Alert archive / Illinois / Tornado Warnings in 1990

Tornado Warning 24, NWS Lincoln, IL

July 18, 1990Boone County, Illinois

NWS Lincoln, IL issued this tornado warning at Jul 18, 1990, 2:06 PM CDT for Boone County, Illinois. It was in force for 39 min. 1 report came from inside the area while it was in force.

The area

The counties it named, with what was reported inside it.

The facts

Issued
Jul 18, 1990, 2:06 PM CDT (19:06 UTC)
Expired
Jul 18, 1990, 2:45 PM CDT
In force
39 min
Issued by
NWS Lincoln, IL
Area
Whole counties

County Boone County, IL

The radar

The WSR-88D network and its archive begin in 1991, so there is no radar volume for this alert.

What was reported inside it

TimeReportWhereRemark
Jul 18, 2:40 PM CDTThunderstorm Wind 0Boone, IL

NCEI Storm Data entries that began inside the alert's area while it was in force. Before 2003 the local storm report archive is thin, so this is the record of what happened rather than what was phoned in. Storm Data before 1996 records only tornadoes, thunderstorm wind and hail.

The nearest sounding before it

Green Bay/Straub, WI (KGRB), launched 12:00Z, 7.1 hours before the alert went out and 247 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, Green Bay/Straub, WI at 12:00Z on 1990-07-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1306 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Green Bay/Straub, WI at 12:00Z on 1990-07-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 127 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
1306 J/kg
Mixed-layer CIN
-170 J/kg
Mixed-layer LCL
919 m above ground
0-6 km bulk shear
29 kt
0-1 km storm-relative helicity
127 m²/s²
0-3 km storm-relative helicity
165 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.

000 
TTAA00 KRFD 181906
TORRFD
ILC201-007-181945-

BULLETIN - IMMEDIATE BROADCAST REQUESTED/EBS ACTIVATION REQUESTED 
TORNADO WARNING 
NATIONAL WEATHER SERVICE ROCKFORD IL
206 PM CDT WED JUL 18 1990

THE NATIONAL WEATHER SERVICE HAS ISSUED A TORNADO WARNING 
EFFECTIVE UNTIL 245 PM CDT FOR PEOPLE IN THE FOLLOWING 
COUNTIES

   IN THE NORTH CENTRAL PART OF ILLINOIS
      EASTERN WINNEBAGO...BOONE

AT 205 CDT THIS AFTERNOON RADAR AND PUBLIC REPORTS INDICATED A
POSSIBLE TORNADO JUST NORTH OF THE ROCKFORD AIRPORT. IT WAS
MOVING TO THE EAST SOUTHEAST AT 25 MPH.

SOME COMMUNITIES THAT WILL BE AFFECTED BY THIS TORNADO...
ROCKFORD..AND BELVIDERE.

PERSONS IN THE PATH OF THIS DANGEROUS STORM TAKE COVER IMMEDIATELY
IN A BASEMENT OR SMALL CENTRAL INTERIOR ROOM ON THE LOWEST FLOOR.
ABANDON CARS... FARM MACHINERY AND MOBILE HOMES FOR REINFORCED
BUILDING.  IF OUT-OF-DOORS GO TO A REINFORCED SHELTER OR DITCH...
CULVERT OR RAVINE.  THIS IS A SERIOUS SITUATION... YOUR& LIFE MAY
DEPEND ON HOW QUICKLY YOU RESPOND TO THIS TORNADO WARNING!

ATTN: ISP DIST  1..2..16                             FIELDS

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 18, 2:06 PM CDTTornado WarningILXWinnebago34 min

Nearby

Tornado Warnings in Illinois, 1990Every tornado warning in 1990Tornadoes in 1990

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; verification from NCEI's Storm Data; the sounding from the Mesonet's radiosonde archive.