Alert archive / Iowa / Tornado Warnings in 2001

Tornado Warning 22, NWS Omaha, NE

April 30, 2001Monona County, Iowa

NWS Omaha, NE issued this tornado warning at Apr 30, 2001, 8:07 PM CDT for Monona County, Iowa. It was in force for 23 min. 1 report 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: Apr 30, 2001, 8:07 PM CDT (01:07 UTC)
Expired: Apr 30, 2001, 8:30 PM CDT
In force: 23 min
Issued by: NWS Omaha, NE
Area: Whole counties; the outline is the Mesonet’s reconstruction

County Monona County, IA

The radar

The Omaha radar (KOAX), 99 km from the middle of the area, began a volume at 01:09 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 30, 8:14 PM CDT	Hail 1.75	Whiting, 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

Omaha, NE (KOAX), launched 00:00Z, 1.1 hours before the alert went out and 99 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: 1160 J/kg
Mixed-layer CIN: -37 J/kg
Mixed-layer LCL: 1364 m above ground
0-6 km bulk shear: 34 kt
0-1 km storm-relative helicity: 142 m²/s²
0-3 km storm-relative helicity: 241 m²/s²
Significant tornado parameter: 0.7
Supercell composite: 5.3

Open this sounding in Storm Lab

The text

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

000 
WFUS53 KOAX 010107
TOROMA
IAC133-010130-

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE OMAHA NE
807 PM CDT MON APR 30 2001

THE NATIONAL WEATHER SERVICE IN OMAHA HAS ISSUED A

* TORNADO WARNING FOR...
  MONONA COUNTY IN WEST CENTRAL IOWA

* UNTIL 830 PM CDT

* AT 804 PM CDT...LAW ENFORCEMENT OFFICIALS REPORTED A TORNADO 6
  MILES NORTH OF WHITING...OR ABOUT 23 MILES SOUTHEAST OF SIOUX
  CITY...MOVING SOUTHEAST AT 25 MPH.

* SOME LOCATIONS AFFECTED...
  RODNEY
  CASTANA...TURIN

THIS REPLACES THE SEVERE THUNDERSTORM WARNING PREVIOUSLY ISSUED FOR
THE WARNED AREA.

IF YOU ARE IN THE PATH OF A TORNADO...GO TO A BASEMENT. IF A BASEMENT
IS NOT AVAILABLE...TAKE COVER IN AN INTERIOR ROOM ON THE LOWEST LEVEL
OF YOUR HOME OR BUSINESS. AVOID WINDOWS.

LAT...LON 4233 9615 4219 9630 4192 9588 4210 9570

$$
FOBERT

The office that day

Everything else NWS Omaha, NE issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Apr 30, 7:38 PM CDT	Severe Thunderstorm Warning	OAX	Monona	37 min
Apr 30, 8:28 PM CDT	Tornado Warning	OAX	Monona	32 min
Apr 30, 8:59 PM CDT	Severe Thunderstorm Warning	OAX	Harrison, Monona	46 min
Apr 30, 9:43 PM CDT	Severe Thunderstorm Warning	OAX	Pottawattamie	47 min
Apr 30, 9:43 PM CDT	Severe Thunderstorm Warning	OAX	Mills	47 min
May 1, 3:16 PM CDT	Severe Thunderstorm Warning	OAX	Monona	44 min
May 1, 4:00 PM CDT	Severe Thunderstorm Warning	OAX	Monona	45 min
May 1, 4:10 PM CDT	Severe Thunderstorm Warning	OAX	Harrison	50 min
May 1, 4:45 PM CDT	Severe Thunderstorm Warning	OAX	Monona	45 min
May 1, 5:00 PM CDT	Severe Thunderstorm Warning	OAX	Harrison	60 min
May 1, 5:59 PM CDT	Severe Thunderstorm Warning	OAX	Harrison	61 min
May 1, 6:58 PM CDT	Tornado Warning	OAX	Harrison	47 min

Nearby

Tornado Warnings in Iowa, 2001 Every tornado warning in 2001 Tornadoes in 2001

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.