• Floods Likely OK/AR/MO

    From Mike Powell@618:250/1 to All on Tue Jul 8 09:44:00 2025
    AWUS01 KWNH 081435
    FFGMPD
    MOZ000-ARZ000-OKZ000-082015-

    Mesoscale Precipitation Discussion 0619
    NWS Weather Prediction Center College Park MD
    1034 AM EDT Tue Jul 08 2025

    Areas affected...Eastern OK...Western/Northern AR...Southern MO

    Concerning...Heavy rainfall...Flash flooding likely

    Valid 081422Z - 082015Z

    SUMMARY...Locally slow-moving clusters of heavy showers and
    thunderstorms will tend to increase in coverage going into the
    afternoon hours. High rainfall rates and slow cell-motions will
    likely yield isolated to scattered areas of flash flooding, which
    will include a concern for locally significant/dangerous flash
    flooding impacts near areas of rugged terrain.

    DISCUSSION...The morning GOES-E IR satellite imagery shows a
    small-scale vort center drifting gradually east along the OK/AR
    border in close proximity to the Ozark Plateau. This energy is
    embedded in a very moist and unstable environment as evidenced by
    the 12Z KLIT RAOB sounding along with RAP analyses, and is already
    producing slow-moving clusters of very heavy showers and
    thunderstorms.

    Much of the convection is somewhat elevated in nature, but is
    embedded within MUCAPE values ranging from 1000 to 2000 J/kg, and
    with PWs that are near 2 inches. The activity is also seen locally
    backbuilding along the OK/AR border in an environment with
    relatively notable low-level moisture convergence.

    Some expansion of heavy shower and thunderstorm activity is
    expected over the next several hours as the diurnal heating cycle
    evolves and promotes more surface-based convection. The
    aforementioned vort energy will continue to be slow-moving going
    into the afternoon hours, but will be interacting with greater
    surface-based instability along with differential heating
    boundaries that will favor small-scale convergence zones/forcing
    for additional convective development.

    Corfidi vectors depict a strongly favorable environment for
    backbuilding convection over the next several hours, and with such
    a strongly moist and increasingly unstable airmass pooled across
    the region, there will be notable concerns for slow-moving showers
    and thunderstorms with very high rainfall rates.

    The last couple of runs of the HRRR guidance shows potential for
    rainfall rates to reach 2 to 3+ inches/hour, with locally some
    rainfall totals by mid-afternoon of as much as 3 to 6+ inches
    given the slow cell-motions. Some of the 06Z HREF guidance also
    supports similar rates and totals.

    While the antecedent conditions are very dry, and reflective of
    high FFG values, the very high rainfall rate potential and
    localized storm potential suggests an elevated flash flood threat.
    Some of these rains will also potentially be occurring over rugged
    terrain which suggests an enhanced threat for runoff potential.
    Therefore, going into the afternoon hours, at least isolated to
    scattered areas of flash flooding will be likely. Some concern
    will exist for locally significant/dangerous flash flooding
    impacts nears areas of rugged terrain.

    Orrison

    ATTN...WFO...LSX...LZK...MEG...OUN...PAH...SGF...SHV...TSA...

    ATTN...RFC...KRF...MSR...ORN...TUA...NWC...

    LAT...LON 37559266 37559084 36808969 35609021 34559200
    33839433 34419578 35669604 36669506


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