Alert archive / Utah / Mesoscale Discussions in 2007

Mesoscale Discussion 1792

August 18, 200712 counties in Utah; Uinta County, Wyoming

The Storm Prediction Center issued this mesoscale discussion at Aug 18, 2007, 2:50 PM MDT for 12 counties in Utah; Uinta County, Wyoming. It was in force for 115 min.

The area

The outline as issued.

The facts

Issued: Aug 18, 2007, 2:50 PM MDT (20:50 UTC)
Expired: Aug 18, 2007, 4:45 PM MDT
In force: 115 min
Issued by: the Storm Prediction Center

Counties Box Elder County, UT, Cache County, UT, Davis County, UT, Juab County, UT, Morgan County, UT, Rich County, UT, Salt Lake County, UT, Summit County, UT, Tooele County, UT, Utah County, UT, Wasatch County, UT, Weber County, UT, Uinta County, WY

The radar

The Salt Lake City radar (KMTX), 59 km from the middle of the area, began a volume at 20:54 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 614Aug 18, 4:10 PM MDT

The nearest sounding before it

Salt Lake City I, UT (KSLC), launched 12:00Z, 8.8 hours before the alert went out and 15 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: 16 J/kg
Mixed-layer CIN: -302 J/kg
Mixed-layer LCL: 2435 m above ground
0-6 km bulk shear: 34 kt
0-1 km storm-relative helicity: 215 m²/s²
0-3 km storm-relative helicity: 211 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

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SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Aug 18, 4:08 PM MDT	Severe Thunderstorm Watch	SPC	Box Elder, Cache, Rich	7 hr
Aug 18, 1:50 PM MDT	Mesoscale Discussion	SPC	Lincoln, Park, Sublette, Teton	115 min

Nearby

Mesoscale Discussions in Utah, 2007 Mesoscale Discussions in Wyoming, 2007 Every mesoscale discussion in 2007

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.