Alert archive / Iowa / Severe Thunderstorm Warnings in 2003

Severe Thunderstorm Warning 72, NWS La Crosse, WI

July 31, 2003Chickasaw County, Floyd County, Iowa

NWS La Crosse, WI issued this severe thunderstorm warning at Jul 31, 2003, 9:00 PM CDT for Chickasaw County, Floyd County, Iowa. It was in force for 75 min. 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 31, 2003, 9:00 PM CDT (02:00 UTC)
Expired: Jul 31, 2003, 10:15 PM CDT
In force: 75 min
Issued by: NWS La Crosse, WI
Area: Counties, with a storm outline in the text

Counties Chickasaw County, IA, Floyd County, IA

The radar

The La Crosse radar (KARX), 129 km from the middle of the area, began a volume at 02:00 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 watch it was issued in

The SPC watch in force over the same counties when this warning went out.

Issued	Product	Office	Lasted
Jul 31, 5:40 PM CDT	Severe Thunderstorm Watch	SPC	5 hr

The nearest sounding before it

Minneapolis, MN (KMPX), launched 00:00Z, 2.0 hours before the alert went out and 217 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: 992 J/kg
Mixed-layer CIN: -7 J/kg
Mixed-layer LCL: 1397 m above ground
0-6 km bulk shear: 37 kt
0-1 km storm-relative helicity: 4 m²/s²
0-3 km storm-relative helicity: 50 m²/s²
Significant tornado parameter: 0.1
Supercell composite: 1.6

Open this sounding in Storm Lab

The text

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

665 
WUUS53 KARX 010200
SVRARX
IAC037-067-010315-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE LA CROSSE WI
900 PM CDT THU JUL 31 2003

THE NATIONAL WEATHER SERVICE IN LA CROSSE HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  FLOYD COUNTY IN NORTH CENTRAL IOWA
  CHICKASAW COUNTY IN NORTHEAST IOWA

* UNTIL 1015 PM CDT

* AT 859 PM CDT...NATIONAL WEATHER SERVICE RADAR DETECTED 
  SEVERAL SEVERE THUNDERSTORMS WITH LARGE HAIL FROM 10 MILES
  NORTHEAST OF CHARLES CITY...TO 15 MILES NORTH OF NEW HAMPTON.
  THESE STORMS WERE MOVING SOUTHEAST AT 15 MPH.

* THE SEVERE THUNDERSTORM IS EXPECTED TO BE...
  NEAR NORTH WASHINGTON...AND DEVON AT 910 PM CDT...
  NEAR IONIA...AND SAUDE AT 930 PM CDT...
  NEAR NASHUA AT 935 PM CDT...
  NEAR NEW HAMPTON AT 940 PM CDT...
  NEAR REPUBLIC AT 950 PM CDT...

LARGE DESTRUCTIVE HAIL IS THE MAIN THREAT WITH THESE STORMS. FOR YOUR
PROTECTION...SEEK SHELTER IN A STURDY BUILDING AND STAY AWAY FROM
WINDOWS.

LAT...LON 4322 9248 4321 9275 4293 9270 4292 9237
          4292 9210 4321 9209

$$

SHEA

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 31, 7:23 PM CDT	Severe Thunderstorm Warning	ARX	Howard, Winneshiek	52 min
Jul 31, 8:22 PM CDT	Severe Thunderstorm Warning	ARX	Winneshiek	53 min

Nearby

Severe Thunderstorm Warnings in Iowa, 2003 Every severe thunderstorm warning in 2003

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.