• MESO: Mesoscale Discussion 1670

    From COD Weather Processor @1:2320/107 to All on Mon Jul 20 12:56:04 2026
    ACUS11 KWNS 201255
    SWOMCD
    SPC MCD 201255
    IAZ000-WIZ000-MNZ000-201500-

    Mesoscale Discussion 1670
    NWS Storm Prediction Center Norman OK
    0755 AM CDT Mon Jul 20 2026

    Areas affected...Far Southeast Minnesota...Eastern Iowa

    Concerning...Severe potential...Watch unlikely

    Valid 201255Z - 201500Z

    Probability of Watch Issuance...20 percent

    SUMMARY...An isolated wind-damage threat will likely continue with a
    short line of strong to severe storms near the Iowa-Minnesota state
    line. This line will move south-southeastward across eastern Iowa
    over the next couple of hours. The threat is expected to be marginal
    and weather watch issuance appears unlikely.

    DISCUSSION...The latest surface analysis shows a north-to-south
    corridor of low-level moisture from far western Missouri northward
    into western Iowa, along which dewpoints are in the mid 70s F.
    Slightly further east, the RAP has an axis of moderate instability
    with MLCAPE in the 1000 to 2000 J/kg range analyzed over central
    Iowa. Scattered thunderstorms are ongoing along the instability
    gradient to the east of this axis. The storms are being supported by
    a subtle mid-level shortwave trough evident on water vapor imagery
    moving southeastward across the upper Mississippi Valley. Although
    forecast soundings across eastern Iowa this morning have a
    near-surface inversion in place, effective shear is estimated to be
    near 40 knots. This could support an isolated and marginal threat
    for severe wind gusts over the next couple of hours, especially as
    surface temperatures ahead of the storms begin to increase.

    ..Broyles/Smith.. 07/20/2026

    ...Please see https://urldefense.com/v3/__http://www.spc.noaa.gov__;!!DZ3fjg!_haG6xeM_6Jd-iqmwWGUDizFTahH4hf4wXz2HoF39bNcvJZwlo8xcOx5FOMnCroOzEXIO1dSdw4Tnqk8mFJiM0jx8Cw$ for graphic product...

    ATTN...WFO...DVN...ARX...MPX...DMX...

    LAT...LON 43549372 43049385 41999340 41419293 41159252 41039199
    41089155 41329112 41759080 42189082 42839106 43439143
    43809184 43999228 43979296 43799344 43549372

    MOST PROBABLE PEAK WIND GUST...55-70 MPH
    MOST PROBABLE PEAK HAIL SIZE...UP TO 1.25 IN


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    --- scorpsmtpd
    * Origin: capitolcityonline.net * KY, USA (1:2320/107)