Alert archive / Wyoming / Severe Thunderstorm Warnings in 2020
Severe Thunderstorm Warning 107, NWS Cheyenne, WY
NWS Cheyenne, WY issued this severe thunderstorm warning at Jul 20, 2020, 4:52 PM MDT for Converse County, Wyoming. It was in force for 18 min. No storm report in the archive falls inside the area while it was in force.
The area
The counties it named.
The facts
- Issued
- Jul 20, 2020, 4:52 PM MDT (22:52 UTC)
- Expired
- Jul 20, 2020, 5:10 PM MDT
- In force
- 18 min
- Issued by
- NWS Cheyenne, WY
- Area
- Storm-based polygon
- Hail
- 1.0 in
- Wind
- 60.0 mph
County Converse County, WY
The radar
The Cheyenne radar (KCYS), 210 km from the middle of the area, began a volume at 22:53 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, 10.9 hours before the alert went out and 244 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
- 89 J/kg
- Mixed-layer CIN
- -242 J/kg
- Mixed-layer LCL
- 1354 m above ground
- 0-6 km bulk shear
- 35 kt
- 0-1 km storm-relative helicity
- 79 m²/s²
- 0-3 km storm-relative helicity
- 120 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- -0.0
What forecasters said that day
The local office's own words before this severe thunderstorm warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS Cheyenne, WY wrote its last area forecast discussion before this severe thunderstorm warning went out at Jul 20, 2:06 PM MDT, 2 hours 46 minutes earlier.
Area forecast discussion, Jul 20, 2:06 PM MDT, 2 hours 46 minutes before
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</html>Hazardous weather outlook, Jul 20, 1:27 PM MDT, 3 hours 25 minutes before
Hazardous Weather Outlook National Weather Service Cheyenne WY 127 PM MDT Mon Jul 20 2020 NEZ002-003-019>021-054-055-095-096-WYZ101-102-107-108-118-119- 211930- Dawes-Box Butte-Scotts Bluff County-Banner County-Morrill- Kimball County-Cheyenne-North Sioux-South Sioux- Converse County Lower Elevations-Niobrara County- East Platte County-Goshen County-Central Laramie County- East Laramie County- 127 PM MDT Mon Jul 20 2020 This hazardous weather outlook is for portions of panhandle Nebraska...western Nebraska...east central Wyoming and southeast Wyoming. .DAY ONE...THIS AFTERNOON AND TONIGHT Isolated to scattered strong to severe thunderstorms possible. Damaging winds and large hail main threats in strongest storms. .DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY Recurring chances for afternoon and evening strong to severe thunderstorms this week. Damaging winds and large hail possible threats in strongest storms. .Spotter information statement... Spotters are encouraged to report any hail and thunderstorm wind damage to the Cheyenne, Wyoming National Weather Service. WYZ103>106-109>117-211930- North Laramie Range-Ferris/Seminoe/Shirley Mountains- Shirley Basin-Central Laramie Range and Southwest Platte County- Central Carbon County-North Snowy Range Foothills- Southwest Carbon County-Sierra Madre Range- Upper North Platte River Basin-Snowy Range-Laramie Valley- South Laramie Range-South Laramie Range Foothills- 127 PM MDT Mon Jul 20 2020 This hazardous weather outlook is for portions of south central Wyoming and southeast Wyoming. .DAY ONE...THIS AFTERNOON AND TONIGHT No hazardous weather is expected at this time. .DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY Non-severe thunderstorms possible this week. Frequent lightning, gusty winds, and small hail possible. .Spotter information statement... Spotter activation will not be needed.
In the hours before
Special weather statement, Jul 20, 1:27 PM MDT, 3 hours 25 minutes before
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</html>Special weather statement, Jul 20, 2:53 PM MDT, 1 hour 59 minutes before
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</html>Special weather statement, Jul 20, 3:45 PM MDT, 1 hour 7 minutes before
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</html>Special weather statement, Jul 20, 4:26 PM MDT, 26 minutes before
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</html>Special weather statement, Jul 20, 4:27 PM MDT, 25 minutes before
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</html>The office that day
Everything else NWS Cheyenne, WY issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 19, 6:02 PM MDT | Severe Thunderstorm Warning | CYS | Converse, Niobrara | 58 min |
| Jul 19, 6:44 PM MDT | Tornado Warning | CYS | Converse, Niobrara | 31 min |
| Jul 19, 7:14 PM MDT | Severe Thunderstorm Warning | CYS | Converse, Niobrara | 46 min |
| Jul 19, 7:24 PM MDT | Tornado Warning | CYS | Niobrara | 36 min |
| Jul 19, 7:57 PM MDT | Tornado Warning | CYS | Niobrara | 33 min |
| Jul 19, 8:03 PM MDT | Severe Thunderstorm Warning | CYS | Goshen | 42 min |
| Jul 19, 8:14 PM MDT | Severe Thunderstorm Warning | CYS | Goshen, Niobrara | 46 min |
| Jul 19, 8:30 PM MDT | Tornado Warning | CYS | Goshen, Niobrara | 17 min |
| Jul 19, 8:45 PM MDT | Severe Thunderstorm Warning | CYS | Goshen, Niobrara | 45 min |
| Jul 19, 9:39 PM MDT | Severe Thunderstorm Warning | CYS | Goshen | 51 min |
| Jul 20, 12:04 PM MDT | Special Weather Statement | CYS | Platte | 26 min |
| Jul 20, 12:51 PM MDT | Special Weather Statement | CYS | Platte | 24 min |
| Jul 20, 1:15 PM MDT | Special Weather Statement | CYS | Albany | 30 min |
| Jul 20, 1:27 PM MDT | Special Weather Statement | CYS | Niobrara | 33 min |
| Jul 20, 2:27 PM MDT | Special Weather Statement | CYS | Niobrara | 33 min |
| Jul 20, 2:53 PM MDT | Special Weather Statement | CYS | Converse, Niobrara | 52 min |
| Jul 20, 3:45 PM MDT | Special Weather Statement | CYS | Converse | 45 min |
| Jul 20, 4:27 PM MDT | Special Weather Statement | CYS | Converse | 48 min |
| Jul 20, 5:05 PM MDT | Special Weather Statement | CYS | Platte | 40 min |
| Jul 20, 5:13 PM MDT | Special Weather Statement | CYS | Niobrara | 47 min |
| Jul 20, 5:14 PM MDT | Special Weather Statement | CYS | Niobrara | 46 min |
| Jul 20, 5:16 PM MDT | Special Weather Statement | CYS | Converse | 44 min |
| Jul 20, 5:41 PM MDT | Special Weather Statement | CYS | Laramie | 49 min |
| Jul 19, 6:32 PM MDT | Severe Thunderstorm Warning | CYS | Box Butte, Dawes, Sioux | 58 min |
| Jul 19, 8:11 PM MDT | Severe Thunderstorm Warning | CYS | Box Butte, Dawes | 49 min |
| Jul 19, 8:54 PM MDT | Severe Thunderstorm Warning | CYS | Box Butte, Dawes | 38 min |
| Jul 19, 9:31 PM MDT | Special Weather Statement | CYS | Box Butte | 44 min |
| Jul 19, 9:35 PM MDT | Special Weather Statement | CYS | Sioux | 40 min |
| Jul 20, 4:26 PM MDT | Special Weather Statement | CYS | Sioux | 49 min |
| Jul 20, 4:56 PM MDT | Special Weather Statement | CYS | Sioux | 49 min |
| Jul 20, 5:39 PM MDT | Special Weather Statement | CYS | Box Butte | 51 min |
Nearby
Severe Thunderstorm Warnings in Wyoming, 2020Every severe thunderstorm warning in 2020
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.