Mesoscale Discussion 1892
NWS Storm Prediction Center Norman OK
0150 PM CDT Tue Aug 13 2024
Areas affected...parts of southwestern Montana....western
Wyoming...eastern Idaho and northern Utah
Concerning...Severe potential...Watch unlikely
Valid 131850Z - 132115Z
Probability of Watch Issuance...20 percent
SUMMARY...Widely scattered stronger storms will probably continue to
develop and intensify through 3-4 PM MDT, with at least a couple
becoming severe and posing a risk for large hail and locally
damaging wind gusts. Due to the relatively isolated nature of the
severe threat, a severe weather watch appears unlikely, but trends
will be monitored.
DISCUSSION...Precipitable water in excess of 1 inch is advecting
northward in a narrow plume, near and to the west of the Wasatch
toward the mountains of southwestern Montana. This is occurring in
advance of a mid-level trough and embedded cyclonic circulation now
progressing east-northeastward across the northern Intermountain
Region, and contributing to modest destabilization with daytime
heating. Mixed-layer CAPE is now in excess of 1000 J/kg, with
large-scale forcing for ascent contributing to weakening inhibition
and increasing scattered thunderstorm development.
Into and through 21-23Z, a gradual further intensification of storms
appears likely, aided by increasingly unstable low-level
storm-relative inflow, in the presence of strengthening westerly
mid/upper wind fields, including 30-50 kt in the 500-300 mb layer.
The evolution of widely scattered supercells is possible,
accompanied by a risk for severe hail and locally strong surface
gusts.
..Kerr/Mosier.. 08/13/2024
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...BYZ...RIW...TFX...SLC...PIH...MSO...
LAT...LON 41391352 42421292 43221291 43761314 44321324 44751313
45681217 46021090 45590996 44280975 41801078 40851160
40691295 41391352
Storm Prediction Center Mesoscale Discussion 1892
13
Aug