Alert archive / Utah / Mesoscale Discussions in 2018

Mesoscale Discussion 1341

August 22, 2018Bear Lake County, Franklin County, Oneida County, Idaho; 7 counties in Utah

The Storm Prediction Center issued this mesoscale discussion at Aug 22, 2018, 12:25 PM MDT for Bear Lake County, Franklin County, Oneida County, Idaho; 7 counties in Utah. It was in force for 110 min.

The area

The outline as issued.

The facts

Issued: Aug 22, 2018, 12:25 PM MDT (18:25 UTC)
Expired: Aug 22, 2018, 2:15 PM MDT
In force: 110 min
Issued by: the Storm Prediction Center
Chance of a watch: 80%

Counties Bear Lake County, ID, Franklin County, ID, Oneida County, ID, Cache County, UT, Davis County, UT, Morgan County, UT, Rich County, UT, Salt Lake County, UT, Utah County, UT, Weber County, UT

The radar

The Salt Lake City radar (KMTX), 55 km from the middle of the area, began a volume at 18:29 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 watches that followed

Watches SPC issued over any of the same counties within four hours of this discussion.

Severe Thunderstorm Watch 347Aug 22, 12:50 PM MDT

The nearest sounding before it

Salt Lake City I, UT (KSLC), launched 12:00Z, 6.4 hours before the alert went out and 17 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: 132 J/kg
Mixed-layer CIN: -300 J/kg
Mixed-layer LCL: 1766 m above ground
0-6 km bulk shear: 35 kt
0-1 km storm-relative helicity: 78 m²/s²
0-3 km storm-relative helicity: 289 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 1.4

Open this sounding in Storm Lab

The text

As transmitted.

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SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Aug 22, 6:32 AM MDT	Mesoscale Discussion	SPC	Bannock, Bear Lake, Caribou, Franklin, Oneida	118 min
Aug 22, 12:51 PM MDT	Severe Thunderstorm Watch	SPC	Bannock, Bear Lake, Bingham, Bonneville, Caribou, Cassia and 3 more	8 hr
Aug 22, 2:57 PM MDT	Mesoscale Discussion	SPC	Bannock, Bear Lake, Bingham, Caribou, Franklin, Oneida and 1 more	93 min
Aug 22, 5:13 PM MDT	Mesoscale Discussion	SPC	Bannock, Bear Lake, Bingham, Caribou, Franklin, Oneida and 1 more	92 min

Nearby

Mesoscale Discussions in Utah, 2018 Mesoscale Discussions in Idaho, 2018 Every mesoscale discussion in 2018

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.