Alert archive / Nebraska / Mesoscale Discussions in 2021

Mesoscale Discussion 1073

June 24, 20214 states

The Storm Prediction Center issued this mesoscale discussion at Jun 24, 2021, 1:36 AM CDT for 4 states. It was in force for 114 min.

The area

The outline as issued.

The facts

Issued
Jun 24, 2021, 1:36 AM CDT (06:36 UTC)
Expired
Jun 24, 2021, 3:30 AM CDT
In force
114 min
Issued by
the Storm Prediction Center
Concerning
Severe thunderstorm watch 307
All 55 counties

Adams County, IA, Cass County, IA, Fremont County, IA, Harrison County, IA, Mills County, IA, Montgomery County, IA, Page County, IA, Pottawattamie County, IA, Ringgold County, IA, Taylor County, IA, Atchison County, KS, Brown County, KS, Doniphan County, KS, Nemaha County, KS, Andrew County, MO, Atchison County, MO, Buchanan County, MO, Clinton County, MO, DeKalb County, MO, Gentry County, MO, Harrison County, MO, Holt County, MO, Nodaway County, MO, Platte County, MO, Worth County, MO, Boone County, NE, Burt County, NE, Butler County, NE, Cass County, NE, Colfax County, NE, Cuming County, NE, Dodge County, NE, Douglas County, NE, Fillmore County, NE, Gage County, NE, Hamilton County, NE, Howard County, NE, Johnson County, NE, Lancaster County, NE, Madison County, NE, Merrick County, NE, Nance County, NE, Nemaha County, NE, Otoe County, NE, Pawnee County, NE, Platte County, NE, Polk County, NE, Richardson County, NE, Saline County, NE, Sarpy County, NE, Saunders County, NE, Seward County, NE, Stanton County, NE, Washington County, NE, York County, NE

The radar

The Omaha radar (KOAX), 64 km from the middle of the area, began a volume at 06:39 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 00:00Z, 6.6 hours before the alert went out and 64 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 00:00Z on 2021-06-24Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2039 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 00:00Z on 2021-06-24The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 60 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
2039 J/kg
Mixed-layer CIN
-306 J/kg
Mixed-layer LCL
1664 m above ground
0-6 km bulk shear
44 kt
0-1 km storm-relative helicity
60 m²/s²
0-3 km storm-relative helicity
168 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.4

Open this sounding in Storm Lab

The text

As transmitted.

760 
ACUS11 KWNS 240637
SWOMCD
SPC MCD 240636 
IAZ000-MOZ000-KSZ000-NEZ000-240830-

Mesoscale Discussion 1073
NWS Storm Prediction Center Norman OK
0136 AM CDT Thu Jun 24 2021

Areas affected...Eastern Nebraska...Far Northeast Kansas...Northwest
Missouri...Southwest Iowa

Concerning...Severe Thunderstorm Watch 307...

Valid 240636Z - 240830Z

The severe weather threat for Severe Thunderstorm Watch 307
continues.

SUMMARY...A potential for wind damage, isolated large hail and a
brief tornado will likely continue for several more hours. As the
MCS in northeast Nebraska moves southeastward toward the edge of
weather watch 307, a new watch will need to be considered.

DISCUSSION...The latest high-resolution radar imagery from Omaha
shows a well-developed bowing line segment located in northeast
Nebraska. A pronounced surface high-low couplet is evident behind
the bowing segment. Surface dewpoints ahead of the line are
generally in the lower 70s F, which is contributing to strong
instability. The RAP is analyzing a pocket of MLCAPE between 4000
and 4500 J/Kg. In addition, the Omaha WSR-88D VWP shows strong
directional shear in the low-levels with some speed shear in the mid
to upper levels. This wind profile along with a strong rear inflow
jet will continue support the bowing line segment as it moves
quickly southeastward across eastern Nebraska over the next couple
of hours. Wind damage will be likely along the leading edge with
wind gusts above 70 knots possible. Recently, the BVN observing site
reported a wind gust at 73 knots. Large hail and a brief tornado
will also be possible with the more intense rotating cells embedded
in the line. The line is expected to exit weather watch 307 by 09Z.
As it approaches the edge of the watch, a new watch will need to be
considered further downstream.

..Broyles/Edwards.. 06/24/2021

...Please see www.spc.noaa.gov for graphic product...

ATTN...WFO...DMX...EAX...OAX...TOP...GID...

LAT...LON   41569496 41919625 42079740 41919794 41539859 41219852
            40639779 40129703 39559597 39349525 39329462 39849402
            40379381 40849411 41569496

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jun 23, 8:10 PM CDTMesoscale DiscussionSPCMonona, Plymouth, Woodbury95 min
Jun 23, 10:12 PM CDTMesoscale DiscussionSPCHarrison, Mills, Monona, Pottawattamie93 min
Jun 23, 10:37 PM CDTSevere Thunderstorm WatchSPCFremont, Harrison, Mills, Monona, Pottawattamie, Shelby and 1 more6 hr
Jun 24, 2:20 AM CDTSevere Thunderstorm WatchSPCAdair, Adams, Audubon, Boone, Carroll, Cass and 15 more6 hr
Jun 24, 5:02 AM CDTMesoscale DiscussionSPCAppanoose, Clarke, Davis, Decatur, Lucas, Madison and 8 more118 min
Jun 24, 3:44 PM CDTTornado WatchSPCFremont, Page5 hr
Jun 24, 5:30 PM CDTMesoscale DiscussionSPCFremont, Page60 min
Jun 24, 6:19 PM CDTMesoscale DiscussionSPCAppanoose, Clarke, Davis, Decatur, Lucas, Monroe and 3 more56 min
Jun 24, 6:33 PM CDTTornado WatchSPCAdams, Appanoose, Clarke, Davis, Decatur, Lucas and 6 more3 hr
Jun 24, 2:45 PM CDTMesoscale DiscussionSPCAtchison, Brown, Douglas, Jackson, Jefferson, Leavenworth and 7 more3 hr
Jun 24, 2:49 PM CDTMesoscale DiscussionSPCCheyenne, Logan, Rawlins, Sherman, Thomas, Wallace116 min
Jun 24, 3:14 PM CDTMesoscale DiscussionSPCGray, Haskell, Meade, Seward91 min
Jun 24, 4:56 PM CDTSevere Thunderstorm WatchSPCCheyenne, Decatur, Finney, Gove, Grant, Gray and 13 more6 hr
Jun 24, 6:31 PM CDTMesoscale DiscussionSPCCheyenne, Greeley, Hamilton, Kearny, Lane, Logan and 6 more119 min

Nearby

Mesoscale Discussions in Nebraska, 2021Mesoscale Discussions in Missouri, 2021Mesoscale Discussions in Iowa, 2021Every mesoscale discussion in 2021

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.