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  • DAY3SVR: Day 3 Convective Outlook

    From COD Weather Processor @1:2320/107 to All on Fri Oct 9 19:31:46 2026
    ACUS03 KWNS 091931
    SWODY3
    SPC AC 091930

    Day 3 Convective Outlook
    NWS Storm Prediction Center Norman OK
    0230 PM CDT Fri Oct 09 2026

    Valid 111200Z - 121200Z

    ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS SUNDAY ACROSS
    THE MID ATLANTIC AND PORTIONS OF THE LOWER COLORADO VALLEY INTO
    EASTERN GREAT BASIN...

    ...SUMMARY...
    Strong thunderstorms on Sunday may impact parts of the Mid Atlantic,
    and the lower Colorado Valley into eastern Great Basin, accompanied
    by at least some risk for damaging wind gusts and a couple of
    tornadoes.

    ...Discussion...
    Models indicate further consolidation of troughing within initially
    separate branches of the westerlies, with slow progression inland of
    the Pacific coast Sunday through Sunday night. Within southerly
    flow ahead of the evolving large-scale trough axis, remnants of
    Tropical Storm Rachel are forecast to rapidly advect from the
    southeastern California Sonoran Desert toward the western slopes of
    the Wasatch through the day Sunday. As downstream mid/upper ridging
    builds through the southeastern Great Plains and middle/lower
    Mississippi Valley, it appears that an upper trough and remnant
    mid-level cyclonic circulation will be forced east-northeastward
    across the Appalachians through Mid Atlantic. Associated forcing
    for ascent may support modest secondary surface cyclogenesis to the
    lee of the Blue Ridge, southeast of the weakening remnants of Isaias
    across the Cumberland/Allegheny Plateau vicinity, and in the wake of
    weakening surface ridging shifting offshore of the Atlantic
    Seaboard.

    Spread among the models remains substantive concerning the shorter
    wavelength perturbations, but a couple areas with at least some
    potential for severe thunderstorm development are evident.

    ...Mid Atlantic...
    Given the seasonably high boundary-layer moisture content advecting
    northward toward the Mid Atlantic in advance of the developing
    surface low, there appears potential for boundary-layer
    destabilization coincident with strengthening low-level and
    deep-layer shear. Models suggest that a developing mid-level dry
    slot could provide a focus for the most substantive boundary-layer destabilization by late Sunday afternoon across parts of eastern
    Virginia into eastern North Carolina, where insolation prior to the
    onset of mid-level ascent/cooling may support a period of vigorous
    thunderstorm development. It appears that this could include
    supercell structures within an evolving broken line of storms, which
    may pose a risk for a couple of tornadoes and/or locally damaging
    wind gusts.

    ...Lower Colorado Valley into eastern Great Basin...
    Boundary-layer destabilization and convective potential is more
    unclear along the forecast track of Rachel for Sunday. However,
    given the development of sufficient instability, the remnant strong south-southwesterly wind fields could provide support for organized
    convection, including supercell structures, posing at least a risk
    for damaging wind gusts.

    ..Kerr.. 10/09/2026

    $$
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    --- scorpsmtpd
    * Origin: capitolcityonline.net * KY, USA (1:2320/107)
  • From COD Weather Processor @1:2320/107 to All on Sat Oct 10 07:23:28 2026
    ACUS03 KWNS 100723
    SWODY3
    SPC AC 100721

    Day 3 Convective Outlook
    NWS Storm Prediction Center Norman OK
    0221 AM CDT Sat Oct 10 2026

    Valid 121200Z - 131200Z

    ...NO SEVERE THUNDERSTORM AREAS FORECAST...

    ...SUMMARY...
    No severe weather is expected Monday through Monday night.

    ...Synopsis...

    A midlevel low initially over the Columbia Basin is forecast to
    progress south toward the Sierra Nevada, while an upper-level jet
    streak develops from the lower-CO Valley into the Upper Midwest.
    Ahead of the latter feature, a low-amplitude short-wave trough is
    projected to move from the northern High Plains into the Upper
    Midwest, embedded within a belt of 40-50 kt midlevel flow. In the
    low levels, an area of low pressure loosely related to the
    short-wave trough is expected to develop from the mid-MO Valley into
    the Upper Midwest along a stationary front. A cold front will trail
    southwest from that feature, linking with a secondary cyclone over
    the central High Plains.

    ...Upper Midwest/Upper Great Lakes...

    A plume of relatively steep midlevel lapse rates of around 7 C/km
    will overlie the northern extension of a moistening boundary layer,
    supporting a corridor of moderate instability by afternoon to the
    south of the surface low and associated front described in the
    synopsis. Capping at the base of the lapse-rate plume/EML is likely
    to inhibit surface-based storm development in the warm sector.
    However, the 00Z models suggest that a cluster of elevated
    thunderstorms may persist Monday afternoon into night to the
    immediate north of the warm sector within a zone of forcing for
    ascent preceding the short-wave trough. While a few strong storms
    capable of small hail appear possible, marginal parcel buoyancy and
    only modest cloud-bearing shear are expected to limit the threat for
    severe weather.

    ..Mead.. 10/10/2026

    $$
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    --- scorpsmtpd
    * Origin: capitolcityonline.net * KY, USA (1:2320/107)
  • From COD Weather Processor @1:2320/107 to All on Sat Oct 10 19:02:28 2026
    ACUS03 KWNS 101902
    SWODY3
    SPC AC 101901

    Day 3 Convective Outlook
    NWS Storm Prediction Center Norman OK
    0201 PM CDT Sat Oct 10 2026

    Valid 121200Z - 131200Z

    ...NO SEVERE THUNDERSTORM AREAS FORECAST...

    ...SUMMARY...
    No severe weather is expected Monday through Monday night.

    ...Discussion...

    An upper low and attendant shortwave trough will pivot across
    portions of the Southwest and Great Basin on Monday. An enhanced
    midlevel jet streak associated with this system and lingering
    boundary layer moisture will support showers and isolated
    thunderstorm activity. Instability will remain weak, limiting severe thunderstorm potential.

    Further northeast, a weak midlevel shortwave impulse will migrate
    northeast from the central High Plains toward the Mid/Upper MS
    Valley, flattening the central U.S. upper ridge. A weak surface low
    over the Upper MS Valley will shift east through the Great Lakes,
    and a trailing cold front will sweep southeast across the Upper
    Midwest to the Mid-MO Valley. Boundary layer moisture will remain
    modest, but cool temperatures aloft will support modest instability
    atop midlevel capping across parts of central/southern WI. A few
    elevated thunderstorms are possible within this modestly sheared and
    weakly unstable environment ahead of the cold front. Small hail
    could occur with the strongest storms. However, severe potential
    appears too limited to include low probabilities at this time.

    Additional thunderstorms are possible across portions of
    south/southeast TX within a low-level warm advection regime on the
    western periphery of surface high pressure centered over the central
    Gulf coast vicinity. Isolated thunderstorms may also occur as a cold
    front develops south across southern FL and the Keys during the
    afternoon.

    ..Leitman.. 10/10/2026

    $$
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    --- scorpsmtpd
    * Origin: capitolcityonline.net * KY, USA (1:2320/107)
  • From COD Weather Processor @1:2320/107 to All on Sun Oct 11 07:02:36 2026
    ACUS03 KWNS 110702
    SWODY3
    SPC AC 110701

    Day 3 Convective Outlook
    NWS Storm Prediction Center Norman OK
    0201 AM CDT Sun Oct 11 2026

    Valid 131200Z - 141200Z

    ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER PARTS OF THE
    CENTRAL AND SOUTHERN HIGH PLAINS...

    ...SUMMARY...
    Widely scattered severe storms appear possible over portions of the
    central and southern High Plains Tuesday afternoon into night. More
    isolated severe weather may occur into the mid Mississippi Valley,
    and in parts of the lower Great Lakes.

    ...Synopsis...

    A midlevel low will slowly progress through the Great Basin with a
    downstream belt of enhanced, mid/upper-level flow extending from the
    southern Rockies into the Great Lakes. Within that airstream, a
    short-wave trough will progress from the Great Lakes into the
    Northeast, while a more subtle disturbance advances from the central
    and southern High Plains into the Upper Midwest. At the surface, an
    area of low pressure associated with the former disturbance
    mentioned above is expected to develop from lower MI through the
    northern Mid-Atlantic into New England with a boundary trailing that
    feature from the southern Great Lakes into the central High Plains,
    where it will link with a deepening lee cyclone over southeast CO.


    ...Central and Southern Plains into the Mid-Mississippi Valley...

    While midlevel lapse rates are not forecast to be particularly
    steep, daytime heating combined with boundary-layer dewpoints in the
    mid 60s to lower 70s is expected to contribute to a moderately
    unstable warm sector by afternoon. The specific details regarding
    convective evolution remain uncertain; however, forcing for ascent
    associated with the midlevel disturbance and convergence in the
    vicinity of the synoptic front, dryline, and lee cyclone are likely
    to aid in diurnally enhanced thunderstorm development. Highest
    confidence in that occurrence remains over portions of southwest KS
    into the OK and TX Panhandles, where the low-level mass response to
    the deepening CO low will be the greatest from late afternoon into
    evening. Vertical shear will be sufficiently strong to support
    supercells capable of mainly large hail initially. Tornado potential
    may increase during the evening with any ongoing supercells as the
    low-level jet strengthens. Upscale growth into one or multiple storm
    complexes appears possible, at which point, the threat for damaging
    winds would correspondingly increase.

    An areal expansion in level-2/Slight Risk probabilities may be
    required in later outlooks once finer-scale details become more
    clear.


    ...Lower Great Lakes...

    Showers and thunderstorms may be ongoing Monday morning within a
    zone of low-level warm advection and moisture transport preceding
    the surface low and short-wave trough. Clouds and precipitation may
    linger into afternoon, limiting the destabilization in those areas.
    However, where stronger heating can occur, the presence of
    boundary-layer dewpoints in the 60s will support at least a
    marginally unstable environment by afternoon. Both low-level and
    deep-layer shear will be relatively strong, and on the condition
    that surface-based storms develop and are sustained, the threat for
    locally damaging winds and perhaps a tornado or two would exist.

    ..Mead.. 10/11/2026

    $$
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    --- scorpsmtpd
    * Origin: capitolcityonline.net * KY, USA (1:2320/107)