Alert archive / Kansas / Mesoscale Discussions in 2021

Mesoscale Discussion 1076

June 24, 202113 counties in Kansas; 5 counties in Nebraska

The Storm Prediction Center issued this mesoscale discussion at Jun 24, 2021, 2:45 PM CDT for 13 counties in Kansas; 5 counties in Nebraska. It was in force for 3 hr.

The area

The outline as issued.

The facts

Issued
Jun 24, 2021, 2:45 PM CDT (19:45 UTC)
Expired
Jun 24, 2021, 5:15 PM CDT
In force
3 hr
Issued by
the Storm Prediction Center
Concerning
Severe potential...tornado watch likely
Chance of a watch
80%

Counties Atchison County, KS, Brown County, KS, Douglas 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, Wabaunsee County, KS, Washington County, KS, Gage County, NE, Jefferson County, NE, Johnson County, NE, Pawnee County, NE, Richardson County, NE

The radar

The Topeka radar (KTWX), 79 km from the middle of the area, began a volume at 19:45 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, 7.8 hours before the alert went out and 93 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 2021-06-24Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2072 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 2021-06-24The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 342 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
2072 J/kg
Mixed-layer CIN
-283 J/kg
Mixed-layer LCL
688 m above ground
0-6 km bulk shear
26 kt
0-1 km storm-relative helicity
342 m²/s²
0-3 km storm-relative helicity
386 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.2

Open this sounding in Storm Lab

The text

As transmitted.

609 
ACUS11 KWNS 241946
SWOMCD
SPC MCD 241945 
MOZ000-KSZ000-NEZ000-242215-

Mesoscale Discussion 1076
NWS Storm Prediction Center Norman OK
0245 PM CDT Thu Jun 24 2021

Areas affected...southeast NE...northeast KS

Concerning...Severe potential...Tornado Watch likely 

Valid 241945Z - 242215Z

Probability of Watch Issuance...80 percent

SUMMARY...A tornado watch is likely this afternoon for much of this
area.

DISCUSSION...Visible-satellite imagery shows a capped cumulus field
across east-central KS.  A few storms have recently developed over
eastern KS on the north side of a modifying outflow boundary draped
from southeast KS arcing northwest into northeast KS.  Surface
temperatures have warmed into the upper 80s across northeast KS,
whereas persistent cloud cover over west-central MO in wake of an
earlier MCS, has limited heating with temperatures only in the
mid-upper 70s.

The Topeka, KS 2pm raob shows a supercell wind profile with a
capped, warm/moist boundary layer.  Comparing the observed Topeka
raob versus the 1-hr 18z run of the RAP valid at 19z, showed a
slightly warmer and drier boundary layer (17 g/kg lowest 100 mb mean
mixing ratio vs. 18.6 g/kg).  Using an internal dynamics method
(Bunkers) motion estimate, around 150-200 m2/s2 0-1km SRH was noted
both in the observed raob and the Topeka 88D VAD data.

Current forecast thinking is for convective initiation to prefer the
synoptic wind shift over southern NE late this afternoon.  Isolated
storms could develop farther south over northeast KS but uncertainty
is high for this scenario.  Eventually scattered thunderstorms will
probably develop over the lower MO Valley during the evening.  A
supercell threat with associated hazards will probably transition to
an high-precipitation supercell and later a squall line/bowing
segment evolution.

..Smith/Hart.. 06/24/2021

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

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

LAT...LON   40539675 40249734 39729743 38969632 38789560 38949500
            39329489 40349590 40539675

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jun 24, 1:36 AM CDTMesoscale DiscussionSPCAtchison, Brown, Doniphan, Nemaha114 min
Jun 24, 2:20 AM CDTSevere Thunderstorm WatchSPCAtchison, Brown, Doniphan, Nemaha6 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, 3:44 PM CDTTornado WatchSPCAtchison, Brown, Clay, Cloud, Doniphan, Jackson and 8 more5 hr
Jun 24, 4:56 PM CDTSevere Thunderstorm WatchSPCCheyenne, Decatur, Finney, Gove, Grant, Gray and 13 more6 hr
Jun 24, 5:30 PM CDTMesoscale DiscussionSPCBrown, Clay, Cloud, Doniphan, Marshall, Nemaha and 5 more60 min
Jun 24, 6:19 PM CDTMesoscale DiscussionSPCDoniphan, Wyandotte56 min
Jun 24, 6:31 PM CDTMesoscale DiscussionSPCCheyenne, Greeley, Hamilton, Kearny, Lane, Logan and 6 more119 min
Jun 23, 8:10 PM CDTMesoscale DiscussionSPCAntelope, Blaine, Boone, Boyd, Brown, Burt and 22 more95 min
Jun 23, 10:12 PM CDTMesoscale DiscussionSPCAntelope, Blaine, Boone, Boyd, Brown, Buffalo and 39 more93 min
Jun 23, 10:37 PM CDTSevere Thunderstorm WatchSPCAntelope, Blaine, Boone, Brown, Buffalo, Burt and 38 more6 hr

Nearby

Mesoscale 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.