Alert archive / Wyoming / Mesoscale Discussions in 2017

Mesoscale Discussion 719

May 15, 20174 states

The Storm Prediction Center issued this mesoscale discussion at May 15, 2017, 3:07 PM MDT for 4 states. It was in force for 113 min.

The area

The outline as issued.

The facts

Issued
May 15, 2017, 3:07 PM MDT (21:07 UTC)
Expired
May 15, 2017, 5:00 PM MDT
In force
113 min
Issued by
the Storm Prediction Center
Chance of a watch
40%
All 22 counties

Carter County, MT, Custer County, MT, Powder River County, MT, Prairie County, MT, Box Butte County, NE, Dawes County, NE, Scotts Bluff County, NE, Sioux County, NE, Butte County, SD, Custer County, SD, Fall River County, SD, Lawrence County, SD, Oglala Lakota County, SD, Pennington County, SD, Campbell County, WY, Converse County, WY, Crook County, WY, Goshen County, WY, Niobrara County, WY, Platte County, WY, Sheridan County, WY, Weston County, WY

The radar

The Rapid City radar (KUDX), 163 km from the middle of the area, began a volume at 21:11 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.

The nearest sounding before it

Riverton, WY (KRIW), launched 12:00Z, 9.1 hours before the alert went out and 301 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-pSkew-T log-p diagram, Riverton, WY at 12:00Z on 2017-05-15Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 km2 km3 km6 km9 km12 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Riverton, WY at 12:00Z on 2017-05-15The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -80 square meters per square second.1939587897Sfc1 km3 km6 km9 kmRMLM
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
1899 m above ground
0-6 km bulk shear
62 kt
0-1 km storm-relative helicity
-80 m²/s²
0-3 km storm-relative helicity
79 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

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.

IssuedProductOfficeCountiesLasted
May 15, 4:40 PM MDTSevere Thunderstorm WatchSPCCarter, Custer, Fallon, Powder River7 hr
May 15, 2:44 PM MDTSevere Thunderstorm WatchSPCDundy, Hitchcock, Red Willow7 hr
May 15, 4:58 PM MDTMesoscale DiscussionSPCAdams, Boone, Buffalo, Clay, Custer, Dawson and 23 more2 hr
May 15, 5:53 PM MDTSevere Thunderstorm WatchSPCAdams, Buffalo, Clay, Custer, Dawson, Fillmore and 20 more6 hr
May 15, 8:15 AM MDTMesoscale DiscussionSPCHutchinson, Lincoln, McCook, Minnehaha, Turner90 min

Nearby

Mesoscale Discussions in Wyoming, 2017Mesoscale Discussions in South Dakota, 2017Mesoscale Discussions in Montana, 2017Every mesoscale discussion in 2017

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.