Mesoscale Discussion 2028

Issued

Dec 15, 2021, 2:29 PM CST (20:29 UTC)

Expired

Dec 15, 2021, 4:30 PM CST

In force

2 hr

Issued by

the Storm Prediction Center

Concerning

Severe potential...watch possible

Chance of a watch

60%

The Topeka radar (KTWX), 62 km from the middle of the area, began a volume at 20:31 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.

• Severe Thunderstorm Watch 564Dec 15, 3:20 PM CST
• Severe Thunderstorm Watch 566Dec 15, 6:00 PM CST

645 
ACUS11 KWNS 152030
SWOMCD
SPC MCD 152029 
MOZ000-KSZ000-OKZ000-NEZ000-152230-

Mesoscale Discussion 2028
NWS Storm Prediction Center Norman OK
0229 PM CST Wed Dec 15 2021

Areas affected...Much of eastern Kansas and adjacent northeastern
Oklahoma into western Missouri

Concerning...Severe potential...Watch possible 

Valid 152029Z - 152230Z

Probability of Watch Issuance...60 percent

SUMMARY...A narrow line of intensifying showers and thunderstorms
may gradually evolve and overspread the region through 4-6 PM CST,
accompanied by the risk for potentially damaging wind gusts.

DISCUSSION...Strong mid/upper forcing for ascent associated with the
intense, cyclonically curved jet streak (in the 500-250 mb layer) is
passing to the north of the region, as the speed maximum propagates
across the central Great Plains toward the middle Missouri Valley. 
However, convection is deepening beneath the dry, subsident upper
regime to the south of the jet, along a modest lead surface cold
front as it gradually overtakes the dryline across central Kansas. 
This appears to be occurring just ahead of the leading edge of
stronger cooling around the 700 mb level, which is forecast to
approach the St. Joseph MO, Kansas City MO, Chanute KS, Ponca City
OK areas by around 16/00Z.

Aided by some further destabilization of a seasonably moist boundary
layer ahead of the front, the developing narrow line of convection
may continue to intensify and become capable of producing lightning.
 It is possible that this may tend to be undercut by the leading
edge of surface cooling, but steepening low-level lapse rates
(beneath the cooling just above the boundary-layer) will aid the
downward transport of higher momentum to the surface, in an
environmental flow regime characterized by 50-70+ kt southwesterly
mean wind speeds in the lowest 5-6 km AGL.

..Kerr/Hart.. 12/15/2021

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

ATTN...WFO...SGF...EAX...TSA...OAX...TOP...ICT...OUN...

LAT...LON   39209722 39729614 40389440 40349343 38559393 36949508
            36529700 36629803 37459770 38029731 39209722

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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.