Alert archive / Nebraska / Mesoscale Discussions in 2018

Mesoscale Discussion 1043

July 12, 2018Phillips County, Sedgwick County, Colorado; 33 counties in Nebraska; 15 counties in South Dakota

The Storm Prediction Center issued this mesoscale discussion at Jul 12, 2018, 1:47 PM MDT for Phillips County, Sedgwick County, Colorado; 33 counties in Nebraska; 15 counties in South Dakota. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued
Jul 12, 2018, 1:47 PM MDT (19:47 UTC)
Expired
Jul 12, 2018, 4:15 PM MDT
In force
2 hr
Issued by
the Storm Prediction Center
Chance of a watch
60%
All 50 counties

Phillips County, CO, Sedgwick County, CO, Antelope County, NE, Arthur County, NE, Blaine County, NE, Box Butte County, NE, Boyd County, NE, Brown County, NE, Cedar County, NE, Chase County, NE, Cherry County, NE, Cheyenne County, NE, Deuel County, NE, Dixon County, NE, Dundy County, NE, Garden County, NE, Garfield County, NE, Grant County, NE, Hayes County, NE, Holt County, NE, Hooker County, NE, Keith County, NE, Keya Paha County, NE, Knox County, NE, Lincoln County, NE, Logan County, NE, Loup County, NE, McPherson County, NE, Morrill County, NE, Perkins County, NE, Pierce County, NE, Rock County, NE, Sheridan County, NE, Thomas County, NE, Wheeler County, NE, Bon Homme County, SD, Charles Mix County, SD, Clay County, SD, Douglas County, SD, Gregory County, SD, Hanson County, SD, Hutchinson County, SD, Lincoln County, SD, McCook County, SD, Minnehaha County, SD, Todd County, SD, Tripp County, SD, Turner County, SD, Union County, SD, Yankton County, SD

The radar

The North Platte radar (KLNX), 48 km from the middle of the area, began a volume at 19:51 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

N. Platte/Lee Bi, NE (KLBF), launched 12:00Z, 7.8 hours before the alert went out and 115 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, N. Platte/Lee Bi, NE at 12:00Z on 2018-07-12Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 338 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, N. Platte/Lee Bi, NE at 12:00Z on 2018-07-12The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -12 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
338 J/kg
Mixed-layer CIN
-214 J/kg
Mixed-layer LCL
2031 m above ground
0-6 km bulk shear
15 kt
0-1 km storm-relative helicity
-12 m²/s²
0-3 km storm-relative helicity
31 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.1

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 12, 2:24 PM MDTSevere Thunderstorm WatchSPCArthur, Blaine, Boyd, Brown, Cedar, Cherry and 9 more7 hr
Jul 12, 5:36 PM MDTMesoscale DiscussionSPCAntelope, Arthur, Blaine, Boyd, Brown, Cedar and 12 more84 min
Jul 12, 3:47 PM MDTMesoscale DiscussionSPCMoody88 min

Nearby

Mesoscale Discussions in Nebraska, 2018Mesoscale Discussions in South Dakota, 2018Mesoscale Discussions in Colorado, 2018Every 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.