• DAY1 2/5 Risk Area Posted Cent Plains/MO Valley

    From Mike Powell@618:250/6 to All on Thu Apr 9 08:32:32 2026
    ACUS01 KWNS 091252
    SWODY1
    SPC AC 091250

    Day 1 Convective Outlook
    NWS Storm Prediction Center Norman OK
    0750 AM CDT Thu Apr 09 2026

    Valid 091300Z - 101200Z

    ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE CENTRAL
    PLAINS AND LOWER/MIDDLE MISSOURI VALLEY...

    ...SUMMARY...
    Severe storms capable of large hail and severe wind gusts are
    expected late this afternoon and evening across Kansas, southeast
    Nebraska into northwest Missouri and southwest Iowa. Isolated severe
    storms may also occur across the south-central High Plains and
    northern California/western Oregon.

    ...Central Plains and Lower/Middle Missouri Valley...

    A frontal zone will focus and shift northward toward across Kansas
    toward the Kansas/Nebraska and Iowa/Missouri border vicinities
    today, before gradually accelerating southeastward tonight. The
    region will be influenced later today by a secondary shortwave
    trough digging southeastward over the northern Plains, with the
    persistence of cyclonic and somewhat strengthening mid/upper-level
    flow. On the nose of south-southwesterly lower tropospheric winds,
    low-level moisture will diurnally increase along/south of the front,
    offset by ample mixing across Kansas, resulting in surface dewpoints
    mainly in the lower/middle 50s F into peak heating. Beneath very
    steep mid-level lapse rates, 1000-1500 J/kg MLCAPE values are
    expected near/south of the front.

    After some early day thunderstorms, more intense surface-based
    thunderstorm development should occur as early as 22-23z/5-6pm CDT
    near the boundary including portions of northern Kansas/southeast
    Nebraska to the Iowa/Missouri border region, with other more
    isolated and higher-based storms possible across western Kansas and
    the nearby High Plains in vicinity of the lee trough/surface low.

    Moderately strong westerlies will reside along/north of the
    boundary, with 40+ kt effective shear supporting supercells capable
    of large hail, potentially some in excess of 2 inches in diameter.
    Some tornado potential may exist mainly across northeast Kansas/far
    southeast Nebraska and northwest Missouri near the boundary, but
    this overall potential will tend to be mitigated by modest-caliber
    moisture and the influence of diurnal mixing. Severe winds are also
    possible into evening as storms tend to cluster and spread/increase east-southeastward during the evening, although the modest early
    season moisture and nocturnal influences will lead to a diminished
    intensity trend into late evening.

    ...Northern California/western Oregon...

    As the upper-level low approaches the West Coast, forcing for ascent
    will overspread portions of northern California into southern Oregon
    with scattered thunderstorm development expected into afternoon.
    Sufficient moisture and CAPE will exist inland beneath strengthening
    deep-layer southwesterly winds ahead of the trough. As lapse rates
    steepen and flow aloft increases, storms may be capable of strong to
    severe wind gusts and possibly some hail.

    ..Guyer/Weinman.. 04/09/2026

    $$
    --- MultiMail/DOS
    * Origin: Project Scorpio TEST (618:250/6)