• MESO: Mesoscale Discussion 0300

    From COD Weather Processor@1:2320/105 to wx-storm@lists.illinois.edu on Mon Mar 25 17:21:12 2024
    ACUS11 KWNS 251721
    SWOMCD
    SPC MCD 251720=20
    LAZ000-ARZ000-TXZ000-252015-

    Mesoscale Discussion 0300
    NWS Storm Prediction Center Norman OK
    1220 PM CDT Mon Mar 25 2024

    Areas affected...parts of western/northern Louisiana and adjacent
    southern Arkansas

    Concerning...Severe potential...Watch possible=20

    Valid 251720Z - 252015Z

    Probability of Watch Issuance...40 percent

    SUMMARY...Potential exists for one or two supercell storms to
    gradually develop this afternoon, particularly near/west of the
    Alexandria through Monroe vicinities by 3-4 PM CDT, if not earlier.=20
    This may be accompanied by increasing risk to produce
    tornadoes--perhaps a strong one.

    DISCUSSION...In advance of a pre-frontal low-level wind
    shift/confluence zone slowly advancing eastward across parts of
    western Arkansas and eastern Texas, new thunderstorm development has
    initiated across upper Texas and southwestern Louisiana coastal
    areas. This appears to be in response to low-level moistening and
    lift within a fairly strong warm advection regime, which may be
    maximized near or just above 850 mb.

    This is forecast to continue to shift north-northeastward toward
    north central Louisiana, near/west of Monroe, through 20-21Z, where
    somewhat weaker mid-level inhibition and increasing mid/upper
    forcing beneath more pronounced difluent flow aloft may support
    thunderstorm intensification. Given the strong deep-layer shear,
    and forecast of enlarging low-level hodographs beneath strengthening
    southerly 850 flow (to 50+ kt), the structure of the near-surface
    thermodynamic profiles remains the primary uncertainty concerning
    severe weather potential.

    For example, notable differences are evident between the NAM and
    Rapid Refresh forecast soundings, with the NAM soundings suggesting
    convection may remain elevated above a saturated but weakly stable
    profile from the surface through around 850 mb. Lapse rates within
    this layer in the Rapid Refresh forecast soundings appear at least
    somewhat more unstable, and perhaps supportive of convection rooted
    closer to the surface, where hodographs within the low-level inflow
    layer may be more conducive to the evolution of strong low-level
    mesocyclones.

    ..Kerr/Hart.. 03/25/2024

    ...Please see https://urldefense.com/v3/__http://www.spc.noaa.gov__;!!DZ3fj= g!7nPFuMYFXHO24_94bv2iuXg92mpWxieBHK0XG3v__Nuq6NJRM0ijAAH7IEcJLYQFzeYcPoEIl= bg86rdkXYva9Ynl92M$ for graphic product...

    ATTN...WFO...JAN...LCH...SHV...

    LAT...LON 30549391 32379358 33199256 32489169 31259207 30369248
    29969331 30549391=20


    =3D =3D =3D
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