Alert archive / Wyoming / Severe Thunderstorm Warnings in 2019

Severe Thunderstorm Warning 398, NWS Cheyenne, WY

September 10, 20194 counties in Wyoming

NWS Cheyenne, WY issued this severe thunderstorm warning at Sep 10, 2019, 1:59 PM MDT for 4 counties in Wyoming. It was in force for 31 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
Sep 10, 2019, 1:59 PM MDT (19:59 UTC)
Expired
Sep 10, 2019, 2:30 PM MDT
In force
31 min
Issued by
NWS Cheyenne, WY
Area
Storm-based polygon
Hail
1.75 in
Wind
60.0 mph

Counties Converse County, WY, Goshen County, WY, Niobrara County, WY, Platte County, WY

The radar

The Cheyenne radar (KCYS), 157 km from the middle of the area, began a volume at 20:00 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.

IssuedProductOfficeLasted
Sep 10, 1:53 PM MDTTornado WatchSPC7 hr

The nearest sounding before it

Rapid City, SD (KUNR), launched 12:00Z, 8.0 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.

Skew-T log-pSkew-T log-p diagram, Rapid City, SD at 12:00Z on 2019-09-10Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Rapid City, SD at 12:00Z on 2019-09-10The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 85 square meters per square second.1939587897Sfc1 km3 km6 km9 kmRMLM
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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1302 m above ground
0-6 km bulk shear
49 kt
0-1 km storm-relative helicity
85 m²/s²
0-3 km storm-relative helicity
82 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

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 Sep 10, 1:00 PM MDT, 59 minutes earlier.

Area forecast discussion, Sep 10, 1:00 PM MDT, 59 minutes before
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Hazardous weather outlook, Sep 10, 4:55 AM MDT, 9 hours 4 minutes before
Hazardous Weather Outlook
National Weather Service Cheyenne WY
455 AM MDT Tue Sep 10 2019

NEZ020-054-055-WYZ103>106-109>119-111100-
Banner-Kimball-Cheyenne-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-
Central Laramie County-East Laramie County-
455 AM MDT Tue Sep 10 2019

This hazardous weather outlook is for portions of western
Nebraska...south central Wyoming and southeast Wyoming.

.DAY ONE...TODAY AND TONIGHT

Widely scattered afternoon and evening thunderstorms are forecast
across most of southeast Wyoming Tuesday and Wednesday. Severe
weather appears unlikely at this time, but some storms may contain
small hail and gusty winds.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY

Scattered to numerous thunderstorms are expected on Wednesday.
Some accumulating snow is possible in the higher mountains above
10,000 feet late Wednesday night and Thursday morning.

.Spotter information statement...

Spotter activation is unlikely today.

NEZ002-003-019-021-095-096-WYZ101-102-107-108-111100-
Dawes-Box Butte-Scotts Bluff-Morrill-North Sioux-South Sioux-
Converse County Lower Elevations-Niobrara County-
East Platte County-Goshen County-
455 AM MDT Tue Sep 10 2019

This hazardous weather outlook is for most of the western
Nebraska panhandle north of Interstate 80 and east central
Wyoming.

.DAY ONE...TODAY AND TONIGHT

There is a risk for scattered severe thunderstorms today across
eastern Wyoming and most of western Nebraska. Thunderstorms will
develop along Interstate 25 during the afternoon and track
northeast. These thunderstorms may contain large hail, very heavy
rainfall, and damaging winds.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY

Scattered to numerous thunderstorms are forecast for Wednesday. A
few of these thunderstorms may become strong and contain small
hail, frequent lightning, and gusty winds.

.Spotter information statement...

Spotters are urged to report severe weather to the National
Weather Service.

In the hours before

Special weather statement, Sep 10, 10:18 AM MDT, 3 hours 41 minutes before
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Special weather statement, Sep 10, 11:42 AM MDT, 2 hours 17 minutes before
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Special weather statement, Sep 10, 1:17 PM MDT, 42 minutes before
Special Weather Statement
National Weather Service Cheyenne WY
117 PM MDT Tue Sep 10 2019

WYZ101>103-107-102000-
East Platte County WY-Converse County Lower Elevations WY-
North Laramie Range WY-Niobrara County WY-
117 PM MDT Tue Sep 10 2019

...SPECIAL WEATHER STATEMENT...

At 117 PM MDT, Doppler radar was tracking a strong thunderstorm 7
miles north of Esterbrook Campground, or 16 miles south of Douglas,
moving northeast at 25 mph.

Half inch hail and winds in excess of 30 mph will be possible with
this storm.

Locations impacted include...
Glendo, Keeline and Lost Springs.

This includes Interstate 25 in Wyoming between mile markers 113 and
132.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

This storm may intensify, so be certain to monitor local radio
stations and available television stations for additional information
and possible warnings from the National Weather Service.

&&

LAT...LON 4240 10526 4250 10546 4294 10511 4273 10456
TIME...MOT...LOC 1917Z 213DEG 22KT 4253 10530

Worley

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 10, 3:07 AM MDTSpecial Weather StatementCYSLaramie38 min
Sep 10, 3:44 AM MDTSpecial Weather StatementCYSLaramie46 min
Sep 10, 4:26 AM MDTSpecial Weather StatementCYSGoshen49 min
Sep 10, 5:06 AM MDTSevere Thunderstorm WarningCYSGoshen39 min
Sep 10, 11:42 AM MDTSpecial Weather StatementCYSConverse48 min
Sep 10, 12:16 PM MDTFreeze WatchCYSAlbany, Carbon27 hr
Sep 10, 1:17 PM MDTSpecial Weather StatementCYSConverse43 min
Sep 10, 2:09 PM MDTSpecial Weather StatementCYSNiobrara51 min
Sep 10, 2:35 PM MDTSpecial Weather StatementCYSNiobrara40 min
Sep 10, 2:54 PM MDTSpecial Weather StatementCYSGoshen51 min
Sep 10, 3:01 PM MDTSevere Thunderstorm WarningCYSGoshen, Platte29 min
Sep 10, 3:08 PM MDTTornado WarningCYSGoshen, Platte37 min
Sep 10, 3:37 PM MDTTornado Warning Tornado observedCYSGoshen23 min
Sep 10, 4:00 PM MDTSevere Thunderstorm WarningCYSGoshen45 min
Sep 10, 4:11 PM MDTAreal Flood AdvisoryCYSGoshen, Platte3 hr
Sep 10, 4:17 PM MDTTornado WarningCYSGoshen28 min
Sep 10, 4:36 PM MDTTornado WarningCYSGoshen39 min
Sep 10, 4:48 PM MDTSevere Thunderstorm WarningCYSGoshen, Platte42 min
Sep 10, 4:58 PM MDTTornado Warning Tornado observedCYSGoshen, Platte32 min
Sep 10, 5:15 PM MDTSevere Thunderstorm WarningCYSGoshen16 min
Sep 10, 5:24 PM MDTSevere Thunderstorm WarningCYSGoshen66 min
Sep 10, 5:35 PM MDTFlash Flood WarningCYSGoshen100 min
Sep 10, 5:41 PM MDTTornado WarningCYSGoshen19 min
Sep 10, 5:59 PM MDTTornado WarningCYSGoshen31 min
Sep 10, 4:01 AM MDTSpecial Weather StatementCYSScotts Bluff44 min
Sep 10, 10:18 AM MDTSpecial Weather StatementCYSSioux57 min
Sep 10, 5:59 PM MDTSevere Thunderstorm WarningCYSBox Butte, Dawes, Scotts Bluff, Sioux46 min

Nearby

Severe Thunderstorm Warnings in Wyoming, 2019Every severe thunderstorm warning in 2019

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.