Mesoscale Discussion 1899
NWS Storm Prediction Center Norman OK
0112 PM CDT Wed Aug 14 2024
Areas affected...much of Wyoming
Concerning...Severe potential...Watch unlikely
Valid 141812Z - 142045Z
Probability of Watch Issuance...5 percent
SUMMARY...Widely scattered strong storms, some with small to
marginally severe hail, appear likely to continue to develop with
increasing potential to produce localized severe surface gusts
through 3-5 PM MDT.
DISCUSSION...A significant upper-level trough is in the process of
slowly progressing east of the northern Intermountain Region into
northern Rockies. Beneath the mid-level cold core of this feature,
large-scale ascent and destabilization are contributing to an area
of sustained convective development and embedded thunderstorms, with
additional scattered thunderstorms initiating in advance of this
cluster across the Absaroka, Wind River and Bighorn Ranges of
Wyoming.
Across downstream lower elevations, boundary-layer warming and
mixing are well underway in response to insolation, with surface
temperature/dew point spreads already exceeding 30 F at some
locations. With further heating and cooling aloft, mixed-layer CAPE
in excess of 500 J/kg (and perhaps locally up to around 1000 J/kg)
is forecast to continue to develop through mid/late afternoon. As
this occurs, scattered thunderstorm development is likely to be
maintained and intensify.
Beneath modestly sheared mean westerly flow, including speeds on the
order of 25-30 kt in the cloud-bearing layer, stronger storms may be
accompanied by small to, perhaps, marginally severe hail. And
negative buoyancy, aided by melting and evaporative cooling, in
downdrafts may increasingly support localized strong to severe
surface gusts through 21-23Z.
..Kerr/Thompson.. 08/14/2024
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...UNR...CYS...RIW...SLC...PIH...
LAT...LON 44560819 44220616 43580501 41820495 41250589 41200812
41111017 42901021 43311103 43911109 44401005 44560819
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