• DAY2SVR: Enhanced Risk MW

    From Dumas Walker@21:1/175 to All on Monday, May 06, 2024 13:23:00
    ACUS02 KWNS 061730
    SWODY2
    SPC AC 061728

    Day 2 Convective Outlook
    NWS Storm Prediction Center Norman OK
    1228 PM CDT Mon May 06 2024

    Valid 071200Z - 081200Z

    ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM NORTHEAST
    INDIANA INTO NORTHWEST AND CENTRAL OHIO...

    ...SUMMARY...
    Scattered severe thunderstorms will be possible Tuesday from the
    Mid-South northeastward into the Ohio Valley. A few tornadoes, large
    to very large hail, and severe/damaging winds all appear possible,
    particularly from northeast Indiana into northwest and central Ohio.

    ...Synopsis...
    A mid/upper cyclone is forecast to remain largely in place over the
    western Dakotas while continuing to occlude. A convectively
    augmented shortwave trough will likely move through the base of this
    cyclone, progressing from the Mid MS Valley quickly northeastward
    into the Upper Midwest and Upper Great Lakes during the day. Primary
    surface low will occlude beneath the parent cyclone, but a secondary
    low will likely develop at the triple point, moving from the MN/IA
    border vicinity east-northeastward across central/southern MN into
    Lower MI. The cold front extending southward from this secondary low
    is forecast to push eastward across the Mid MS and OH Valleys, while
    the warm front shifts northeastward into Lower MI and the Upper OH
    Valley.

    ...Mid-South/Mid Mississippi Valley into the Ohio Valley...
    A decaying convective line will likely extend from southern WI
    through western IL and into western portions of the Mid-South early
    Tuesday morning. Buoyancy will be modest ahead of this line, which
    will likely limit the severe potential. Even so, there is still a low-probability chance for a few instances of hail and/or damaging
    gusts, particularly along the southern end of the convective line in
    the Mid-South vicinity where buoyancy is greatest.

    The convective line is expected to make quick northeastward
    progress, clearing the through the Lower OH Valley by the late
    morning and much of the Middle OH Valley by the early afternoon. The
    air mass is expected to recover quickly in its wake, with mid to
    upper 60s dewpoints advecting in from the southwest. Additional
    thunderstorm development is expected around 17-18Z across IL,
    supported by both warm-air advection and increasing large-scale
    ascent attendant to the approaching shortwave trough. This initial
    activity will likely be elevated, but shear is strong enough to
    support some more organized structures capable of hail. As the
    downstream airmass across OH and IN destabilizes, these initial
    storms will likely trend towards becoming more surface-based. Given
    the strong vertical shear in place, the potential for supercells
    will increase as storms become surface based. All severe hazards
    will be possible with these supercells, including large hail and
    tornadoes. The tornado threat is expected to maximize from northeast
    IN into western and central OH during the late afternoon/early
    evening, where the proximity to the warm front will contribute to
    better low-level shear.

    ...Upper Midwest...
    Despite relatively cool surface temperatures, cooling mid-levels
    coupled with modest low-level moisture are expected to result in
    airmass destabilization and modest buoyancy ahead of the triple
    point and associated surface boundaries. Thunderstorm development is anticipated both near the triple point, as well as along and
    north/northeast of the occluded front. Much of the activity in the
    vicinity of the occluded front will likely be elevated, but a few
    stronger updrafts capable of hail are still possible. More
    surface-based storms are possible near the triple point across
    southern WI. Here, isolated hail and gusty winds may occur with the
    more robust cores, and a brief tornado or two also appears possible.

    ...Mid-Atlantic...
    Isolated to perhaps widely scattered thunderstorms may develop
    Tuesday afternoon across parts of VA/NC, generally along/east of a
    weak surface lee trough. Sufficient forecast instability and shear
    should be present to support some threat for hail and strong winds
    with any thunderstorms that form. The overall severe threat is
    expected to remain fairly isolated/marginal.

    ...Lower Mississippi Valley/Deep South...
    This region will be displaced south of the stronger forcing for
    ascent, but moderate buoyancy and vertical shear still suggest there
    is isolated severe potential with any storms that do form. Current
    guidance suggests the greatest probability of storms exists across
    MS and AL where the low-level moisture convergence is greatest.

    ...Central Texas...
    The severe thunderstorm threat remains highly conditional across
    parts of central TX Tuesday afternoon along/near a low-level
    moisture gradient/sharpening dryline. Large-scale ascent will be
    negligible, with thunderstorm initiation relying on surface
    convergence. If any thunderstorms can form and persist, they
    could become severe given a strongly unstable airmass. This scenario
    remain too uncertain to add low severe probabilities with this
    outlook.

    ..Mosier.. 05/06/2024

    $$
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