Alert archive / Nebraska / Mesoscale Discussions in 2018

Mesoscale Discussion 914

June 28, 201812 counties in Iowa; Atchison County, Holt County, Nodaway County, Missouri; 32 counties in Nebraska

The Storm Prediction Center issued this mesoscale discussion at Jun 28, 2018, 7:20 AM CDT for 12 counties in Iowa; Atchison County, Holt County, Nodaway County, Missouri; 32 counties in Nebraska. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued
Jun 28, 2018, 7:20 AM CDT (12:20 UTC)
Expired
Jun 28, 2018, 9:45 AM CDT
In force
2 hr
Issued by
the Storm Prediction Center
Chance of a watch
60%
All 47 counties

Adair County, IA, Adams County, IA, Cass County, IA, Fremont County, IA, Harrison County, IA, Mills County, IA, Monona County, IA, Montgomery County, IA, Page County, IA, Pottawattamie County, IA, Shelby County, IA, Taylor County, IA, Atchison County, MO, Holt County, MO, Nodaway County, MO, Antelope County, NE, Boone County, NE, Burt County, NE, Butler County, NE, Cass County, NE, Colfax County, NE, Cuming County, NE, Dakota County, NE, Dodge County, NE, Douglas County, NE, Garfield County, NE, Greeley County, NE, Howard County, NE, Lancaster County, NE, Loup County, NE, Madison County, NE, Merrick County, NE, Nance County, NE, Nemaha County, NE, Otoe County, NE, Pierce County, NE, Platte County, NE, Polk County, NE, Sarpy County, NE, Saunders County, NE, Seward County, NE, Stanton County, NE, Thurston County, NE, Valley County, NE, Washington County, NE, Wayne County, NE, Wheeler County, NE

The radar

The Omaha radar (KOAX), 106 km from the middle of the area, began a volume at 12:23 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, 0.3 hours before the alert went out and 106 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 2018-06-28Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 3530 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 2018-06-28The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 40 square meters per square second.1939Sfc1 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
3530 J/kg
Mixed-layer CIN
-227 J/kg
Mixed-layer LCL
892 m above ground
0-6 km bulk shear
24 kt
0-1 km storm-relative helicity
40 m²/s²
0-3 km storm-relative helicity
161 m²/s²
Significant tornado parameter
0.0
Supercell composite
5.9

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 28, 8:12 AM CDTSevere Thunderstorm WatchSPCAdair, Adams, Appanoose, Audubon, Boone, Carroll and 28 more6 hr
Jun 28, 10:57 AM CDTMesoscale DiscussionSPCAdair, Adams, Appanoose, Audubon, Boone, Carroll and 27 more2 hr
Jun 28, 1:04 PM CDTSevere Thunderstorm WatchSPCDes Moines, Henry, Jefferson, Keokuk, Lee, Van Buren7 hr
Jun 28, 2:00 AM CDTMesoscale DiscussionSPCAdair, Audrain, Bollinger, Boone, Callaway, Cape Girardeau and 38 more3 hr
Jun 28, 8:43 AM CDTMesoscale DiscussionSPCAudrain, Bollinger, Boone, Callaway, Cape Girardeau, Cole and 25 more62 min
Jun 28, 3:34 PM CDTMesoscale DiscussionSPCLincoln, Marion, Montgomery, Pike, Ralls, Saint Charles and 3 more116 min
Jun 28, 5:33 PM CDTSevere Thunderstorm WatchSPCBollinger, Butler, Cape Girardeau, Dunklin, Iron, Madison and 10 more7 hr
Jun 28, 6:10 PM CDTMesoscale DiscussionSPCArthur, Cherry, Garden, Grant, Hooker, Sheridan2 hr

Nearby

Mesoscale Discussions in Nebraska, 2018Mesoscale Discussions in Iowa, 2018Mesoscale Discussions in Missouri, 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.