Mesoscale Discussion 2173
NWS Storm Prediction Center Norman OK
0706 PM CDT Thu Sep 21 2023
Areas affected…southern Nebraska into northern Kansas
Concerning…Tornado Watch 687…688…
Valid 220006Z – 220200Z
The severe weather threat for Tornado Watch 687, 688 continues.
SUMMARY…The primary severe risk currently extends from parts of
southern into southwest Nebraska into northwest Kansas.
DISCUSSION…Relatively cooler/precipitation-reinforced air
currently exists over much of south-central NE into northeast KS,
with gusty easterly winds north of a front. This boundary extends
southeast from a cluster of strong to severe storms now over
southwest NE. South of this cluster and into the warm sector, a
plume of 80s F temperatures remains over northwest KS and over a
small part of southwest NE east of MCK.
Low-level shear is strongest near the outflow-reinforced boundary,
but surface-based instability is also weaker into the cooler air. A
relatively focused area of supercell tornado potential does exist to
the south and east of MCK and into the KS portions of the tornado
watches. CIN is expected to increase this evening, and this will
hamper additional development farther south away from the
boundaries. However, existing storms may continue to pose a severe
risk over the next few hours as they propagate southeastward along
the existing KS/NE boundary.
…Please see www.spc.noaa.gov for graphic product…
LAT…LON 39730135 40000067 40310033 40420011 40389963 40319919
40149902 39839892 39619903 39489953 39199993 38860037
39060095 39330132 39500135 39730135