Alert archive / Iowa / Severe Thunderstorm Warnings in 2000

Severe Thunderstorm Warning 9, NWS Quad Cities, IA

April 20, 2000Lee County, Iowa

NWS Quad Cities, IA issued this severe thunderstorm warning at Apr 20, 2000, 12:21 AM CDT for Lee County, Iowa. It was in force for 24 min. 1 report came from inside the area while it was in force.

The area

The counties it named, with what was reported inside it.

The facts

Issued: Apr 20, 2000, 12:21 AM CDT (05:21 UTC)
Expired: Apr 20, 2000, 12:45 AM CDT
In force: 24 min
Issued by: NWS Quad Cities, IA
Area: Whole counties

County Lee County, IA

The radar

The Quad Cities radar (KDVN), 131 km from the middle of the area, began a volume at 05:24 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.

What was reported inside it

Time	Report	Where	Remark
Apr 20, 12:30 AM CDT	Hail 1	Denmark, IA	1 inch hail reported by law enforcement official.

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 watch it was issued in

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

Issued	Product	Office	Lasted
Apr 19, 8:45 PM CDT	Severe Thunderstorm Watch	SPC	4 hr

The nearest sounding before it

Davenport, (KDVN), launched 00:00Z, 5.4 hours before the alert went out and 136 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: 4 J/kg
Mixed-layer CIN: -616 J/kg
Mixed-layer LCL: 865 m above ground
0-6 km bulk shear: 66 kt
0-1 km storm-relative helicity: 471 m²/s²
0-3 km storm-relative helicity: 491 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.1

Open this sounding in Storm Lab

The text

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

000 
WUUS53 KDVN 200522
SVRMLI
IAC111-200600-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
1221 AM CDT THU APR 20 2000

THE NATIONAL WEATHER SERVICE IN THE QUAD CITIES HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  LEE COUNTY IN SOUTHEAST IOWA

* UNTIL 1245 AM CDT

* AT 1220 AM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM WITH LARGE HAIL AND DAMAGING WINDS 3 MILES WEST
  OF DENMARK...OR 9 MILES NORTH OF FORT MADISON...MOVING NORTHEAST AT
  40 MPH.

* THE SEVERE THUNDERSTORM IS EXPECTED TO BE NEAR...  
   WEST POINT...NOW
   SAWYER BY 1225 AM CDT.
   SOUTH AUGUSTA BY 1225 AM CDT.
   DENMARK BY 1230 AM CDT.

THIS SEVERE THUNDERSTORM IS CAPABLE OF PRODUCING HAIL UP TO 1 INCH IN
DIAMETER AND WINDS IN EXCESS OF 55 MPH. TAKE COVER IN A STURDY
STRUCTURE UNTIL THE STORM PASSES.

REPORT SEVERE WEATHER TO THE NEAREST LAW ENFORCEMENT AGENCY. THEY
WILL RELAY YOUR REPORT TO THE NATIONAL WEATHER SERVICE FORECAST
OFFICE IN THE QUAD CITIES.

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 100 AM CDT
THURSDAY MORNING FOR EASTERN IOWA AND NORTHWEST ILLINOIS.

LAT...L[ON 4078 9153 4064 9138 4070 9115 4081 9135

MCCLURE

The office that day

Everything else NWS Quad Cities, IA issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Apr 19, 8:19 PM CDT	Severe Thunderstorm Warning	DVN	Benton, Buchanan	41 min
Apr 19, 9:03 PM CDT	Severe Thunderstorm Warning	DVN	Buchanan	42 min
Apr 19, 11:20 PM CDT	Severe Thunderstorm Warning	DVN	Muscatine	40 min
Apr 20, 12:32 AM CDT	Severe Thunderstorm Warning	DVN	Des Moines	43 min
Apr 20, 4:46 AM CDT	Severe Thunderstorm Warning	DVN	Louisa	44 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.