939
ACUS11 KWNS 172326
SWOMCD
SPC MCD 172325
SDZ000-NDZ000-MTZ000-WYZ000-180200-

Mesoscale Discussion 2081
NWS Storm Prediction Center Norman OK
0625 PM CDT Tue Sep 17 2024

Areas affected...Portions of eastern Montana...western North
Dakota...and northwestern South Dakota

Concerning...Severe potential...Watch possible

Valid 172325Z - 180200Z

Probability of Watch Issuance...60 percent

SUMMARY...The risk of severe wind gusts and large hail should
gradually increase over the next few hours. The area is being
monitored for a possible watch, though timing is still uncertain.

DISCUSSION...A few strong to severe storms have developed along a
north/south-oriented confluence zone across eastern MT. These storms
are evolving in an environment characterized by around 40 kt of
deep-layer shear (per regional VWP) and moderate surface-based
instability -- supportive of organized clusters and supercell
structures. Isolated large hail and severe wind gusts could
accompany this activity.

During the next few hours, large-scale ascent preceding an
approaching midlevel trough may encourage an uptick in convection
from northeastern MT into western ND and northwestern SD. Sufficient
deep-layer shear/mostly straight hodographs and steep deep-layer
lapse rates should favor organized clusters and supercells capable
of severe wind gusts and large hail. The overall timing and coverage
of the severe threat still remains somewhat uncertain, and
convective trends are being monitored for a possible watch for parts
of the area.

..Weinman/Hart.. 09/17/2024

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

ATTN...WFO...BIS...UNR...BYZ...GGW...TFX...

LAT...LON   44600402 46000472 46820548 47140652 47420795 47610861
            48260896 48790884 49020819 49010575 48900484 48720435
            48260376 46750285 45540234 44960227 44600266 44430348
            44600402