Alert archive / Iowa / Tornado Warnings in 1999

Tornado Warning 2, NWS Quad Cities, IA

April 8, 1999Jefferson County, Iowa

NWS Quad Cities, IA issued this tornado warning at Apr 8, 1999, 6:13 PM CDT for Jefferson County, Iowa. It was in force for 47 min. 2 reports 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
Apr 8, 1999, 6:13 PM CDT (23:13 UTC)
Expired
Apr 8, 1999, 7:00 PM CDT
In force
47 min
Issued by
NWS Quad Cities, IA
Area
Whole counties

County Jefferson County, IA

The radar

The Quad Cities radar (KDVN), 131 km from the middle of the area, began a volume at 23:15 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
Apr 8, 6:25 PM CDTTornado F0Batavia, IA
Apr 8, 6:25 PM CDTTornado F0Pleasant Plain, IA

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.

The watch it was issued in

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

IssuedProductOfficeLasted
Apr 8, 5:15 PM CDTTornado WatchSPC4 hr

The nearest sounding before it

Davenport, (KDVN), launched 12:00Z, 11.2 hours before the alert went out and 138 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 1999-04-08Temperature 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 1999-04-08The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 6 square meters per square second.1939587897117Sfc1 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
2467 m above ground
0-6 km bulk shear
61 kt
0-1 km storm-relative helicity
6 m²/s²
0-3 km storm-relative helicity
115 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.

999 
WFUS1 KMLI 082315 RRA
TORMLI
IAC101-090000-

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
613 PM CDT THU APR 8 1999

THE NATIONAL WEATHER SERVICE IN QUAD CITIES IA HAS ISSUED A

* TORNADO WARNING FOR...
  JEFFERSON COUNTY IN SOUTHEASTERN IOWA

* UNTIL 700 PM CDT

* AT 614 PM CDT... DOPPLER RADAR AND SPOTTER REPORTS INDICATED A
  TORNADO 10 MILES SOUTHEAST OF OTTUMWA OR 6 MILES SOUTHWEST OF
  BATAVIA MOVING NORTHEAST AT 45 MPH.

* THE TORNADO IS EXPECTED TO BE NEAR...
  BATAVIA                                    AROUND 620 PM CDT
  LIBERTYVILLE                               AROUND 620 PM CDT
  ABINGDON                                   AROUND 625 PM CDT
  FAIRFIELD                                  AROUND 630 PM CDT
  PEKIN                                      AROUND 635 PM CDT

A TORNADO IS ON THE GROUND GO TO THE BASEMENT IF A BASEMENT IS
NOT AVAILABLE...GO TO A SMALL INTERIOR ROOM ON THE LOWEST FLOOR

WOLF

The office that day

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

IssuedProductOfficeCountiesLasted
Apr 8, 10:10 AM CDTSevere Thunderstorm WarningDVNKeokuk30 min
Apr 8, 5:52 PM CDTTornado WarningDVNVan Buren48 min
Apr 8, 6:17 PM CDTTornado WarningDVNLee48 min
Apr 8, 6:33 PM CDTTornado WarningDVNKeokuk, Washington47 min

Nearby

Tornado Warnings in Iowa, 1999Every tornado warning in 1999Tornadoes in 1999

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; radar from the NEXRAD Level II archive.