Mesoscale Discussion 1081

Issued

Jun 24, 2021, 5:30 PM CDT (22:30 UTC)

Expired

Jun 24, 2021, 6:30 PM CDT

In force

60 min

Issued by

the Storm Prediction Center

Concerning

Tornado watch 309

The Topeka radar (KTWX), 131 km from the middle of the area, began a volume at 22:31 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.

• Tornado Watch 311Jun 24, 6:35 PM CDT
• Severe Thunderstorm Watch 312Jun 24, 8:55 PM CDT

595 
ACUS11 KWNS 242230
SWOMCD
SPC MCD 242230 
IAZ000-MOZ000-KSZ000-NEZ000-242330-

Mesoscale Discussion 1081
NWS Storm Prediction Center Norman OK
0530 PM CDT Thu Jun 24 2021

Areas affected...far northern Kansas and extreme southeastern
Nebraska

Concerning...Tornado Watch 309...

Valid 242230Z - 242330Z

The severe weather threat for Tornado Watch 309 continues.

SUMMARY...A few tornadoes may develop along an enhanced corridor
near a warm front across far northern Kansas and southern Nebraska.
A strong tornado will also be possible. Severe weather, including
tornadoes remain possible over the rest of the watch area.

DISCUSSION...22z objective analysis showed a well defined baroclinic
zone stretching from Jefferson County Nebraska to Brown County
kansas. Along this boundary, strong instability has developed with
surface dewpoints in the 70s F. Surface pressure falls have backed
low-level winds, supporting local strengthening of an already
impressive low-level shear profile. With 200-300 m2/s2 0-1 km SRH
observed via the 22z Topeka sounding, storms interacting with this
zone of enhanced vertical vorticity will likely be capable of
producing a few tornadoes as they track east over the next 1 to 3
hours. A strong tornado may also be possible given the favorable
parameter space with an observed effective-layer STP of 4.  

To the south and west, increasing convergence along the stationary
front may also support rapid severe storm development in the next
couple of hours. Low-level shear remains strong in this region as
well suggesting all severe hazards are possible. Recent mesoanalysis
shows moderate surface pressure rises to the west suggesting a
southeastward surge of the front may develop in the next couple of
hours. Should this occur, increased convergence resulting in upscale
growth of any initial discrete convection will likely occur. A
greater damaging wind threat may evolve over this region later this
evening.

..Lyons.. 06/24/2021

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

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

LAT...LON   40439484 39849493 39289650 39079732 38979802 39359808
            39609809 40179814 40289817 40479806 40579770 40649712
            40769635 40779578 40849486 40439484

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

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.