Alert archive / Iowa / Flash Flood Warnings in 1990

Flash Flood Warning 20, NWS Quad Cities, IA

June 29, 1990Clinton County, Scott County, Iowa

NWS Quad Cities, IA issued this flash flood warning at Jun 29, 1990, 8:03 AM CDT for Clinton County, Scott County, Iowa. It was in force for 3 hr.

The area

The counties it named.

The facts

Issued: Jun 29, 1990, 8:03 AM CDT (13:03 UTC)
Expired: Jun 29, 1990, 11:00 AM CDT
In force: 3 hr
Issued by: NWS Quad Cities, IA
Area: Whole counties

Counties Clinton County, IA, Scott 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

Green Bay/Straub, WI (KGRB), launched 12:00Z, 1.1 hours before the alert went out and 362 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: 249 J/kg
Mixed-layer CIN: -194 J/kg
Mixed-layer LCL: 597 m above ground
0-6 km bulk shear: 44 kt
0-1 km storm-relative helicity: 97 m²/s²
0-3 km storm-relative helicity: 159 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.1

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KMLI 291303
FFWMLI
IAC163-045-ILC161-073-195-291600-

BULLETIN - IMMEDIATE BROADCAST REQUESTED/EBS ACTIVATION REQUESTED 
FLASH FLOOD WARNING 
NATIONAL WEATHER SERVICE MOLINE IL
803 AM CDT FRI JUN 29 1990

THE NATIONAL WEATHER SERVICE HAS ISSUED A FLASH FLOOD WARNING 
EFFECTIVE UNTIL 1100 AM CDT FOR PEOPLE IN THE FOLLOWING 
COUNTIES

   IN THE EXTREME EAST PART OF IOWA
      SCOTT...CLINTON...

   IN THE NORTHWEST PART OF ILLINOIS
      CENTRAL AND NORTHERN ROCK-ISLAND...HENRY...WHITESIDE...

HEAVY RAINFALL CONTINUES OVER EXTREME EASTERN IA AND PARTS OF
NORTHWEST ILLINOIS.  RAINFALL AMOUNTS OF 3 TO 4 INCHES PRODUCED
FLASH FLOODING OVER PARTS OF THESE COUNTIES.

AT 8 AM CDT DUCK CREEK IN SCOTT COUNTY CONTINUES TO RISE AS WELL
AS OTHER SMALL STREAMS AND CREEKS.  THE WAPSIPINICON RIVERS WAS
AT 11.7 EARLY THIS MORNING AND ALSO RISING.  FLOOD STAGE THERE IS
10 FEET.

FLASH FLOOD WARNING MEANS FLASH FLOODING IS OCCURRING OR IS
IMMINENT IN THE SPECIFIED AREA.

PERSONS ALONG OR NEAR STREAMS SUBJECT TO FLASH FLOODING OR SHARP
RISES SHOULD BE PREPARED TO MOVE TO A PLACE OF SAFETY IMMEDIATELY.

MOST FLASH FLOOD DEATHS OCCUR IN AUTOMOBILES.  DO NOT ATTEMPT TO
CROSS BRIDGES...DIPS...OR LOW SPOTS IF WATER COVERS THE ROADWAY.
NEVER TRY TO CROSS A FLOWING STREAM...EVEN A SMALL ONE...ON FOOT.

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

ATTN ISP 7 AND 1

KRAEMER~

What forecasters said that day

The local office's own words before this flash flood 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, Jun 29, 7:02 AM CDT, 1 hour 1 minute before

ILZ004-291300

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOLINE IL
650 AM CDT FRI JUN 29 1990

...STRONG THUNDERSTORMS CONTINUE IN EASTERN IOWA AND
   NORTHWEST ILLINOIS...

AT 645 AM CDT RADAR SHOWS THE STRONGEST THUNDERSTORMS LYING
ACROSS NORTHERN SCOTT COUNTY IN IOWA THROUGH UPPER ROCK ISLAND
COUNTY INTO NORTHERN AND CENTRAL HENRY COUNTY IN ILLINOIS.

BESIDES THE HEAVY RAINFALL PRODUCING FLASH FLOODING...SOME
THUNDERSTORMS WERE PRODUCING GUSTY WINDS OF 40 TO 50 MPH.
SOME TREE DAMAGE WAS REPORTED IN UPPER ROCK ISLAND COUNTY AT
6 AM CDT AND AT KALONA IN NORTHWEST HENRY COUNTY AT 630 AM CDT.
KALONA IS ABOUT 10 MILES EAST OF MOLINE.

THE THUNDERSTORMS WERE MOVING TOWARD THE EAST 0SOUTHEAST AT 30 MPH.
KRAEMER

The office that day

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

Issued	Product	Office	Counties	Lasted
Jun 29, 4:23 AM CDT	Flash Flood Warning	DVN	Scott	4 hr
Jun 29, 11:02 AM CDT	Flash Flood Warning	DVN	Clinton	3 hr
Jun 29, 11:02 AM CDT	Flash Flood Warning	DVN	Scott	3 hr

Nearby

Flash Flood Warnings in Iowa, 1990 Every flash flood 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.