Alert archive / Iowa / Severe Thunderstorm Warnings in 1990

Severe Thunderstorm Warning 39, NWS Quad Cities, IA

August 29, 1990Lee County, Iowa

NWS Quad Cities, IA issued this severe thunderstorm warning at Aug 29, 1990, 2:31 AM CDT for Lee County, Iowa. It was in force for 44 min.

The area

The counties it named.

The facts

Issued: Aug 29, 1990, 2:31 AM CDT (07:31 UTC)
Expired: Aug 29, 1990, 3:15 AM CDT
In force: 44 min
Issued by: NWS Quad Cities, IA
Area: Whole counties

County Lee 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

Topeka, KS (KTOP), launched 00:00Z, 7.5 hours before the alert went out and 399 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: 3134 J/kg
Mixed-layer CIN: -79 J/kg
Mixed-layer LCL: 2146 m above ground
0-6 km bulk shear: 40 kt
0-1 km storm-relative helicity: 138 m²/s²
0-3 km storm-relative helicity: 301 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 7.9

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KMLI 290731
SVRMLI
IAC111-290815-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING 
NATIONAL WEATHER SERVICE MOLINE IL
231 AM CDT WED AUG 29 1990

THE NATIONAL WEATHER SERVICE HAS ISSUED A SEVERE THUNDERSTORM 
WARNING EFFECTIVE UNTIL 315 AM CDT FOR PEOPLE IN THE FOLLOWING 
COUNTY

   IN THE SOUTHEAST PART OF IOWA
      SOUTHERN LEE

AT 225 AM CDT RADAR SHOWS A LINE OF INTENSE THUNDERSTORMS FROM
FT MADISON IOWA ACROSS SOUTHERN VAN BUREN COUNTY OF IOWA.

THESED THUNDERSTORMS HAVE A HISTORY OF LARGE HAIL.  THE
THUNDERSTORMS WERE MOVING SOUTHEAST AT 25 MPH.

SOME CITIES/TOWNS IN THE PATH OF THIS STORM INCLUDE... FT MADISON
AND KEOKUK.

FOR YOUR PROTECTION GO TO A SAFE PLACE IMMEDIATELY.  STAY INDOORS
AND AVOID WINDOWS.  IF OUTDOORS...DO NOT STAND UNDER A TREE OR IN
OPEN AREAS SUCH AS A FIELD.

A SEVERE THUNDERSTORM CAN PRODUCE DAMAGING WIND OF 60 MPH OR MORE...
LARGE HAIL...FREQUENT DANGEROUS LIGHTNING AND HEAVY RAIN.

IF TIME PERMITS...ASK THE NEAREST LAW ENFORCEMENT AGENCY TO RELAY
YOUR REPORT OF SEVERE WEATHER TO THE NATIONAL WEATHER SERVICE.

KRAEMER

What forecasters said that day

The local office's own words before this severe thunderstorm 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 28, 11:30 PM CDT, 3 hours 1 minute before

ILZ004-IAZ015-290530-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOLINE IL
1130 PM CDT TUE AUG 28 1990

AT 1120 PM CDT...RADAR WAS INDICATING A LINE OF STRONG THUNDERSTORMS
EXTENDING FROM JUST SOUTHEAST OF IOWA CITY THROUGH MUSCATINE AND INTO
ROCK ISLAND AND MOLINE.  THESE THUNDERSTORMS WERE MOVING EAST-SOUTHEAST
AT 30 MPH AND CONTAIN HEAVY RAIN AND FREQUENT LIGHTNING.  THESE STORMS
MAY ALSO CONTAIN SMALL HAIL AND GUSTY WINDS.  THESE STORMS WILL BE
MOVING THROUGH MUSCATINE COUNTY OF IOWA AND ROCK ISLAND AND NORTHERN
MERCER COUNTIES OF ILLINOIS OVER THE NEXT 45 MINUTES TO AN HOUR.

COOPER

Special weather statement, Aug 28, 11:38 PM CDT, 2 hours 53 minutes before

ILZ004-IAZ015-290530-

SPECIAL WEATHER STATEMENT...CORRECTION TO LAST LINE
NATIONAL WEATHER SERVICE MOLINE IL
1130 PM CDT TUE AUG 28 1990

AT 1120 PM CDT...RADAR WAS INDICATING A LINE OF STRONG THUNDERSTORMS
EXTENDING FROM JUST SOUTHEAST OF IOWA CITY THROUGH MUSCATINE AND INTO
ROCK ISLAND AND MOLINE.  THESE THUNDERSTORMS WERE MOVING EAST-SOUTHEAST
AT 30 MPH AND CONTAIN HEAVY RAIN AND FREQUENT LIGHTNING.  THESE STORMS
MAY ALSO CONTAIN SMALL HAIL AND GUSTY WINDS.  THESE STORMS WILL BE
MOVING THROUGH MUSCATINE COUNTY OF IOWA AND ROCK ISLAND AND NORTHERN
MERCER AND WESTERN HENRY COUNTIES OF ILLINOIS OVER THE NEXT HOUR.

COOPER

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 29, 12:26 AM CDT	Severe Thunderstorm Warning	DVN	Des Moines, Henry, Louisa	34 min
Aug 29, 1:49 AM CDT	Severe Thunderstorm Warning	DVN	Lee	41 min

Nearby

Severe Thunderstorm Warnings in Iowa, 1990 Every severe thunderstorm warning 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.