Alert archive / Nebraska / Mesoscale Discussions in 2020

Mesoscale Discussion 955

June 21, 2020Monona County, Plymouth County, Woodbury County, Iowa; 46 counties in Nebraska; Clay County, Union County, South Dakota

The Storm Prediction Center issued this mesoscale discussion at Jun 21, 2020, 2:19 PM CDT for Monona County, Plymouth County, Woodbury County, Iowa; 46 counties in Nebraska; Clay County, Union County, South Dakota. It was in force for 116 min.

The area

The outline as issued.

The facts

Issued
Jun 21, 2020, 2:19 PM CDT (19:19 UTC)
Expired
Jun 21, 2020, 4:15 PM CDT
In force
116 min
Issued by
the Storm Prediction Center
Concerning
Severe potential...watch likely
Chance of a watch
80%
All 51 counties

Monona County, IA, Plymouth County, IA, Woodbury County, IA, Adams County, NE, Antelope County, NE, Boone County, NE, Buffalo County, NE, Burt County, NE, Butler County, NE, Cedar County, NE, Clay County, NE, Colfax County, NE, Cuming County, NE, Custer County, NE, Dakota County, NE, Dawson County, NE, Dixon County, NE, Dodge County, NE, Franklin County, NE, Furnas County, NE, Garfield County, NE, Gosper County, NE, Greeley County, NE, Hall County, NE, Hamilton County, NE, Harlan County, NE, Holt County, NE, Howard County, NE, Kearney County, NE, Knox County, NE, Loup County, NE, Madison County, NE, Merrick County, NE, Nance County, NE, Phelps County, NE, Pierce County, NE, Platte County, NE, Polk County, NE, Saunders County, NE, Seward County, NE, Sherman County, NE, Stanton County, NE, Thurston County, NE, Valley County, NE, Washington County, NE, Wayne County, NE, Webster County, NE, Wheeler County, NE, York County, NE, Clay County, SD, Union County, SD

The radar

The Grand Island radar (KUEX), 142 km from the middle of the area, began a volume at 19:22 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

Omaha, NE (KOAX), launched 12:00Z, 7.3 hours before the alert went out and 145 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, Omaha, NE at 12:00Z on 2020-06-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 502 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, Omaha, NE at 12:00Z on 2020-06-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 79 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
502 J/kg
Mixed-layer CIN
-162 J/kg
Mixed-layer LCL
1703 m above ground
0-6 km bulk shear
33 kt
0-1 km storm-relative helicity
79 m²/s²
0-3 km storm-relative helicity
165 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
Jun 21, 2:44 PM CDTMesoscale DiscussionSPCCerro Gordo, Clay, Dickinson, Emmet, Hancock, Kossuth and 7 more2 hr
Jun 21, 3:19 PM CDTSevere Thunderstorm WatchSPCBuena Vista, Cherokee, Clay, Dickinson, Harrison, Ida and 10 more7 hr
Jun 21, 3:55 PM CDTSevere Thunderstorm WatchSPCCerro Gordo, Crawford, Emmet, Hancock, Howard, Humboldt and 8 more6 hr
Jun 21, 6:14 PM CDTMesoscale DiscussionSPCCerro Gordo, Emmet, Hancock, Humboldt, Kossuth, Mitchell and 3 more2 hr
Jun 21, 6:59 PM CDTMesoscale DiscussionSPCBuena Vista, Cherokee, Clay, Crawford, Dickinson, Harrison and 10 more2 hr
Jun 21, 2:05 PM CDTMesoscale DiscussionSPCCherry, Dawes, Sheridan2 hr
Jun 20, 7:28 PM CDTMesoscale DiscussionSPCAurora, Beadle, Brule, Buffalo, Charles Mix, Clark and 16 more2 hr

Nearby

Mesoscale Discussions in Nebraska, 2020Mesoscale Discussions in Iowa, 2020Mesoscale Discussions in South Dakota, 2020Every mesoscale discussion in 2020

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.