Alert archive / South Dakota / Mesoscale Discussions in 2016

Mesoscale Discussion 1402

July 26, 20167 counties in Nebraska; 19 counties in South Dakota; Niobrara County, Wyoming

The Storm Prediction Center issued this mesoscale discussion at Jul 26, 2016, 5:32 PM CDT for 7 counties in Nebraska; 19 counties in South Dakota; Niobrara County, Wyoming. It was in force for 118 min.

The area

The outline as issued.

The facts

Issued
Jul 26, 2016, 5:32 PM CDT (22:32 UTC)
Expired
Jul 26, 2016, 7:30 PM CDT
In force
118 min
Issued by
the Storm Prediction Center
Chance of a watch
40%
All 27 counties

Boyd County, NE, Brown County, NE, Cherry County, NE, Dawes County, NE, Keya Paha County, NE, Rock County, NE, Sheridan County, NE, Aurora County, SD, Bennett County, SD, Brule County, SD, Buffalo County, SD, Charles Mix County, SD, Custer County, SD, Fall River County, SD, Gregory County, SD, Haakon County, SD, Jackson County, SD, Jones County, SD, Lawrence County, SD, Lyman County, SD, Mellette County, SD, Oglala Lakota County, SD, Pennington County, SD, Stanley County, SD, Todd County, SD, Tripp County, SD, Niobrara County, WY

The radar

The North Platte radar (KLNX), 154 km from the middle of the area, began a volume at 22:33 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

Rapid City, SD (KRAP), launched 12:00Z, 10.5 hours before the alert went out and 170 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, Rapid City, SD at 12:00Z on 2016-07-26Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1292 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Rapid City, SD at 12:00Z on 2016-07-26The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 22 square meters per square second.193958Sfc1 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
1292 J/kg
Mixed-layer CIN
-232 J/kg
Mixed-layer LCL
2137 m above ground
0-6 km bulk shear
40 kt
0-1 km storm-relative helicity
22 m²/s²
0-3 km storm-relative helicity
83 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.3

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
Jul 26, 6:05 PM CDTSevere Thunderstorm WatchSPCArthur, Boyd, Brown, Cherry, Garden, Grant and 8 more6 hr
Jul 26, 12:09 PM CDTMesoscale DiscussionSPCAurora, Beadle, Brown, Brule, Buffalo, Clark and 17 more96 min

Nearby

Mesoscale Discussions in South Dakota, 2016Mesoscale Discussions in Nebraska, 2016Mesoscale Discussions in Wyoming, 2016Every mesoscale discussion in 2016

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.