Alert archive / Nebraska / Tornado Warnings in 1999
Tornado Warning 5, NWS Cheyenne, WY
NWS Cheyenne, WY issued this tornado warning at May 21, 1999, 7:11 PM MDT for Cheyenne County, Nebraska. It was in force for 19 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
- May 21, 1999, 7:11 PM MDT (01:11 UTC)
- Expired
- May 21, 1999, 7:30 PM MDT
- In force
- 19 min
- Issued by
- NWS Cheyenne, WY
- Area
- Whole counties
County Cheyenne County, NE
The radar
The Cheyenne radar (KCYS), 152 km from the middle of the area, began a volume at 01:11 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 21, 7:20 PM MDT | Hail 1 | Sunol, NE | 1 inch hail fell 6 miles south of Sunol, 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
Denver, CO (KDNR), launched 00:00Z, 1.2 hours before the alert went out and 151 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.
- Mixed-layer CAPE
- 810 J/kg
- Mixed-layer CIN
- -5 J/kg
- Mixed-layer LCL
- 2631 m above ground
- 0-6 km bulk shear
- 51 kt
- 0-1 km storm-relative helicity
- -21 m²/s²
- 0-3 km storm-relative helicity
- 14 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.2
The text
As transmitted, in the capitals the NWS used until 2016.
000 TTAA00 KCYS 220111 RRA TORCYS NEC033-220130- BULLETIN - EAS ACTIVATION REQUESTED TORNADO WARNING NATIONAL WEATHER SERVICE CHEYENNE WY 711 PM MDT FRI MAY 21 1999 THE NATIONAL WEATHER SERVICE IN CHEYENNE HAS ISSUED A * TORNADO WARNING FOR... SOUTHEASTERN CHEYENNE COUNTY IN THE NEBRASKA PANHANDLE * UNTIL 730 PM MDT * AT 709 PM MDT... NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A POSSIBLE TORNADO 8 MILES SOUTHEAST OF SIDNEY...MOVING EAST AT 15 MPH. THE TORNADO IS EXPECTED TO REMAIN IN OPEN COUNTRY. GO TO THE BASEMENT OR A SMALL INTERIOR ROOM ON THE LOWEST FLOOR! THIS WARNING REPLACES THE PREVIOUSLY ISSUED TORNADO WARNING FOR EASTERN CHEYENNE COUNTY. WEILAND
What forecasters said that day
The local office's own words before this tornado warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
In the hours before
Special weather statement, May 21, 6:53 PM MDT, 18 minutes before
WYZ059-060-067-068-220200- SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE CHEYENNE WY 653 PM MDT FRI MAY 21 1999 ...THE SEVERE THUNDERSTORM WATCH HAS BEEN CANCELLED FOR EAST CENTRAL AND PARTS OF SOUTHEAST WYOMING... THUNDERSTORMS HAVE DECREASED CONSIDERABLY IN COVERAGE AND INTENSITY OVER EAST CENTRAL AND PARTS OF SOUTHEAST WYOMING SINCE 530 PM. THE THREAT OF SEVERE WEATHER FROM THE REMAINING THUNDERSTORMS IS LOW... SO THE SEVERE THUNDERSTORM WATCH HAS BEEN CANCELLED. WCJIN-WYSE- WEILAND
The office that day
Everything else NWS Cheyenne, WY issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 21, 6:08 PM MDT | Tornado Warning | CYS | Cheyenne | 32 min |
| May 21, 6:10 PM MDT | Tornado Warning | CYS | Box Butte | 35 min |
| May 21, 6:38 PM MDT | Tornado Warning | CYS | Cheyenne | 32 min |
Nearby
Tornado Warnings in Nebraska, 1999Every tornado warning in 1999Tornadoes 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; radar from the NEXRAD Level II archive.