• DAY1 3/5 RISK AREA POSTED Midwest/Plains

    From Mike Powell@618:250/6 to All on Fri Apr 3 10:18:40 2026
    ACUS01 KWNS 031242
    SWODY1
    SPC AC 031240

    Day 1 Convective Outlook
    NWS Storm Prediction Center Norman OK
    0740 AM CDT Fri Apr 03 2026

    Valid 031300Z - 041200Z

    ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS NORTHERN
    MISSOURI AND SOUTHERN IOWA INTO WEST/NORTHWEST ILLINOIS...

    ...SUMMARY...
    A few tornadoes and isolated very large hail are possible late this
    afternoon and evening across northern Missouri into southern Iowa
    and north-central Illinois with any sustained supercells that
    develop. Storms are otherwise expected to evolve into an extensive
    line by Friday evening from Iowa to Oklahoma and northwest Texas,
    with the primary threats of large hail and damaging winds.

    ...Northern Missouri/southern Iowa/north-central Illinois...

    The shortwave trough emerging from the north-central High Plains
    this morning will spread east-northeastward toward the Upper Midwest
    through early Saturday. This will be accompanied by a strengthening
    (70+ kt) belt of cyclonically curved mid/high-level westerlies. A
    surface low across the south-central Plains will transition
    northeastward toward the Iowa/Illinois border vicinity tonight,
    while a warm front shifts northward from northern Missouri into Iowa
    and across northern portions of Illinois/Indiana, where low/middle
    60s F dewpoints will become common across the Midwest near and south
    of the warm front.

    Within the warm sector, residually steep mid-level lapse rates and
    modest insolation will contribute to MLCAPE values up to 2000 J/kg
    (and MUCAPE values approach 3000 J/kg). Deep-layer shear will be
    sufficient for supercells along and south of the warm front and east
    of the Pacific cold front/dryline. While the likelihood/extent of
    semi-discrete supercellular development remains a bit uncertain, the
    main potential for such will increase during the afternoon near the
    triple point around the Kansas/Missouri/Iowa border vicinity and
    eastward, potentially as far east into western/north-central
    Illinois in vicinity of the northward-shifting warm front.
    Semi-discrete development would offer tornado/very large hail
    potential, as well as a possible multi-round scenario of severe
    storms in some of this corridor via a more prevalent line of storms
    during the evening, with a damaging wind risk and some continued
    tornado potential as the low-level restrengthens.

    ...Northern Indiana to western portions of Pennsylvania/New York...

    Relatively strong westerlies atop the frontal zone, which will be
    more southeast-progressive as a cold front with eastward extent,
    will support at least isolated severe thunderstorms late this
    afternoon into evening, including a few supercells regionally.

    ...Southeast Kansas/Southwest Missouri to Northwest Texas...

    Thunderstorms will develop southward from northern Missouri into
    Oklahoma during the afternoon as the Pacific cold front/dryline
    advances southeastward into an increasingly unstable airmass. At the
    same time, additional thunderstorms are likely to develop across
    Northwest Texas and southwest Oklahoma in association with a subtle perturbation within the subtropical jet. Forecast wind fields
    indicate low-level flow will be weaker here than areas farther north
    and east. The combination of this wind field and the widespread
    nature of the convection would lend itself to large hail and
    damaging winds as the main severe hazards, although a tornado could
    occur with any discrete storm or along the leading edge of any
    organized linear segments.

    ...Southwest Texas...

    Isolated thunderstorms are expected by late afternoon and early
    evening in vicinity of the dry line and near some of the
    mountains/higher terrain. Wind fields will support supercells
    capable of producing large hail and localized severe-caliber winds.

    ..Guyer/Weinman.. 04/03/2026

    $$
    --- MultiMail/DOS
    * Origin: Project Scorpio TEST (618:250/6)
  • From Mike Powell@618:250/6 to All on Fri Apr 3 10:18:40 2026
    ACUS01 KWNS 031242
    SWODY1
    SPC AC 031240

    Day 1 Convective Outlook
    NWS Storm Prediction Center Norman OK
    0740 AM CDT Fri Apr 03 2026

    Valid 031300Z - 041200Z

    ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS NORTHERN
    MISSOURI AND SOUTHERN IOWA INTO WEST/NORTHWEST ILLINOIS...

    ...SUMMARY...
    A few tornadoes and isolated very large hail are possible late this
    afternoon and evening across northern Missouri into southern Iowa
    and north-central Illinois with any sustained supercells that
    develop. Storms are otherwise expected to evolve into an extensive
    line by Friday evening from Iowa to Oklahoma and northwest Texas,
    with the primary threats of large hail and damaging winds.

    ...Northern Missouri/southern Iowa/north-central Illinois...

    The shortwave trough emerging from the north-central High Plains
    this morning will spread east-northeastward toward the Upper Midwest
    through early Saturday. This will be accompanied by a strengthening
    (70+ kt) belt of cyclonically curved mid/high-level westerlies. A
    surface low across the south-central Plains will transition
    northeastward toward the Iowa/Illinois border vicinity tonight,
    while a warm front shifts northward from northern Missouri into Iowa
    and across northern portions of Illinois/Indiana, where low/middle
    60s F dewpoints will become common across the Midwest near and south
    of the warm front.

    Within the warm sector, residually steep mid-level lapse rates and
    modest insolation will contribute to MLCAPE values up to 2000 J/kg
    (and MUCAPE values approach 3000 J/kg). Deep-layer shear will be
    sufficient for supercells along and south of the warm front and east
    of the Pacific cold front/dryline. While the likelihood/extent of
    semi-discrete supercellular development remains a bit uncertain, the
    main potential for such will increase during the afternoon near the
    triple point around the Kansas/Missouri/Iowa border vicinity and
    eastward, potentially as far east into western/north-central
    Illinois in vicinity of the northward-shifting warm front.
    Semi-discrete development would offer tornado/very large hail
    potential, as well as a possible multi-round scenario of severe
    storms in some of this corridor via a more prevalent line of storms
    during the evening, with a damaging wind risk and some continued
    tornado potential as the low-level restrengthens.

    ...Northern Indiana to western portions of Pennsylvania/New York...

    Relatively strong westerlies atop the frontal zone, which will be
    more southeast-progressive as a cold front with eastward extent,
    will support at least isolated severe thunderstorms late this
    afternoon into evening, including a few supercells regionally.

    ...Southeast Kansas/Southwest Missouri to Northwest Texas...

    Thunderstorms will develop southward from northern Missouri into
    Oklahoma during the afternoon as the Pacific cold front/dryline
    advances southeastward into an increasingly unstable airmass. At the
    same time, additional thunderstorms are likely to develop across
    Northwest Texas and southwest Oklahoma in association with a subtle perturbation within the subtropical jet. Forecast wind fields
    indicate low-level flow will be weaker here than areas farther north
    and east. The combination of this wind field and the widespread
    nature of the convection would lend itself to large hail and
    damaging winds as the main severe hazards, although a tornado could
    occur with any discrete storm or along the leading edge of any
    organized linear segments.

    ...Southwest Texas...

    Isolated thunderstorms are expected by late afternoon and early
    evening in vicinity of the dry line and near some of the
    mountains/higher terrain. Wind fields will support supercells
    capable of producing large hail and localized severe-caliber winds.

    ..Guyer/Weinman.. 04/03/2026

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