• MESO: Mesoscale Discussion 1795

    From COD Weather Processor@1:2320/105 to wx-storm@lists.illinois.edu on Sat Jul 26 22:05:32 2025
    ACUS11 KWNS 262205
    SWOMCD
    SPC MCD 262205=20
    NDZ000-MTZ000-270000-

    Mesoscale Discussion 1795
    NWS Storm Prediction Center Norman OK
    0505 PM CDT Sat Jul 26 2025

    Areas affected...Southwest to northeast Montana

    Concerning...Severe potential...Watch unlikely=20

    Valid 262205Z - 270000Z

    Probability of Watch Issuance...20 percent

    SUMMARY...Thunderstorms developing across southwest to central
    Montana may produce sporadic severe gusts through early evening.
    This threat is expected to remain sufficiently limited to preclude
    watch issuance.

    DISCUSSION...Over the past 1-2 hours, thunderstorms have been slowly deepening/maturing across southwest to central MT as they develop
    within a modestly moist/deeply mixed air mass. Based on observed
    dewpoint depressions (around 30 F) and recent forecast soundings,
    LCLs are likely around 3 km, which will favor strong sub-cloud
    evaporational cooling and downdraft acceleration within ongoing
    convection. Additionally, ascent ahead of an approaching, but
    low-amplitude, upper-level wave will continue to promote
    thunderstorm development over the next few hours. As such, the
    potential for a few severe gusts should increase across the region,
    especially if a more consolidated/organized cluster emerges out of
    this activity as hinted by recent CAM guidance. Given the unfocused
    forcing for ascent and recent convective trends, confidence in
    where/when/if such as cluster emerges is low.

    More robust/long-lived severe storms, including the potential for a
    supercell or two and/or organized cluster, may exists across
    northeast MT where richer low-level moisture is promoting MLCAPE
    values on the order of 1000-2000 J/kg, and deep-layer shear is
    adequate (30-35 knots) for storm organization. Weaker forcing for
    ascent casts uncertainty on storm coverage, but trends will be
    monitored given the favorable convective environment and the
    potential for a focused corridor of relatively higher severe threat.

    ..Moore/Mosier.. 07/26/2025

    ...Please see https://urldefense.com/v3/__http://www.spc.noaa.gov__;!!DZ3fj= g!8WGkD2uQs7NFStabhr5sWU99MQYZxw0eMlWvwCpEscVStEaMHmfiZBAJU8znogKZJTz57tw5C= ZNvFcTMgCXqhrH3RNI$ for graphic product...

    ATTN...WFO...BYZ...GGW...TFX...MSO...

    LAT...LON 47120441 46780483 46480569 45600977 45610994 45441148
    45541209 45841265 46261291 46621275 46981229 49010822
    49050506 48940443 48720417 48310404 47840404 47550413
    47280426 47120441=20

    MOST PROBABLE PEAK WIND GUST...55-70 MPH
    MOST PROBABLE PEAK HAIL SIZE...UP TO 1.25 IN


    =3D =3D =3D
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