Alert archive / Iowa / Flash Flood Warnings in 2000

Flash Flood Warning 1, NWS Des Moines, IA

May 11, 2000Black Hawk County, Iowa

NWS Des Moines, IA issued this flash flood warning at May 11, 2000, 9:12 PM CDT for Black Hawk 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 outline the Iowa Environmental Mesonet reconstructed for it; the warning itself named whole counties.

The facts

Issued: May 11, 2000, 9:12 PM CDT (02:12 UTC)
Expired: May 12, 2000, 12:15 AM CDT
In force: 3 hr
Issued by: NWS Des Moines, IA
Area: Whole counties; the outline is the Mesonet’s reconstruction

County Black Hawk County, IA

The radar

The Des Moines radar (KDMX), 154 km from the middle of the area, began a volume at 02:15 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

Davenport, (KDVN), launched 00:00Z, 2.2 hours before the alert went out and 177 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: 2323 J/kg
Mixed-layer CIN: -39 J/kg
Mixed-layer LCL: 1261 m above ground
0-6 km bulk shear: 47 kt
0-1 km storm-relative helicity: 171 m²/s²
0-3 km storm-relative helicity: 218 m²/s²
Significant tornado parameter: 1.8
Supercell composite: 13.9

Open this sounding in Storm Lab

The text

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

000 
WGUS53 KDMX 120216
FFWDMX
IAC013-120515-

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE DES MOINES IA
912 PM CDT THU MAY 11 2000

THE NATIONAL WEATHER SERVICE IN DES MOINES HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  NORTHEASTERN BLACK HAWK COUNTY IN NORTHEAST IOWA

* UNTIL 1215 AM CDT

* AT 912 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  THUNDERSTORMS WITH FLASH FLOOD PRODUCING RAINS OVER NORTHEAST
  BLACK HAWK COUNTY.

* THUNDERSTORMS ARE CONTINUOUSLY REDEVELOPING OVER THE WARNING
  AREA...RESULTING IN EXCESSIVE RAINFALL. RAINFALL RATES WILL AVERAGE
  1 INCH PER HOUR. THIS WILL PRODUCE FLASH FLOODING ALONG THE CRANE
  CREEK AND ITS TRIBUTARIES AND ALONG THE MAIN STEM OF THE
  WAPSIPINICON RIVER.

EXCESSIVE RUNOFF FROM THIS STORM WILL CAUSE FLASH FLOODING OF SMALL
CREEKS AND STREAMS...HIGHWAYS AND UNDERPASSES. ADDITIONALLY...COUNTRY
ROADS AND FARMLANDS ALONG THE BANKS OF CREEKS AND STREAMS AND OTHER
LOW LYING AREAS ARE SUBJECT TO FLASH FLOODING.

A FLASH FLOOD WARNING MEANS THAT FLOODING IS IMMINENT OR OCCURRING.
IF YOU ARE IN THE WARNING AREA...LIVING NEAR THE AFFECTED
WATERWAYS...YOU SHOvULD TAKE IMMEDIATE PRECAUTIONS TO PROTECT LIFE AND
PROPERTY.

LAT...LON 4264 9233 4245 9230 4245 9208 4264 9209
JOHNSON
NNNN

The office that day

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

Issued	Product	Office	Counties	Lasted
May 11, 7:21 PM CDT	Tornado Warning	DMX	Black Hawk	29 min
May 11, 7:44 PM CDT	Tornado Warning	DMX	Black Hawk	31 min
May 11, 8:13 PM CDT	Tornado Warning	DMX	Black Hawk	32 min
May 11, 10:51 PM CDT	Severe Thunderstorm Warning	DMX	Boone, Hamilton	29 min

Nearby

Flash Flood Warnings in Iowa, 2000 Every flash flood warning in 2000

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.