Alert archive / Iowa / Flash Flood Warnings in 1993

Flash Flood Warning 87, NWS Des Moines, IA

July 31, 1993Benton County, Linn County, Iowa

NWS Des Moines, IA issued this flash flood warning at Jul 31, 1993, 6:19 AM CDT for Benton County, Linn County, Iowa. It was in force for 56 min.

The area

The counties it named.

The facts

Issued
Jul 31, 1993, 6:19 AM CDT (11:19 UTC)
Expired
Jul 31, 1993, 7:15 AM CDT
In force
56 min
Issued by
NWS Des Moines, IA
Area
Whole counties

Counties Benton County, IA, Linn County, IA

The nearest sounding before it

Minneapolis, MN (KSTC), launched 00:00Z, 11.3 hours before the alert went out and 339 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 1993-07-31Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1153 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 1993-07-31The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 80 square meters per square second.1939Sfc1 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
1153 J/kg
Mixed-layer CIN
-243 J/kg
Mixed-layer LCL
1041 m above ground
0-6 km bulk shear
29 kt
0-1 km storm-relative helicity
80 m²/s²
0-3 km storm-relative helicity
246 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.

000 
TTAA00 KDSM 311121
FFWDSM
IAC011-113-311215-
 
BULLETIN - EBS ACTIVATION REQUESTED
SEVERE THUNDERSTORM AND FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE DES MOINES IA
619 AM CDT SAT JUL 31 1993
 
THE NATIONAL WEATHER SERVICE IN DES MOINES HAS ISSUED A
SEVERE THUNDERSTORM AND FLASH FLOOD WARNING
EFFECTIVE UNTIL 715 AM CDT
FOR PEOPLE IN THE FOLLOWING LOCATION...
 
IN EAST CENTRAL IOWA
 
   ...NORTHERN BENTON COUNTY...LINN COUNTY
 
AT 615 AM CDT RADAR INDICATED A SEVERE THUNDERSTORM OVER NORTHERN BENTON
COUNTY...10 MILES NORTHEAST OF VINTON...OR 20 MILES NORTHWEST OF CEDAR
RAPIDS. THIS STORM WAS LOCATED ALONG THE CEDAR RIVER FROM WATERLOO TO
CEDAR RAPIDS...AND HAS THE POTENTIAL TO PRODUCE TORRENTIAL RAIN OVER THE
NEXT 2 HOURS. THE CEDAR RIVER AND ITS TRIBUTARIES...INCLUDING THE BLUE
CREEK...AND WEST AND EAST OTTER CREEKS ARE ESPECIALLY VULNERABLE THIS
MORNING.
 
IF YOU ARE CAUGHT OUTSIDE...SEEK SHELTER FROM THE WEATHER IN A
STRONG BUILDING.  DAMAGING WIND...~LARGE HAIL...VERY HEAVY RAIN...
AND DEADLY LIGHTNING ARE ALL POSSIBLE IN SEVERE THUNDERSTORMS.
STAY INSIDE AWAY FROM WINDOWS UNTIL THE STORM HAS PASSED.
 
LEWIS

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, Jul 31, 2:45 AM CDT, 3 hours 34 minutes before
IAZ006-007-008-009-010-011-016-017-018-019-026-027-028-029-038-
039-040-310845-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE WATERLOO IA
243 AM CDT SAT JUL 31 1993

...ISOLATED STRONG THUNDERSTORMS ARE DEVELOPING IN NORTH CENTRAL IOWA...

AT 240 AM CDT...AN ISOLATED STRONG THUNDERSTORM HAD DEVELOPED NEAR THE
IOWA/MINNESOTA BORDER 3 MILES SOUTH OF NORTHWOOD.  IN ADDITION...
SCATTERED SHOWERS AND THUNDERSTORMS WERE DEVELOPING ALONG THE
HIGHWAY 218 CORRIDOR FROM NEAR WAVERLY TO NORTHWOOD.  THROUGH 340 AM
CDT...THESE STORMS WILL MOVE INTO THE ST. ANSGAR...OSAGE...CHARLES CITY
AND NASHUA AREAS AND COULD PRODUCE BRIEF HEAVY RAINS...STRONG GUSTY WINDAND DEADLY LIGHTNING.

OTHERWISE...CLOUDS WILL STEADILY THICKEN ACROSS THE REST OF NORTHEAST ANNORTH CENTRAL IOWA THROUGH THE NIGHTTIME HOURS WITH THE CHANCE OF WIDELY
SCATTERED SHOWERS AND THUNDERSTORMS CONTINUING.  THE MERCURY IS EXPECTED
TO HOLD STEADY IN THE MIDDLE 70S WITH THE WInNDS REMAINING SOUTH TO
SOUTHEAST AT 5 TO 10 MILES AN HOUR.

TRS
Special weather statement, Jul 31, 2:47 AM CDT, 3 hours 32 minutes before
IAZ006-007-008-009-010-011-016-017-018-019-026-027-028-029-038-
039-040-310845-

SPECIAL WEATHER STATEMENT...CORRECTION FOR TEXT
NATIONAL WEATHER SERVICE WATERLOO IA
243 AM CDT SAT JUL 31 1993

...ISOLATED STRONG THUNDERSTORMS ARE DEVELOPING IN NORTH CENTRAL IOWA...

AT 240 AM CDT...AN ISOLATED STRONG THUNDERSTORM HAD DEVELOPED NEAR THE
IOWA/MINNESOTA BORDER 3 MILES SOUTH OF NORTHWOOD.  IN ADDITION...
SCATTERED SHOWERS AND THUNDERSTORMS WERE DEVELOPING ALONG THE
HIGHWAY 218 CORRIDOR FROM NEAR WAVERLY TO NORTHWOOD.  THROUGH 340 AM
CDT...THESE STORMS WILL MOVE INTO THE ST. ANSGAR...OSAGE...CHARLES CITY
AND NASHUA AREAS AND COULD PRODUCE BRIEF HEAVY RAINS...STRONG GUSTY WINDS
AND DEADLY LIGHTNING.

OTHERWISE...CLOUDS WILL STEADILY THICKEN ACROSS THE REST OF NORTHEAST AND
NORTH CENTRAL IOWA THROUGH THE NIGHTTIME HOURS WITH THE CHANCE OF WIDELY
SCATTERED SHOWERS AND THUNDERSTORMS CONTINUING.  THE MERCURY IS EXPECTED
TO HOLD STEADY IN rTHE MIDDLE 70S WITH THE WINDS REMAINING SOUTH TO
SOUTHEAST AT 5 TO 10 MILES AN HOUR.

TRS
Special weather statement, Jul 31, 4:28 AM CDT, 1 hour 51 minutes before
IAZ006-007-008-009-010-011-016-017-018-019-026-027-028-029-038-
039-040-311030-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE WATERLOO IA
428 AM CDT SAT JUL 31 1993

...SCATTERED STRONG THUNDERSTORMS ARE MOVING INTO THE WATERLOO/CEDAR
   FALLS AREA EARLY THIS MORNING...

AT 430 AM CDT...SHOWERS AND SCATTERED STRONG THUNDERSTORMS HAD DEVELOPED
IN THE WATERLOO/CEDAR FALLS AREAS AND CONTINUED ALONG THE HIGHWAY 218
CORRIDOR.  THROUGH 530 AM CDT...THESE SHOWERS AND THUNDERSTORMS WILL
CONTINUE TO AFFECT THE WATERLOO METRO AREA IN ADDITION TO CHARLES
CITY...NASHUA...PLAINFILED...WAVERLY AND LA PORTE CITY.  THESE
THUNDERSTORMS WILL PRODUCE BRIEF HEAVY RAINS...STRONG GUSTY WINDS AND
FREQUENT DEADLY LIGHTNING.

THROUGH THE EARLY MORNING HOURS...NORTHEAST AND NORTH CENTRAL IOWA WILL
SEE THE SCATTERED SHOWERS AND THUNDERSTORMS CONTINUING ALONG AND TO THE
EAST OF HIGHWAY 218.  THE TEMPERATURES WILL HOLD STEADY IN THE LOWER TO
MIDDLE 70S WITH THE WINDS REMAINING SOUTH TO SOUTHEAST AT 5 TO 15 MILES
AN HOUR.

THE PUBLIC IS ADVISED TO STAY TUNED TO NOAA WEATHER RADIO...OR THEIR
LOCAL TV OR RADIO BROADCASTS FOR ADDITIONAL STATEMENTS AND WEATHER
UPDATES.

TRS
Special weather statement, Jul 31, 4:29 AM CDT, 1 hour 50 minutes before
IAZ006-007-008-009-010-011-016-017-018-019-026-027-028-029-038-
039-040-311030-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE WATERLOO IA
428 AM CDT SAT JUL 31 1993

...SCATTERED STRONG THUNDERSTORMS ARE MOVING INTO THE WATERLOO/CEDAR
   FALLS AREA EARLY THIS MORNING...

AT 430 AM CDT...SHOWERS AND SCATTERED STRONG THUNDERSTORMS HAD DEVELOPED
IN THE WATERLOO/CEDAR FALLS AREAS AND CONTINUED ALONG THE HIGHWAY 218
CORRIDOR.  THROUGH 530 AM CDT...THESE SHOWERS AND THUNDERSTORMS WILL
CONTINUE TO AFFECT THE WATERLOO METRO AREA IN ADDITION TO CHARLES
CITY...NASHUA...PLAINFILED...WAVERLY AND LA PORTE CITY.  THESE
THUNDERSTORMS WILL PRODUCE BRIEF HEAVY RAINS...STRONG GUSTY WINDS AND
FREQUENT DEADLY LIGHTNING.

THROUGH THE EARLY MORNING HOURS...NORTHEAST AND NORTH CENTRAL IOWA WILL
SEE THE SCATTERED SHOWERS AND THUNDERSTORMS CONTINUING ALONG AND TO THE
EAST OF HIGHWAY 218.  THE TEMPERATURES WILL HOLD STEADY IN THE LOWER TO
MIDDLE 70^S WITH THE WINDS REMAINING SOUTH TO SOUTHEAST AT 5 TO 15 MILES
AN HOUR.

THE PUBLIC IS ADVISED TO STAY TUNED TO NOAA WEATHER RADIO...OR THEIR
LOCAL TV OR RADIO BROADCASTS FOR ADDITIONAL STATEMENTS AND WEATHER
UPDATES.

TRS
Special weather statement, Jul 31, 5:47 AM CDT, 32 minutes before
IAZALL-311145-

SPECIAL WEATHER STATEMENT AND RADAR SUMMARY
NATIONAL WEATHER SERVICE DES MOINES IA
547 AM CDT SAT JUL 31 1993

AT 531 AM CDT...VERY STRONG AND INTENSE THUNDERSTORMS CONTINUED OVER
NORTHEAST AND SOUTHEAST IOWA.  THE STRONGEST STORMS WERE LOCATED NEAR
WATERLOO AND 5 TO 10 MILES SOUTHEAST OF WATERLOO.  THESE STORMS...IN
ADDITION TO PRODUCING TORRENTIAL DOWNPOURS...CAN CONTAIN LARGE HAIL...
DAMAGING WIND...AND DEADLY LIGHTNING.  PERSONS IN THE PATH OF THESE
STORMS SHOULD MONITOR LOCAL RADIO BROADCASTS AND MOVE TO A PLACE OF
SHELTER IF THREATENING WEATHER APPROACHES.

OTHER VERY STRONG THUNDERSTORMS WERE SCATTERED OVER SOUTHEAST IOWA
10 TO 20 MILES SOUTHEAST OF OTTUMWA.

THE THUNDERSTORMS WERE MOVING SOUTHEAST AT 20 MILES AN HOUR.

MILLER
Special weather statement, Jul 31, 5:47 AM CDT, 32 minutes before
IAZALL-311145-

SPECIAL WEATHER STATEMENT AND RADAR SUMMARY
NATIONAL WEATHER SERVICE DES MOINES IA
547 AM CDT SAT JUL 31 1993

AT 531 AM CDT...VERY STRONG AND INTENSE THUNDERSTORMS CONTINUED OVER
NORTHEAST AND SOUTHEAST IOWA.  THE STRONGEST STORMS WERE LOCATED NEAR
WATERLOO AND 5 TO 10 MILES SOUTHEAST OF WATERLOO.  THESE STORMS...IN
ADDITION TO PRODUCING TORRENTIAL DOWNPOURS...CAN CONTAIN LARGE HAIL...
DAMAGING WIND...AND DEADLY LIGHTNING.  PERSONS IN THE PATH OF THESE
STORMS SHOULD MONITOR LOCAL RADIO BROADCASTS AND MOVE TO A PLACE OF
SHELTER IF THREATENING WEATHER APPROACHES.

OTHER VERY STRONG THUNDERSTORMS WERE SCATTERED OVER SOUTHEAST IOWA
10 TO 20 MILES SOUTHEAST OF OTTUMWA.

THE THUNDERSTORMS WERE MOVING SOUTHEAST AT 20 MILES AN HOUR.

MILLER

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 31, 5:08 AM CDTSevere Thunderstorm WarningDMXBlack Hawk, Bremer52 min
Jul 31, 6:19 AM CDTSevere Thunderstorm WarningDMXBenton, Linn56 min
Jul 31, 7:05 AM CDTSevere Thunderstorm WarningDMXBenton45 min
Jul 31, 7:23 AM CDTFlash Flood WarningDMXBenton3 hr
Jul 31, 7:40 AM CDTSevere Thunderstorm WarningDMXLinn35 min
Jul 31, 8:15 AM CDTSevere Thunderstorm WarningDMXCerro Gordo45 min
Jul 31, 8:25 AM CDTSevere Thunderstorm WarningDMXFranklin65 min
Jul 31, 8:56 AM CDTSevere Thunderstorm WarningDMXHamilton, Hardin34 min
Jul 31, 9:10 AM CDTSevere Thunderstorm WarningDMXChickasaw27 min
Jul 31, 9:19 AM CDTSevere Thunderstorm WarningDMXGreene41 min
Jul 31, 9:30 AM CDTSevere Thunderstorm WarningDMXHamilton, Hardin60 min
Jul 31, 9:51 AM CDTSevere Thunderstorm WarningDMXBoone, Webster44 min
Jul 31, 10:42 AM CDTSevere Thunderstorm WarningDMXStory27 min
Jul 31, 11:02 AM CDTSevere Thunderstorm WarningDMXJasper, Marshall30 min
Jul 31, 11:12 AM CDTSevere Thunderstorm WarningDMXMarion, Warren48 min
Jul 31, 11:38 AM CDTSevere Thunderstorm WarningDMXPoweshiek, Tama33 min
Jul 31, 11:52 AM CDTSevere Thunderstorm WarningDMXWright52 min
Jul 31, 12:00 PM CDTSevere Thunderstorm WarningDMXBenton, Iowa30 min
Jul 31, 12:08 PM CDTFlash Flood WarningDMXJohnson, Linn67 min
Jul 31, 12:08 PM CDTSevere Thunderstorm WarningDMXJohnson, Linn67 min
Jul 31, 12:16 PM CDTFlash Flood WarningDMXHardin59 min
Jul 31, 12:16 PM CDTSevere Thunderstorm WarningDMXHardin59 min

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.