Alert archive / Iowa / Flash Flood Warnings in 1996

Flash Flood Warning 8, NWS Des Moines, IA

June 20, 1996Sac County, Iowa

NWS Des Moines, IA issued this flash flood warning at Jun 20, 1996, 1:16 AM CDT for Sac County, Iowa. It was in force for 3 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: Jun 20, 1996, 1:16 AM CDT (06:16 UTC)
Expired: Jun 20, 1996, 4:10 AM CDT
In force: 3 hr
Issued by: NWS Des Moines, IA
Area: Whole counties

County Sac County, IA

The radar

The Des Moines radar (KDMX), 135 km from the middle of the area, began a volume at 06:20 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

The nearest sounding before it

Omaha, NE (KOAX), launched 00:00Z, 6.3 hours before the alert went out and 158 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: 3601 J/kg
Mixed-layer CIN: -70 J/kg
Mixed-layer LCL: 1562 m above ground
0-6 km bulk shear: 37 kt
0-1 km storm-relative helicity: 94 m²/s²
0-3 km storm-relative helicity: 276 m²/s²
Significant tornado parameter: 1.4
Supercell composite: 19.9

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KDSM 200615
FFWDSM
IAC161-200910-

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE DES MOINES IA
116 AM CDT THU JUN 20 1996

* FLASH FLOOD WARNING FOR
  SOUTHWESTERN AND  CENTRAL SAC COUNTY - WEST CENTRAL IOWA

* UNTIL 410 AM CDT
 
* SOME STREAMS AFFECTED
    TRIBUTARIES OF THE BOYER RIVER
    ODEBOLT AND VICINITY

* CAUSE AND EFFECT
    THUNDERSTORMS HAVE CROSSED SOUTHWEST AND CENTRAL SAC COUNTIES FOR
    THE PAST ONE AND ONE-HALF HOURS. NWS SPOTTERS AND DOPPLER RADAR
    ESTIMATES RAINFALL IN EXCESS OF 2 INCHES SINCE 1130 PM.

* FORECAST CONDITIONS
   INTENSE THUNDERSTORMS LOCATED OVER IDA COUNTY WILL PRODUCE
   ADDITIONAL RAIN IN EXCESS OF 2 INCHES. THIS WILL LEAD TO
   FLOODING OF ROADWAYS AND SMALL STREAMS.

DO NOT DRIVE THROUGH WATER-COVERED ROADWAYS.

KULA

The office that day

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

Issued	Product	Office	Counties	Lasted
Jun 19, 11:44 PM CDT	Severe Thunderstorm Warning	DMX	Sac	31 min
Jun 20, 12:39 AM CDT	Severe Thunderstorm Warning	DMX	Sac	21 min
Jun 20, 1:00 AM CDT	Severe Thunderstorm Warning	DMX	Crawford	25 min
Jun 20, 1:23 AM CDT	Severe Thunderstorm Warning	DMX	Crawford	32 min
Jun 20, 9:25 AM CDT	Severe Thunderstorm Warning	DMX	Audubon, Cass	30 min
Jun 20, 9:49 AM CDT	Severe Thunderstorm Warning	DMX	Adair, Guthrie	41 min
Jun 20, 10:16 AM CDT	Severe Thunderstorm Warning	DMX	Dallas, Madison	44 min
Jun 20, 10:36 AM CDT	Severe Thunderstorm Warning	DMX	Polk, Warren	39 min
Jun 20, 10:51 AM CDT	Severe Thunderstorm Warning	DMX	Madison, Union	29 min
Jun 20, 1:18 PM CDT	Flash Flood Warning	DMX	Audubon	3 hr
Jun 20, 4:23 PM CDT	Severe Thunderstorm Warning	DMX	Crawford	37 min
Jun 20, 5:11 PM CDT	Severe Thunderstorm Warning	DMX	Crawford	34 min
Jun 20, 5:32 PM CDT	Severe Thunderstorm Warning	DMX	Crawford	43 min

Nearby

Flash Flood Warnings in Iowa, 1996 Every flash flood warning in 1996

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; radar from the NEXRAD Level II archive.