Alert archive / Iowa / Flash Flood Warnings in 1997

Flash Flood Warning 9, NWS Omaha, NE

September 2, 1997Mills County, Pottawattamie County, Iowa

NWS Omaha, NE issued this flash flood warning at Sep 2, 1997, 2:51 AM CDT for Mills County, Pottawattamie County, Iowa. It was in force for 4 hr. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued
Sep 2, 1997, 2:51 AM CDT (07:51 UTC)
Expired
Sep 2, 1997, 7:00 AM CDT
In force
4 hr
Issued by
NWS Omaha, NE
Area
Whole counties

Counties Mills County, IA, Pottawattamie County, IA

The nearest sounding before it

Omaha, NE (KOAX), launched 00:00Z, 7.9 hours before the alert went out and 68 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 1997-09-02Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1781 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 1997-09-02The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 47 square meters per square second.193958Sfc1 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
1781 J/kg
Mixed-layer CIN
-50 J/kg
Mixed-layer LCL
1077 m above ground
0-6 km bulk shear
17 kt
0-1 km storm-relative helicity
47 m²/s²
0-3 km storm-relative helicity
170 m²/s²
Significant tornado parameter
0.0
Supercell composite
2.3

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KOMA 020751
FFWOMA
IAC129-155-021200-

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
251 AM CDT TUE SEP 2 1997

* FLASH FLOOD WARNING FOR
  POTTAWATTAMIE COUNTY IN SOUTHWESTERN IOWA
  MILLS COUNTY IN SOUTHWESTERN IOWA

* UNTIL 700 AM CDT
 
* SOME STREAMS AFFECTED
  KEG CREEK
  SILVER CREEK

* CAUSE AND EFFECT
  THUNDERSTORMS HAVE PRODUCED VERY HEAVY RAINS IN EXCESS OF 3 INCHES
  SINCE LATE MONDAY EVENING ACROSS PORTIONS OF POTTAWATTAMIE AND MILLS
  COUNTIES.  ADDITIONAL RAINFALL OF 2 OR SO INCHES IS POSSIBLE THROUGH
  6AM AS MORE THUNDERSTORMS MOVE THROUGH THE AREA.
 
IF FLASH FLOODING IS OBSERVED...ACT QUICKLY.  MOVE TO ESCAPE FLOOD
WATERS.  DO NOT SXTAY IN AREAS SUBJECT TO FLOODING WHEN WATER BEGINS
RISING.

SKERRITT

The office that day

Everything else NWS Omaha, NE issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Sep 2, 12:31 AM CDTSevere Thunderstorm WarningOAXMills49 min
Sep 2, 12:46 AM CDTSevere Thunderstorm WarningOAXPottawattamie49 min

Nearby

Flash Flood Warnings in Iowa, 1997Every flash flood warning in 1997

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.