Alert archive / Wyoming / Severe Thunderstorm Warnings in 2021
Severe Thunderstorm Warning 115, NWS Cheyenne, WY
NWS Cheyenne, WY issued this severe thunderstorm warning at Aug 6, 2021, 3:29 PM MDT for 5 counties in Wyoming. It was in force for 61 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
- Aug 6, 2021, 3:29 PM MDT (21:29 UTC)
- Expired
- Aug 6, 2021, 4:30 PM MDT
- In force
- 61 min
- Issued by
- NWS Cheyenne, WY
- Area
- Storm-based polygon
- Damage threat
- Considerable
- Hail
- 0.75 in
- Wind
- 70.0 mph
Counties Albany County, WY, Converse County, WY, Goshen County, WY, Niobrara County, WY, Platte County, WY
The radar
The Cheyenne radar (KCYS), 187 km from the middle of the area, began a volume at 21:30 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.
The watch it was issued in
The SPC watch in force over the same counties when this warning went out.
| Issued | Product | Office | Lasted |
|---|---|---|---|
| Aug 6, 1:43 PM MDT | Severe Thunderstorm Watch | SPC | 6 hr |
The nearest sounding before it
Rapid City, SD (KUNR), launched 12:00Z, 9.5 hours before the alert went out and 213 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
- 117 J/kg
- Mixed-layer CIN
- -465 J/kg
- Mixed-layer LCL
- 1438 m above ground
- 0-6 km bulk shear
- 29 kt
- 0-1 km storm-relative helicity
- 19 m²/s²
- 0-3 km storm-relative helicity
- 41 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
920
WUUS55 KCYS 062129
SVRCYS
WYC001-009-015-027-031-062230-
/O.NEW.KCYS.SV.W.0115.210806T2129Z-210806T2230Z/
BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Cheyenne WY
329 PM MDT Fri Aug 6 2021
The National Weather Service in Cheyenne has issued a
* Severe Thunderstorm Warning for...
Western Niobrara County in east central Wyoming...
Northeastern Albany County in southeastern Wyoming...
Northwestern Goshen County in southeastern Wyoming...
Northern Platte County in southeastern Wyoming...
Eastern Converse County in east central Wyoming...
* Until 430 PM MDT.
* At 328 PM MDT, severe thunderstorms were located along a line
extending from 12 miles west of Bill to 6 miles east of Esterbrook
Campground, moving northeast at 45 mph.
HAZARD...70 mph wind gusts and penny size hail.
SOURCE...Radar indicated.
IMPACT...Expect considerable tree damage. Damage is likely to
mobile homes, roofs, and outbuildings.
* Severe thunderstorms will be near...
Glendo Reservoir and Two Moon Campground around 345 PM MDT.
Dull Center around 405 PM MDT.
Keeline around 410 PM MDT.
Manville around 420 PM MDT.
Other locations impacted by these severe thunderstorms include Lost
Springs.
This includes Interstate 25 in Wyoming between mile markers 104 and
143.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
For your protection move to an interior room on the lowest floor of a
building.
&&
LAT...LON 4240 10444 4238 10534 4350 10571 4350 10457
TIME...MOT...LOC 2128Z 235DEG 39KT 4327 10550 4239 10520
THUNDERSTORM DAMAGE THREAT...CONSIDERABLE
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...0.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...70 MPH
$$
Rubin2 follow-up statements
830
WWUS55 KCYS 062150
SVSCYS
Severe Weather Statement
National Weather Service Cheyenne WY
350 PM MDT Fri Aug 6 2021
WYC001-062159-
/O.CAN.KCYS.SV.W.0115.000000T0000Z-210806T2230Z/
Albany WY-
350 PM MDT Fri Aug 6 2021
...THE SEVERE THUNDERSTORM WARNING FOR NORTHEASTERN ALBANY COUNTY IS
CANCELLED...
The storms which prompted the warning have moved out of the warned
area. Therefore, the warning has been cancelled.
A Severe Thunderstorm Watch remains in effect until 800 PM MDT for
east central Wyoming.
LAT...LON 4240 10444 4239 10506 4350 10540 4350 10457
TIME...MOT...LOC 2149Z 241DEG 41KT 4339 10526 4246 10487
$$
WYC009-015-027-031-062230-
/O.CON.KCYS.SV.W.0115.000000T0000Z-210806T2230Z/
Niobrara WY-Goshen WY-Platte WY-Converse WY-
350 PM MDT Fri Aug 6 2021
...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 430 PM MDT
FOR WESTERN NIOBRARA...NORTHWESTERN GOSHEN...NORTHEASTERN PLATTE AND
NORTHEASTERN CONVERSE COUNTIES...
At 349 PM MDT, severe thunderstorms were located along a line
extending from 12 miles north of Bill to near Two Moon Campground,
moving northeast at 45 mph.
HAZARD...70 mph wind gusts and penny size hail.
SOURCE...Radar indicated.
IMPACT...Expect considerable tree damage. Damage is likely to mobile
homes, roofs, and outbuildings.
These severe storms will be near...
Dull Center around 405 PM MDT.
Rawhide Buttes around 415 PM MDT.
Other locations impacted by these severe thunderstorms include Lost
Springs.
This includes Interstate 25 in Wyoming between mile markers 104 and
121.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
For your protection move to an interior room on the lowest floor of a
building.
&&
LAT...LON 4240 10444 4239 10506 4350 10540 4350 10457
TIME...MOT...LOC 2149Z 241DEG 41KT 4339 10526 4246 10487
THUNDERSTORM DAMAGE THREAT...CONSIDERABLE
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...0.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...70 MPH
$$
Rubin240
WWUS55 KCYS 062221
SVSCYS
Severe Weather Statement
National Weather Service Cheyenne WY
421 PM MDT Fri Aug 6 2021
WYC009-015-027-031-062230-
/O.EXP.KCYS.SV.W.0115.000000T0000Z-210806T2230Z/
Niobrara WY-Goshen WY-Platte WY-Converse WY-
421 PM MDT Fri Aug 6 2021
...THE SEVERE THUNDERSTORM WARNING FOR WESTERN NIOBRARA...
NORTHWESTERN GOSHEN...NORTHEASTERN PLATTE AND NORTHEASTERN CONVERSE
COUNTIES WILL EXPIRE AT 430 PM MDT...
The storms which prompted the warning have moved out of the area.
Therefore, the warning will be allowed to expire.
A Severe Thunderstorm Watch remains in effect until 800 PM MDT for
east central Wyoming.
LAT...LON 4240 10444 4239 10506 4350 10540 4350 10457
TIME...MOT...LOC 2220Z 235DEG 39KT 4358 10488 4265 10450
$$
RubinThe office that day
Everything else NWS Cheyenne, WY issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 6, 1:40 PM MDT | Special Weather Statement | CYS | Laramie | 50 min |
| Aug 6, 2:13 PM MDT | Special Weather Statement | CYS | Converse | 47 min |
| Aug 6, 2:33 PM MDT | Special Weather Statement | CYS | Laramie | 42 min |
| Aug 6, 3:12 PM MDT | Special Weather Statement | CYS | Converse | 48 min |
| Aug 6, 3:18 PM MDT | Severe Thunderstorm Warning | CYS | Albany, Laramie | 42 min |
| Aug 6, 4:08 PM MDT | Special Weather Statement | CYS | Niobrara | 52 min |
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.