Alert archive / Iowa / Flash Flood Warnings in 1993

Flash Flood Warning 33, NWS Des Moines, IA

June 27, 1993Johnson County, Washington County, Iowa

NWS Des Moines, IA issued this flash flood warning at Jun 27, 1993, 3:36 AM CDT for Johnson County, Washington County, Iowa. It was in force for 3 hr.

The area

The counties it named.

The facts

Issued
Jun 27, 1993, 3:36 AM CDT (08:36 UTC)
Expired
Jun 27, 1993, 6:30 AM CDT
In force
3 hr
Issued by
NWS Des Moines, IA
Area
Whole counties

Counties Johnson County, IA, Washington County, IA

The nearest sounding before it

Omaha, NE (KOAX), launched 00:00Z, 8.6 hours before the alert went out and 394 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, Omaha, NE at 00:00Z on 1993-06-27Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 911 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, Omaha, NE at 00:00Z on 1993-06-27The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 81 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
911 J/kg
Mixed-layer CIN
-32 J/kg
Mixed-layer LCL
1826 m above ground
0-6 km bulk shear
42 kt
0-1 km storm-relative helicity
81 m²/s²
0-3 km storm-relative helicity
134 m²/s²
Significant tornado parameter
0.1
Supercell composite
4.7

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KDSM 270923 COR
FFWDSM
IAC103-183-271130-

BULLETIN - EBS ACTIVATION REQUESTED
FLASH FLOOD WARNING.................CORRECTION
NATIONAL WEATHER SERVICE DES MOINES IA
420 AM CDT SUN JUN 27 1993

THE NATIONAL WEATHER SERVICE IN DES MOINES HAS ISSUED A
FLASH FLOOD WARNING EFFECTIVE UNTIL  630 AM CDT
FOR PEOPLE IN THE FOLLOWING LOCATION(S)S...

IN EAST CENTRAL IOWA

   ...JOHNSON COUNTY

IN SOUTHEAST IOWA

   ...NORTHEASTERN WASHINGTON COUNTY

AT 326 AM CDT...THE JOHNSON COUNTY SHERIFF REPORTED NUMEROUS ROADS WITH
WATER FLOWING OVER THEM IN AND AROUND THE CORALVILLE RESERVIOR AND
ESPECIALLY DOWNSTREAM IN THE IOWA CITY AREA. PROBLEMS HAVE BEEN REPORTED
AND CREWS ARE ON THE WAY TO CLOSE ROADS IN THE VICINITIES OF NORTH
LIBERTY...TIFFIN AND OAKDALE...WHICH ARE ALL BETWEEN CORALVILLE
RESERVIOR AND I-80 GOING THROUGH IOWA CITY.

THE CORALVILLE RESERVIOR RECEIVED BETWEEN 4 AND 4.5 INCHES IN LESS THAN
AN HOUR BEFORE 315 AM WHICH CAUSED THE LAKE LEVEL TO SUDDENLY RISE.

AS OF 330 AM...DES MOINES NATIONAL WEATHER SERVICE RADAR INDICATED THE
STORMS WHICH PRODUCED THE HEAVY RAINS IN THE CORALVILLE/IOWA CITY AREA
WAS NOW SOUTH OF THAT AREA.  THE BACK EDGE OF THE STORMS WAS ALONG A
LINE FROM 50 MILES EAST OF DES MOINES NEAR MONTEZUMA...TO 15 MILES
SOUTHWEST OF IOWA CITY NEAR KALONA...TO 10 MILES NORTH OF MOLINE
ILLINOIS NEAR LONG GROVE.

MOVEMENT WAS SOUTHEAST AT 30 MILES AN HOUR.



BE ESPECIALLY CAUTIOUS AT NIGHT WHEN IT IS HARDER TO RECOGNIZE
THE DANGERS OF FLOODS AND FLASH FLOODS.  IF FLASH FLOODING IS
OBSERVED...ACT QUICKLY.  MOVE UP TO ESCAPE FLOOD WATERS.  DO
NOT STAY IN AREAS SUBJECT TO FLOODING WHEN WATER BEGINS RISING.

A FLASH FLOOD WARNING MEANS THAT FLOODING IS IMMINENT.  IT'S
IMPORTANT TO KNOW WHERE YOU ARE RELATIVE TO STREAMS...RIVERS...OR
CREEKS WHICH CAN BECOME KILLERS IN HEAVY RAINS.  CAMPERS SHOULD
AVOID CAMPING ALONG STREAMS OR CREEKS DURING THREATENING RAINS.


****CORRECTION - THE ENGINEERS AT CORALVILLE R,ESERVIOR REPORT WATER WAS
                 NOT...REPEAT NOT...GOING OVER THE SPILLWAY...AS
                 INDICATED EARLIER.  THAT REPORT WAS INCORRECT.


BURKE

&

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 27, 12:40 AM CDT, 2 hours 56 minutes before
IAZ026>030-038>042-053-054-270630-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE WATERLOO IA
1240 AM CDT SUN JUN 27 1993

...ISOLATED STRONG THUNDERSTORMS ARE MOVING INTO SOUTHERN JONES
   COUNTY...

AT 1235 AM CDT...ISOLATED STRONG THUNDERSTORMS WERE MOVING INTO
SOUTHERN JONES COUNTY.  THESE ISOLATED STORMS WILL MOVE THROUGH
THE TOWNS OF MORLY...OLIN...HALE AND WYOMING BY 135 AM AND WILL
PRODUCE HEAVY RAINS...FREQUENT DEADLY LIGHTNING AND POSSIBLY SOME
SMALL HAIL.

OTHERWISE...THE REST OF NORTHEAST IOWA IS EXPECTED TO SEE PARTLY
CLOUDY SKIES PREVAILING WITH THE THREAT OF SHOWERS AND THUNDERSTORMS
CONTINUING THROUGH THE NIGHTTIME HOURS.  THE MERCURY IS ANTICIPATED
TO FALL TO AROUND 60 DEGREES THROUGH THE NIGHT WITH WEST TO NORTHWEST
WINDS CONTINUING AT 5 TO 10 MILES AN HOUR.
Special weather statement, Jun 27, 12:43 AM CDT, 2 hours 53 minutes before
IAZ026>030-038>042-053-054-270630-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE WATERLOO IA
1240 AM CDT SUN JUN 27 1993

...ISOLATED STRONG THUNDERSTORMS ARE MOVING INTO SOUTHERN JONES
   COUNTY...

AT 1235 AM CDT...ISOLATED STRONG THUNDERSTORMS WERE MOVING INTO
SOUTHERN JONES COUNTY.  THESE ISOLATED STORMS WILL MOVE THROUGH
THE TOWNS OF MORLY...OLIN...HALE AND WYOMING BY 135 AM AND WILL
PRODUCE HEAVY RAINS...FREQUENT DEADLY LIGHTNING AND POSSIBLY SOME
SMALL HAIL.

OTHERWISE...THE REST OF NORTHEAST IOWA IS EXPECTED TO SEE PARTLY
CLOUDY SKIES PREVAILING WITH THE THREAT OF SHOWERS AND THUNDERSTORMS
CONTINUING THROUGH THE NIGHTTIME HOURS.  THE MERCURY IS ANTICIPATED
TO FALL TO AROUND 60 DEGREES THROUGH THE NIGHT WITH WEST TO NORTHWEST
WINDS CONTINUING AT 5 TO 10 MILES AN HOUR.
Special weather statement, Jun 27, 1:45 AM CDT, 1 hour 51 minutes before
IAZALL-270640-

SPECIAL WEATHER STATEMENT AND RADAR SUMMARY
NATIONAL WEATHER SERVICE DES MOINES IA
145 AM CDT SUN JUN 27 1993

AT 131 AM CDT...SCATTERED THUNDERSTORMS WITH VERY HEAVY RAIN AND
DEADLY LIGHTNING CONTINUED ACROSS CENTRAL AND EAST CENTRAL IOWA.

THIS THUNDERSTORM AREA WAS 50 MILES WIDE AND EXTENDED FROM 20 MILES
WEST OF DES MOINES TO THE QUAD CITIES. STORMS WITH VERY HEAVY RAIN
AND POSSIBLE SMALL HAIL WERE LOCATED 20 MILES NORTH OF DES MOINES
BETWEEN MADRID AND FARRAR...15 MILES SOUTHWEST OF CEDAR RAPIDS AND
JUST NORTHWEST OF IOWA CITY.

MOVEMENT WAS EAST-SOUTHEAST AT 40 MILES AN HOUR.

R A PRENTICE
Special weather statement, Jun 27, 1:46 AM CDT, 1 hour 50 minutes before
IAZALL-270640-

SPECIAL WEATHER STATEMENT AND RADAR SUMMARY
NATIONAL WEATHER SERVICE DES MOINES IA
145 AM CDT SUN JUN 27 1993

AT 131 AM CDT...SCATTERED THUNDERSTORMS WITH VERY HEAVY RAIN AND
DEADLY LIGHTNING CONTINUED ACROSS CENTRAL AND EAST CENTRAL IOWA.

THIS THUNDERSTORM AREA WAS 50 MILES WIDE AND EXTENDED FROM 20 MILES
WEST OF DES MOINES TO THE QUAD CITIES. STORMS WITH VERY HEAVY RAIN
AND POSSIBLE SMALL HAIL WERE LOCATED 20 MILES NORTH OF DES MOINES
BETWEEN MADRID AND FARRAR...15 MILES SOUTHWEST OF CEDAR RAPIDS AND
JUST NORTHWEST OF IOWA CITY.

MOVEMENT WAS EAST-SOUTHEAST AT 40 MILES AN HOUR.

R A PRENTICE
Special weather statement, Jun 27, 2:46 AM CDT, 50 minutes before
IAZALL-270740-

SPECIAL WEATHER STATEMENT AND RADAR SUMMARY
NATIONAL WEATHER SERVICE DES MOINES IA
246 AM CDT SUN JUN 27 1993

AT 230 AM CDT...THUNDERSTORMS WITH VERY HEAVY RAIN...GUSTY WINDS...
DEADLY LIGHTNING AND SMALL HAIL WERE LOCATED BETWEEN 5 MILES NORTHEAST
AND 10 MILES SOUTHEAST OF NEWTON. NEWTON IS 25 MILES EAST OF DES MOINES.
THESE STORMS WILL AFFECT THE TOWNS OF SEARSBORO...LYNNVILLE...
MONTEZUMA AND NEW SHARON BY AROUND 3 AM.

THESE STORMS WERE PART OF A LARGER AREA OF SCATTERED THUNDERSTORMS
WHICH CONTINUED ACROSS CENTRAL...EAST CENTRAL AND SOUTHEAST IOWA. THIS
AREA WAS 55 MILES WIDE AND EXTENDED FROM 20 MILES NORTHEAST OF DES
MOINES TO THE QUAD CITIES. OTHER STORMS WITH VERY HEAVY RAIN WERE
LOCATED 15 MILES EAST AND NORTHEAST OF WASHINGTON.

MOVEMENT WAS EAST-SOUTHEAST AT 40 MILES AN HOUR.

R A PRENTICE
Special weather statement, Jun 27, 2:48 AM CDT, 48 minutes before
IAZALL-270740-

SPECIAL WEATHER STATEMENT AND RADAR SUMMARY
NATIONAL WEATHER SERVICE DES MOINES IA
246 AM CDT SUN JUN 27 1993

AT 230 AM CDT...THUNDERSTORMS WITH VERY HEAVY RAIN...GUSTY WINDS...
DEADLY LIGHTNING AND SMALL HAIL WERE LOCATED BETWEEN 5 MILES NORTHEAST
AND 10 MILES SOUTHEAST OF NEWTON. NEWTON IS 25 MILES EAST OF DES MOINES.
THESE STORMS WILL AFFECT THE TOWNS OF SEARSBORO...LYNNVILLE...
MONTEZUMA AND NEW SHARON BY AROUND 3 AM.

THESE STORMS WERE PART OF A LARGER AREA OF SCATTERED THUNDERSTORMS
WHICH CONTINUED ACROSS CENTRAL...EAST CENTRAL AND SOUTHEAST IOWA. THIS
AREA WAS 55 MILES WIDE AND EXTENDED FROM 20 MILES NORTHEAST OF DES
MOINES TO THE QUAD CITIES. OTHER STORMS WITH VERY HEAVY RAIN WERE
LOCATED 15 MILES EAST AND NORTHEAST OF WASHINGTON.

MOVEMENT WAS EAST-SOUTHEAST AT 40 MILES AN HOUR.

R A PRENTICE

The office that day

Everything else NWS Des Moines, IA issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jun 26, 8:22 PM CDTSevere Thunderstorm WarningDMXAudubon36 min
Jun 26, 8:48 PM CDTSevere Thunderstorm WarningDMXGuthrie27 min
Jun 26, 9:24 PM CDTSevere Thunderstorm WarningDMXDallas36 min
Jun 26, 9:39 PM CDTSevere Thunderstorm WarningDMXBoone25 min
Jun 27, 2:14 AM CDTFlash Flood WarningDMXJohnson, Washington3 hr

Nearby

Flash Flood Warnings in Iowa, 1993Every flash flood warning in 1993

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.