Alert archive / Wyoming / Severe Thunderstorm Warnings in 2021
Severe Thunderstorm Warning 139, NWS Cheyenne, WY
NWS Cheyenne, WY issued this severe thunderstorm warning at Sep 3, 2021, 5:31 PM MDT for Goshen County, Niobrara County, Platte County, Wyoming. It was in force for 26 min. No storm report in the archive falls inside the area while it was in force.
The area
The outline as issued.
The facts
- Issued
- Sep 3, 2021, 5:31 PM MDT (23:31 UTC)
- Expired
- Sep 3, 2021, 5:57 PM MDT
- In force
- 26 min
- Issued by
- NWS Cheyenne, WY
- Area
- Storm-based polygon
- Hail
- 1.5 in
- Wind
- 60.0 mph
Counties Goshen County, WY, Niobrara County, WY, Platte County, WY
The radar
The Cheyenne radar (KCYS), 147 km from the middle of the area, began a volume at 23:32 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
Rapid City, SD (KUNR), launched 12:00Z, 11.5 hours before the alert went out and 230 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
- 0 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- 1231 m above ground
- 0-6 km bulk shear
- 34 kt
- 0-1 km storm-relative helicity
- 0 m²/s²
- 0-3 km storm-relative helicity
- 15 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
389
WUUS55 KCYS 032331
SVRCYS
WYC015-027-031-040015-
/O.NEW.KCYS.SV.W.0139.210903T2331Z-210904T0015Z/
BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Cheyenne WY
531 PM MDT Fri Sep 3 2021
The National Weather Service in Cheyenne has issued a
* Severe Thunderstorm Warning for...
Southern Niobrara County in east central Wyoming...
Northwestern Goshen County in southeastern Wyoming...
Northeastern Platte County in southeastern Wyoming...
* Until 615 PM MDT.
* At 531 PM MDT, a severe thunderstorm was located 7 miles north of
Guernsey Campground, or 26 miles north of Wheatland, moving
northeast at 35 mph.
HAZARD...Ping pong ball size hail and 60 mph wind gusts.
SOURCE...Radar indicated.
IMPACT...People and animals outdoors will be injured. Expect hail
damage to roofs, siding, windows, and vehicles. Expect
wind damage to roofs, siding, and trees.
* Locations impacted include...
Rawhide Buttes.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
For your protection move to an interior room on the lowest floor of a
building.
&&
LAT...LON 4235 10490 4243 10495 4271 10457 4258 10439
4242 10438
TIME...MOT...LOC 2331Z 241DEG 31KT 4242 10483
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.50 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH
$$
Charnick2 follow-up statements
973
WWUS55 KCYS 032346
SVSCYS
Severe Weather Statement
National Weather Service Cheyenne WY
546 PM MDT Fri Sep 3 2021
WYC015-027-031-040015-
/O.CON.KCYS.SV.W.0139.000000T0000Z-210904T0015Z/
Niobrara WY-Goshen WY-Platte WY-
546 PM MDT Fri Sep 3 2021
...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 615 PM MDT
FOR SOUTHERN NIOBRARA...NORTHWESTERN GOSHEN AND NORTHEASTERN PLATTE
COUNTIES...
At 546 PM MDT, a severe thunderstorm was located 10 miles southwest
of Rawhide Buttes, or 22 miles southwest of Lusk, moving northeast at
35 mph.
HAZARD...60 mph wind gusts and quarter size hail.
SOURCE...Radar indicated.
IMPACT...Hail damage to vehicles is expected. Expect wind damage to
roofs, siding, and trees.
Locations impacted include...
Rawhide Buttes.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
For your protection move to an interior room on the lowest floor of a
building.
&&
LAT...LON 4243 10477 4251 10484 4271 10457 4258 10439
4245 10438
TIME...MOT...LOC 2346Z 241DEG 31KT 4248 10467
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.00 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH
$$
Charnick059
WWUS55 KCYS 032357
SVSCYS
Severe Weather Statement
National Weather Service Cheyenne WY
557 PM MDT Fri Sep 3 2021
WYC015-027-031-040006-
/O.CAN.KCYS.SV.W.0139.000000T0000Z-210904T0015Z/
Niobrara WY-Goshen WY-Platte WY-
557 PM MDT Fri Sep 3 2021
...THE SEVERE THUNDERSTORM WARNING FOR SOUTHERN NIOBRARA...
NORTHWESTERN GOSHEN AND NORTHEASTERN PLATTE COUNTIES IS CANCELLED...
The storm which prompted the warning has weakened below severe
limits, and no longer poses an immediate threat to life or property.
Therefore, the warning has been cancelled. However small hail is
still possible with this thunderstorm.
LAT...LON 4243 10477 4251 10484 4271 10457 4258 10439
4245 10438
TIME...MOT...LOC 2354Z 241DEG 31KT 4252 10456
$$
CharnickThe office that day
Everything else NWS Cheyenne, WY issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Sep 3, 4:14 AM MDT | Special Weather Statement | CYS | Niobrara | 46 min |
| Sep 3, 1:38 PM MDT | Special Weather Statement | CYS | Laramie | 37 min |
| Sep 3, 2:20 PM MDT | Special Weather Statement | CYS | Laramie | 25 min |
| Sep 3, 2:47 PM MDT | Special Weather Statement | CYS | Laramie | 43 min |
| Sep 3, 3:45 PM MDT | Special Weather Statement | CYS | Laramie | 30 min |
| Sep 3, 3:53 PM MDT | Special Weather Statement | CYS | Laramie | 37 min |
| Sep 3, 4:33 PM MDT | Special Weather Statement | CYS | Laramie | 27 min |
| Sep 3, 4:45 PM MDT | Severe Thunderstorm Warning | CYS | Laramie | 31 min |
| Sep 3, 5:14 PM MDT | Areal Flood Advisory | CYS | Laramie | 12 min |
| Sep 3, 5:25 PM MDT | Flash Flood Warning | CYS | Laramie | 3 hr |
Nearby
Severe Thunderstorm Warnings in Wyoming, 2021Every severe thunderstorm warning in 2021
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.