• DAY1 3/5 RISK AREA UPDAT

    From Mike Powell@618:250/6 to All on Fri Apr 24 17:14:00 2026
    ACUS01 KWNS 241632
    SWODY1
    SPC AC 241630

    Day 1 Convective Outlook
    NWS Storm Prediction Center Norman OK
    1130 AM CDT Fri Apr 24 2026

    Valid 241630Z - 251200Z

    ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS
    SOUTHEAST OKLAHOMA AND ARKLATEX...

    ...SUMMARY...
    Scattered severe thunderstorms are expected today from parts of the
    southern Plains into the ArkLaTex and lower Mississippi Valley.
    Large hail, damaging winds, and a few tornadoes will be possible.
    The greatest threat for supercells with very large hail (2+ inches)
    should focus across parts of southeast Oklahoma to the ArkLaTex region.

    ...Oklahoma/North Texas to ArkLaTex/Lower Mississippi Valley...

    A persistent band of non-severe thunderstorms this morning, and its
    related outflow, continue to settle southward across southeast
    Oklahoma, south-central/southeast Arkansas into northwest
    Mississippi. The southeastern-most portion of the convective line
    may re-intensify across the ArkLaMiss today as the boundary layer
    warms, with some potential for a secondary round of upscale-growing
    storms into tonight across generally the same ArkLaMiss/Lower
    Mississippi Valley region. This includes damaging winds and some
    tornado potential, primarily QLCS-related, especially into this
    evening/tonight via a somewhat stronger wind field.

    The western periphery of the ongoing complex and its outflow should
    continue to decelerate, stall, and modify through the afternoon,
    setting the stage for a semi-corridor of heightened severe potential
    via this modifying outflow in conjunction with the surface triple
    point to this west, with intensifying storm development anticipated
    toward the 4pm-6pm/21z-23z time frame across southeast Oklahoma and
    nearby ArkLaTex. This will be in the presence of ample buoyancy and
    steep mid-level lapse rates. Wind profiles will further support
    intense supercells capable of large to very large hail, along with a
    tornado risk, accentuated by backed low-level winds near the outflow
    boundary and east of the triple point. With time, some clustering
    may occur with an increased damaging wind threat as convection
    spreads east-southeastward.

    Additionally, locally intense storms may also focus farther west
    across southern Oklahoma/Red River vicinity along/north of the southward-sagging front where relatively rich low-level moisture
    will persist in the presence of strong deep-layer shear.

    ...Texas Dryline - North/Central TX to Hill Country/Rio Grande...

    A highly conditional scenario exists in vicinity of the south/southwestward-extending dryline late this afternoon/early
    evening, with a concerning (mostly hail) severe potential should
    storms develop. Short-term guidance varies on the aggressiveness of eastward-mixing/dryline through peak heating, although the 12z Fort
    Worth sounding sampled respectable warm-sector moisture content this
    morning (upper quartile climo; 14.4 g/kg mean mixing ratio).
    Regardless, a concerning high degree of instability (3000+ J/kg
    MLCAPE) will exist near/east of the dryline late this afternoon.

    Short-term models remain rather sparse on explicit indications of
    near-dryline convective initiation. However, sufficient dry line
    convergence and post-dryline heating/mixing could plausibly lead to
    isolated but intense thunderstorm development in the presence of
    negligible capping/boundary-layer inhibition. And while mid-level
    capping will be more prevalent, especially with southward extent,
    upstream 12z soundings from Midland/El Paso (both around -14C 500mb)
    suggest that some additional mid-level cooling is probable. Notably
    stronger mid/high-level winds were also observed in these RAOBs with
    50+ kt winds and 100+ kt winds at 500mb/250mb, respectively.

    Several sub-regional zones of potential isolated deep convective
    development are at least plausible, including in closer proximity to
    the surface triple point across North Texas/Metroplex general
    vicinity, extending into parts of central Texas where low-level
    mixing may be less impactful, and lastly in the immediate vicinity
    of the Rio Grande, potentially influenced by possible storm
    development across the border. If/where storms do develop late this afternoon/early evening, very large hail could occur along with
    localized severe-caliber wind gusts.

    ...Great Lakes/Ohio Valley...

    A weak/convectively influenced mid-level shortwave trough will move northeastward across the Midwest and Upper Great Lakes today.
    Convection ahead of a cold front has generally weakened this morning
    across the mid Mississippi Valley, but multi-layer cloud cover
    remains prevalent. Modest-caliber low-level moisture will continue
    to advect north-northeastward through the day ahead of the front,
    supporting weak instability with filtered daytime heating. Loosely
    organized clusters/cells that develop/intensify this afternoon may
    pose an isolated threat for damaging winds as they move
    northeastward this afternoon and evening. The residual clouds and a
    weakening low-level wind field should curb the overall magnitude of
    the severe risk, hence maintenance of MRGL/Category 1 risk.

    ...Western Nebraska...

    A couple of stronger storms may develop late this afternoon/early
    evening near a southeastward-moving front, further influenced by a
    mid-level impulse embedded within the base of the large-scale trough
    centered over the Canadian Prairies. In the presence of a strong
    deep-layer wind field, modest-caliber CAPE atop a well-mixed
    boundary layer could potentially yield an isolated severe gust/hail.

    ..Guyer/Weinman.. 04/24/2026

    $$

    --- ScorpioBBS/QWK v0.32a (Linux/x86_64)
    * Origin: Project Scorpio TEST (618:250/6)
  • From Mike Powell@618:250/6 to All on Fri Apr 24 21:24:00 2026
    ACUS01 KWNS 241958
    SWODY1
    SPC AC 241956

    Day 1 Convective Outlook
    NWS Storm Prediction Center Norman OK
    0256 PM CDT Fri Apr 24 2026

    Valid 242000Z - 251200Z

    ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FOR SOUTHEAST
    OKLAHOMA INTO THE ARKLATEX...

    ...SUMMARY...
    Scattered severe thunderstorms are expected today from parts of the
    southern Plains into the ArkLaTex and lower Mississippi Valley.
    Large hail, damaging winds, and a few tornadoes will be possible.
    The greatest threat for supercells with very large hail (2+ inches)
    should focus across parts of southeast Oklahoma to the ArkLaTex region.

    ...20Z Update...
    Much of the previous forecast (see below) remains on track. The
    primary changes made to the current outlook were to trim severe
    probabilities across portions of the OH Valley/Great Lakes, and the
    Mid-MS Valley, where either the passage of a surface cold front, or
    robust convection, has promoted boundary layer stabilization. More
    minor changes involved small adjustments to current severe and
    thunder probabilities ahead of storms to account for observations
    and the latest guidance consensus.

    ..Squitieri.. 04/24/2026

    .PREV DISCUSSION... /ISSUED 1130 AM CDT Fri Apr 24 2026/

    ...Oklahoma/North Texas to ArkLaTex/Lower Mississippi Valley...

    A persistent band of non-severe thunderstorms this morning, and its
    related outflow, continue to settle southward across southeast
    Oklahoma, south-central/southeast Arkansas into northwest
    Mississippi. The southeastern-most portion of the convective line
    may re-intensify across the ArkLaMiss today as the boundary layer
    warms, with some potential for a secondary round of upscale-growing
    storms into tonight across generally the same ArkLaMiss/Lower
    Mississippi Valley region. This includes damaging winds and some
    tornado potential, primarily QLCS-related, especially into this
    evening/tonight via a somewhat stronger wind field.

    The western periphery of the ongoing complex and its outflow should
    continue to decelerate, stall, and modify through the afternoon,
    setting the stage for a semi-corridor of heightened severe potential
    via this modifying outflow in conjunction with the surface triple
    point to this west, with intensifying storm development anticipated
    toward the 4pm-6pm/21z-23z time frame across southeast Oklahoma and
    nearby ArkLaTex. This will be in the presence of ample buoyancy and
    steep mid-level lapse rates. Wind profiles will further support
    intense supercells capable of large to very large hail, along with a
    tornado risk, accentuated by backed low-level winds near the outflow
    boundary and east of the triple point. With time, some clustering
    may occur with an increased damaging wind threat as convection
    spreads east-southeastward.

    Additionally, locally intense storms may also focus farther west
    across southern Oklahoma/Red River vicinity along/north of the southward-sagging front where relatively rich low-level moisture
    will persist in the presence of strong deep-layer shear.

    ...Texas Dryline - North/Central TX to Hill Country/Rio Grande...

    A highly conditional scenario exists in vicinity of the south/southwestward-extending dryline late this afternoon/early
    evening, with a concerning (mostly hail) severe potential should
    storms develop. Short-term guidance varies on the aggressiveness of eastward-mixing/dryline through peak heating, although the 12z Fort
    Worth sounding sampled respectable warm-sector moisture content this
    morning (upper quartile climo; 14.4 g/kg mean mixing ratio).
    Regardless, a concerning high degree of instability (3000+ J/kg
    MLCAPE) will exist near/east of the dryline late this afternoon.

    Short-term models remain rather sparse on explicit indications of
    near-dryline convective initiation. However, sufficient dry line
    convergence and post-dryline heating/mixing could plausibly lead to
    isolated but intense thunderstorm development in the presence of
    negligible capping/boundary-layer inhibition. And while mid-level
    capping will be more prevalent, especially with southward extent,
    upstream 12z soundings from Midland/El Paso (both around -14C 500mb)
    suggest that some additional mid-level cooling is probable. Notably
    stronger mid/high-level winds were also observed in these RAOBs with
    50+ kt winds and 100+ kt winds at 500mb/250mb, respectively.

    Several sub-regional zones of potential isolated deep convective
    development are at least plausible, including in closer proximity to
    the surface triple point across North Texas/Metroplex general
    vicinity, extending into parts of central Texas where low-level
    mixing may be less impactful, and lastly in the immediate vicinity
    of the Rio Grande, potentially influenced by possible storm
    development across the border. If/where storms do develop late this afternoon/early evening, very large hail could occur along with
    localized severe-caliber wind gusts.

    ...Great Lakes/Ohio Valley...

    A weak/convectively influenced mid-level shortwave trough will move northeastward across the Midwest and Upper Great Lakes today.
    Convection ahead of a cold front has generally weakened this morning
    across the mid Mississippi Valley, but multi-layer cloud cover
    remains prevalent. Modest-caliber low-level moisture will continue
    to advect north-northeastward through the day ahead of the front,
    supporting weak instability with filtered daytime heating. Loosely
    organized clusters/cells that develop/intensify this afternoon may
    pose an isolated threat for damaging winds as they move
    northeastward this afternoon and evening. The residual clouds and a
    weakening low-level wind field should curb the overall magnitude of
    the severe risk, hence maintenance of MRGL/Category 1 risk.

    ...Western Nebraska...

    A couple of stronger storms may develop late this afternoon/early
    evening near a southeastward-moving front, further influenced by a
    mid-level impulse embedded within the base of the large-scale trough
    centered over the Canadian Prairies. In the presence of a strong
    deep-layer wind field, modest-caliber CAPE atop a well-mixed
    boundary layer could potentially yield an isolated severe gust/hail.

    $$

    --- ScorpioBBS/QWK v0.32a (Linux/x86_64)
    * Origin: Project Scorpio TEST (618:250/6)