448
ACUS11 KWNS 202216
SWOMCD
SPC MCD 202215
NEZ000-COZ000-WYZ000-202345-

Mesoscale Discussion 1347
NWS Storm Prediction Center Norman OK
0515 PM CDT Thu Jun 20 2024

Areas affected...Portions of northeast Colorado into the Nebraska
Panhandle

Concerning...Severe Thunderstorm Watch 439...

Valid 202215Z - 202345Z

The severe weather threat for Severe Thunderstorm Watch 439
continues.

SUMMARY...While large hail and a tornado or two will remain
possible, particularly within more favorable mesoscale corridors,
the primary hazard over the next few hours will likely be severe
gusts associated with a developing MCS in the Nebraska Panhandle.

DISCUSSION...A supercell in eastern Wyoming, which was responsible
for a few 4.5 in. hail reports, has grown upscale into a linear
segment in the western Nebraska. This has occurred as the activity
moved into a very well-mixed boundary layer. Given this trend,
potential for severe gusts will likely increase with time. This
complex recently produced a 61 kt gust at Scottsbluff, NE. Large
hail will also remain possible, though very-large hail will be
conditional on a supercell mode. Some tornado risk will also remain
with the remnant supercell circulation/bookend vortex as well as
with any storm favorably interacting with the warm front in northern
Nebraska. As a cold pool circulation matures in the Nebraska
Panhandle, an increasing low-level jet should promote storm
maintenance into the evening farther east.

Farther south into the Foothills, storms will likely remain more
disorganized due to weaker shear. However, large hail and perhaps a
weak tornado (due to ambient low-level vorticity stretched by
updrafts) may still occur.

..Wendt.. 06/20/2024

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

ATTN...WFO...LBF...BOU...CYS...

LAT...LON   40260515 41310442 41780406 42350381 42820258 42660202
            41710215 40470323 40130420 40090491 40260515