Alert archive / Iowa / Flash Flood Warnings in 2004

Flash Flood Warning 10, NWS La Crosse, WI

May 21, 2004Allamakee County, Winneshiek County, Iowa

NWS La Crosse, WI issued this flash flood warning at May 21, 2004, 10:45 PM CDT for Allamakee County, Winneshiek County, Iowa. It was in force for 3 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
May 21, 2004, 10:45 PM CDT (03:45 UTC)
Expired
May 22, 2004, 1:45 AM CDT
In force
3 hr
Issued by
NWS La Crosse, WI
Area
Counties, with a storm outline in the text

Counties Allamakee County, IA, Winneshiek County, IA

The radar

The La Crosse radar (KARX), 76 km from the middle of the area, began a volume at 03:45 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, 3.8 hours before the alert went out and 232 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, Minneapolis, MN at 00:00Z on 2004-05-22Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2 joules per kilogram.LCLEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Minneapolis, MN at 00:00Z on 2004-05-22The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 215 square meters per square second.1939587897Sfc1 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
2 J/kg
Mixed-layer CIN
0 J/kg
Mixed-layer LCL
512 m above ground
0-6 km bulk shear
74 kt
0-1 km storm-relative helicity
215 m²/s²
0-3 km storm-relative helicity
257 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.3

Open this sounding in Storm Lab

The text

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

000 
WGUS53 KARX 220344
FFWARX
IAC005-191-220645-

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE LA CROSSE WI
1045 PM CDT FRI MAY 21 2004

THE NATIONAL WEATHER SERVICE IN LA CROSSE HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  WINNESHIEK COUNTY IN NORTHEAST IOWA
  ALLAMAKEE COUNTY IN NORTHEAST IOWA

* UNTIL 145 AM CDT

* AT 1040 PM CDT...NATIONAL WEATHER SERVICE RADAR DETECTED
  THUNDERSTORMS PRODUCING VERY HEAVY RAIN OVER CONOVER...OR ABOUT    
  9 MILES SOUTHWEST OF DECORAH. NATIONAL WEATHER SERVICE RADAR       
  CONTINUES TO SHOW THUNDERSTORMS WITH VERY HEAVY RAIN MOVING ACROSS  
  THE AREA. ADDITIONAL THUNDERSTORMS CONTINUE TO DEVELOP TO THE     
  WEST. LAW ENFORCEMENT OFFICIALS IN ALLAMAKEE COUNTY REPORTS
  MUDSLIDES ON HIGHWAY 76 IN THE EFFIGY MOUNDS REGION AND ALSO OVER 
  THE GREAT RIVER ROAD IN WAUKON JUNCTION. THE STORMS PRODUCING THE
  VERY HEAVY RAINFALL WERE MOVING EAST AT 40 MPH. THIS WARNING
  EXTENDS THE PREVIOUS FLASH FLOOD WARNING ISSUED FOR WINNESHIEK AND 
  ALLAMAKEE COUNTIES.

* SOME LOCATIONS THAT MAY BE AFFECTED INCLUDE...CALMAR...DECORAH...
  OSSIAN...SPILLVILLE...WAUKON...STATE ROAD 51 AND COUNTY W 48 AND
  COUNTY ROADS X 16 AND W 48.

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

LAT...LON 4315 9204 4312 9136 4343 9129 4343 9188

$$

RABERDING
1 follow-up statement
000 
WGUS73 KARX 220508
FFSARX
IAC005-191-220645-

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE LA CROSSE WI
1208 AM CDT SAT MAY 22 2004

...A FLASH FLOOD WARNING REMAINS IN EFFECT FOR WINNESHIEK AND
ALLAMAKEE COUNTIES UNTIL 145 AM CDT...

AT 1207 AM CDT NATIONAL WEATHER SERVICE RADAR DETECTED THUNDERSTORMS 
PRODUCING VERY HEAVY RAIN ACROSS MUCH OF THE AREA. RAINFALL RATES UP 
TO AN INCH PER HOUR WILL CONTINUE OVER THE WARNED AREA.

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

$$

RABERDING

The office that day

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

IssuedProductOfficeCountiesLasted
May 21, 7:00 PM CDTFlash Flood WarningARXChickasaw, Floyd3 hr
May 21, 7:25 PM CDTSevere Thunderstorm WarningARXClayton35 min
May 21, 7:41 PM CDTFlash Flood WarningARXAllamakee, Winneshiek3 hr
May 21, 8:35 PM CDTFlash Flood WarningARXClayton, Fayette3 hr
May 21, 9:08 PM CDTFlash Flood WarningARXHoward, Mitchell3 hr
May 21, 9:09 PM CDTSevere Thunderstorm WarningARXClayton51 min
May 21, 9:57 PM CDTFlash Flood WarningARXChickasaw, Floyd3 hr
May 21, 11:28 PM CDTFlash Flood WarningARXClayton, Fayette3 hr
May 22, 12:11 AM CDTFlash Flood WarningARXHoward, Mitchell3 hr
May 22, 12:18 AM CDTSevere Thunderstorm WarningARXFloyd57 min
May 22, 12:59 AM CDTFlash Flood WarningARXChickasaw, Floyd3 hr
May 22, 2:07 AM CDTSevere Thunderstorm WarningARXFayette38 min
May 22, 2:16 AM CDTSevere Thunderstorm WarningARXClayton44 min

Nearby

Flash Flood Warnings in Iowa, 2004Every flash flood warning in 2004

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.