MD 1238 CONCERNING SEVERE THUNDERSTORM WATCH 366…368…369… FOR FAR SOUTHEAST SD…FAR NORTHEAST NE…FAR NORTHWEST IA…FAR SOUTHWEST MN
Mesoscale Discussion 1238
NWS Storm Prediction Center Norman OK
0437 AM CDT Sat Jun 24 2023
Areas affected...Far Southeast SD...Far Northeast NE...Far Northwest
IA...Far Southwest MN
Concerning...Severe Thunderstorm Watch 366...368...369...
Valid 240937Z - 241100Z
The severe weather threat for Severe Thunderstorm Watch 366, 368,
369 continues.
SUMMARY...Damaging gusts are expected to persist for the next hour
or so before the line then begins weakening as it moves into
southwest MN.
DISCUSSION...Forward progression of the northern portion of the
convective line moving across southeast SD and eastern NE has
trended a bit more northeastward over the past hour or so. This
shift has likely occurred into response to the strengthening
mid-level flow attendant to the shortwave trough moving across NE
and SD. This shift towards more northeasterly motion aligns that
portion of the line more favorably to the deep-layer flow. Recent
velocity data from KFSD shows stronger inbounds along the leading
edge approaching from the southwest. Damaging gusts are possible as
this line continues northeastward through far southeast SD and far
northwest IA into far southwest MN over the next hour.
Instability drops off quickly with northeastward extent into
southwest MN, where cooler temperatures, less low-level moisture,
and modest mid-level lapse rates are present. Consequently, the line
is expected to weaken as it moves into this less buoyant
environment, likely precluding the need for a downstream watch over
southwest MN.
..Mosier.. 06/24/2023
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...FSD...
LAT...LON 42989708 43279729 44069732 44359689 44309606 43919534
42819534 42449677 42989708
