.TO.W.0025.000000T0000Z-110812T2315Z/
OGLE IL-
556 PM CDT FRI AUG 12 2011

...A TORNADO WARNING REMAINS IN EFFECT FOR NORTH CENTRAL OGLE COUNTY
UNTIL 615 PM CDT...

AT 551 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO.  THIS DANGEROUS
STORM WAS LOCATED 6 MILES SOUTHEAST OF GERMAN VALLEY...OR 8 MILES
NORTH OF MOUNT MORRIS...MOVING EAST AT 15 MPH.

LOCATIONS IMPACTED INCLUDE...
  BYRON.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW. MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR OF A
STURDY BUILDING. AVOID WINDOWS. IF IN A MOBILE HOME...A VEHICLE OR
OUTDOORS...MOVE TO THE CLOSEST SUBSTANTIAL SHELTER AND PROTECT
YOURSELF FROM FLYING DEBRIS.

&&

LAT...LON 4215 8950 4220 8950 4220 8933 4218 8922
      4206 8930
TIME...MOT...LOC 2256Z 291DEG 14KT 4215 8936

$$

BMD
717 
WWUS53 KLOT 122318
SVSLOT

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
618 PM CDT FRI AUG 12 2011

ILC141-122328-
/O.EXP.KLOT.TO.W.0025.000000T0000Z-110812T2315Z/
OGLE IL-
618 PM CDT FRI AUG 12 2011

...THE TORNADO WARNING FOR NORTH CENTRAL OGLE COUNTY HAS EXPIRED...

THE STORM WHICH PROMPTED THE WARNING HAS MOVED OUT OF THE WARNED
AREA...HOWEVER HEAVY RAIN IS STILL POSSIBLE WITH THIS THUNDERSTORM.

REMEMBER...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT FOR
EASTERN OGLE COUNTY UNTIL 715 PM CDT.

LAT...LON 4215 8950 4220 8950 4220 8933 4218 8922
      4206 8930
TIME...MOT...LOC 2256Z 291DEG 14KT 4215 8936

$$

BEACHLER

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 12, 5:21 PM CDTSpecial Weather StatementLOTOgle24 min
Aug 12, 6:11 PM CDTAreal Flood AdvisoryLOTOgle, Winnebago4 hr
Aug 12, 6:17 PM CDTSevere Thunderstorm WarningLOTOgle, Winnebago58 min

Nearby

Tornado Warnings in Illinois, 2011Every tornado warning in 2011Tornadoes in 2011

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.