Alert archive / Illinois / Tornado Warnings in 2003

Tornado Warning 4, NWS Chicago, IL

May 10, 2003DeKalb County, LaSalle County, Illinois

NWS Chicago, IL issued this tornado warning at May 10, 2003, 9:57 PM CDT for DeKalb County, LaSalle County, Illinois. It was in force for 63 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: May 10, 2003, 9:57 PM CDT (02:57 UTC)
Expired: May 10, 2003, 11:00 PM CDT
In force: 63 min
Issued by: NWS Chicago, IL
Area: Counties, with a storm outline in the text

Counties DeKalb County, IL, LaSalle County, IL

The radar

The Chicago radar (KLOT), 69 km from the middle of the area, began a volume at 02:58 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 watch it was issued in

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

Issued	Product	Office	Lasted
May 10, 8:05 PM CDT	Tornado Watch	SPC	6 hr

The nearest sounding before it

Davenport, (KDVN), launched 00:00Z, 3.0 hours before the alert went out and 132 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 1566 J/kg
Mixed-layer CIN: -80 J/kg
Mixed-layer LCL: 910 m above ground
0-6 km bulk shear: 57 kt
0-1 km storm-relative helicity: 234 m²/s²
0-3 km storm-relative helicity: 259 m²/s²
Significant tornado parameter: 2.8
Supercell composite: 12.7

Open this sounding in Storm Lab

The text

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

505 
WFUS53 KLOT 110257
TORLOT
ILC037-099-110400-

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE CHICAGO IL
956 PM CDT SAT MAY 10 2003

THE NATIONAL WEATHER SERVICE IN CHICAGO HAS ISSUED A

* TORNADO WARNING FOR...
  DE KALB COUNTY IN NORTH CENTRAL ILLINOIS
  NORTHWEST LA SALLE COUNTY IN NORTH CENTRAL ILLINOIS

* UNTIL 1100 PM CDT

* AT 956 PM CDT...DOPPLER RADAR INDICATED STRONG ROTATION IN A SEVERE
  THUNDERSTORM 10 MILES WEST OF MENDOTA...MOVING NORTHEAST AT 30
  MPH.  THIS STORM HAS A HISTORY OF PRODUCING TORNADOES.

* THE STORM WILL BE NEAR...
  EARLVILLE AROUND 1020 PM CDT.
  LELAND AROUND 1030 PM CDT.
  SHABBONA AROUND 1040 PM CDT.
  WATERMAN AROUND 1045 PM CDT.



LAT...LON 4188 8887 4178 8865 4151 8875 4145 8916
          4162 8916 4163 8895 4175 8888
$$

MERZLOCK

NNNN

The office that day

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

Issued	Product	Office	Counties	Lasted
May 10, 9:01 PM CDT	Severe Thunderstorm Warning	LOT	Grundy, Will	44 min
May 10, 9:36 PM CDT	Tornado Warning	LOT	Lee	39 min
May 10, 9:42 PM CDT	Severe Thunderstorm Warning	LOT	DeKalb, LaSalle	48 min
May 10, 10:23 PM CDT	Tornado Warning	LOT	Kane	52 min
May 10, 10:37 PM CDT	Tornado Warning	LOT	Livingston	53 min
May 10, 10:41 PM CDT	Severe Thunderstorm Warning	LOT	Cook, DuPage, Will	49 min
May 10, 10:57 PM CDT	Tornado Warning	LOT	Cook, DuPage	48 min
May 10, 11:00 PM CDT	Tornado Warning	LOT	Cook, DuPage	45 min
May 10, 11:14 PM CDT	Special Marine Warning	LOT		61 min
May 10, 11:14 PM CDT	Special Marine Warning	LOT		61 min
May 10, 11:14 PM CDT	Special Marine Warning	LOT		61 min
May 10, 11:14 PM CDT	Special Marine Warning	LOT		61 min
May 10, 11:18 PM CDT	Severe Thunderstorm Warning	LOT	Lake	42 min
May 10, 11:42 PM CDT	Severe Thunderstorm Warning	LOT	DeKalb, Kane	48 min

Nearby

Tornado Warnings in Illinois, 2003 Every tornado warning in 2003 Tornadoes in 2003

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.