Alert archive / Wyoming / Special Weather Statements in 2021

Special Weather Statement, NWS Cheyenne, WY

May 15, 2021Carbon County, Wyoming

NWS Cheyenne, WY issued this special weather statement at May 15, 2021, 6:19 PM MDT for Carbon County, Wyoming. It was in force for 56 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: May 15, 2021, 6:19 PM MDT (00:19 UTC)
Expired: May 15, 2021, 7:15 PM MDT
In force: 56 min
Issued by: NWS Cheyenne, WY

County Carbon County, WY

The radar

The Cheyenne radar (KCYS), 192 km from the middle of the area, began a volume at 00:12 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

Riverton, WY (KRIW), launched 00:00Z, 0.3 hours before the alert went out and 196 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 100 J/kg
Mixed-layer CIN: -11 J/kg
Mixed-layer LCL: 1412 m above ground
0-6 km bulk shear: 14 kt
0-1 km storm-relative helicity: -16 m²/s²
0-3 km storm-relative helicity: 133 m²/s²
Significant tornado parameter: 0.0
Supercell composite: -0.0

Open this sounding in Storm Lab

The text

As transmitted.

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What forecasters said that day

The local office's own words before this special weather statement 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 special weather statement went out at May 15, 5:49 PM MDT, 30 minutes earlier.

Area forecast discussion, May 15, 5:49 PM MDT, 30 minutes before

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Hazardous weather outlook, May 15, 2:04 PM MDT, 4 hours 15 minutes before

Hazardous Weather Outlook
National Weather Service Cheyenne WY
204 PM MDT Sat May 15 2021

NEZ002-003-019>021-054-055-095-096-WYZ101>119-162015-
Dawes County-Box Butte County-Scotts Bluff County-Banner County-
Morrill County-Kimball County-Cheyenne County-
Northern Sioux County-Southern Sioux County-
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-
204 PM MDT Sat May 15 2021

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

.DAY ONE...THIS AFTERNOON AND TONIGHT

Isolated to scattered showers and thunderstorms possible into the
evening hours. Some may be on the strong to low-end severe with
wind gusts up to 60 mph and hail up to one inch in diameter.

.DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY

Daily chances in the afternoon and evening of thunderstorms, some
on the strong to severe side with gusty winds, heavy rainfall,
and hail possible.

.Spotter information statement...

Spotters are encouraged to report any thunderstorm wind damage,
hail, and heavy rainfall to the Cheyenne, Wyoming National Weather
Service.

In the hours before

Special weather statement, May 15, 2:46 PM MDT, 3 hours 33 minutes before

Special Weather Statement
National Weather Service Cheyenne WY
246 PM MDT Sat May 15 2021

WYZ115-116-152130-
South Laramie Range-Laramie Valley-
246 PM MDT Sat May 15 2021

...A STRONG THUNDERSTORM WILL AFFECT SOUTH CENTRAL ALBANY COUNTY...

At 245 PM MDT, a strong thunderstorm was located 10 miles northeast
of Four Corners, or 25 miles southwest of Laramie, moving northeast
at 20 mph.

Locations impacted include...
Pumpkin Vine, Tie Siding and The Buttes.

Torrential rainfall is occurring with this storm, and may cause
localized flooding. Do not drive your vehicle through flooded
roadways.

Frequent cloud to ground lightning is also occurring with this storm.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.

LAT...LON 4127 10556 4107 10533 4099 10548 4099 10589
      4100 10590
TIME...MOT...LOC 2045Z 230DEG 18KT 4097 10577

Braun

Special weather statement, May 15, 4:37 PM MDT, 1 hour 42 minutes before

Special Weather Statement
National Weather Service Cheyenne WY
437 PM MDT Sat May 15 2021

WYZ103-106-152330-
Central Laramie Range and Southwest Platte County WY-
North Laramie Range WY-
437 PM MDT Sat May 15 2021

...SIGNIFICANT WEATHER ADVISORY FOR NORTHEASTERN ALBANY COUNTY UNTIL
530 PM MDT...

At 436 PM MDT, Doppler radar was tracking a strong thunderstorm near
Wheatland Reservoir 3, or 35 miles west of Wheatland, moving
northeast at 25 mph.

Half inch hail and winds in excess of 40 mph will be possible with
this storm.

This storm will remain over mainly rural areas of northeastern Albany
County.

LAT...LON 4189 10567 4193 10573 4228 10545 4230 10529
      4210 10530 4193 10537
TIME...MOT...LOC 2236Z 226DEG 22KT 4196 10564

Rubin

Special weather statement, May 15, 4:46 PM MDT, 1 hour 33 minutes before

Special Weather Statement
National Weather Service Cheyenne WY
446 PM MDT Sat May 15 2021

WYZ109-152345-
Central Carbon County WY-
446 PM MDT Sat May 15 2021

...SIGNIFICANT WEATHER ADVISORY FOR CENTRAL CARBON COUNTY UNTIL 545
PM MDT...

At 446 PM MDT, Doppler radar was tracking a strong thunderstorm over
Teton Reservoir, or 12 miles south of Rawlins, moving northeast at 10
mph.

Half inch hail and winds in excess of 40 mph will be possible with
this storm.

This storm will remain over mainly rural areas of central Carbon
County.

LAT...LON 4155 10730 4165 10741 4177 10721 4163 10698
TIME...MOT...LOC 2246Z 230DEG 8KT 4161 10728

Rubin

Special weather statement, May 15, 6:03 PM MDT, 16 minutes before

Special Weather Statement
National Weather Service Cheyenne WY
603 PM MDT Sat May 15 2021

WYZ109-160100-
Central Carbon County WY-
603 PM MDT Sat May 15 2021

...SIGNIFICANT WEATHER ADVISORY FOR CENTRAL CARBON COUNTY UNTIL 700
PM MDT...

At 602 PM MDT, Doppler radar was tracking a strong thunderstorm near
Rawlins, moving east at 15 mph.

Half inch hail and winds in excess of 40 mph will be possible with
this storm.

This strong thunderstorm will be near...
  Rawlins around 615 PM MDT.
  Sinclair around 635 PM MDT.

This includes Interstate 80 in Wyoming between mile markers 206 and
227.

LAT...LON 4173 10737 4184 10738 4191 10699 4165 10697
TIME...MOT...LOC 0002Z 270DEG 14KT 4177 10730

Rubin

Special weather statement, May 15, 6:19 PM MDT, 0 minutes before

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The office that day

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

Issued	Product	Office	Counties	Lasted
May 15, 6:03 PM MDT	Special Weather Statement	CYS	Carbon	57 min
May 16, 12:52 PM MDT	Areal Flood Advisory	CYS	Albany	3 hr
May 16, 4:42 PM MDT	Special Weather Statement	CYS		33 min
May 16, 5:11 PM MDT	Special Weather Statement	CYS	Carbon	34 min
May 16, 5:26 PM MDT	Severe Thunderstorm Warning	CYS	Carbon	49 min

Nearby

Special Weather Statements in Wyoming, 2021 Every special weather statement 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.