• DAY1 3/5 RISK AREA POSTED UPDT

    From Mike Powell@618:250/6 to All on Thu Apr 23 13:40:02 2026
    ACUS01 KWNS 231651
    SWODY1
    SPC AC 231615

    Day 1 Convective Outlook
    NWS Storm Prediction Center Norman OK
    Issued by 15th OWS Scott Air Force Base IL
    1115 AM CDT Thu Apr 23 2026

    Valid 231630Z - 241200Z

    ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS EASTERN
    KANSAS...NORTHERN OKLAHOMA...

    ...SUMMARY...
    Severe thunderstorms are expected to develop this afternoon and
    evening from the southern and central Plains into the lower to mid
    Missouri Valley, and upper Mississippi Valley. Tornadoes, large hail
    and severe wind gusts will be possible.

    ...MN/IA to KS/northern OK this afternoon into tonight...

    The interaction of a southeastward moving midlevel trough over
    southern BC/AB and a northeastward moving trough over the western
    Dakotas will lead to the formation of a deep closed low over
    southern SK. An associated, occluding surface cyclone will weaken
    across southern MB by this evening, as a trailing cold front moves
    across MN/IA/KS/MO and northern OK. Low-level moisture will spread
    northward across IA/MN in advance of the cold front, beneath the
    northeast edge of an elevated mixed layer. Surface heating and the
    degree of buoyancy may be limited by extensive clouds from IA into
    MN, and forecast wind profiles show complex/messy hodographs
    structures (stronger low-level shear lingering across IA). Mixed
    convective modes are expected along and ahead of the front this
    afternoon, which could produce occasional wind damage, large hail
    and perhaps a couple of tornadoes.

    The more substantial severe threat is expected late this afternoon
    through late evening from eastern KS into northern OK, near and just
    northeast of a cold front/dryline triple point and weak secondary
    cyclone. A midlevel speed max near the Four Corners will progress
    eastward to the TX Panhandle by this evening, with ascent in the
    left exit region of the jet coincident with the triple point near or
    just north of the KS/OK border. An influx of mid 60s boundary-layer
    dewpoints beneath steep midlevel lapse rates will contribute to
    MLCAPE of 2000-3000 J/kg, with weakening convective inhibition
    across KS by mid afternoon.

    Storm development is expected along the cold front in KS by mid
    afternoon, with storms expected to develop southward to near the
    triple point. The large buoyancy, steep midlevel lapse rates and
    deep-layer shear sufficient for supercells will favor very large
    hail (2-3 inches in diameter) with the initial/more discrete storms.
    The tornado threat will peak this evening as low-level
    shear/hodograph curvature increase near the KS/OK border - there
    will be strong tornado potential with the anchor/southern supercells
    near the triple point. Upscale storm growth and cold pool
    development will favor a more linear convective mode with occasional
    wind damage as the outflow/effective cold front spreads
    southeastward into northeast OK and southwest MO overnight.

    ...OK dryline this evening...

    Storm development along the dryline in OK is uncertain late this afternoon/evening. Forecast soundings suggest that the degree of
    surface heating/mixing along the dryline and residence time in the
    dryline circulation will be close to supporting deep convection. If
    storms do form, the environment will conditionally favor very large
    hail initially, and the possibility of an evening tornado threat
    with any sustained storm.

    ..Afwa.. 04/23/2026

    $$
    --- MultiMail/DOS
    * Origin: Project Scorpio TEST (618:250/6)