Alert archive / Iowa / Flash Flood Warnings in 2017

Flash Flood Warning 16, NWS La Crosse, WI

July 21, 2017Fayette County, Iowa

NWS La Crosse, WI issued this flash flood warning at Jul 21, 2017, 10:18 AM CDT for Fayette County, Iowa. It was in force for 3 hr. 1 report 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
Jul 21, 2017, 10:18 AM CDT (15:18 UTC)
Expired
Jul 21, 2017, 1:15 PM CDT
In force
3 hr
Issued by
NWS La Crosse, WI
Area
Storm-based polygon
Flood severity
None

County Fayette County, IA

The radar

The La Crosse radar (KARX), 119 km from the middle of the area, began a volume at 15:20 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.

What was reported inside it

TimeReportWhereRemark
Jul 21, 11:38 AM CDTFLASH FLOOD6 Nw Westgate, IAWATER OVER THE ROAD.

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, 3.3 hours before the alert went out and 181 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-pSkew-T log-p diagram, Davenport, at 12:00Z on 2017-07-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 81 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Davenport, at 12:00Z on 2017-07-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 125 square meters per square second.1939Sfc1 km3 km6 km9 kmRMLM
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
81 J/kg
Mixed-layer CIN
-302 J/kg
Mixed-layer LCL
1173 m above ground
0-6 km bulk shear
26 kt
0-1 km storm-relative helicity
125 m²/s²
0-3 km storm-relative helicity
192 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

835 
WGUS53 KARX 211518
FFWARX
IAC065-211815-
/O.NEW.KARX.FF.W.0016.170721T1518Z-170721T1815Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service La Crosse WI
1018 AM CDT FRI JUL 21 2017

The National Weather Service in La Crosse has issued a

* Flash Flood Warning for...
  Fayette County in northeastern Iowa...

* Until 115 PM CDT

* At 1016 AM CDT, trained weather spotters reported over three 
  inches of rain in Sumner Iowa with flooded fields and some roads 
  starting to become flooded. Radar shows heavy rain has already 
  fallen across mainly central Fayette County, with more rain to 
  come.

* Some locations that will experience flooding include...
  West Union, Fayette, Elgin, Clermont, Maynard, Hawkeye, Arlington, 
  Waucoma, Wadena, and Westgate.

LAT...LON 4275 9208 4308 9208 4308 9161 4274 9161

$$

Shea
3 follow-up statements
114 
WGUS73 KARX 211608
FFSARX

Flash Flood Statement
National Weather Service La Crosse WI
1108 AM CDT FRI JUL 21 2017

IAC065-211815-
/O.CON.KARX.FF.W.0016.000000T0000Z-170721T1815Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Fayette IA-
1108 AM CDT FRI JUL 21 2017

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 115 PM CDT FOR
FAYETTE COUNTY...

At 1106 AM CDT, Doppler radar continues to show 2 to 4 inches of 
rain has fallen over parts of Fayette County, from Sumner through 
Fayette to Wadena. Law enforcement has not heard of any flooded 
roads to this point but drainage areas are likely experiencing 
flooding.

If you are driving through Fayette County Iowa, use caution and 
never cross flooded sections of roads.

LAT...LON 4275 9208 4308 9208 4308 9161 4274 9161

$$

Shea
410 
WGUS73 KARX 211725
FFSARX

Flash Flood Statement
National Weather Service La Crosse WI
1225 PM CDT FRI JUL 21 2017

IAC065-211815-
/O.CON.KARX.FF.W.0016.000000T0000Z-170721T1815Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Fayette IA-
1225 PM CDT FRI JUL 21 2017

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 115 PM CDT FOR
FAYETTE COUNTY...

At 1219 PM CDT, Doppler radar indicated as much as 2 to locally 5 
inches of rain has fallen across parts of Fayette county. The 
heaviest rain was mainly in the Richfield to east of Sumner to 
Randalia, Fayette and Albany areas. Sharp rises are being reported 
on the Volga river and its tributaries, but so far only water in 
ditches has been reported. 

Some locations that could experience flooding include areas near
Fayette, Wadena, Randalia, Waucoma Campground, Albany, Volga River 
State Park, Richfield and east of Sumner.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4275 9208 4308 9208 4308 9161 4274 9161

$$

RRS
030 
WGUS73 KARX 211808
FFSARX

Flash Flood Statement
National Weather Service La Crosse WI
108 PM CDT FRI JUL 21 2017

IAC065-211817-
/O.EXP.KARX.FF.W.0016.000000T0000Z-170721T1815Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Fayette IA-
108 PM CDT FRI JUL 21 2017

...THE FLASH FLOOD WARNING FOR FAYETTE COUNTY WILL EXPIRE AT 115 PM
CDT...

The heavy rain has ended. Flood waters are receding. Flash flooding 
is no longer expected to pose a threat. Please continue to heed any 
remaining road closures.

LAT...LON 4275 9208 4308 9208 4308 9161 4274 9161

$$

RRS

The office that day

Everything else NWS La Crosse, WI issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jul 21, 9:22 AM CDTFlash Flood WarningARXHoward3 hr
Jul 21, 10:45 AM CDTFlash Flood WarningARXChickasaw3 hr
Jul 21, 5:08 PM CDTSevere Thunderstorm WarningARXClayton35 min
Jul 21, 5:57 PM CDTSevere Thunderstorm WarningARXClayton, Fayette48 min
Jul 21, 6:20 PM CDTSevere Thunderstorm WarningARXFayette25 min
Jul 21, 6:45 PM CDTSpecial Weather StatementARXClayton60 min
Jul 21, 6:54 PM CDTFlash Flood WarningARXClayton15 hr

Nearby

Flash Flood Warnings in Iowa, 2017Every 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.