• MESO: Mesoscale Discussion 2239

    From COD Weather Processor@1:2320/105 to wx-storm@lists.illinois.edu on Thu Oct 12 01:51:31 2023
    ACUS11 KWNS 120151
    SWOMCD
    SPC MCD 120150=20
    IAZ000-NEZ000-SDZ000-120415-

    Mesoscale Discussion 2239
    NWS Storm Prediction Center Norman OK
    0850 PM CDT Wed Oct 11 2023

    Areas affected...portions of northern and central
    Nebraska...southeastern South Dakota and west central Iowa

    Concerning...Severe potential...Watch unlikely=20

    Valid 120150Z - 120415Z

    Probability of Watch Issuance...20 percent

    SUMMARY...Increasing low-level warm advection may support additional thunderstorms capable of isolated hail this evening. Confidence in
    storm coverage and severity is low and a watch is not expected.

    DISCUSSION...As of 0140 UTC, regional IR satellite imagery showed
    cooling cloud tops along a band of convection across portions of the
    central Plains. Located along and north of a warm front emanating
    from a deepening lee low over eastern CO, convection is expected to
    continue to slowly deepen and increase in coverage near the frontal
    corridor through this evening and into the overnight hours. Area
    VADs and surface obs show low-level mass response ahead of the
    deepening low, along with a moderately strong low-level jet. Favored
    by the uptick in low and mid-level warm advection, forcing for
    ascent should continue to build this evening supporting additional
    storm development. While not overly robust, sufficient buoyancy
    (~500-1000 J/kg of MUCAPE) along the warm front should support a few
    stronger updrafts. Bolstered by a band of westerly mid-level flow
    associated with the deepening low, 30-40 kt effective shear may also
    support some organization of these updrafts into sustained
    multicells or transient supercell structures. Generally north of the
    surface warm front and with nocturnal cooling ongoing at the
    surface, storms should remain elevated with the main risk being
    isolated hail with the more sustained/robust updrafts. Hi-res
    guidance varies on the degree of storm coverage/intensity through
    this evening, casting uncertainty on how widespread any severe risk
    will be. However, current radar and observational trends do suggest
    a few stronger storms with hail potential may evolve over
    north-central NE and spread into portions of southern SD and western
    IA tonight.

    ..Lyons/Guyer.. 10/12/2023

    ...Please see https://urldefense.com/v3/__http://www.spc.noaa.gov__;!!DZ3fj= g!8enZu1JAlNrAqROQ4PzOzghm6M0NKJknxR9KOs03foGKt-LEHTWAo1ZB1BR42tZBhQ9KDmHWc= 2oV8LFSjLzV-bbHE7E$ for graphic product...

    ATTN...WFO...DMX...FSD...OAX...GID...LBF...UNR...

    LAT...LON 41389491 41249657 41279934 41540048 41580061 42210136
    43050101 43280048 43629845 43569762 43369652 43139586
    42669435 42249336 41639310 41429388 41389491=20


    =3D =3D =3D
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