Alert archive / Wyoming / Special Weather Statements in 2021

Special Weather Statement, NWS Cheyenne, WY

August 6, 2021Laramie County, Wyoming

NWS Cheyenne, WY issued this special weather statement at Aug 6, 2021, 2:33 PM MDT for Laramie County, Wyoming. It was in force for 42 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 6, 2021, 2:33 PM MDT (20:33 UTC)
Expired
Aug 6, 2021, 3:15 PM MDT
In force
42 min
Issued by
NWS Cheyenne, WY
Hail
0.50 in
Wind
55

County Laramie County, WY

The radar

The Cheyenne radar (KCYS), 19 km from the middle of the area, began a volume at 20:36 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, 8.6 hours before the alert went out and 211 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 2021-08-06Temperature 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°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Denver, CO at 12:00Z on 2021-08-06The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 61 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
3319 m above ground
0-6 km bulk shear
21 kt
0-1 km storm-relative helicity
61 m²/s²
0-3 km storm-relative helicity
40 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

373 
WWUS85 KCYS 062033
SPSCYS

Special Weather Statement
National Weather Service Cheyenne WY
233 PM MDT Fri Aug 6 2021
 
WYZ116>118-062115-
South Laramie Range WY-Central Laramie County WY-
South Laramie Range Foothills WY-
233 PM MDT Fri Aug 6 2021

...A strong thunderstorm will impact portions of southwestern Laramie
County through 315 PM MDT...

At 232 PM MDT, Doppler radar was tracking a strong thunderstorm over
Crystal Lake Campground, or 19 miles west of Cheyenne, moving
northeast at 35 mph.

HAZARD...Wind gusts of 50 to 55 mph and half inch hail.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around 
         unsecured objects. Minor damage to outdoor objects is 
         possible.

This strong thunderstorm will be near...
  Federal around 245 PM MDT.
  North Cheyenne around 305 PM MDT.
  Whitaker around 315 PM MDT.

This includes the following highways...
 Interstate 25 in Wyoming between mile markers 12 and 33.
 Interstate 80 in Wyoming between mile markers 338 and 350.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building. 

&&

LAT...LON 4105 10519 4111 10527 4149 10492 4123 10459
TIME...MOT...LOC 2032Z 231DEG 31KT 4113 10516 

MAX HAIL SIZE...0.50 IN
MAX WIND GUST...55 MPH

$$

Rubin

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 6, 1:40 PM MDTSpecial Weather StatementCYSLaramie50 min
Aug 6, 2:13 PM MDTSpecial Weather StatementCYSConverse47 min
Aug 6, 3:12 PM MDTSpecial Weather StatementCYSConverse48 min
Aug 6, 3:18 PM MDTSevere Thunderstorm Warning Destructive damage threatCYSAlbany, Laramie42 min
Aug 6, 3:29 PM MDTSevere Thunderstorm Warning Considerable damage threatCYSAlbany, Converse, Goshen, Niobrara, Platte61 min
Aug 6, 4:08 PM MDTSpecial Weather StatementCYSNiobrara52 min
Aug 6, 3:09 PM MDTSpecial Weather StatementCYSScotts Bluff51 min
Aug 6, 3:31 PM MDTSpecial Weather StatementCYSBanner44 min
Aug 6, 3:53 PM MDTSpecial Weather StatementCYSBanner, Cheyenne, Morrill, Scotts Bluff52 min
Aug 6, 5:15 PM MDTSpecial Weather StatementCYSDawes45 min
Aug 6, 5:57 PM MDTSevere Thunderstorm WarningCYSDawes18 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.