Alert archive / Iowa / Severe Thunderstorm Warnings in 2000

Severe Thunderstorm Warning 39, NWS La Crosse, WI

May 18, 2000Clayton County, Iowa

NWS La Crosse, WI issued this severe thunderstorm warning at May 18, 2000, 12:33 PM CDT for Clayton County, Iowa. It was in force for 57 min. 2 reports came from inside the area while it was in force.

The area

The outline the Iowa Environmental Mesonet reconstructed for it; the warning itself named whole counties, with what was reported inside it.

The facts

Issued: May 18, 2000, 12:33 PM CDT (17:33 UTC)
Expired: May 18, 2000, 1:30 PM CDT
In force: 57 min
Issued by: NWS La Crosse, WI
Area: Whole counties; the outline is the Mesonet’s reconstruction

County Clayton County, IA

The radar

The La Crosse radar (KARX), 114 km from the middle of the area, began a volume at 17:35 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
May 18, 12:37 PM CDT	Hail 0.75	Strawberry Pt, IA
May 18, 12:39 PM CDT	Hail 1	Strawberry Pt, IA

NCEI Storm Data entries that began inside the alert's area while it was in force. Before 2003 the local storm report archive is thin, so this is the record of what happened rather than what was phoned in.

The nearest sounding before it

Davenport, (KDVN), launched 12:00Z, 5.6 hours before the alert went out and 154 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: 1779 J/kg
Mixed-layer CIN: -77 J/kg
Mixed-layer LCL: 796 m above ground
0-6 km bulk shear: 59 kt
0-1 km storm-relative helicity: 178 m²/s²
0-3 km storm-relative helicity: 310 m²/s²
Significant tornado parameter: 2.4
Supercell composite: 10.8

Open this sounding in Storm Lab

The text

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

000 
WUUS53 KARX 181734
SVRLSE
IAC043-181830-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE LA CROSSE WI
1233 PM CDT THU MAY 18 2000

THE NATIONAL WEATHER SERVICE IN LA CROSSE HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  CLAYTON COUNTY IN NORTHEAST IOWA

* UNTIL 130 PM CDT

* AT 1233 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM PRODUCING LARGE HAIL 3 MILES NORTHEAST OF
  STRAWBERRY POINT...OR ABOUT 11 MILES SOUTHWEST OF ELKADER. THIS
  ACTIVITY WAS MOVING NORTH AT 20 MPH.

* THE SEVERE THUNDERSTORM WILL BE...
  NEAR MONONA AT 135 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.

BAUMGARDT

LAT...LON 4267 9160 4266 9112 4308 9117 4307 9160
          4276 9158

The office that day

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

Issued	Product	Office	Counties	Lasted
May 18, 5:51 AM CDT	Severe Thunderstorm Warning	ARX	Clayton	39 min
May 18, 6:35 AM CDT	Severe Thunderstorm Warning	ARX	Allamakee	55 min

Nearby

Severe Thunderstorm Warnings in Iowa, 2000 Every severe thunderstorm warning in 2000

Sources

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