MD 1416 CONCERNING SEVERE THUNDERSTORM WATCH 441…442…443… FOR FAR SOUTHEASTERN MT…NORTHEASTERN WY…WESTERN SD…AND FAR NORTHWESTERN NE
Mesoscale Discussion 1416
NWS Storm Prediction Center Norman OK
1038 PM CDT Mon Jul 03 2023
Areas affected...Far southeastern MT...northeastern WY...western
SD...and far northwestern NE
Concerning...Severe Thunderstorm Watch 441...442...443...
Valid 040338Z - 040515Z
The severe weather threat for Severe Thunderstorm Watch 441, 442,
443 continues.
SUMMARY...The severe risk continues across Severe Thunderstorm
Watches 441, 442, and 443 tonight. Significant gusts upwards of
80-90 mph and isolated large hail remain possible.
DISCUSSION...An intense upscale-growing MCS is tracking
northeastward at around 40 kt across southwestern SD and
northwestern NE tonight. This line has a history of producing
significant gusts upwards of 80 mph. Within the pre-convective
environment, rich boundary-layer moisture (lower/middle 60s
dewpoints) beneath steep midlevel lapse rates are contributing to
moderate surface-based instability. In addition, regional VWP data
indicates a plume of strengthening low-level warm advection ahead of
the approaching line of storms. These factors, along with around 50
kt of effective shear oriented perpendicular to the leading-edge
gust front, should support the maintenance of this bowing segment
with east-northeastward extent. The primary concern with this
activity is significant gusts upward of 80-90 mph. A new Severe
Thunderstorm Watch has been issued for parts of
northwest/north-central NE, as this line could move into this region
during the next hour.
Farther north in northeastern WY into western SD, slightly stronger
deep-layer shear characterized by large, clockwise-turning low-level
hodographs, is supporting supercell clusters capable of producing
large hail and damaging winds.
..Weinman.. 07/04/2023
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...LBF...UNR...CYS...BYZ...
LAT...LON 42440345 42860371 43360414 44540470 45000451 45240417
45320367 45300308 45110262 44760223 43160143 42660138
42420188 42360275 42440345
