• MESO: Mesoscale Discussion 0418

    From COD Weather Processor@1:2320/107 to wx-storm@lists.illinois.edu on Tue Apr 14 16:50:56 2026
    ACUS11 KWNS 141650
    SWOMCD
    SPC MCD 141650=20
    NHZ000-VTZ000-MAZ000-CTZ000-NYZ000-PAZ000-141915-

    Mesoscale Discussion 0418
    NWS Storm Prediction Center Norman OK
    1150 AM CDT Tue Apr 14 2026

    Areas affected...Parts of the Northeast

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

    Valid 141650Z - 141915Z

    Probability of Watch Issuance...60 percent

    SUMMARY...The severe risk will gradually increase across the
    Northeast through the afternoon. The primary concern will be
    damaging wind gusts, though isolated severe hail and some tornado
    threat is also possible. While timing is uncertain, a watch may
    eventually be needed for parts of the area.

    DISCUSSION...Water-vapor and mosaic radar imagery depict a
    convectively augmented low-amplitude impulse advancing eastward
    across parts of Ontario into Quebec. As this feature continues
    eastward, an accompanying weak surface cyclone/frontal wave will
    evolve eastward along an east/west-oriented quasi-stationary front
    extending across northern NY/VT/NH this afternoon. Preceding the
    midlevel impulse and frontal wave, widely scattered thunderstorms
    should continue spreading/developing eastward across western/central
    NY, as well as along the quasi-stationary boundary farther north.=20

    Continued diurnal heating amid upper 50s to near 60 dewpoints and
    increasing low-level warm advection will destabilize the downstream
    air mass, yielding a gradual increase in thunderstorm coverage and
    intensity with eastward extent this afternoon. Despite only weak to
    locally moderate surface-based buoyancy, ample deep-layer shear
    (around 40 kt of effective shear) will promote a mix of organized
    clusters/line segments and a couple supercell structures (especially initially). The primary risk will be damaging wind gusts, though
    isolated severe hail and perhaps some tornado risk will also be
    possible (especially with any supercells that evolve). Given fairly
    nebulous large-scale forcing for ascent (especially with southward
    extent), overall storm coverage (and to some extent intensity) is a
    bit uncertain. While substantial cloud coverage farther north along
    the quasi-stationary boundary will limit destabilization compared to
    areas farther south, enhanced low-level SRH along the boundary will conditionally support a risk of organized clusters/supercells. Any
    storms that can become surface-based here will be capable of
    damaging wind gusts and potentially a locally greater tornado risk,
    though this is uncertain.=20

    Despite some uncertainty on timing and overall convective evolution,
    the overall severe risk will gradually increase from west to east
    into this afternoon, and a watch may eventually be needed for parts
    of the area.

    ..Weinman/Gleason.. 04/14/2026

    ...Please see https://urldefense.com/v3/__http://www.spc.noaa.gov__;!!DZ3fj= g!8enr-r-uRcfRtpvoDXMpDSRNKMp8ZXQ0pG5wz32teN6pu4GPcRmeG2ajTSU_ShhnzGzjosI4A= R_k2TJ9Gz8AWvwHGRo$ for graphic product...

    ATTN...WFO...GYX...BOX...BTV...OKX...ALY...BGM...BUF...

    LAT...LON 41577388 41397517 41457582 41767633 42317640 42827628
    43317598 43867548 44327462 44567415 44687353 44657255
    44447186 44097157 43617159 43227175 42677215 42237271
    41577388=20

    MOST PROBABLE PEAK TORNADO INTENSITY...85-115 MPH
    MOST PROBABLE PEAK WIND GUST...55-70 MPH
    MOST PROBABLE PEAK HAIL SIZE...1.00-1.75 IN


    =3D =3D =3D
    To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM.

    --- SBBSecho 3.28-Linux
    * Origin: Capitol City Online (1:2320/107)