Alert archive / Iowa / Flash Flood Warnings in 2015

Flash Flood Warning 4, NWS Des Moines, IA

June 20, 2015Mahaska County, Iowa

NWS Des Moines, IA issued this flash flood warning at Jun 20, 2015, 5:41 PM CDT for Mahaska 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 20, 2015, 5:41 PM CDT (22:41 UTC)
Expired: Jun 20, 2015, 11:45 PM CDT
In force: 6 hr
Issued by: NWS Des Moines, IA
Area: Storm-based polygon
Flood severity: None

County Mahaska County, IA

The radar

The Des Moines radar (KDMX), 104 km from the middle of the area, began a volume at 22:44 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 12:00Z, 10.7 hours before the alert went out and 180 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 769 m above ground
0-6 km bulk shear: 33 kt
0-1 km storm-relative helicity: 29 m²/s²
0-3 km storm-relative helicity: 77 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

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

319 
WGUS53 KDMX 202241
FFWDMX
IAC123-210445-
/O.NEW.KDMX.FF.W.0004.150620T2241Z-150621T0445Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE DES MOINES IA
541 PM CDT SAT JUN 20 2015

THE NATIONAL WEATHER SERVICE IN DES MOINES  HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  MAHASKA COUNTY IN SOUTH CENTRAL IOWA...

* UNTIL 1145 PM CDT SATURDAY
    
* AT 540 PM CDT...DOPPLER RADAR INDICATED A THUNDERSTORM PRODUCING
  HEAVY RAIN ACROSS THE WARNED AREA. UP TO THREE INCHES OF RAIN HAVE
  ALREADY FALLEN. FLASH FLOODING IS EXPECTED TO BEGIN SHORTLY.

* SOME LOCATIONS THAT WILL EXPERIENCE FLOODING INCLUDE...
  OSKALOOSA...NEW SHARON...FREMONT...BEACON...UNIVERSITY PARK...ROSE
  HILL...LEIGHTON...KEOMAH VILLAGE...OSKALOOSA MUNICIPAL AIRPORT AND
  LAKE KEOMAH STATE PARK.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

MOVE TO HIGHER GROUND NOW. ACT QUICKLY TO PROTECT YOUR LIFE.

TURN AROUND...DONT DROWN WHEN ENCOUNTERING FLOODED ROADS. MOST FLOOD
DEATHS OCCUR IN VEHICLES.

&&

LAT...LON 4116 9247 4121 9287 4151 9287 4151 9280
      4145 9241 4116 9241

$$

DONAVON

2 follow-up statements

687 
WGUS73 KDMX 210001
FFSDMX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE DES MOINES IA
701 PM CDT SAT JUN 20 2015

IAC123-210445-
/O.CON.KDMX.FF.W.0004.000000T0000Z-150621T0445Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
MAHASKA IA-
701 PM CDT SAT JUN 20 2015

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 1145 PM CDT
SATURDAY FOR MAHASKA COUNTY...

AT 659 PM CDT...THUNDERSTORMS ARE BEGINNING TO END ACROSS THE AREA 
HOWEVER RUNOFF FROM THUNDERSTORMS THAT PRODUCED HEAVY RAIN ACROSS 
THE WARNED AREA EARLIER WILL CONTINUE. TWO TO FOUR INCHES OF RAIN 
HAVE ALREADY FALLEN ACROSS THE AREA. FLASH FLOODING IS EXPECTED TO 
BEGIN SHORTLY.

SOME LOCATIONS THAT WILL EXPERIENCE FLOODING INCLUDE...
OSKALOOSA...NEW SHARON...FREMONT...BEACON...UNIVERSITY PARK...ROSE
HILL...LEIGHTON...KEOMAH VILLAGE...OSKALOOSA MUNICIPAL AIRPORT AND
LAKE KEOMAH STATE PARK.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

MOVE TO HIGHER GROUND NOW. ACT QUICKLY TO PROTECT YOUR LIFE.

TURN AROUND...DONT DROWN WHEN ENCOUNTERING FLOODED ROADS. MOST FLOOD
DEATHS OCCUR IN VEHICLES.

&&

LAT...LON 4116 9247 4121 9287 4151 9287 4151 9280
      4145 9241 4116 9241

$$

DONAVON

143 
WGUS73 KDMX 210217
FFSDMX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE DES MOINES IA
917 PM CDT SAT JUN 20 2015

IAC123-210227-
/O.CAN.KDMX.FF.W.0004.000000T0000Z-150621T0445Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
MAHASKA IA-
917 PM CDT SAT JUN 20 2015

...THE FLASH FLOOD WARNING FOR MAHASKA COUNTY IS CANCELLED...

THE HEAVY RAIN HAS ENDED...AND FLOODING IS NO LONGER EXPECTED TO POSE
A THREAT.

LAT...LON 4116 9247 4121 9287 4151 9287 4151 9280
      4145 9241 4116 9241

$$

DONAVON

The office that day

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

Issued	Product	Office	Counties	Lasted
Jun 20, 8:48 AM CDT	Special Weather Statement	DMX	Butler, Franklin, Wright	57 min
Jun 20, 8:55 AM CDT	Special Weather Statement	DMX	Poweshiek, Tama	50 min
Jun 20, 10:25 AM CDT	Special Weather Statement	DMX	Tama	20 min
Jun 20, 4:48 PM CDT	Severe Thunderstorm Warning	DMX	Jasper, Mahaska, Marion, Poweshiek	42 min
Jun 20, 5:13 PM CDT	Severe Thunderstorm Warning	DMX	Poweshiek, Tama	32 min
Jun 20, 5:18 PM CDT	Severe Thunderstorm Warning	DMX	Mahaska, Marion	57 min
Jun 20, 5:45 PM CDT	Severe Thunderstorm Warning	DMX	Lucas, Mahaska, Marion, Monroe, Wapello	45 min
Jun 20, 6:18 PM CDT	Severe Thunderstorm Warning	DMX	Appanoose, Davis, Monroe, Wapello	42 min
Jun 20, 6:57 PM CDT	Flash Flood Warning	DMX	Davis, Monroe, Wapello	6 hr
Jun 20, 6:57 PM CDT	Severe Thunderstorm Warning	DMX	Appanoose	48 min

Nearby

Flash Flood Warnings in Iowa, 2015 Every flash flood warning in 2015

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.