Alert archive / Wyoming / Freeze Warnings in 2019

Freeze Warning 2, NWS Cheyenne, WY

September 20, 2019Albany County, Carbon County, Wyoming

NWS Cheyenne, WY issued this freeze warning at Sep 20, 2019, 2:59 AM MDT for Albany County, Carbon County, Wyoming. It took effect at Sep 21, 2019, 12:00 AM MDT. It was in force for 9 hr. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued: Sep 20, 2019, 2:59 AM MDT (08:59 UTC)
In effect from: Sep 21, 2019, 12:00 AM MDT
Expired: Sep 21, 2019, 9:00 AM MDT
In force: 9 hr
Issued by: NWS Cheyenne, WY

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 08:59 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 00:00Z, 9.0 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: 161 J/kg
Mixed-layer CIN: -5 J/kg
Mixed-layer LCL: 3612 m above ground
0-6 km bulk shear: 35 kt
0-1 km storm-relative helicity: 31 m²/s²
0-3 km storm-relative helicity: 93 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.2

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this freeze warning 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 freeze warning went out at Sep 20, 12:45 AM MDT, 2 hours 14 minutes earlier.

Area forecast discussion, Sep 20, 12:45 AM MDT, 2 hours 14 minutes before

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Hazardous weather outlook, Sep 19, 3:39 PM MDT, 11 hours 20 minutes before

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The office that day

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

Issued	Product	Office	Counties	Lasted
Sep 20, 2:07 PM MDT	High Wind Warning	CYS	Albany, Carbon	19 hr
Sep 20, 2:29 PM MDT	Special Weather Statement	CYS	Goshen	46 min
Sep 20, 2:42 PM MDT	Severe Thunderstorm Warning	CYS	Goshen, Laramie, Platte	48 min
Sep 20, 3:27 PM MDT	Severe Thunderstorm Warning	CYS	Goshen	48 min
Sep 20, 4:00 PM MDT	Special Weather Statement	CYS	Goshen	45 min
Sep 20, 4:11 PM MDT	Severe Thunderstorm Warning	CYS	Goshen	49 min
Sep 20, 4:15 PM MDT	Special Weather Statement	CYS	Niobrara	45 min
Sep 20, 4:20 PM MDT	Severe Thunderstorm Warning	CYS	Niobrara	40 min
Sep 20, 4:39 PM MDT	Special Weather Statement	CYS	Goshen	51 min
Sep 20, 4:39 PM MDT	Severe Thunderstorm Warning	CYS	Niobrara	36 min
Sep 20, 4:42 PM MDT	Special Weather Statement	CYS	Niobrara	48 min
Sep 20, 5:12 PM MDT	Special Weather Statement	CYS	Niobrara	48 min
Sep 20, 5:22 PM MDT	Severe Thunderstorm Warning	CYS	Converse, Niobrara	38 min
Sep 20, 4:16 PM MDT	Special Weather Statement	CYS	Dawes	44 min
Sep 20, 4:26 PM MDT	Severe Thunderstorm Warning	CYS	Dawes	49 min
Sep 20, 4:45 PM MDT	Special Weather Statement	CYS	Box Butte	45 min
Sep 20, 4:52 PM MDT	Severe Thunderstorm Warning	CYS	Box Butte, Dawes, Sioux	53 min
Sep 20, 4:58 PM MDT	Severe Thunderstorm Warning	CYS	Sioux	34 min
Sep 20, 5:17 PM MDT	Special Weather Statement	CYS	Dawes	43 min
Sep 20, 5:28 PM MDT	Severe Thunderstorm Warning	CYS	Box Butte, Morrill, Scotts Bluff, Sioux	62 min
Sep 20, 5:33 PM MDT	Severe Thunderstorm Warning	CYS	Dawes	27 min
Sep 20, 5:46 PM MDT	Special Weather Statement	CYS	Dawes	44 min

Nearby

Freeze Warnings in Wyoming, 2019 Every freeze warning in 2019

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.