MD 1985 CONCERNING SEVERE POTENTIAL…WATCH UNLIKELY FOR PARTS OF NORTHEASTERN MONTANA
Mesoscale Discussion 1985
NWS Storm Prediction Center Norman OK
0400 PM CDT Sat Aug 24 2024
Areas affected…parts of northeastern Montana
Concerning…Severe potential…Watch unlikely
Valid 242100Z – 242330Z
Probability of Watch Issuance…20 percent
SUMMARY…Thunderstorm activity may begin to initiate, with the
evolution of an isolated supercell possible, by 4-5 PM MDT. This
may pose a risk for large hail, locally damaging wind gusts, and
perhaps some potential for a brief tornado.
DISCUSSION…Low-level convergence appears to be locally
strengthening within weak surface troughing near the Wolf Point
vicinity, where surface dew points remain in the lower/mid 60s F, as
temperatures warm into the 90s F. Inhibition is gradually eroding
with continuing insolation, and this may be aided by weak mid-level
cooling through late afternoon, downstream of a mid-level
perturbation progressing across and northeast of the Canadian
Rockies.
Initial attempts at deepening convective development appear slowly
underway, in the presence of thermodynamic profiles already
characterized by steep lower/mid-tropospheric lapse rates and CAPE
in excess of 2000 J/kg. Beneath 35-60+ kt south-southwesterly flow
in the 500-300 mb layer, deep-layer shear is already strong and
conditionally supportive of supercells.
Although the strength of mid/upper forcing for ascent remains a bit
unclear, the High Resolution Rapid Refresh and Rapid Refresh, in
particular, suggest that at least isolated thunderstorms may
initiate as early as 22-23Z. Once this occurs, intensification may
be fairly rapid, with storms becoming capable of producing large
hail, locally damaging gusts gusts, and perhaps some risk for a
brief tornado, despite generally small/linear low-level hodographs.
..Kerr/Guyer.. 08/24/2024
…Please see www.spc.noaa.gov for graphic product…
ATTN…WFO…GGW…
LAT…LON 49550459 48250422 47870592 48790686 49660673 49550459
