• MESO: Mesoscale Discussion 2092

    From COD Weather Processor@1:2320/105 to wx-storm@lists.illinois.edu on Fri Sep 20 20:43:26 2024
    ACUS11 KWNS 202043
    SWOMCD
    SPC MCD 202042=20
    NDZ000-MTZ000-202215-

    Mesoscale Discussion 2092
    NWS Storm Prediction Center Norman OK
    0342 PM CDT Fri Sep 20 2024

    Areas affected...portions of northern Montana and North Dakota

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

    Valid 202042Z - 202215Z

    Probability of Watch Issuance...5 percent

    SUMMARY...Isolated strong to severe gusts are possible with
    convection near an upper low this afternoon/evening. Storm coverage
    and the lack of broader organization should keep the threat limited.

    DISCUSSION...As of 2040 UTC, regional observations showed low-topped
    showers and thunderstorms ongoing beneath an upper low over parts of
    northern MT. Cold temperatures aloft (H5 temps ~ -20C) with the
    upper low are supporting steep low and mid-level lapse rates.
    Despite poor surface moisture, (dewpoints in the 30s and 40s F) weak
    buoyancy (~500 J/Kg MUCAPE) should be sufficient to support isolated
    convection this afternoon and into the early evening hours. The
    steep lapse rates, and momentum transfer from strong flow aloft will
    support a risk for strong to severe damaging wind gusts with any
    storms able to persist. Storm coverage may gradually expand eastward
    with the upper low as it spreads into northwestern ND. Moisture
    there is slightly deeper, but buoyancy remains weak. A few strong to
    severe gusts are possible through the remainder of the afternoon and
    into the early part of this evening. Given the lack of deeper
    surface moisture and instability, a WW appears unlikely.

    ..Lyons/Guyer.. 09/20/2024

    ...Please see https://urldefense.com/v3/__http://www.spc.noaa.gov__;!!DZ3fj= g!5VZZNwBi2ov-s-J5Lb9rmYPBoR5FD3p62-KQUDkONAcqrs8k6h2BnpT1XqVhSKPtXqUZGXFek= PAY4DV6R26HxCSJl3g$ for graphic product...

    ATTN...WFO...BIS...GGW...TFX...

    LAT...LON 48611213 49141268 49341059 49200676 49140335 48760310
    48030422 47780567 47750777 48131048 48611213=20


    =3D =3D =3D
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