Alert archive / Wyoming / Special Weather Statements in 2021

Special Weather Statement, NWS Cheyenne, WY

May 16, 2021

NWS Cheyenne, WY issued this special weather statement at May 16, 2021, 4:42 PM MDT. It was in force for 33 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
May 16, 2021, 4:42 PM MDT (22:42 UTC)
Expired
May 16, 2021, 5:15 PM MDT
In force
33 min
Issued by
NWS Cheyenne, WY

The radar

The Riverton/Lander radar (KRIW), 215 km from the middle of the area, began a volume at 22:44 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

Riverton, WY (KRIW), launched 12:00Z, 10.7 hours before the alert went out and 213 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, Riverton, WY at 12:00Z on 2021-05-16Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 7 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Riverton, WY at 12:00Z on 2021-05-16The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -50 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
7 J/kg
Mixed-layer CIN
-44 J/kg
Mixed-layer LCL
1066 m above ground
0-6 km bulk shear
25 kt
0-1 km storm-relative helicity
-50 m²/s²
0-3 km storm-relative helicity
20 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

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What forecasters said that day

The local office's own words before this special weather statement went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Cheyenne, WY wrote its last area forecast discussion before this special weather statement went out at May 16, 2:41 PM MDT, 2 hours 1 minute earlier.

Area forecast discussion, May 16, 2:41 PM MDT, 2 hours 1 minute before
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Hazardous weather outlook, May 16, 11:22 AM MDT, 5 hours 20 minutes before
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In the hours before

Local storm report, May 16, 2:23 PM MDT, 2 hours 19 minutes before
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Special weather statement, May 16, 4:42 PM MDT, 0 minutes before
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        Please try again in a few minutes.
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The office that day

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

IssuedProductOfficeCountiesLasted
May 15, 6:03 PM MDTSpecial Weather StatementCYSCarbon57 min
May 15, 6:19 PM MDTSpecial Weather StatementCYSCarbon56 min
May 16, 12:52 PM MDTAreal Flood AdvisoryCYSAlbany3 hr
May 16, 5:11 PM MDTSpecial Weather StatementCYSCarbon34 min
May 16, 5:26 PM MDTSevere Thunderstorm WarningCYSCarbon49 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.