Alert archive / Nebraska / Mesoscale Discussions in 2021

Mesoscale Discussion 1222

July 9, 20214 states

The Storm Prediction Center issued this mesoscale discussion at Jul 9, 2021, 9:12 PM CDT for 4 states. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued
Jul 9, 2021, 9:12 PM CDT (02:12 UTC)
Expired
Jul 9, 2021, 11:15 PM CDT
In force
2 hr
Issued by
the Storm Prediction Center
Concerning
Severe potential...severe thunderstorm watch likely
Chance of a watch
95%
All 61 counties

Adair County, IA, 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, Shelby County, IA, Taylor County, IA, Union County, IA, Atchison County, KS, Brown County, KS, Clay County, KS, Cloud County, KS, Doniphan County, KS, Jackson County, KS, Jefferson County, KS, Leavenworth County, KS, Marshall County, KS, Nemaha County, KS, Pottawatomie County, KS, Riley County, KS, Shawnee County, KS, Washington County, KS, Wyandotte County, KS, Andrew County, MO, Atchison County, MO, Buchanan County, MO, Caldwell County, MO, Clay County, MO, Clinton County, MO, Daviess County, MO, DeKalb County, MO, Gentry County, MO, Harrison County, MO, Holt County, MO, Nodaway County, MO, Platte County, MO, Worth County, MO, Burt County, NE, Cass County, NE, Cuming County, NE, Dodge County, NE, Douglas County, NE, Gage County, NE, Jefferson County, NE, Johnson County, NE, Lancaster County, NE, Nemaha County, NE, Otoe County, NE, Pawnee County, NE, Richardson County, NE, Saline County, NE, Sarpy County, NE, Saunders County, NE, Seward County, NE, Thurston County, NE, Washington County, NE

The radar

The Omaha radar (KOAX), 108 km from the middle of the area, began a volume at 02:14 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, 2.2 hours before the alert went out and 108 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 2021-07-10Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2603 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 2021-07-10The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 90 square meters per square second.19395878Sfc1 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
2603 J/kg
Mixed-layer CIN
-130 J/kg
Mixed-layer LCL
1447 m above ground
0-6 km bulk shear
45 kt
0-1 km storm-relative helicity
90 m²/s²
0-3 km storm-relative helicity
186 m²/s²
Significant tornado parameter
0.6
Supercell composite
8.1

Open this sounding in Storm Lab

The text

As transmitted.

460 
ACUS11 KWNS 100212
SWOMCD
SPC MCD 100212 
MOZ000-IAZ000-KSZ000-NEZ000-100415-

Mesoscale Discussion 1222
NWS Storm Prediction Center Norman OK
0912 PM CDT Fri Jul 09 2021

Areas affected...eastern NE...southwest IA...northeast
KS...northwest MO

Concerning...Severe potential...Severe Thunderstorm Watch likely 

Valid 100212Z - 100415Z

Probability of Watch Issuance...95 percent

SUMMARY...A severe thunderstorm watch will likely be needed by late
evening for a severe risk expected to develop during the overnight. 
Severe gusts will be the primary risk with the stronger storms.

DISCUSSION...Radar mosaic shows several clusters of storms from the
SD/NE border into parts of western NE.  Water-vapor imagery
indicates the leading plume of large-scale ascent associated with a
mid-level shortwave trough, is currently over the Sandhills.  The
airmass over northeast KS northward into eastern NE/southwest IA is
very unstable with 2500-3000 J/kg MLCAPE according to modified
Topeka, KS and Omaha, NE 00z raobs.  The onset of an intensifying
LLJ over the central Great Plains is being observed in KUEX and KTWX
88D VAD data.  Models indicate the LLJ and associated warm air
advection/isentropic lift will increase through midnight with the
terminus of the LLJ focused over southeast NE/southwest IA and
adjacent parts of northeast KS/northwest MO.  Current expectation is
the ongoing strong to severe thunderstorm clusters over central NE
will move east-southeast over the next couple of hours, with an
associated severe hazard and move into western parts of the
discussion area by 11pm-12am.

..Smith/Thompson.. 07/10/2021

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

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

LAT...LON   42239676 41879537 41059389 39949371 39229415 38929566
            39319777 42239676

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jul 9, 7:08 PM CDTSevere Thunderstorm WatchSPCDes Moines, Henry, Iowa, Jefferson, Johnson, Keokuk and 4 more3 hr
Jul 9, 9:58 PM CDTSevere Thunderstorm WatchSPCAdair, Adams, Audubon, Carroll, Cass, Clarke and 16 more7 hr
Jul 10, 1:20 PM CDTMesoscale DiscussionSPCFremont, Mills, Montgomery, Page115 min
Jul 10, 2:18 PM CDTSevere Thunderstorm WatchSPCAdams, Audubon, Cass, Fremont, Harrison, Mills and 5 more7 hr
Jul 10, 3:44 PM CDTMesoscale DiscussionSPCFremont, Page91 min
Jul 9, 8:45 PM CDTSevere Thunderstorm WatchSPCJewell, Mitchell, Osborne, Phillips, Rooks, Smith8 hr
Jul 9, 8:49 PM CDTMesoscale DiscussionSPCGove, Greeley, Hamilton, Kearny, Lane, Logan and 4 more86 min
Jul 9, 9:37 PM CDTSevere Thunderstorm WatchSPCFinney, Gove, Greeley, Hamilton, Kearny, Lane and 8 more4 hr
Jul 9, 11:39 PM CDTMesoscale DiscussionSPCFinney, Grant, Gray, Greeley, Hamilton, Kearny and 4 more66 min
Jul 10, 1:10 AM CDTMesoscale DiscussionSPCEdwards, Finney, Ford, Grant, Gray, Hamilton and 10 more65 min
Jul 10, 1:21 AM CDTMesoscale DiscussionSPCAtchison, Brown, Doniphan, Jackson, Jefferson, Leavenworth and 2 more84 min
Jul 10, 2:57 AM CDTMesoscale DiscussionSPCAnderson, Clay, Cloud, Coffey, Dickinson, Douglas and 16 more93 min
Jul 10, 2:17 PM CDTMesoscale DiscussionSPCAllen, Bourbon, Butler, Chautauqua, Cherokee, Cowley and 11 more118 min
Jul 10, 3:02 PM CDTSevere Thunderstorm WatchSPCAllen, Bourbon, Butler, Chautauqua, Cherokee, Cowley and 9 more8 hr
Jul 10, 5:27 PM CDTMesoscale DiscussionSPCAtchison, Brown, Doniphan, Douglas, Jackson, Jefferson and 9 more2 hr
Jul 9, 7:54 PM CDTMesoscale DiscussionSPCAdair, Audrain, Chariton, Clark, Grundy, Knox and 18 more36 min
Jul 9, 8:18 PM CDTTornado WatchSPCAdair, Audrain, Boone, Callaway, Carroll, Chariton and 32 more6 hr
Jul 9, 10:26 PM CDTMesoscale DiscussionSPCAdair, Audrain, Boone, Callaway, Chariton, Cole and 21 more64 min
Jul 10, 1:01 AM CDTMesoscale DiscussionSPCBollinger, Boone, Callaway, Cape Girardeau, Chariton, Cole and 23 more59 min
Jul 10, 1:36 AM CDTSevere Thunderstorm WatchSPCBollinger, Butler, Cape Girardeau, Carter, Perry, Ripley and 3 more4 hr
Jul 10, 3:09 AM CDTMesoscale DiscussionSPCBollinger, Butler, Cape Girardeau, Carter, Perry, Ripley and 3 more2 hr
Jul 10, 5:04 AM CDTMesoscale DiscussionSPCButler, Carter, Ripley, Stoddard56 min
Jul 10, 11:37 AM CDTMesoscale DiscussionSPCBarry, Christian, Douglas, Howell, Laclede, McDonald and 9 more83 min
Jul 10, 1:25 PM CDTMesoscale DiscussionSPCBollinger, Butler, Camden, Cape Girardeau, Carter, Cedar and 34 more2 hr
Jul 10, 2:01 PM CDTSevere Thunderstorm WatchSPCBollinger, Butler, Cape Girardeau, Carter, Crawford, Franklin and 16 more8 hr
Jul 9, 8:21 PM CDTMesoscale DiscussionSPCAdams, Antelope, Arthur, Blaine, Boone, Boyd and 44 more114 min
Jul 9, 9:06 PM CDTSevere Thunderstorm WatchSPCArthur, Blaine, Boyd, Brown, Cherry, Custer and 15 more6 hr
Jul 9, 10:20 PM CDTMesoscale DiscussionSPCButler, Clay, Fillmore, Gage, Hamilton, Jefferson and 7 more115 min
Jul 9, 10:44 PM CDTMesoscale DiscussionSPCBox Butte, Garden, Grant, Sheridan91 min
Jul 10, 1:37 AM CDTMesoscale DiscussionSPCCuster, Dawson, Lincoln, Logan, Thomas53 min
Jul 10, 1:45 AM CDTMesoscale DiscussionSPCCuster, Dawson, Lincoln, Logan, Thomas60 min

Nearby

Mesoscale Discussions in Nebraska, 2021Mesoscale Discussions in Kansas, 2021Mesoscale Discussions in Missouri, 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.