Alert archive / Wyoming / Special Weather Statements in 2021

Special Weather Statement, NWS Cheyenne, WY

June 18, 2021Laramie County, Wyoming

NWS Cheyenne, WY issued this special weather statement at Jun 18, 2021, 7:21 PM MDT for Laramie County, Wyoming. It was in force for 39 min. 5 reports came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued
Jun 18, 2021, 7:21 PM MDT (01:21 UTC)
Expired
Jun 18, 2021, 8:00 PM MDT
In force
39 min
Issued by
NWS Cheyenne, WY

County Laramie County, WY

The radar

The Cheyenne radar (KCYS), 10 km from the middle of the area, began a volume at 01:23 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.

What was reported inside it

TimeReportWhereRemark
Jun 18, 7:45 PM MDTHAIL 1.54 Nw Cheyenne, WYFACEBOOK POST. VANDEHEI AND I-25.
Jun 18, 7:55 PM MDTHAIL 1.55 N Cheyenne, WYQUARTER TO PING PONG BALL HAIL AT RANCHETTES.
Jun 18, 7:58 PM MDTHAIL 13 Nnw Cheyenne, WY
Jun 18, 8:00 PM MDTHAIL 1.256 Ne Cheyenne, WY
Jun 18, 8:05 PM MDTHAIL 1.52 Nnw Cheyenne, WY

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Denver, CO (KDNR), launched 00:00Z, 1.4 hours before the alert went out and 203 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, Denver, CO at 00:00Z on 2021-06-19Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 580 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Denver, CO at 00:00Z on 2021-06-19The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 35 square meters per square second.193958Sfc1 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
580 J/kg
Mixed-layer CIN
-27 J/kg
Mixed-layer LCL
2917 m above ground
0-6 km bulk shear
35 kt
0-1 km storm-relative helicity
35 m²/s²
0-3 km storm-relative helicity
78 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.7

Open this sounding in Storm Lab

The text

As transmitted.

488 
WWUS85 KCYS 190121
SPSCYS

Special Weather Statement
National Weather Service Cheyenne WY
721 PM MDT Fri Jun 18 2021
 
WYZ117-118-190200-
Central Laramie County WY-South Laramie Range Foothills WY-
721 PM MDT Fri Jun 18 2021

...SIGNIFICANT WEATHER ADVISORY FOR CENTRAL LARAMIE COUNTY UNTIL 800
PM MDT...

At 721 PM MDT, Doppler radar was tracking a strong thunderstorm over
North Cheyenne, or near Cheyenne, moving east at 5 mph.

Nickel size hail and wind gusts up to 50 mph will be possible with
this storm.

Locations impacted include...
Cheyenne, North Cheyenne, Ranchettes and Warren AFB. 

This includes Interstate 25 in Wyoming between mile markers 13 and
25.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

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 4117 10498 4134 10490 4137 10457 4116 10468
TIME...MOT...LOC 0121Z 289DEG 6KT 4124 10480 

$$

Cox

The office that day

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

IssuedProductOfficeCountiesLasted
Jun 18, 7:18 PM MDTRed Flag WarningCYS25 hr
Jun 18, 7:35 PM MDTSevere Thunderstorm WarningCYSLaramie40 min
Jun 18, 7:54 PM MDTSevere Thunderstorm WarningCYSLaramie51 min
Jun 18, 8:13 PM MDTSevere Thunderstorm WarningCYSLaramie47 min
Jun 18, 8:29 PM MDTSevere Thunderstorm WarningCYSLaramie46 min
Jun 18, 8:30 PM MDTSpecial Weather StatementCYSLaramie45 min
Jun 19, 12:54 PM MDTFire Weather WatchCYS7 hr
Jun 19, 1:18 PM MDTSpecial Weather StatementCYSLaramie42 min
Jun 19, 1:51 PM MDTSpecial Weather StatementCYSLaramie24 min
Jun 19, 1:41 PM MDTSpecial Weather StatementCYSBanner49 min
Jun 19, 2:04 PM MDTSevere Thunderstorm WarningCYSBanner, Morrill, Scotts Bluff41 min
Jun 19, 2:23 PM MDTSpecial Weather StatementCYSKimball52 min
Jun 19, 2:38 PM MDTSpecial Weather StatementCYSBox Butte52 min
Jun 19, 2:42 PM MDTSevere Thunderstorm WarningCYSBanner, Cheyenne, Kimball, Morrill36 min
Jun 19, 2:46 PM MDTSevere Thunderstorm WarningCYSBox Butte, Morrill17 min
Jun 19, 2:53 PM MDTSpecial Weather StatementCYSMorrill37 min
Jun 19, 3:20 PM MDTSpecial Weather StatementCYSCheyenne55 min
Jun 19, 3:31 PM MDTSevere Thunderstorm WarningCYSCheyenne59 min

Nearby

Special Weather Statements in Wyoming, 2021Every 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.