• MESO: Mesoscale Discussion 0556

    From COD Weather Processor@1:2320/107 to wx-storm@lists.illinois.edu on Mon Apr 27 01:39:06 2026
    ACUS11 KWNS 270139
    SWOMCD
    SPC MCD 270138=20
    MOZ000-KSZ000-NEZ000-270345-

    Mesoscale Discussion 0556
    NWS Storm Prediction Center Norman OK
    0838 PM CDT Sun Apr 26 2026

    Areas affected...Northern Kansas into adjacent portions of Nebraska
    and Missouri

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

    Valid 270138Z - 270345Z

    Probability of Watch Issuance...80 percent

    SUMMARY...Elevated convection is expected to increase in coverage
    and intensity through late evening across northern Kansas, and will
    likely pose a threat for severe hail. Watch issuance is likely in
    the coming hours to address this concern.

    DISCUSSION...Recent regional radar mosaics and GOES IR imagery shows
    a gradual uptick in convection across western KS associated with
    increasing ascent ahead of a low-amplitude upper-level wave. Despite
    prior convective overturning earlier today, westerly mid-level flow
    is advecting 7.5 to 8.0 C/km lapse rates eastward across the state
    (this was recently sampled by the 00z TOP and DDC RAOBs).
    Additionally, VWPs across OK are beginning to show the onset of the
    nocturnal jet, which will bolster northward low-level moisture
    return and promote increasing isentropic ascent through the lowest
    1-2 km. This combination of low-level moistening/ascent and
    destabilization aloft will promote additional thunderstorm
    development in the coming hours. This may manifest as an
    intensification of ongoing weak convection across western KS as it
    spreads east or as new development across north-central KS. Given
    forecast effective bulk shear values on the order of 45-50 knots,
    organized convection (including a few supercells) is likely with an
    attendant threat for large to very large hail (possibly as high as
    2.5 inches).=20

    Although most of this activity will most likely remain rooted above
    the surface, recent forecast guidance suggests that the effective
    surface warm front (currently residing along the OK/KS border) may
    advance as far north as roughly the I-70 corridor. Strong convection
    developing in proximity to this boundary may see a higher potential
    for becoming surface based and utilizing the increasing low-level
    wind shear. While confidence in this scenario is limited, some
    tornado threat may manifest later this evening across portions of
    central KS where STP values could increase into the 2-4 range along
    and south of the front.

    ..Moore/Leitman.. 04/27/2026

    ...Please see https://urldefense.com/v3/__http://www.spc.noaa.gov__;!!DZ3fj= g!_9jfAIeuV31b3EfMCUADJx5RcZBMLaR8vhOzH_bVOsVp3kUC3oagN-Rv16uSLVEZqwBpMi87S= 38DMpUNhSP2aMRMoTM$ for graphic product...

    ATTN...WFO...EAX...OAX...TOP...ICT...GID...DDC...GLD...

    LAT...LON 39979871 40289509 40309460 40169427 39859404 39439404
    39039429 38729466 38529501 38459543 38359973 38470023
    38780029 39190015 39569971 39819920 39979871=20

    MOST PROBABLE PEAK TORNADO INTENSITY...100-125 MPH
    MOST PROBABLE PEAK WIND GUST...55-70 MPH
    MOST PROBABLE PEAK HAIL SIZE...2.00-3.50 IN


    =3D =3D =3D
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