Alert archive / Wyoming / Special Weather Statements in 2021

Special Weather Statement, NWS Cheyenne, WY

August 9, 2021Goshen County, Wyoming

NWS Cheyenne, WY issued this special weather statement at Aug 9, 2021, 4:06 PM MDT for Goshen County, Wyoming. It was in force for 39 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
Aug 9, 2021, 4:06 PM MDT (22:06 UTC)
Expired
Aug 9, 2021, 4:45 PM MDT
In force
39 min
Issued by
NWS Cheyenne, WY
Hail
0.00 in
Wind
55

County Goshen County, WY

The radar

The Cheyenne radar (KCYS), 68 km from the middle of the area, began a volume at 22:08 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

Denver, CO (KDNR), launched 12:00Z, 10.1 hours before the alert went out and 238 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 12:00Z on 2021-08-09Temperature 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, Denver, CO at 12:00Z on 2021-08-09The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
3514 m above ground
0-6 km bulk shear
21 kt
0-1 km storm-relative helicity
-1 m²/s²
0-3 km storm-relative helicity
28 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

803 
WWUS85 KCYS 092206
SPSCYS

Special Weather Statement
National Weather Service Cheyenne WY
406 PM MDT Mon Aug 9 2021
 
WYZ106>108-092245-
East Platte County WY-
Central Laramie Range and Southwest Platte County WY-
Goshen County WY-
406 PM MDT Mon Aug 9 2021

...A strong thunderstorm will impact portions of southern Goshen and
southeastern Platte Counties through 445 PM MDT...

At 406 PM MDT, Doppler radar was tracking a thunderstorm over 
Chugwater, or 23 miles south of Wheatland, moving east at 40 mph.

HAZARD...Wind gusts of 50 to 55 mph.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around 
         unsecured objects.

This strong thunderstorm will be near...
  Hawk Springs, Hawk Springs Recreation Area and Hawk Springs 
  Campground around 445 PM MDT.

This includes Interstate 25 in Wyoming between mile markers 50 and
57.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building. 

&&

LAT...LON 4169 10486 4176 10488 4196 10422 4163 10415
TIME...MOT...LOC 2206Z 261DEG 36KT 4173 10480 

MAX HAIL SIZE...0.00 IN
MAX WIND GUST...55 MPH

$$

Rubin

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 9, 2:46 PM MDTFire Weather WatchCYS13 hr
Aug 9, 4:08 PM MDTSpecial Weather StatementCYSCheyenne52 min
Aug 9, 4:26 PM MDTSpecial Weather StatementCYSCheyenne49 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.