Alert archive / Iowa / Flash Flood Warnings in 2010

Flash Flood Warning 21, NWS La Crosse, WI

July 24, 2010Fayette County, Iowa

NWS La Crosse, WI issued this flash flood warning at Jul 24, 2010, 2:22 AM CDT for Fayette County, Iowa. It was in force for 5 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
Jul 24, 2010, 2:22 AM CDT (07:22 UTC)
Expired
Jul 24, 2010, 7:30 AM CDT
In force
5 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), 125 km from the middle of the area, began a volume at 07:24 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, 7.4 hours before the alert went out and 176 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 00:00Z on 2010-07-24Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2120 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 00:00Z on 2010-07-24The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 193 square meters per square second.193958Sfc1 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
2120 J/kg
Mixed-layer CIN
-86 J/kg
Mixed-layer LCL
1074 m above ground
0-6 km bulk shear
37 kt
0-1 km storm-relative helicity
193 m²/s²
0-3 km storm-relative helicity
216 m²/s²
Significant tornado parameter
0.3
Supercell composite
4.2

Open this sounding in Storm Lab

The text

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

519 
WGUS53 KARX 240722
FFWARX
IAC065-241230-
/O.NEW.KARX.FF.W.0021.100724T0722Z-100724T1230Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE LA CROSSE WI
222 AM CDT SAT JUL 24 2010

THE NATIONAL WEATHER SERVICE IN LA CROSSE HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  FAYETTE COUNTY IN NORTHEAST IOWA...

* UNTIL 730 AM CDT

* AT 220 AM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  THUNDERSTORMS WITH VERY HEAVY RAINFALL ACROSS THE COUNTY. RADAR
  ESTIMATES THAT 2 TO 3 INCHES OF RAIN HAS ALREADY FALLEN...AND
  ANOTHER INCH OR SO IS EXPECTED BEFORE THE RAIN ENDS OVERNIGHT. 

* RUNOFF FROM THIS EXCESSIVE RAINFALL WILL CAUSE FLASH FLOODING TO
  OCCUR. SOME LOCATIONS THAT WILL EXPERIENCE FLOODING INCLUDE...
  OELWEIN...WEST UNION...ARLINGTON...CLERMONT...ELGIN...FAYETTE...
  HAWKEYE...MAYNARD AND WAUCOMA.

* THIS WARNING EXTENDS THE PREVIOUS FLASH FLOOD WARNING FOR FAYETTE
  COUNTY. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

BE ESPECIALLY CAUTIOUS AT NIGHT WHEN IT IS HARDER TO RECOGNIZE THE
DANGERS OF FLOODING. IF FLASH FLOODING IS OBSERVED ACT QUICKLY. DO
NOT ENTER THE WATER. TURN AROUND AND MOVE UP TO HIGHER GROUND TO
ESCAPE FLOOD WATERS. DO NOT STAY IN AREAS SUBJECT TO FLOODING WHEN
WATER BEGINS RISING.

DO NOT UNDERESTIMATE THE POWER OF FLOOD WATERS. ONLY A FEW INCHES OF
RAPIDLY FLOWING WATER CAN QUICKLY CARRY AWAY YOUR VEHICLE. TURN
AROUND... DONT DROWN.

&&

LAT...LON 4264 9208 4308 9208 4309 9161 4264 9162

$$

MW
1 follow-up statement
684 
WGUS73 KARX 241223
FFSARX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE LA CROSSE WI
ISSUED BY NATIONAL WEATHER SERVICE DES MOINES IA
723 AM CDT SAT JUL 24 2010

IAC065-241237-
/O.EXP.KARX.FF.W.0021.000000T0000Z-100724T1230Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
FAYETTE IA-
723 AM CDT SAT JUL 24 2010

...THE FLASH FLOOD WARNING THAT WAS IN EFFECT FOR FAYETTE COUNTY WILL
BE ALLOWED TO EXPIRE AT 730 AM CDT...

THE FLASH FLOOD WARNING HAS BEEN REPLACED BY AN AREAL FLOOD WARNING 
IN EFFECT UNTIL SUNDAY MORNING. IF FLOODING HAS BEEN 
OBSERVED...PLEASE REPORT IT TO YOUR LOCAL LAW ENFORCEMENT AGENCY.

LAT...LON 4264 9208 4308 9208 4309 9161 4264 9162

$$

DONAVON

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 23, 11:08 PM CDTFlash Flood WarningARXClayton3 hr
Jul 23, 11:27 PM CDTFlash Flood WarningARXFayette3 hr
Jul 24, 1:27 AM CDTFlash Flood WarningARXChickasaw, Floyd5 hr
Jul 24, 1:59 AM CDTFlash Flood WarningARXClayton6 hr
Jul 24, 7:21 AM CDTAreal Flood WarningARXClayton, Fayette7 hr

Nearby

Flash Flood Warnings in Iowa, 2010Every flash flood warning in 2010

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.