• MESO: Mesoscale Discussion 0472

    From COD Weather Processor@1:2320/107 to wx-storm@lists.illinois.edu on Friday, April 17, 2026 12:45:47
    ACUS11 KWNS 171245
    SWOMCD
    SPC MCD 171244=20
    MNZ000-WIZ000-171415-

    Mesoscale Discussion 0472
    NWS Storm Prediction Center Norman OK
    0744 AM CDT Fri Apr 17 2026

    Areas affected...Parts of southern MN into extreme northwest WI

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

    Valid 171244Z - 171415Z

    Probability of Watch Issuance...40 percent

    SUMMARY...A threat for isolated hail and locally strong to severe
    gusts may develop through mid morning.

    DISCUSSION...Elevated convection has developed in the vicinity of a
    cold front across parts of southern MN. Short-term guidance suggests
    this convection will expand in coverage and potentially intensify
    through the morning, within the northern gradient of an expanding
    buoyancy plume extending from the Great Plains into the Upper
    Midwest. Moderate mid/upper-level flow will support sufficient
    effective shear for storm organization as convection deepens and
    becomes rooted closer to the surface.=20

    In the short term, convective mode may remain rather complex, though
    strong embedded updrafts and possibly an elevated supercell could
    evolve out of the developing convection. Hail is expected to be the
    primary near-term threat, though localized strong/damaging gusts
    cannot be ruled out.

    Some guidance (notably recent HRRR runs) suggest that this ongoing
    convection may eventually become surface-based and pose a threat of
    all severe hazards across parts of WI, due to downstream low-level
    moisture transport and diurnal heating/destabilization. However,
    this evolution may not occur until late morning or during the
    afternoon. The need for watch issuance through mid morning is
    uncertain, but trends will be monitored for the development of
    more-organized elevated storms and eventual transition to
    surface-based convection.

    ..Dean/Smith.. 04/17/2026

    ...Please see https://urldefense.com/v3/__http://www.spc.noaa.gov__;!!DZ3fj= g!4iqROxmpFPc88OI9BWdZQ65HnBF3NOy0tK-wkFINIAfJ4vYxaw8eUPUIAJEMGtZDlZYoyvA1N= 0HJAGHzgkQ4umWxajA$ for graphic product...

    ATTN...WFO...DLH...ARX...MPX...

    LAT...LON 44979427 45449409 45739306 45569259 45149242 44729238
    44539242 44229261 43909284 43649314 43529456 43779458
    44979427=20

    MOST PROBABLE PEAK WIND GUST...55-70 MPH
    MOST PROBABLE PEAK HAIL SIZE...1.00-1.75 IN


    =3D =3D =3D
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    * Origin: Capitol City Online (1:2320/107)