Alert archive / Iowa / Flash Flood Warnings in 2017

Flash Flood Warning 3, NWS Des Moines, IA

June 29, 2017Franklin County, Iowa

NWS Des Moines, IA issued this flash flood warning at Jun 29, 2017, 9:40 PM CDT for Franklin 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 outline as issued.

The facts

Issued: Jun 29, 2017, 9:40 PM CDT (02:40 UTC)
Expired: Jun 30, 2017, 3:45 AM CDT
In force: 6 hr
Issued by: NWS Des Moines, IA
Area: Storm-based polygon
Flood severity: None

County Franklin County, IA

The radar

The Des Moines radar (KDMX), 116 km from the middle of the area, began a volume at 02:41 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

Minneapolis, MN (KMPX), launched 00:00Z, 2.7 hours before the alert went out and 240 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: 111 J/kg
Mixed-layer CIN: -211 J/kg
Mixed-layer LCL: 1070 m above ground
0-6 km bulk shear: 36 kt
0-1 km storm-relative helicity: -100 m²/s²
0-3 km storm-relative helicity: 8 m²/s²
Significant tornado parameter: 0.0
Supercell composite: -0.7

Open this sounding in Storm Lab

The text

As transmitted.

923 
WGUS53 KDMX 300240
FFWDMX
IAC069-300845-
/O.NEW.KDMX.FF.W.0003.170630T0240Z-170630T0845Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Des Moines IA
940 PM CDT THU JUN 29 2017

The National Weather Service in Des Moines  has issued a

* Flash Flood Warning for...
  Franklin County in north central Iowa...

* Until 345 AM CDT Friday.

* At 939 PM CDT, emergency management reported heavy rain across the 
  warned area. Flash flooding is already occurring. Radar estimates 
  that as much as 3.5 to 4.5 inches of rain has fallen across the 
  warned area.

* Some locations that will experience flooding include...
  Hampton, Sheffield, Dows, Latimer, Coulter, Meservey, Alexander,
  Geneva, Bradford, Hansell, Chapin, Popejoy, Beeds Lake State Park
  and Hampton Municipal Airport.

This includes Interstate 35 between mile markers 155 and 177.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.

Be especially cautious at night when it is harder to recognize the
dangers of flooding.

&&

LAT...LON 4268 9303 4267 9322 4256 9324 4256 9350
      4291 9350 4291 9303

$$

Zogg

2 follow-up statements

877 
WGUS73 KDMX 300644
FFSDMX

Flash Flood Statement
National Weather Service Des Moines IA
144 AM CDT FRI JUN 30 2017

IAC069-300845-
/O.CON.KDMX.FF.W.0003.000000T0000Z-170630T0845Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Franklin IA-
144 AM CDT FRI JUN 30 2017

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 345 AM CDT FOR
FRANKLIN COUNTY...

At 142 AM CDT, Doppler radar indicated a few thunderstorms across 
the warned area.  Flash flooding occurred earlier but conditions are 
improving.  The additional storms may produce a brief rise in water 
levels in isolated areas, however a continued general improvement 
in conditions are expected early this morning. 
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.

Be especially cautious at night when it is harder to recognize the
dangers of flooding.

&&

LAT...LON 4268 9303 4267 9322 4256 9324 4256 9350
      4291 9350 4291 9303

$$

Cogil

663 
WGUS73 KDMX 300846
FFSDMX

Flash Flood Statement
National Weather Service Des Moines IA
346 AM CDT FRI JUN 30 2017

IAC069-300855-
/O.EXP.KDMX.FF.W.0003.000000T0000Z-170630T0845Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Franklin IA-
346 AM CDT FRI JUN 30 2017

...THE FLASH FLOOD WARNING FOR FRANKLIN COUNTY HAS EXPIRED...

Flooding is no longer expected to pose a threat. Please continue to 
heed any remaining road closures.

LAT...LON 4268 9303 4267 9322 4256 9324 4256 9350
      4291 9350 4291 9303

$$

Cogil

The office that day

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

Issued	Product	Office	Counties	Lasted
Jun 29, 7:03 PM CDT	Severe Thunderstorm Warning	DMX	Franklin, Wright	42 min
Jun 29, 7:05 PM CDT	Severe Thunderstorm Warning	DMX	Carroll, Crawford	40 min
Jun 29, 7:31 PM CDT	Severe Thunderstorm Warning	DMX	Carroll	44 min
Jun 29, 7:55 PM CDT	Special Weather Statement	DMX	Webster	35 min
Jun 29, 8:54 PM CDT	Severe Thunderstorm Warning	DMX	Grundy, Hamilton, Hardin, Marshall, Story	36 min
Jun 29, 9:02 PM CDT	Severe Thunderstorm Warning	DMX	Butler, Franklin	28 min
Jun 29, 9:16 PM CDT	Severe Thunderstorm Warning	DMX	Cerro Gordo, Worth	29 min
Jun 29, 9:23 PM CDT	Severe Thunderstorm Warning	DMX	Jasper, Marshall, Story, Tama	22 min
Jun 29, 9:42 PM CDT	Severe Thunderstorm Warning	DMX	Jasper, Marshall, Poweshiek, Tama	33 min
Jun 29, 9:47 PM CDT	Severe Thunderstorm Warning	DMX	Black Hawk, Bremer	28 min
Jun 29, 9:50 PM CDT	Severe Thunderstorm Warning	DMX	Tama	25 min

Nearby

Flash Flood Warnings in Iowa, 2017 Every flash flood warning in 2017

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.