Alert archive / Nebraska / Tornado Warnings in 1998

Tornado Warning 4, NWS Cheyenne, WY

May 20, 1998Morrill County, Nebraska

NWS Cheyenne, WY issued this tornado warning at May 20, 1998, 6:29 PM MDT for Morrill County, Nebraska. It was in force for 31 min. 2 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: May 20, 1998, 6:29 PM MDT (00:29 UTC)
Expired: May 20, 1998, 7:00 PM MDT
In force: 31 min
Issued by: NWS Cheyenne, WY
Area: Whole counties

County Morrill County, NE

The radar

The Cheyenne radar (KCYS), 162 km from the middle of the area, began a volume at 00:30 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 20, 6:45 PM MDT	Hail 2.75	Redington, NE	A storm produced golf ball to baseball size hail in the Redington area.
May 20, 6:58 PM MDT	Tornado F1	Bridgeport, NE	Area law enforcement reported a brief tornado 11 miles southeast of Bridgeport.

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
May 20, 1:30 PM MDT	Tornado Watch	SPC	6 hr

The nearest sounding before it

Denver, CO (KDNR), launched 00:00Z, 0.5 hours before the alert went out and 206 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: 87 J/kg
Mixed-layer CIN: -39 J/kg
Mixed-layer LCL: 3075 m above ground
0-6 km bulk shear: 18 kt
0-1 km storm-relative helicity: -42 m²/s²
0-3 km storm-relative helicity: 46 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KCYS 210030 RRA
TORCYS
NEC123-210100-

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE CHEYENNE WY
629 PM MDT WED MAY 20 1998

THE NATIONAL WEATHER SERVICE IN CHEYENNE HAS ISSUED A

* TORNADO WARNING FOR...
  WESTERN MORRILL COUNTY IN WESTERN NEBRASKA PANHANDLE

* UNTIL 700 PM MDT

* AT 627 PM MDT... NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  TORNADO 8 SOUTHWEST OF BRIDGEPORT... MOVING EAST AT 10 MPH.

* THE TORNADO IS EXPECTED TO BE NEAR...
  BRIDGEPORT AT 650 PM
  REDINGTON NOW

GO TO THE BASEMENT OR A SMALL INTERIOR ROOM ON THE LOWEST FLOOR!


IF YOU ARE CAUGHT OUTSIDE...SEEK SAFETY IN A NEARBY STURDY
BUILDING. AS A LAST RESORT... SEEK REFUGE IN A CULVERT...
DITCH OR LOW SPOT AND COVER YOUR HEAD WITH YOUR HANDS. BEWARE
THE THREAT OF RISING WATER.

PAL

The office that day

Everything else NWS Cheyenne, WY issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
May 20, 6:10 PM MDT	Severe Thunderstorm Warning	CYS	Morrill	30 min
May 20, 6:59 PM MDT	Tornado Warning	CYS	Morrill	31 min
May 20, 7:39 PM MDT	Severe Thunderstorm Warning	CYS	Cheyenne	31 min
May 20, 7:54 PM MDT	Tornado Warning	CYS	Cheyenne	31 min
May 20, 8:49 PM MDT	Severe Thunderstorm Warning	CYS	Cheyenne	31 min
May 21, 4:57 AM MDT	Severe Thunderstorm Warning	CYS	Box Butte	48 min
May 21, 5:48 AM MDT	Severe Thunderstorm Warning	CYS	Box Butte	37 min
May 21, 10:55 AM MDT	Tornado Warning	CYS	Scotts Bluff, Sioux	30 min
May 21, 11:30 AM MDT	Tornado Warning	CYS	Scotts Bluff	35 min

Nearby

Tornado Warnings in Nebraska, 1998 Every tornado warning in 1998 Tornadoes in 1998

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.