Alert archive / Nebraska / Tornado Warnings in 2001

Tornado Warning 13, NWS Omaha, NE

April 20, 2001Cedar County, Nebraska

NWS Omaha, NE issued this tornado warning at Apr 20, 2001, 8:02 PM CDT for Cedar County, Nebraska. It was in force for 43 min. No storm report in the archive falls 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.

The facts

Issued: Apr 20, 2001, 8:02 PM CDT (01:02 UTC)
Expired: Apr 20, 2001, 8:45 PM CDT
In force: 43 min
Issued by: NWS Omaha, NE
Area: Whole counties; the outline is the Mesonet’s reconstruction

County Cedar County, NE

The radar

The Sioux Falls radar (KFSD), 129 km from the middle of the area, began a volume at 01:02 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

Omaha, NE (KOAX), launched 00:00Z, 1.0 hours before the alert went out and 156 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: 939 J/kg
Mixed-layer CIN: -84 J/kg
Mixed-layer LCL: 1568 m above ground
0-6 km bulk shear: 51 kt
0-1 km storm-relative helicity: 119 m²/s²
0-3 km storm-relative helicity: 247 m²/s²
Significant tornado parameter: 0.2
Supercell composite: 4.8

Open this sounding in Storm Lab

The text

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

000 
WFUS53 KOAX 210103
TOROMA
NEC027-210145-

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE OMAHA NE
802 PM CDT FRI APR 20 2001

THE NATIONAL WEATHER SERVICE IN OMAHA HAS ISSUED A

* TORNADO WARNING FOR...
  CEDAR COUNTY IN NORTHEAST NEBRASKA

* UNTIL 845 PM CDT

* AT 758 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  TORNADO 17 MILES SOUTHWEST OF HARTINGTON...OR ABOUT 27 MILES NORTH
  OF NORFOLK...MOVING NORTHEAST AT 20 MPH.

* THE TORNADO IS EXPECTED TO BE MAGNET...THEN COLERIDGE.

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 4244 9748 4244 9738 4255 9709 4273 9735

ZAPOTOCNY

The office that day

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

Issued	Product	Office	Counties	Lasted
Apr 20, 7:50 PM CDT	Severe Thunderstorm Warning	OAX	Cedar	25 min
Apr 20, 7:56 PM CDT	Severe Thunderstorm Warning	OAX	Knox, Pierce	49 min
Apr 20, 8:43 PM CDT	Severe Thunderstorm Warning	OAX	Jefferson, Saline	47 min
Apr 20, 8:43 PM CDT	Tornado Warning	OAX	Cedar	22 min
Apr 20, 8:52 PM CDT	Severe Thunderstorm Warning	OAX	Seward	38 min
Apr 20, 9:17 PM CDT	Severe Thunderstorm Warning	OAX	Gage, Lancaster, Saline, Seward	38 min
Apr 20, 9:17 PM CDT	Severe Thunderstorm Warning	OAX	Butler	38 min
Apr 20, 9:39 PM CDT	Severe Thunderstorm Warning	OAX	Butler, Dodge, Lancaster, Saunders	36 min
Apr 20, 9:39 PM CDT	Severe Thunderstorm Warning	OAX	Cass, Otoe	36 min
Apr 20, 9:42 PM CDT	Severe Thunderstorm Warning	OAX	Johnson, Pawnee	33 min
Apr 20, 9:48 PM CDT	Severe Thunderstorm Warning	OAX	Dodge, Douglas, Washington	37 min
Apr 20, 9:48 PM CDT	Severe Thunderstorm Warning	OAX	Cass, Sarpy, Saunders	37 min
Apr 20, 10:00 PM CDT	Severe Thunderstorm Warning	OAX	Nemaha	45 min
Apr 20, 10:14 PM CDT	Severe Thunderstorm Warning	OAX	Pawnee	31 min
Apr 20, 10:26 PM CDT	Severe Thunderstorm Warning	OAX	Thurston, Wayne	34 min

Nearby

Tornado Warnings in Nebraska, 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.