Alert archive / Iowa / Flash Flood Warnings in 2016

Flash Flood Warning 30, NWS Des Moines, IA

September 21, 2016Butler County, Iowa

NWS Des Moines, IA issued this flash flood warning at Sep 21, 2016, 6:58 PM CDT for Butler County, Iowa. It was in force for 12 hr. 4 reports came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued: Sep 21, 2016, 6:58 PM CDT (23:58 UTC)
Expired: Sep 22, 2016, 7:00 AM CDT
In force: 12 hr
Issued by: NWS Des Moines, IA
Area: Storm-based polygon
Flood severity: None

County Butler County, IA

The radar

The Des Moines radar (KDMX), 146 km from the middle of the area, began a volume at 00:01 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.

What was reported inside it

Time	Report	Where	Remark
Sep 21, 10:40 PM CDT	FLASH FLOOD	Greene, IA	MANY ROADS CLOSED THROUGHOUT THE NORTHERN FOURTH OF BUTLER COUNTY. SHELL ROCK RIVER BEGINNING TO LEAVE ITS BANKS AND MOVING TOWARD BUSINESS IN DOWNTOWN GREENE. SANDBAGGING GOING ON IN GREENE AND CLARKSVILLE. .
Sep 21, 10:47 PM CDT	HEAVY RAIN 7.5	Greene, IA	STORM TOTAL.
Sep 22, 1:47 AM CDT	FLASH FLOOD	Greene, IA	MULTIPLE HOMES IN GREENE NOW BEING IMPACTED BY FLOODWATERS FROM THE RAPIDLY RISING SHELL ROCK RIVER. EM ESTIMATES THAT THE RIVER IS NEAR THE LEVEL IT REACHED IN 2008.
Sep 22, 5:00 AM CDT	FLASH FLOOD	Greene, IA	EVACUATIONS OCCURRING IN GREENE FROM FLASH FLOODING. .

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Davenport, (KDVN), launched 12:00Z, 12.0 hours before the alert went out and 231 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: 3354 J/kg
Mixed-layer CIN: -30 J/kg
Mixed-layer LCL: 946 m above ground
0-6 km bulk shear: 22 kt
0-1 km storm-relative helicity: 72 m²/s²
0-3 km storm-relative helicity: 84 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 3.4

Open this sounding in Storm Lab

The text

As transmitted.

907 
WGUS53 KDMX 212358
FFWDMX
IAC023-220600-
/O.NEW.KDMX.FF.W.0030.160921T2358Z-160922T0600Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE DES MOINES IA
658 PM CDT WED SEP 21 2016

THE NATIONAL WEATHER SERVICE IN DES MOINES  HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  NORTHERN BUTLER COUNTY IN NORTH CENTRAL IOWA...

* UNTIL 100 AM CDT THURSDAY.

* AT 655 PM CDT...DOPPLER RADAR INDICATED THUNDERSTORMS PRODUCING
  HEAVY RAIN ACROSS FLOYD AND FAR NORTHERN BUTLER COUNTIES. UP TO
  THREE INCHES OF RAIN HAVE ALREADY FALLEN. FLASH FLOODING IS
  EXPECTED TO BEGIN SHORTLY. THE SHELL ROCK RIVER WILL ALSO RISE
  VERY QUICKLY IN THE GREENE AREA THIS EVENING AND MAY FLOOD AREAS
  OF TOWN IN A VERY SHORT AMOUNT OF TIME.

* SOME LOCATIONS THAT WILL EXPERIENCE FLOODING INCLUDE...
  CLARKSVILLE AND GREENE. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

EXCESSIVE RUNOFF FROM HEAVY RAINFALL WILL CAUSE FLOODING OF SMALL
CREEKS AND STREAMS...COUNTRY ROADS...FARMLAND...AND OTHER LOW LYING
SPOTS.

&&

LAT...LON 4274 9256 4284 9292 4290 9301 4291 9299
      4291 9256

$$

SKOW

4 follow-up statements

103 
WGUS73 KDMX 220413
FFSDMX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE DES MOINES IA
1113 PM CDT WED SEP 21 2016

IAC023-220600-
/O.CON.KDMX.FF.W.0030.000000T0000Z-160922T0600Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BUTLER IA-
1113 PM CDT WED SEP 21 2016

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 100 AM CDT FOR
NORTHERN BUTLER COUNTY...

AT 1106 PM CDT...WHILE HEAVY RAIN HAS ENDED ACROSS THE WARNED
AREA...THE THREAT FOR FLASH FLOODING CONTINUES. UPWARDS OF SEVEN TO
TEN INCHES OF RAIN OR MORE IS ESTIMATED TO HAVE FALLEN IN NORTHERN
BUTLER AND FLOYD COUNTY IN A VERY SHORT AMOUNT OF TIME. THIS WILL
LEAD TO EXTREMELY RAPID RISES ALONG THE SHELL ROCK RIVER AND ITS
TRIBUTARIES. THE SHELL ROCK RIVER HAS RISEN ALMOST FIVE FEET IN SIX
HOURS AT MARBLE ROCK AND THE RIVER SHOULD CONTINUE TO RISE THROUGH
THE NIGHT. ADDITIONAL HEAVY RAINFALL IS ALSO FORECAST TONIGHT WHICH
MAY EXACERBATE THE FLOODING CONDITIONS.

SOME LOCATIONS THAT WILL EXPERIENCE FLOODING INCLUDE...
CLARKSVILLE AND GREENE. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

BE ESPECIALLY CAUTIOUS AT NIGHT WHEN IT IS HARDER TO RECOGNIZE THE
DANGERS OF FLOODING.

EXCESSIVE RUNOFF FROM HEAVY RAINFALL WILL CAUSE FLOODING OF SMALL
CREEKS AND STREAMS...COUNTRY ROADS...FARMLAND...AND OTHER LOW LYING
SPOTS.

&&

LAT...LON 4274 9256 4284 9292 4290 9301 4291 9299
      4291 9256

$$

SKOW

907 
WGUS53 KDMX 220541
FFWDMX
IAC023-221200-
/O.EXT.KDMX.FF.W.0030.000000T0000Z-160922T1200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE DES MOINES IA
1241 AM CDT THU SEP 22 2016

THE NATIONAL WEATHER SERVICE IN DES MOINES  HAS EXTENDED THE

* FLASH FLOOD WARNING FOR...
  NORTHERN BUTLER COUNTY IN NORTH CENTRAL IOWA...

* UNTIL 700 AM CDT THURSDAY.

* AT 1240 AM CDT...WHILE HEAVY RAIN HAS ENDED FOR NOW ACROSS THE
  WARNED AREA...THE THREAT FOR FLASH FLOODING CONTINUES. SEVEN TO
  TEN INCHES OF RAIN WITH LOCALLY HIGHER AMOUNTS FELL IN NORTHERN
  BUTLER AND FLOYD COUNTIES IN A VERY SHORT AMOUNT OF TIME ON
  WEDNESDAY EVENING. THIS IS LEADING TO VERY RAPID RISES ALONG THE
  SHELL ROCK RIVER AND ITS TRIBUTARIES. THE SHELL ROCK RIVER HAS
  RISEN ALMOST SIX FEET IN SEVEN HOURS AT MARBLE ROCK AND THE RIVER
  SHOULD CONTINUE TO RISE THROUGH THE NIGHT. ADDITIONAL HEAVY
  RAINFALL IS ALSO FORECAST TONIGHT WHICH WOULD EXACERBATE THE
  FLOODING CONDITIONS.

* SOME LOCATIONS THAT WILL EXPERIENCE FLOODING INCLUDE...
  CLARKSVILLE AND GREENE. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

BE ESPECIALLY CAUTIOUS AT NIGHT WHEN IT IS HARDER TO RECOGNIZE THE
DANGERS OF FLOODING.

EXCESSIVE RUNOFF FROM HEAVY RAINFALL WILL CAUSE FLOODING OF SMALL
CREEKS AND STREAMS...COUNTRY ROADS...FARMLAND...AND OTHER LOW LYING
SPOTS.

&&

LAT...LON 4274 9256 4284 9292 4290 9301 4291 9299
      4291 9256

$$

SKOW

503 
WGUS73 KDMX 220725
FFSDMX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE DES MOINES IA
225 AM CDT THU SEP 22 2016

IAC023-221200-
/O.CON.KDMX.FF.W.0030.000000T0000Z-160922T1200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BUTLER IA-
225 AM CDT THU SEP 22 2016

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 700 AM CDT FOR
NORTHERN BUTLER COUNTY...

AT 221 AM CDT...EMERGENCY MANAGEMENT REPORTED FLASH FLOODING IN THE
TOWN OF GREENE DUE TO VERY RAPID RISES ON THE SHELL ROCK RIVER.
MULTIPLE HOMES ARE BEING IMPACTED BY THE FLOODWATERS. THE EMERGENCY
MANAGER REPORTS THAT WATER LEVELS IN THE TOWN OF GREENE ARE NEAR
THOSE SEEN DURING THE 2008 FLOODS. A TOTAL OF SEVEN TO TEN INCHES OF
RAIN FELL IN FLOYD AND NORTHERN BUTLER COUNTIES LAST EVENING. THE
RESULTANT FLOODWATERS AND ADDITIONAL HEAVY RAIN OCCURRING AT THE
PRESENT TIME WILL RESULT IN A CONTINUED FLASH FLOOD THREAT WELL INTO
THE MORNING TODAY. 

SOME LOCATIONS THAT WILL EXPERIENCE FLOODING INCLUDE...
CLARKSVILLE AND GREENE. 

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 4274 9256 4284 9292 4290 9301 4291 9299
      4291 9256

$$

SKOW

684 
WGUS73 KDMX 220933
FFSDMX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE DES MOINES IA
433 AM CDT THU SEP 22 2016

IAC023-221200-
/O.CON.KDMX.FF.W.0030.000000T0000Z-160922T1200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BUTLER IA-
433 AM CDT THU SEP 22 2016

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 700 AM CDT FOR
NORTHERN BUTLER COUNTY...

AT 432 AM CDT...ANOTHER ROUND OF HEAVY RAIN IS EXPECTED TO MOVE
ACROSS THE WARNED AREA THROUGH 6 AM.  ANOTHER ONE TO THREE
INCHES OF RAIN WILL BE POSSIBLE ON TOP OF THE HEAVY RAIN THAT
FELL LAST EVENING.  THIS WILL EXACERBATE ANY FLOODING THAT IS
OCCURRING.  

SOME LOCATIONS THAT WILL EXPERIENCE FLOODING INCLUDE...
CLARKSVILLE AND GREENE. 

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 4274 9256 4284 9292 4290 9301 4291 9299
      4291 9256

$$

COGIL

The office that day

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

Issued	Product	Office	Counties	Lasted
Sep 21, 3:26 PM CDT	Special Weather Statement	DMX	Cerro Gordo	49 min
Sep 21, 3:32 PM CDT	Severe Thunderstorm Warning	DMX	Cerro Gordo	43 min
Sep 21, 4:23 PM CDT	Severe Thunderstorm Warning	DMX	Cerro Gordo	37 min
Sep 21, 4:50 PM CDT	Flash Flood Warning	DMX	Cerro Gordo	6 hr
Sep 21, 4:57 PM CDT	Severe Thunderstorm Warning	DMX	Cerro Gordo	31 min
Sep 21, 5:13 PM CDT	Severe Thunderstorm Warning	DMX	Butler, Franklin	47 min
Sep 21, 5:19 PM CDT	Tornado Warning	DMX	Butler	56 min
Sep 21, 5:45 PM CDT	Severe Thunderstorm Warning	DMX	Cerro Gordo, Worth	45 min
Sep 21, 6:17 PM CDT	Tornado Warning	DMX	Butler	43 min
Sep 21, 6:33 PM CDT	Flash Flood Warning	DMX	Cerro Gordo, Worth	6 hr
Sep 21, 6:44 PM CDT	Severe Thunderstorm Warning	DMX	Cerro Gordo	46 min
Sep 21, 6:59 PM CDT	Tornado Warning	DMX	Bremer, Butler	46 min

Nearby

Flash Flood Warnings in Iowa, 2016 Every flash flood warning in 2016

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.