Alert archive / Nebraska / Tornado Warnings in 1999

Tornado Warning 21, NWS Omaha, NE

April 21, 1999Cass County, Otoe County, Nebraska

NWS Omaha, NE issued this tornado warning at Apr 21, 1999, 7:17 PM CDT for Cass County, Otoe County, Nebraska. It was in force for 33 min. 3 reports 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 21, 1999, 7:17 PM CDT (00:17 UTC)
Expired: Apr 21, 1999, 7:50 PM CDT
In force: 33 min
Issued by: NWS Omaha, NE
Area: Whole counties

Counties Cass County, NE, Otoe County, NE

What was reported inside it

Time	Report	Where	Remark
Apr 21, 7:20 PM CDT	Tornado F0	Alvo, NE	Very brief touchdown.
Apr 21, 7:30 PM CDT	Hail 1.75	Douglas, NE
Apr 21, 7:40 PM CDT	Hail 1.75	Palmyra, NE

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, 0.3 hours before the alert went out and 63 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 649 m above ground
0-6 km bulk shear: 41 kt
0-1 km storm-relative helicity: 322 m²/s²
0-3 km storm-relative helicity: 634 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 5.1

Open this sounding in Storm Lab

The text

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

999 
WFUS1 KOMA 220018 RRA
TOROMA
NEC025-131-220050-

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
717 PM CDT WED APR 21 1999

THE NATIONAL WEATHER SERVICE IN OMAHA HAS ISSUED A

* TORNADO WARNING FOR...
  CASS COUNTY IN SOUTHEASTERN NEBRASKA
  OTOE COUNTY IN SOUTHEASTERN NEBRASKA

* UNTIL 750 PM CDT

* AT 715 PM CDT... DOPPLER RADAR AND SPOTTERS INDICATED A POSSIBLE
  TORNADO 16 MILES EAST OF LINCOLN OR 5 MILES SOUTH OF EAGLE...
  MOVING NORTHEAST AT 30 MPH.  AT 715 PM CDT SPOTTERS INDICATED
  ROTATION DEVELOPING WITH THIS STORM NEAR PALMYRA.

* THE TORNADO IS EXPECTED TO BE NEAR...
  EAGLE                        AROUND 720 PM CDT
  ALVO                         AROUND 730 PM CDT
  ELMWOOD                      AROUND 730 PM CDT
  MURDOCK                      AROUND 740 PM CDT

PERSONS IN THE WARNED AREA SHOULD TAKE SHELTER IN A BASEMENT IF
AVAILABLE.  OTHERWISE GO TO A SMALL INTERIOR ROOM ON THE LOWEST
LEVEL OF YOUR HOME OR BUSINESS.

BZ

The office that day

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

Issued	Product	Office	Counties	Lasted
Apr 21, 7:11 PM CDT	Severe Thunderstorm Warning	OAX	Lancaster	34 min
Apr 21, 7:42 PM CDT	Severe Thunderstorm Warning	OAX	Johnson	33 min
Apr 21, 7:44 PM CDT	Severe Thunderstorm Warning	OAX	Saunders	46 min
Apr 21, 7:53 PM CDT	Severe Thunderstorm Warning	OAX	Cass, Otoe	47 min
Apr 21, 8:39 PM CDT	Severe Thunderstorm Warning	OAX	Cass, Otoe	46 min
Apr 21, 9:25 PM CDT	Severe Thunderstorm Warning	OAX	Cass, Otoe	35 min
Apr 21, 10:10 PM CDT	Severe Thunderstorm Warning	OAX	Cass, Otoe	30 min
Apr 21, 10:22 PM CDT	Flash Flood Warning	OAX	Cass, Otoe	4 hr

Nearby

Tornado Warnings in Nebraska, 1999 Every tornado warning in 1999 Tornadoes in 1999

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.