Alert archive / Illinois / Tornado Warnings in 1998

Tornado Warning 9, NWS Quad Cities, IA

April 7, 1998Mercer County, Illinois

NWS Quad Cities, IA issued this tornado warning at Apr 7, 1998, 6:06 PM CDT for Mercer County, Illinois. It was in force for 49 min. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued
Apr 7, 1998, 6:06 PM CDT (23:06 UTC)
Expired
Apr 7, 1998, 6:55 PM CDT
In force
49 min
Issued by
NWS Quad Cities, IA
Area
Whole counties

County Mercer County, IL

The radar

The Quad Cities radar (KDVN), 47 km from the middle of the area, began a volume at 23:10 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.

IssuedProductOfficeLasted
Apr 7, 2:00 PM CDTTornado WatchSPC6 hr

The nearest sounding before it

Davenport, (KDVN), launched 12:00Z, 11.1 hours before the alert went out and 50 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 1998-04-07Temperature 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°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Davenport, at 12:00Z on 1998-04-07The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 101 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1589 m above ground
0-6 km bulk shear
20 kt
0-1 km storm-relative helicity
101 m²/s²
0-3 km storm-relative helicity
31 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.

309 
WFUS1 KMLI 072307 RRA
TORMLI
ILC131-072355-

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
606 PM CDT TUE APR 7 1998

* TORNADO WARNING FOR
  EASTERN MERCER COUNTY - NORTHWESTERN ILLINOIS

* UNTIL 655 PM CDT
 
* SOME LOCATIONS AFFECTED BY THIS TORNADO
  NORWOOD                                    AROUND 615 PM CDT
  ALEXIS                                     AROUND 615 PM CDT
  NORTH HENDERSON                            AROUND 620 PM CDT
  BURGESS                                    AROUND 625 PM CDT
  GILCHRIST                                  AROUND 635 PM CDT

* AT 604 PM CDT...DOPPLER RADAR AND SPOTTER REPORTS INDICATED A
  TORNADO 14 MILES WEST OF GALESBURG OR 5 MILES SOUTH OF NORWOOD
  MOVING NORTH AT 25 MPH.

GO TO THE BASEMENT AND GET UNDER A WORKBENCH OR STURDY PIECE OF
FURNITURE. IF NO BASEMENT IS AVAILABLE...GO TO A SMALL INTERIOR
ROOM ON THE LOWEST FLOOR

HLADIK

The office that day

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

IssuedProductOfficeCountiesLasted
Apr 7, 4:25 PM CDTSevere Thunderstorm WarningDVNHancock50 min
Apr 7, 4:35 PM CDTTornado WarningDVNHancock35 min
Apr 7, 4:50 PM CDTTornado WarningDVNMcDonough50 min
Apr 7, 5:01 PM CDTSevere Thunderstorm WarningDVNWarren49 min
Apr 7, 5:31 PM CDTTornado WarningDVNWarren34 min
Apr 7, 6:05 PM CDTTornado WarningDVNWarren35 min

Nearby

Tornado Warnings in Illinois, 1998Every tornado warning in 1998Tornadoes in 1998

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.