Alert archive / Utah / Winter Weather Advisories in 2021

Winter Weather Advisory 28, NWS Salt Lake City, UT

December 28, 202125 counties in Utah; Uinta County, Wyoming

NWS Salt Lake City, UT issued this winter weather advisory at Dec 28, 2021, 3:42 PM MST for 25 counties in Utah; Uinta County, Wyoming. It took effect at Dec 29, 2021, 3:00 PM MST. It was in force for 61 hr.

The area

The counties it named.

The facts

Issued: Dec 28, 2021, 3:42 PM MST (22:42 UTC)
In effect from: Dec 29, 2021, 3:00 PM MST
Expired: Jan 1, 2022, 3:52 AM MST
In force: 61 hr
Issued by: NWS Salt Lake City, UT

All 26 counties

Beaver County, UT, Box Elder County, UT, Cache County, UT, Carbon County, UT, Davis County, UT, Duchesne County, UT, Emery County, UT, Garfield County, UT, Iron County, UT, Juab County, UT, Kane County, UT, Millard County, UT, Morgan County, UT, Piute County, UT, Rich County, UT, Salt Lake County, UT, Sanpete County, UT, Sevier County, UT, Summit County, UT, Tooele County, UT, Utah County, UT, Wasatch County, UT, Washington County, UT, Wayne County, UT, Weber County, UT, Uinta County, WY

The radar

The Salt Lake City radar (KMTX), 177 km from the middle of the area, began a volume at 22:41 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

Grand Junction, CO (KGJT), launched 12:00Z, 10.7 hours before the alert went out and 297 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 700 m above ground
0-6 km bulk shear: 57 kt
0-1 km storm-relative helicity: 62 m²/s²
0-3 km storm-relative helicity: 176 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 winter weather advisory went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Salt Lake City, UT wrote its last area forecast discussion before this winter weather advisory went out at Dec 28, 4:22 AM MST, 11 hours 20 minutes earlier.

Area forecast discussion, Dec 28, 4:22 AM MST, 11 hours 20 minutes before

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The office that day

Everything else NWS Salt Lake City, UT issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Dec 27, 5:02 PM MST	Snow Squall Warning	SLC	Morgan, Rich, Summit, Weber	43 min
Dec 27, 5:45 PM MST	Snow Squall Warning	SLC	Salt Lake, Summit, Tooele, Utah, Wasatch	60 min
Dec 27, 6:51 PM MST	Special Weather Statement	SLC	Utah, Wasatch	39 min
Dec 28, 3:19 AM MST	Winter Storm Watch	SLC	Beaver, Box Elder, Cache, Carbon, Davis, Duchesne and 18 more	12 hr
Dec 27, 5:24 PM MST	Snow Squall Warning	SLC	Uinta	66 min

Nearby

Winter Weather Advisories in Utah, 2021 Winter Weather Advisories in Wyoming, 2021 Every winter weather 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.