Alert archive / Kansas / Mesoscale Discussions in 2020

Mesoscale Discussion 1012

June 26, 20204 states

The Storm Prediction Center issued this mesoscale discussion at Jun 26, 2020, 6:30 PM CDT for 4 states. It was in force for 90 min.

The area

The outline as issued.

The facts

Issued
Jun 26, 2020, 6:30 PM CDT (23:30 UTC)
Expired
Jun 26, 2020, 8:00 PM CDT
In force
90 min
Issued by
the Storm Prediction Center
Concerning
Severe potential...watch possible
Chance of a watch
60%
All 32 counties

Adams County, IA, Fremont County, IA, Mills County, IA, Montgomery County, IA, Page County, IA, Taylor County, IA, Union County, IA, Brown County, KS, Clay County, KS, Cloud County, KS, Doniphan County, KS, Geary County, KS, Jackson County, KS, Marshall County, KS, Nemaha County, KS, Ottawa County, KS, Pottawatomie County, KS, Republic County, KS, Riley County, KS, Wabaunsee County, KS, Washington County, KS, Atchison County, MO, Holt County, MO, Nodaway County, MO, Cass County, NE, Gage County, NE, Jefferson County, NE, Johnson County, NE, Nemaha County, NE, Otoe County, NE, Pawnee County, NE, Richardson County, NE

The radar

The Topeka radar (KTWX), 112 km from the middle of the area, began a volume at 23:32 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

Topeka, KS (KTOP), launched 12:00Z, 11.5 hours before the alert went out and 130 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 12:00Z on 2020-06-26Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 113 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 12:00Z on 2020-06-26The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 153 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
113 J/kg
Mixed-layer CIN
-475 J/kg
Mixed-layer LCL
1770 m above ground
0-6 km bulk shear
29 kt
0-1 km storm-relative helicity
153 m²/s²
0-3 km storm-relative helicity
119 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

682 
ACUS11 KWNS 262330
SWOMCD
SPC MCD 262330 
IAZ000-MOZ000-KSZ000-NEZ000-270100-

Mesoscale Discussion 1012
NWS Storm Prediction Center Norman OK
0630 PM CDT Fri Jun 26 2020

Areas affected...North-Central/Northeast Kansas...Southeast
Nebraska...Southwest Iowa...Northwest Missouri

Concerning...Severe potential...Watch possible 

Valid 262330Z - 270100Z

Probability of Watch Issuance...60 percent

SUMMARY...Severe thunderstorm watch may be warranted if
thunderstorms develop over the next 1-2 hours. Hail/wind are the
main threats.

DISCUSSION...Weak short-wave ridging, in the wake of northern IL
MCS, is expected to shift east across the mid-MO Valley over the
next few hours. Latest water-vapor imagery suggests this is
underway, and brief subsidence will wane. This should become more
supportive for thunderstorm development over the next few hours.

Latest vis satellite imagery exhibits a substantial cu field from
north-central KS, arcing into southwest IA. Within this field,
several deeper towers are beginning to generate anvils along with a
few showers. Sustained low-level warm advection should aid
convective development over the next few hours, especially as LLJ
strengthens after sunset. CAMs support a considerable increase along
this corridor, just south of the wind shift, and this lends
confidence that a severe thunderstorm watch may be needed by 01z.

..Darrow/Edwards.. 06/26/2020

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

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

LAT...LON   39739781 40379727 41139579 41049424 40199459 38709652
            38999762 39739781

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jun 26, 12:38 PM CDTMesoscale DiscussionSPCAllamakee, Benton, Black Hawk, Bremer, Buchanan, Butler and 17 more2 hr
Jun 26, 1:38 PM CDTSevere Thunderstorm WatchSPCAllamakee, Buchanan, Cedar, Clayton, Clinton, Delaware and 16 more8 hr
Jun 26, 3:39 PM CDTMesoscale DiscussionSPCCedar, Clayton, Clinton, Delaware, Dubuque, Jackson and 2 more2 hr
Jun 26, 5:40 PM CDTMesoscale DiscussionSPCAppanoose, Davis, Des Moines, Henry, Jefferson, Keokuk and 6 more65 min
Jun 25, 7:45 PM CDTMesoscale DiscussionSPCNorton60 min
Jun 26, 1:07 PM CDTMesoscale DiscussionSPCCheyenne, Kimball113 min
Jun 26, 4:51 PM CDTMesoscale DiscussionSPCBanner, Cheyenne, Deuel, Kimball84 min

Nearby

Mesoscale Discussions in Kansas, 2020Mesoscale Discussions in Nebraska, 2020Mesoscale Discussions in Iowa, 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.