Alert archive / Wyoming / Special Weather Statements in 2023

Special Weather Statement, NWS Cheyenne, WY

August 1, 2023Platte County, Wyoming

NWS Cheyenne, WY issued this special weather statement at Aug 1, 2023, 7:21 PM MDT for Platte County, Wyoming. It was in force for 24 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 1, 2023, 7:21 PM MDT (01:21 UTC)
Expired: Aug 1, 2023, 7:45 PM MDT
In force: 24 min
Issued by: NWS Cheyenne, WY
Hail: 0.75 in
Wind: 40

County Platte County, WY

The radar

The Cheyenne radar (KCYS), 66 km from the middle of the area, began a volume at 01:21 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

Rapid City, SD (KUNR), launched 00:00Z, 1.4 hours before the alert went out and 304 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: 864 J/kg
Mixed-layer CIN: -28 J/kg
Mixed-layer LCL: 1857 m above ground
0-6 km bulk shear: 17 kt
0-1 km storm-relative helicity: -10 m²/s²
0-3 km storm-relative helicity: 43 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

476 
WWUS85 KCYS 020121
SPSCYS

Special Weather Statement
National Weather Service Cheyenne WY
721 PM MDT Tue Aug 1 2023
 
WYZ106>108-020145-
East Platte County WY-
Central Laramie Range and Southwest Platte County WY-
Goshen County WY-
721 PM MDT Tue Aug 1 2023

...A strong thunderstorm will impact portions of southwestern Goshen
and southeastern Platte Counties through 745 PM MDT...

At 720 PM MDT, Doppler radar was tracking a strong thunderstorm near 
Chugwater, or 18 miles south of Wheatland, moving southeast at 15 
mph.

HAZARD...Winds in excess of 40 mph and penny size hail.

SOURCE...Radar indicated.

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

Locations impacted include...
Chugwater and Slater. 

This includes Interstate 25 in Wyoming between mile markers 48 and
67.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building. 

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

&&

LAT...LON 4176 10503 4190 10489 4175 10458 4166 10468
      4166 10485
TIME...MOT...LOC 0120Z 307DEG 16KT 4179 10488 

MAX HAIL SIZE...0.75 IN
MAX WIND GUST...40 MPH

$$

Trudel

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 1, 7:01 PM MDT	Special Weather Statement	CYS	Platte	44 min
Aug 2, 2:28 AM MDT	Flood Watch	CYS	Albany, Carbon, Laramie, Platte	19 hr
Aug 2, 1:16 PM MDT	Special Weather Statement	CYS	Goshen	29 min
Aug 2, 2:00 PM MDT	Areal Flood Advisory	CYS	Platte	3 hr
Aug 2, 4:04 PM MDT	Areal Flood Advisory	CYS	Carbon	3 hr
Aug 2, 4:35 PM MDT	Special Weather Statement	CYS	Laramie	40 min
Aug 2, 4:50 PM MDT	Severe Thunderstorm Warning	CYS	Laramie	40 min
Aug 2, 5:20 PM MDT	Severe Thunderstorm Warning	CYS	Laramie	40 min
Aug 2, 3:19 PM MDT	Special Weather Statement	CYS	Cheyenne	56 min
Aug 2, 3:57 PM MDT	Areal Flood Advisory	CYS	Cheyenne	3 hr
Aug 2, 4:05 PM MDT	Special Weather Statement	CYS	Banner	40 min
Aug 2, 4:14 PM MDT	Special Weather Statement	CYS	Cheyenne	46 min
Aug 2, 5:11 PM MDT	Special Weather Statement	CYS	Morrill	49 min
Aug 2, 5:38 PM MDT	Special Weather Statement	CYS	Dawes	37 min

Nearby

Special Weather Statements in Wyoming, 2023 Every special weather statement in 2023

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.