Alert archive / Iowa / Tornado Warnings in 1990

Tornado Warning 17, NWS Quad Cities, IA

August 24, 1990Delaware County, Iowa

NWS Quad Cities, IA issued this tornado warning at Aug 24, 1990, 7:02 PM CDT for Delaware County, Iowa. It was in force for 28 min.

The area

The counties it named.

The facts

Issued
Aug 24, 1990, 7:02 PM CDT (00:02 UTC)
Expired
Aug 24, 1990, 7:30 PM CDT
In force
28 min
Issued by
NWS Quad Cities, IA
Area
Whole counties

County Delaware County, IA

The radar

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

The nearest sounding before it

Minneapolis, MN (KSTC), launched 00:00Z, 0.0 hours before the alert went out and 320 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, Minneapolis, MN at 00:00Z on 1990-08-25Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 325 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, Minneapolis, MN at 00:00Z on 1990-08-25The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 27 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
325 J/kg
Mixed-layer CIN
-89 J/kg
Mixed-layer LCL
1036 m above ground
0-6 km bulk shear
22 kt
0-1 km storm-relative helicity
27 m²/s²
0-3 km storm-relative helicity
72 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.5

Open this sounding in Storm Lab

The text

The text of this product is not in the archive. The NWS text archive before 2002 is incomplete.

What forecasters said that day

The local office's own words before this tornado warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

In the hours before

Special weather statement, Aug 24, 6:26 PM CDT, 36 minutes before
IAZ008-250200-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE DUBUQUE IA
625 PM CDT AUG 24 1990

AT 620 PM CDT...THUNDERSTORMS WERE MOVING THROUGH CLAYTON COUNTY
AND NORTHWEST DELAWARE COUNTY IN NORTHEAST IOWA.

THE LEADING EDGE OF THE STORMS WERE LOCATED IN THE CENTRAL PART
OF CLAYTON COUNTY...40 MILES NORTHWEST OF DUBUQUE AND IN DELAWARE
COUNTY THE STORMS WERE LOCATED AROUND DUNDEE...45 MILES WEST OF
DUBUQUE.

THESE STORMS WILL PRODUCE HEUAVY RAINS...ALONG WITH WIND GUSTS AROUND
40 MILES AN HOUR.  SOME SMALL HAIL MAY ALSO ACCOMPANY THESE STORMS AS
THEY PASS THROUGH.
KOWALSKI

Nearby

Tornado Warnings in Iowa, 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; the sounding from the Mesonet's radiosonde archive.