Mesoscale Discussion
SPC MD 1610
MD 1610 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR PORTIONS OF NORTHEASTERN AND EASTERN MONTANA
Mesoscale Discussion 1610
NWS Storm Prediction Center Norman OK
0727 PM CDT Sun Jul 12 2026
Areas affected...portions of northeastern and eastern Montana
Concerning...Severe potential...Watch unlikely
Valid 130027Z - 130230Z
Probability of Watch Issuance...5 percent
SUMMARY...High-based showers and thunderstorms will be capable of
sporadic severe gusts this evening, but a WW is unlikely.
DISCUSSION...As of 0025 UTC, radar imagery shows high-based showers
and storms have developed over parts of northern and eastern MT.
Very hot surface temperatures (110+ F) are supporting very deep
surface mixed layer depths of the order of 3-5 km. Within this deep
dry boundary layer, dry adiabatic lapse rates and strong evaporation
potential exist, which is supporting stronger downdrafts and dry
microburst potential. Several mesonet stations have shown outflow
gusts of45-55 kt so far. This should continue this evening, given
the modest buoyancy (500-1000 J/kg MUCAPE) atop the deep and dry
inverted v profiles.
Broader storm organization potential appears limited however, owing
to relatively modest buoyancy and dryness in the sub-cloud layer.
While some clustering of stronger showers and outflow could develop
as they move north toward the Canadian border where buoyancy is
larger, a WW appears unlikely given the lack of more coherent
convective organization.
..Lyons/Thompson.. 07/13/2026
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...BYZ...GGW...TFX...
LAT...LON 47351203 48931016 49070973 49040499 47930620 47100805
46491028 46251125 46591184 47351203
MOST PROBABLE PEAK WIND GUST...55-70 MPH
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SPC MD 1609
MD 1609 CONCERNING SEVERE THUNDERSTORM WATCH 487... FOR PORTIONS OF CENTRAL AND SOUTHERN ARIZONA
Mesoscale Discussion 1609
NWS Storm Prediction Center Norman OK
0643 PM CDT Sun Jul 12 2026
Areas affected...portions of central and southern Arizona
Concerning...Severe Thunderstorm Watch 487...
Valid 122343Z - 130115Z
The severe weather threat for Severe Thunderstorm Watch 487
continues.
SUMMARY...The potential for severe wind gusts continues this
evening. The highest likelihood for strong gusts is expected to
remain with the southern storm cluster this evening.
DISCUSSION...As of 2340 UTC, regional radar and visible imagery
showed several clusters of thunderstorms ongoing across portions of
central and southern AZ. The environment ahead of these storms from
the southern Mogollon Rim and adjacent desert remains unstable
(SBCAPE 1000-2000 J/kg) and modestly sheared. Broader storm
organization appears limited and contingent upon consolidating
outflow. However, very warm surface temperatures and steep lapse
rates in the low and mid-levels will favor the potential for severe
gusts with high-based convection over the entire watch area this
evening.
The stronger of the storm clusters across the lower desert has shown
some tendency to cluster over the last few hours and additional
development has been noted east of the PHX Metro early this evening.
Recent measured severe gusts at TUS and high-res guidance suggest
this cluster will maintain the highest likelihood for severe gusts
over the next few hours.
..Lyons.. 07/12/2026
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...TWC...FGZ...PSR...VEF...
LAT...LON 31841250 32121316 32731343 35071336 35441328 34991268
34381210 33871113 33241088 32511062 31601048 31371051
31301086 31351126 31841250
MOST PROBABLE PEAK WIND GUST...65-80 MPH
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