• MESO: Mesoscale Discussion 1843

    From COD Weather Processor@1:2320/105 to wx-storm@lists.illinois.edu on Sat Aug 5 18:44:59 2023
    ACUS11 KWNS 051844
    SWOMCD
    SPC MCD 051844=20
    NEZ000-KSZ000-OKZ000-COZ000-NMZ000-052115-

    Mesoscale Discussion 1843
    NWS Storm Prediction Center Norman OK
    0144 PM CDT Sat Aug 05 2023

    Areas affected...eastern Colorado...extreme northeast New
    Mexico...western Oklahoma Panhandle

    Concerning...Severe potential...Severe Thunderstorm Watch likely=20

    Valid 051844Z - 052115Z

    Probability of Watch Issuance...95 percent

    SUMMARY...The severe threat will increase through the afternoon.
    Severe wind and hail are the main threats, with 65+ kt gusts and up
    to 3-4 inch diameter hail possible. A tornado or two also cannot be
    ruled out. A Severe Thunderstorm Watch issuance will be needed when
    an uptick in convective coverage and intensity are noted.

    DISCUSSION...Mostly clear skies are in place, with surface
    temperatures exceeding 80 F amid low 60s F dewpoints. A plume of 8+
    C/km mid-level lapse rates are overspreading this warming/moistening
    boundary layer, contributing to 2000+ J/kg MLCAPE. 45+ kts of 500 mb
    westerly winds atop weak southerly low-level flow supports 40+ kts
    of effective bulk shear. The aforementioned combination of buoyancy
    and shear will support supercells as the initial convective mode.
    Given the deep-layer of steep lapse rates/high CAPE density
    profiles, elongated hodographs, and a relatively moist 700-500
    mb/2-4 km AGL hail-embryo-bearing layer (evident in pre-convective
    forecast soundings), 2+ inch diameter hail is possible with the
    stronger storms, and locally up to 3-4 inch diameter hail may occur.

    In addition, a vertical-vorticity rich stationary boundary is
    evident from Elbert to Yuma County, CO, coincident with over 100
    J/kg of 0-3 km CAPE (per 18Z mesoanalysis). As such, a landspout
    and/or a brief supercell hybrid tornado is possible with any mature,
    sustained storm that can anchor to the boundary for an appreciable
    period of time. Later this evening, storms are expected to merge
    into an MCS. Intense cold pool mergers will support a severe wind
    threat, and a couple of 65+ kt gusts could occur.

    While cumulus continue to percolate along the aforementioned
    boundary in central/northeast CO, robust convective initiation is
    not yet evident. However, the development of several storms becomes
    apparent, a Severe Thunderstorm Watch will be needed.

    ..Squitieri/Smith.. 08/05/2023

    ...Please see https://urldefense.com/v3/__http://www.spc.noaa.gov__;!!DZ3fj= g!-_v2z_hOCFLiroTxyKPCRR_FLWUhOGWgsBFnvaU7xs32IcrN7xm3qvqaEYOy261Ks8q7r_Z1J= h-B4mFQIzhvbMPYgaM$ for graphic product...

    ATTN...WFO...LBF...DDC...GLD...AMA...PUB...BOU...CYS...ABQ...

    LAT...LON 36790393 37480429 38930429 39840409 40710332 41000276
    41040233 40780198 40340187 39660179 38740181 37970183
    37170212 36650247 36640328 36790393=20


    =3D =3D =3D
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