Alert archive / Missouri / Mesoscale Discussions in 2021

Mesoscale Discussion 1401

July 30, 2021Brown County, Doniphan County, Kansas; 8 counties in Missouri; Nemaha County, Richardson County, Nebraska

The Storm Prediction Center issued this mesoscale discussion at Jul 30, 2021, 11:09 PM CDT for Brown County, Doniphan County, Kansas; 8 counties in Missouri; Nemaha County, Richardson County, Nebraska. It was in force for 96 min.

The area

The outline as issued.

The facts

Issued
Jul 30, 2021, 11:09 PM CDT (04:09 UTC)
Expired
Jul 31, 2021, 12:45 AM CDT
In force
96 min
Issued by
the Storm Prediction Center
Concerning
Severe thunderstorm watch 405

Counties Brown County, KS, Doniphan County, KS, Andrew County, MO, Daviess County, MO, DeKalb County, MO, Gentry County, MO, Harrison County, MO, Holt County, MO, Mercer County, MO, Nodaway County, MO, Nemaha County, NE, Richardson County, NE

The radar

The Pleasant Hill radar (KEAX), 156 km from the middle of the area, began a volume at 04:10 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 nearest sounding before it

Topeka, KS (KTOP), launched 00:00Z, 4.2 hours before the alert went out and 140 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, Topeka, KS at 00:00Z on 2021-07-31Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1481 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, Topeka, KS at 00:00Z on 2021-07-31The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 64 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
1481 J/kg
Mixed-layer CIN
-14 J/kg
Mixed-layer LCL
2071 m above ground
0-6 km bulk shear
30 kt
0-1 km storm-relative helicity
64 m²/s²
0-3 km storm-relative helicity
120 m²/s²
Significant tornado parameter
0.0
Supercell composite
4.2

Open this sounding in Storm Lab

The text

As transmitted.

575 
ACUS11 KWNS 310410
SWOMCD
SPC MCD 310409 
MOZ000-KSZ000-NEZ000-310545-

Mesoscale Discussion 1401
NWS Storm Prediction Center Norman OK
1109 PM CDT Fri Jul 30 2021

Areas affected...Southeast Nebraska...Northern Missouri

Concerning...Severe Thunderstorm Watch 405...

Valid 310409Z - 310545Z

The severe weather threat for Severe Thunderstorm Watch 405
continues.

SUMMARY...Isolated hail/wind threat will continue to sag south
across ww405.

DISCUSSION...Loosely organized squall line has formed along the
IA/MO border. Low-level warm advection appears to be aiding this
activity as it propagates south-southeast at roughly 25kt. Ample
buoyancy and a focused, but veered, LLJ suggest this activity will
continue for several more hours. Primary threats remain gusty winds
and marginally severe hail.

..Darrow.. 07/31/2021

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

ATTN...WFO...EAX...OAX...TOP...

LAT...LON   40439593 40439356 39669358 39679557 40439593

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jul 30, 8:47 PM CDTSevere Thunderstorm WatchSPCAtchison, Brown, Doniphan, Jackson, Jefferson, Leavenworth and 2 more5 hr
Jul 30, 11:05 PM CDTMesoscale DiscussionSPCBrown, Doniphan85 min
Jul 31, 12:54 AM CDTMesoscale DiscussionSPCDoniphan, Wyandotte66 min
Jul 31, 2:40 PM CDTMesoscale DiscussionSPCBarber, Clark, Comanche, Cowley, Harper, Kingman and 5 more2 hr
Jul 30, 8:16 PM CDTMesoscale DiscussionSPCAtchison59 min
Jul 31, 11:00 AM CDTMesoscale DiscussionSPCBollinger, Butler, Cape Girardeau, Carter, Dent, Howell and 16 more2 hr
Jul 31, 5:09 PM CDTMesoscale DiscussionSPCBarton, Bates, Bollinger, Butler, Camden, Carter and 37 more2 hr
Jul 30, 9:36 PM CDTMesoscale DiscussionSPCBrown, Garfield, Loup, Rock24 min
Jul 30, 9:46 PM CDTSevere Thunderstorm WatchSPCAntelope, Blaine, Boone, Brown, Garfield, Greeley and 8 more4 hr

Nearby

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