Alert archive / Wyoming / Severe Thunderstorm Warnings in 2019

Severe Thunderstorm Warning 189, NWS Cheyenne, WY

July 4, 2019Goshen County, Wyoming; Sioux County, Nebraska

NWS Cheyenne, WY issued this severe thunderstorm warning at Jul 4, 2019, 11:38 PM MDT for Goshen County, Wyoming; Sioux County, Nebraska. It was in force for 52 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 4, 2019, 11:38 PM MDT (05:38 UTC)
Expired
Jul 5, 2019, 12:30 AM MDT
In force
52 min
Issued by
NWS Cheyenne, WY
Area
Storm-based polygon
Hail
1.75 in
Wind
60.0 mph

Counties Sioux County, NE, Goshen County, WY

The radar

The Cheyenne radar (KCYS), 141 km from the middle of the area, began a volume at 05:38 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
Jul 4, 2:37 PM MDTTornado WatchSPC9 hr

The nearest sounding before it

Rapid City, SD (KUNR), launched 00:00Z, 5.6 hours before the alert went out and 220 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 00:00Z on 2019-07-05Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 618 joules per kilogram.LCLLFCEL10008507005003002001001 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 00:00Z on 2019-07-05The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 79 square meters per square second.19395878Sfc1 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
618 J/kg
Mixed-layer CIN
-30 J/kg
Mixed-layer LCL
842 m above ground
0-6 km bulk shear
52 kt
0-1 km storm-relative helicity
79 m²/s²
0-3 km storm-relative helicity
172 m²/s²
Significant tornado parameter
0.6
Supercell composite
5.3

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 Jul 4, 11:28 PM MDT, 10 minutes earlier.

Area forecast discussion, Jul 4, 11:28 PM MDT, 10 minutes before
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Hazardous weather outlook, Jul 4, 3:29 AM MDT, 20 hours 9 minutes before
Hazardous Weather Outlook
National Weather Service Cheyenne WY
329 AM MDT Thu Jul 4 2019

NEZ002-003-019>021-054-055-095-096-WYZ101>119-050930-
Dawes-Box Butte-Scotts Bluff-Banner-Morrill-Kimball-Cheyenne-
North Sioux-South Sioux-Converse County Lower Elevations-
Niobrara County-North Laramie Range-
Ferris/Seminoe/Shirley Mountains-Shirley Basin-
Central Laramie Range and Southwest Platte County-
East Platte County-Goshen 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-
329 AM MDT Thu Jul 4 2019

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

.DAY ONE...TODAY AND TONIGHT

A slight to enhanced risk of severe thunderstorms exists this
afternoon and evening across most of the region east of Carbon
County.

A Flash Flood Watch is in effect from 3 PM MDT to midnight for
most of the Nebraska Panhandle as well as Niobrara and Goshen
Counties of southeast Wyoming.

Scattered to numerous thunderstorms will develop this afternoon
and continue into the overnight hours tonight. Some of the storms
will likely become severe, producing quarter size hail or larger
as well as wind gusts in excess of 60 mph. Some of the
thunderstorms will produce locally heavy rain and possible flash
flooding due to their slow movement.

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY

Isolated to scattered afternoon and evening thunderstorms can be
expected nearly every day. There is a marginal risk of severe
thunderstorms for Friday and Saturday, as a few of the storms may
become severe, producing large hail and damaging winds.

.Spotter information statement...

Spotter activation may be necessary this afternoon and evening.

Rubin

In the hours before

Local storm report, Jul 4, 9:52 PM MDT, 1 hour 46 minutes before
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Local storm report, Jul 4, 9:56 PM MDT, 1 hour 42 minutes before
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Local storm report, Jul 4, 10:09 PM MDT, 1 hour 29 minutes before
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Local storm report, Jul 4, 10:34 PM MDT, 1 hour 4 minutes before
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Special weather statement, Jul 4, 11:17 PM MDT, 21 minutes before
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Special weather statement, Jul 4, 11:29 PM MDT, 9 minutes before
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The office that day

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

IssuedProductOfficeCountiesLasted
Jul 4, 6:12 PM MDTSpecial Weather StatementCYSConverse48 min
Jul 4, 6:18 PM MDTSevere Thunderstorm WarningCYSConverse24 min
Jul 4, 6:33 PM MDTSpecial Weather StatementCYSConverse42 min
Jul 4, 6:41 PM MDTSevere Thunderstorm WarningCYSAlbany, Converse, Platte34 min
Jul 4, 7:22 PM MDTSpecial Weather StatementCYSPlatte53 min
Jul 4, 7:28 PM MDTSevere Thunderstorm WarningCYSAlbany, Converse, Platte32 min
Jul 4, 7:31 PM MDTFlash Flood WarningCYSAlbany, Converse, Platte3 hr
Jul 4, 7:49 PM MDTSpecial Weather StatementCYSNiobrara41 min
Jul 4, 7:56 PM MDTSevere Thunderstorm WarningCYSConverse, Platte49 min
Jul 4, 7:59 PM MDTSevere Thunderstorm WarningCYSNiobrara46 min
Jul 4, 8:17 PM MDTSevere Thunderstorm WarningCYSAlbany, Converse43 min
Jul 4, 8:33 PM MDTSevere Thunderstorm WarningCYSConverse, Goshen, Niobrara, Platte42 min
Jul 4, 8:44 PM MDTSevere Thunderstorm WarningCYSNiobrara31 min
Jul 4, 8:54 PM MDTSevere Thunderstorm WarningCYSLaramie36 min
Jul 4, 8:56 PM MDTSevere Thunderstorm WarningCYSAlbany, Converse, Platte34 min
Jul 4, 8:59 PM MDTSpecial Weather StatementCYSNiobrara46 min
Jul 4, 9:09 PM MDTSevere Thunderstorm WarningCYSAlbany, Converse36 min
Jul 4, 9:11 PM MDTSpecial Weather StatementCYSLaramie49 min
Jul 4, 9:26 PM MDTSevere Thunderstorm WarningCYSPlatte49 min
Jul 4, 9:30 PM MDTSpecial Weather StatementCYSLaramie45 min
Jul 4, 9:39 PM MDTSevere Thunderstorm WarningCYSAlbany, Converse, Platte51 min
Jul 4, 9:40 PM MDTSpecial Weather StatementCYSNiobrara50 min
Jul 4, 10:11 PM MDTSevere Thunderstorm WarningCYSGoshen, Platte64 min
Jul 4, 10:30 PM MDTSevere Thunderstorm WarningCYSPlatte60 min
Jul 4, 10:59 PM MDTSevere Thunderstorm WarningCYSGoshen61 min
Jul 4, 11:29 PM MDTSpecial Weather StatementCYSGoshen46 min
Jul 4, 11:57 PM MDTSpecial Weather StatementCYSGoshen48 min
Jul 5, 1:36 PM MDTSpecial Weather StatementCYSLaramie24 min
Jul 5, 2:28 PM MDTSpecial Weather StatementCYSPlatte62 min
Jul 5, 2:30 PM MDTSpecial Weather StatementCYSNiobrara60 min
Jul 5, 2:47 PM MDTSpecial Weather StatementCYSLaramie28 min
Jul 5, 2:53 PM MDTSevere Thunderstorm WarningCYSNiobrara52 min
Jul 5, 3:16 PM MDTSpecial Weather StatementCYSLaramie29 min
Jul 5, 3:36 PM MDTSevere Thunderstorm WarningCYSNiobrara24 min
Jul 5, 3:42 PM MDTSevere Thunderstorm WarningCYSGoshen, Platte48 min
Jul 5, 3:44 PM MDTSevere Thunderstorm WarningCYSPlatte46 min
Jul 5, 3:54 PM MDTSevere Thunderstorm WarningCYSNiobrara36 min
Jul 5, 4:02 PM MDTSpecial Weather StatementCYSLaramie28 min
Jul 5, 4:21 PM MDTSevere Thunderstorm WarningCYSNiobrara39 min
Jul 5, 4:26 PM MDTFlash Flood WarningCYSGoshen, Platte3 hr
Jul 5, 4:29 PM MDTSevere Thunderstorm WarningCYSGoshen, Platte46 min
Jul 5, 4:31 PM MDTSevere Thunderstorm WarningCYSNiobrara44 min
Jul 5, 4:55 PM MDTSevere Thunderstorm WarningCYSGoshen, Platte50 min
Jul 5, 4:56 PM MDTSpecial Weather StatementCYSNiobrara64 min
Jul 5, 5:15 PM MDTSevere Thunderstorm WarningCYSGoshen, Platte15 min
Jul 5, 5:24 PM MDTSevere Thunderstorm WarningCYSGoshen51 min
Jul 4, 11:17 PM MDTSpecial Weather StatementCYSDawes43 min
Jul 5, 12:04 AM MDTSpecial Weather StatementCYSDawes41 min
Jul 5, 12:26 AM MDTSevere Thunderstorm WarningCYSBox Butte, Dawes, Sioux34 min
Jul 5, 1:08 AM MDTSpecial Weather StatementCYSBox Butte, Scotts Bluff52 min
Jul 5, 4:01 PM MDTSpecial Weather StatementCYSBanner29 min
Jul 5, 5:07 PM MDTSevere Thunderstorm WarningCYSSioux38 min
Jul 5, 5:12 PM MDTTornado WarningCYSSioux33 min
Jul 5, 5:35 PM MDTTornado WarningCYSDawes, Sioux25 min

Nearby

Severe Thunderstorm Warnings in Wyoming, 2019Severe Thunderstorm Warnings in Nebraska, 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.