Alert archive / Wyoming / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 79, NWS Cheyenne, WY

July 5, 2021Albany County, Laramie County, Platte County, Wyoming

NWS Cheyenne, WY issued this severe thunderstorm warning at Jul 5, 2021, 3:21 PM MDT for Albany County, Laramie County, Platte County, Wyoming. It was in force for 39 min. 1 report 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: Jul 5, 2021, 3:21 PM MDT (21:21 UTC)
Expired: Jul 5, 2021, 4:00 PM MDT
In force: 39 min
Issued by: NWS Cheyenne, WY
Area: Storm-based polygon
Hail: 1.0 in
Wind: 60.0 mph

Counties Albany County, WY, Laramie County, WY, Platte County, WY

The radar

The Cheyenne radar (KCYS), 78 km from the middle of the area, began a volume at 21:22 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

Time	Report	Where	Remark
Jul 5, 3:27 PM MDT	HAIL 0.88	15 Wsw Bordeaux, 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 12:00Z, 9.4 hours before the alert went out and 269 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: 1 J/kg
Mixed-layer CIN: -470 J/kg
Mixed-layer LCL: 2151 m above ground
0-6 km bulk shear: 20 kt
0-1 km storm-relative helicity: -8 m²/s²
0-3 km storm-relative helicity: 65 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

781 
WUUS55 KCYS 052121
SVRCYS
WYC001-021-031-052200-
/O.NEW.KCYS.SV.W.0079.210705T2121Z-210705T2200Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Cheyenne WY
321 PM MDT Mon Jul 5 2021

The National Weather Service in Cheyenne has issued a

* Severe Thunderstorm Warning for...
  East central Albany County in southeastern Wyoming...
  Northwestern Laramie County in southeastern Wyoming...
  Southwestern Platte County in southeastern Wyoming...

* Until 400 PM MDT.

* At 320 PM MDT, severe thunderstorms were located along a line
  extending from 15 miles west of Bordeaux to 8 miles north of Iron
  Mountain, moving southeast at 25 mph.

  HAZARD...60 mph wind gusts and quarter size hail.

  SOURCE...Radar indicated.

  IMPACT...Hail damage to vehicles is expected. Expect wind damage 
           to roofs, siding, and trees.

* These severe thunderstorms will remain over mainly rural areas of
  east central Albany, northwestern Laramie and southwestern Platte
  Counties.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

Torrential rainfall is occurring with these storms, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.

&&

LAT...LON 4196 10496 4175 10493 4152 10503 4164 10545
      4185 10531 4199 10532
TIME...MOT...LOC 2120Z 299DEG 20KT 4187 10523 4167 10527 

HAIL...1.00IN
WIND...60MPH
 
$$

Brothers

2 follow-up statements

271 
WWUS55 KCYS 052132
SVSCYS

Severe Weather Statement
National Weather Service Cheyenne WY
332 PM MDT Mon Jul 5 2021

WYC001-021-031-052200-
/O.CON.KCYS.SV.W.0079.000000T0000Z-210705T2200Z/
Albany WY-Laramie WY-Platte WY-
332 PM MDT Mon Jul 5 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 400 PM MDT
FOR EAST CENTRAL ALBANY...NORTHWESTERN LARAMIE AND SOUTHWESTERN
PLATTE COUNTIES...

At 330 PM MDT, severe thunderstorms were located along a line
extending from 15 miles southwest of Bordeaux to 10 miles northwest
of Iron Mountain, moving southeast at 15 mph.

HAZARD...60 mph wind gusts and quarter size hail.

SOURCE...Radar indicated.

IMPACT...Hail damage to vehicles is expected. Expect wind damage to 
         roofs, siding, and trees. Large accumulations of small hail 
         possible.

These severe thunderstorms will remain over mainly rural areas of
east central Albany, northwestern Laramie and southwestern Platte
Counties.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

Torrential rainfall is occurring with these storms, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.

&&

LAT...LON 4194 10496 4175 10493 4152 10503 4163 10541
      4179 10525 4192 10525
TIME...MOT...LOC 2130Z 300DEG 15KT 4182 10519 4168 10530 

HAIL...1.00IN
WIND...60MPH
 
$$

Brothers

171 
WWUS55 KCYS 052158
SVSCYS

Severe Weather Statement
National Weather Service Cheyenne WY
358 PM MDT Mon Jul 5 2021

WYC001-021-031-052208-
/O.EXP.KCYS.SV.W.0079.000000T0000Z-210705T2200Z/
Albany WY-Laramie WY-Platte WY-
358 PM MDT Mon Jul 5 2021

...THE SEVERE THUNDERSTORM WARNING FOR EAST CENTRAL ALBANY...
NORTHWESTERN LARAMIE AND SOUTHWESTERN PLATTE COUNTIES WILL EXPIRE AT
400 PM MDT...
            
The storms which prompted the warning have weakened below severe
limits, and no longer pose an immediate threat to life or property.
Therefore, the warning will be allowed to expire.  However gusty
winds and heavy rain are still possible with these thunderstorms.

LAT...LON 4194 10496 4175 10493 4152 10503 4163 10541
      4179 10525 4192 10525
TIME...MOT...LOC 2158Z 299DEG 20KT 4175 10502 4161 10513 

$$

Brothers

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 5, 2:00 PM MDT	Special Weather Statement	CYS	Albany	30 min
Jul 5, 2:31 PM MDT	Special Weather Statement	CYS	Converse	44 min
Jul 5, 2:32 PM MDT	Areal Flood Advisory	CYS	Albany, Converse, Platte	118 min
Jul 5, 2:44 PM MDT	Special Weather Statement	CYS	Albany	31 min
Jul 5, 2:46 PM MDT	Special Weather Statement	CYS	Niobrara	44 min
Jul 5, 3:00 PM MDT	Special Weather Statement	CYS	Platte	30 min
Jul 5, 3:11 PM MDT	Special Weather Statement	CYS	Platte	34 min
Jul 5, 3:36 PM MDT	Special Weather Statement	CYS	Platte	39 min
Jul 5, 3:57 PM MDT	Areal Flood Advisory	CYS	Albany, Laramie	2 hr
Jul 5, 4:04 PM MDT	Special Weather Statement	CYS	Platte	26 min
Jul 5, 4:52 PM MDT	Special Weather Statement	CYS	Carbon	38 min
Jul 5, 5:06 PM MDT	Special Weather Statement	CYS	Goshen	24 min
Jul 5, 5:58 PM MDT	Special Weather Statement	CYS	Albany	47 min

Nearby

Severe Thunderstorm Warnings in Wyoming, 2021 Every severe thunderstorm warning 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.