Alert archive / Wyoming / Mesoscale Discussions in 2015

Mesoscale Discussion 1553

July 27, 20156 counties in Wyoming

The Storm Prediction Center issued this mesoscale discussion at Jul 27, 2015, 3:29 PM MDT for 6 counties in Wyoming. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued: Jul 27, 2015, 3:29 PM MDT (21:29 UTC)
Expired: Jul 27, 2015, 5:30 PM MDT
In force: 2 hr
Issued by: the Storm Prediction Center
Chance of a watch: 20%

Counties Big Horn County, WY, Fremont County, WY, Hot Springs County, WY, Johnson County, WY, Natrona County, WY, Washakie County, WY

The radar

The Riverton/Lander radar (KRIW), 93 km from the middle of the area, began a volume at 21:30 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

Rapid City, SD (KRAP), launched 12:00Z, 9.5 hours before the alert went out and 407 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: 237 J/kg
Mixed-layer CIN: -666 J/kg
Mixed-layer LCL: 1635 m above ground
0-6 km bulk shear: 26 kt
0-1 km storm-relative helicity: 81 m²/s²
0-3 km storm-relative helicity: 59 m²/s²
Significant tornado parameter: 0.0
Supercell composite: -0.2

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
Jul 27, 1:44 PM MDT	Mesoscale Discussion	SPC	Big Horn, Johnson, Sheridan	2 hr
Jul 27, 2:50 PM MDT	Mesoscale Discussion	SPC	Campbell, Crook, Weston	85 min
Jul 27, 2:58 PM MDT	Severe Thunderstorm Watch	SPC	Campbell, Crook, Sheridan, Weston	7 hr
Jul 27, 3:57 PM MDT	Mesoscale Discussion	SPC	Goshen, Laramie	2 hr
Jul 27, 5:32 PM MDT	Mesoscale Discussion	SPC	Crook	118 min

Nearby

Mesoscale Discussions in Wyoming, 2015 Every mesoscale discussion in 2015

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.