Alert archive / Iowa / Flash Flood Warnings in 1999

Flash Flood Warning 40, NWS Omaha, NE

August 7, 1999Pottawattamie County, Iowa

NWS Omaha, NE issued this flash flood warning at Aug 7, 1999, 1:50 AM CDT for Pottawattamie County, Iowa. It was in force for 6 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
Aug 7, 1999, 1:50 AM CDT (06:50 UTC)
Expired
Aug 7, 1999, 8:00 AM CDT
In force
6 hr
Issued by
NWS Omaha, NE
Area
Whole counties

County Pottawattamie County, IA

The nearest sounding before it

Omaha, NE (KOAX), launched 00:00Z, 6.8 hours before the alert went out and 69 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 1999-08-07Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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 1999-08-07The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 142 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1015 m above ground
0-6 km bulk shear
35 kt
0-1 km storm-relative helicity
142 m²/s²
0-3 km storm-relative helicity
347 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.8

Open this sounding in Storm Lab

The text

The text of this product is not in the archive. The NWS text archive before 2002 is incomplete.

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.

NWS Omaha, NE wrote its last area forecast discussion before this flash flood warning went out at Aug 6, 6:55 PM CDT, 6 hours 55 minutes earlier.

Area forecast discussion, Aug 6, 6:55 PM CDT, 6 hours 55 minutes before
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE OMAH

In the hours before

Local storm report, Aug 6, 11:30 PM CDT, 2 hours 20 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
1130 PM CDT FRI AUG 06 1999

TIME(CDT)  .....CITY LOCATION..... STATE   ...EVENT/REMARKS...
           ....COUNTY LOCATION....

0830 PM    ASHLAND                   NE    .88 INCH HAIL
08/06/99   SAUNDERS

0850 PM    SCRIBNER                  NE    FLOOD
08/06/99   DODGE                           4.8 INCHES OF RAIN
                                           SINCE 11 AM CDT.
                                           WATER, OVER ROAD AT HWY
                                           91 & 275 (MUD CREEK).

0910 PM    PAPILLION                 NE    WIND DAMAGE
08/06/99   SARPY                           LARGE TREE LIMBS DOWN
Local storm report, Aug 6, 11:30 PM CDT, 2 hours 20 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
1130 PM CDT FRI AUG 06 1999

TIME(CDT)  .....CITY LOCATION..... STATE   ...EVENT/REMARKS...
           ....COUNTY LOCATION....

0830 PM    ASHLAND                   NE    .88 INCH HAIL
08/06/99   SAUNDERS

0850 PM    SCRIBNER                  NE    FLOOD
08/06/99   DODGE                           4.8 INCHES OF RAIN
                                           SINCE 11 AM CDT.
                                           WATER, OVER ROAD AT HWY
                                           91 & 275 (MUD CREEK).

0910 PM    PAPILLION                 NE    WIND DAMAGE
08/06/99   SARPY                           LARGE TREE LIMBS DOWN

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 6, 8:17 PM CDTFlash Flood WarningOAXDodge6 hr
Aug 6, 8:18 PM CDTSevere Thunderstorm WarningOAXCass, Sarpy, Saunders62 min
Aug 6, 10:15 PM CDTFlash Flood WarningOAXWashington7 hr
Aug 6, 11:05 PM CDTFlash Flood WarningOAXColfax6 hr
Aug 6, 11:15 PM CDTFlash Flood WarningOAXDodge6 hr
Aug 7, 12:36 AM CDTFlash Flood WarningOAXBurt5 hr
Aug 7, 2:00 AM CDTFlash Flood WarningOAXDouglas6 hr
Aug 7, 3:25 AM CDTFlash Flood WarningOAXSarpy6 hr
Aug 7, 5:06 AM CDTFlash Flood WarningOAXBurt, Dodge, Washington5 hr
Aug 7, 7:32 AM CDTFlash Flood WarningOAXDouglas3 hr
Aug 7, 8:42 AM CDTFlash Flood WarningOAXSarpy108 min
Aug 6, 10:49 PM CDTSevere Thunderstorm WarningOAXMills61 min
Aug 7, 12:03 AM CDTFlash Flood WarningOAXHarrison6 hr
Aug 7, 12:45 AM CDTSevere Thunderstorm WarningOAXMontgomery50 min
Aug 7, 1:34 AM CDTSevere Thunderstorm WarningOAXMills36 min
Aug 7, 1:38 AM CDTSevere Thunderstorm WarningOAXMontgomery, Page52 min
Aug 7, 3:25 AM CDTFlash Flood WarningOAXMills, Montgomery6 hr
Aug 7, 5:06 AM CDTFlash Flood WarningOAXHarrison5 hr

Nearby

Flash Flood Warnings in Iowa, 1999Every flash flood warning in 1999

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.