Alert archive / Wyoming / Areal Flood Advisories in 2021

Areal Flood Advisory 2, NWS Cheyenne, WY

May 17, 2021Albany County, Carbon County, Wyoming

NWS Cheyenne, WY issued this areal flood advisory at May 17, 2021, 1:48 PM MDT for Albany County, Carbon County, Wyoming. It was in force for 3 hr.

The area

The counties it named.

The facts

Issued: May 17, 2021, 1:48 PM MDT (19:48 UTC)
Expired: May 17, 2021, 4:27 PM MDT
In force: 3 hr
Issued by: NWS Cheyenne, WY
Area: Storm-based polygon

Counties Albany County, WY, Carbon County, WY

The radar

The Cheyenne radar (KCYS), 140 km from the middle of the area, began a volume at 19:52 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, 7.8 hours before the alert went out and 329 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: 44 J/kg
Mixed-layer CIN: -30 J/kg
Mixed-layer LCL: 779 m above ground
0-6 km bulk shear: 9 kt
0-1 km storm-relative helicity: -7 m²/s²
0-3 km storm-relative helicity: 12 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this areal flood advisory 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 areal flood advisory went out at May 17, 11:10 AM MDT, 2 hours 38 minutes earlier.

Area forecast discussion, May 17, 11:10 AM MDT, 2 hours 38 minutes before

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Hazardous weather outlook, May 17, 5:42 AM MDT, 8 hours 6 minutes before

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In the hours before

Special weather statement, May 17, 1:34 PM MDT, 14 minutes before

Special Weather Statement
National Weather Service Cheyenne WY
134 PM MDT Mon May 17 2021

WYZ117-172000-
South Laramie Range Foothills-
134 PM MDT Mon May 17 2021

...A STRONG THUNDERSTORM WILL AFFECT SOUTHWESTERN LARAMIE COUNTY...

At 133 PM MDT, a strong thunderstorm was located 7 miles west of
Warren AFB, or 10 miles west of Cheyenne, moving northwest at 10 mph.

Winds in excess of 30 mph and pea size hail are likely with this
storm.

This storm will remain over mainly rural areas of southwestern
Laramie County.

If outdoors, consider seeking shelter inside a building.

LAT...LON 4115 10490 4112 10502 4122 10511 4127 10495
TIME...MOT...LOC 1933Z 153DEG 7KT 4117 10499

Jamski

The office that day

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

Issued	Product	Office	Counties	Lasted
May 17, 5:36 AM MDT	Dense Fog Advisory	CYS	Albany, Laramie	5 hr
May 17, 1:34 PM MDT	Special Weather Statement	CYS	Laramie	26 min
May 17, 2:05 PM MDT	Flash Flood Warning	CYS	Albany, Carbon	2 hr
May 17, 4:47 PM MDT	Special Weather Statement	CYS	Laramie	28 min
May 17, 5:22 PM MDT	Special Weather Statement	CYS		38 min

Nearby

Areal Flood Advisories in Wyoming, 2021 Every areal flood advisory 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.