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  • DAY48SVR: Day 4-8 Convective Outlook

    From COD Weather Processor @1:2320/107 to All on Sat Oct 10 08:22:58 2026
    ACUS48 KWNS 100822
    SWOD48
    SPC AC 100820

    Day 4-8 Convective Outlook
    NWS Storm Prediction Center Norman OK
    0320 AM CDT Sat Oct 10 2026

    Valid 131200Z - 181200Z

    ...DISCUSSION...
    The 00Z models have slowed the progression of an upper low and
    associated trough from the Great Basin into the central Rockies on
    Days 4 and 5/Tuesday and Wednesday. By Day 6/Thursday and beyond,
    model spread increases in the handling of that midlevel system,
    leading to greater uncertainty in the evolution of the large-scale
    pattern.

    ...Day 4/Tuesday...

    There is some model signal that a subtle disturbance embedded within
    a belt of enhanced mid/upper-level flow will progress from the
    southern Rockies into the central High Plains, aiding in the
    deepening of a lee cyclone over southeast CO. Elsewhere, a
    low-amplitude disturbance is forecast to advance from the Great
    Lakes into the Northeast, in tandem with another surface low. A
    frontal system will connect the two lows, stretching from the lower
    Great Lakes through the OH Valley into the central Plains. A dryline
    will extend south from the lee cyclone to along the TX-NM border. A
    moist and unstable air mass will reside south of the front,
    especially over the central and southern Plains, where richer
    boundary-layer moisture is expected to reside.

    Isolated severe storms appear possible along the front Tuesday
    afternoon and evening, especially in the Northeast, and from the
    lower-MO Valley into the central and southern Plains. The most
    probable location for organized severe storm potential is over the
    southern High Plains in the vicinity of the lee cyclone and
    strengthening low-level jet where stronger forcing for ascent and
    vertical shear will coincide with a moderately unstable air mass.


    ...Day 5/Wednesday...

    The slowing of the upper-air system and the potential for
    thunderstorms Tuesday night into Wednesday morning lead to greater
    uncertainty in where the strongest instability will develop by
    afternoon. Isolated severe storms appear possible along and south of
    a surface front from the southern Mid-Atlantic into the central and
    southern Plains. However, confidence in delineating an area of more concentrated severe weather potential has diminished. And as such,
    the previously included 15% contour will be removed for this
    forecast update.


    ...Days 6 through 8/Thursday through Saturday...

    As alluded to above, spread increases across the models (especially
    the deterministic solutions) in the handling of the central Rockies
    low/trough. However, the general signal is for a trend toward a
    less-favorable synoptic pattern for severe storms by next weekend.

    ..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 Sun Oct 11 08:18:34 2026
    ACUS48 KWNS 110818
    SWOD48
    SPC AC 110816

    Day 4-8 Convective Outlook
    NWS Storm Prediction Center Norman OK
    0316 AM CDT Sun Oct 11 2026

    Valid 141200Z - 191200Z

    ...DISCUSSION...
    A mid/upper-level low is forecast to progress from the eastern Great
    Basin into the central Rockies on Day 4/Wednesday. By Day
    5/Thursday, there is good model consensus in the break-up of the
    low, with much of it being enveloped by an amplifying polar-branch
    trough over the north-central CONUS. By Days 6 and 7/ Friday and
    Saturday, there is general model agreement that a broader-scale
    trough will spread from the MS Valley toward the Atlantic Coast.


    ...Day 4/Wednesday...

    At least isolated severe storms appear most probable over the
    southern Plains during the afternoon and evening, along and ahead of
    a surface front extending from the southern High Plains through the
    mid-MS Valley. The presence of a moist air mass will support
    moderate instability by afternoon in areas that experience greater
    daytime heating. Thunderstorms are expected to be ongoing Wednesday
    morning within the warm sector, leading to uncertainty in where the
    effective surface front will be located by afternoon to focus more
    robust storm development. While no 15% contour will be included in
    this forecast, at least level-1/Marginal Risk probabilities will
    likely be required in the subsequent Day 3 forecast for this time
    period.

    Elsewhere, a few strong to severe storms appear possible along the
    remaining length of the front from the mid-MS Valley into the
    Mid-Atlantic.


    ...Day 5/Thursday...

    Some severe weather threat may materialize from the Ozark Plateau
    into the OH Valley in the vicinity of a surface low and attending
    frontal system. However, the potential for early-day storms and
    model variability in the particular details of the upper-air pattern
    evolution result in considerable uncertainty in the magnitude of the
    threat.


    ...Days 6 to 8/Friday to Sunday...

    A cold front on the leading edge of a prominent surface high will
    push through most locations east of the Rockies by Saturday morning.
    A strong storm or two appears possible along the front in the
    Mid-Atlantic on Friday. Otherwise, the influx of a drier,
    continental-polar air mass is expected to limit the threat for
    severe storms.

    ..Mead.. 10/11/2026
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    --- scorpsmtpd
    * Origin: capitolcityonline.net * KY, USA (1:2320/107)
  • From COD Weather Processor @1:2320/107 to All on Mon Oct 12 08:27:32 2026
    ACUS48 KWNS 120827
    SWOD48
    SPC AC 120825

    Day 4-8 Convective Outlook
    NWS Storm Prediction Center Norman OK
    0325 AM CDT Mon Oct 12 2026

    Valid 151200Z - 201200Z

    ...DISCUSSION...
    A short-wave trough over central Canada on Day 4/Thursday morning is
    forecast to undergo considerable amplification while progressing
    southeast through the Great Lakes to the Atlantic Coast by Day
    5/Friday. That upper-air system will be attended by a surface low,
    which is expected to develop along a front from the mid-MS Valley
    through the OH Valley to off the New England coast. Meanwhile, a
    strong cold front will surge south, reaching the Gulf Coast by
    Friday night or early Saturday. In its wake, a drier, continental-
    polar airmass will overspread much of the CONUS east of the Rockies,
    limiting the threat for severe thunderstorms this weekend into early
    next week.

    ...Day 4/Thursday and Thursday night...

    Despite the potential for early-day showers and thunderstorms, a
    seasonably moist boundary layer is forecast along and to the south
    of the front and surface low in the mid-MS and OH Valleys. The
    moisture combined with daytime heating will contribute to at least
    modest air mass destabilization by afternoon. Both vertical shear
    and forcing for ascent will strengthen through the period with the
    approach of the midlevel trough. As such, some severe weather
    appears possible on Thursday with the threat possibly continuing
    through Thursday night from the OH Valley into the Mid-Atlantic. At
    least level-1/Marginal Risk probabilities may be required in the
    subsequent Day 3 Outlook for this time period.


    ...Day 5/Friday...

    As mentioned above, some severe weather threat could develop over
    the Mid-Atlantic late Thursday night or Friday morning with
    additional strong to severe storms possible by afternoon along the
    front in the southern Mid-Atlantic or Carolinas.


    ...Days 6 to 8/Saturday to Monday...

    No severe weather is currently expected.

    ..Mead.. 10/12/2026
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    --- scorpsmtpd
    * Origin: capitolcityonline.net * KY, USA (1:2320/107)
  • From COD Weather Processor @1:2320/107 to All on Tue Oct 13 08:33:20 2026
    ACUS48 KWNS 130832
    SWOD48
    SPC AC 130830

    Day 4-8 Convective Outlook
    NWS Storm Prediction Center Norman OK
    0330 AM CDT Tue Oct 13 2026

    Valid 161200Z - 211200Z

    ...DISCUSSION...
    ...Day 4/Friday...

    An intense midlevel trough will progress from the Great Lakes to off
    the Atlantic Coast by Saturday morning. An associated surface low is
    forecast to develop from the lower Great Lakes to off the New
    England coast while a trailing cold front advances through much of
    the eastern CONUS. A moist and at least marginally unstable air mass
    is forecast in portions of the Mid-Atlantic by afternoon, with
    thunderstorms possible along and ahead of the front. Vertical shear
    is expected to be relatively strong, suggesting the potential for
    isolated severe weather. Level-1/Marginal Risk probabilities may be
    required in the subsequent Day 3 Outlook for this time period.


    ...Days 5 through 8/Saturday through Tuesday...

    A considerably drier and more stable low-level air mass will persist
    at many locations over the weekend with non-severe storms possible
    in portions of FL and the lower-CO Valley. By early next week, there
    is good model agreement that a midlevel trough will move into the
    western CONUS. In response, a deepening lee trough over the High
    Plains will lead to increasing moisture return, particularly over
    the southern Plains by Tuesday. However, no severe weather is
    expected through that time frame.

    ..Mead.. 10/13/2026
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    --- scorpsmtpd
    * Origin: capitolcityonline.net * KY, USA (1:2320/107)
  • From COD Weather Processor @1:2320/107 to All on Wed Oct 14 08:27:48 2026
    ACUS48 KWNS 140827
    SWOD48
    SPC AC 140825

    Day 4-8 Convective Outlook
    NWS Storm Prediction Center Norman OK
    0325 AM CDT Wed Oct 14 2026

    Valid 171200Z - 221200Z

    ...DISCUSSION...
    ...Days 4 through 6/Saturday through Monday...

    An intense midlevel trough will move off the Atlantic Coast early on
    Day 4/Saturday in response to strong zonal flow developing along the U.S./Canadian border. Elsewhere, an upper low off the Baja Coast
    will weaken while accelerating through the Southwest into the Great
    Plains. In the low levels, a drier and more stable air mass is
    expected to limit severe weather potential through at least Monday.


    ...Days 7 and 8/Tuesday and Wednesday...

    There is good model agreement that a midlevel trough will move
    inland from the Pacific Coast. Meanwhile, an associated deepening of
    a lee surface trough is expected over the High Plains, which in turn
    will promote the poleward flux of an increasingly moist air mass
    from the Gulf into the Great Plains. An isolated severe weather
    threat could materialize by as early as Tuesday in the
    lower-Colorado Valley, where strengthening vertical shear and
    forcing for ascent overspread a marginally unstable environment.
    Uncertainty remains in how quickly the midlevel trough will move
    through the Interior West; however, it does appear that severe
    weather potential may increase over the central U.S. by Wednesday or
    Thursday of next week.

    ..Mead.. 10/14/2026
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    --- scorpsmtpd
    * Origin: capitolcityonline.net * KY, USA (1:2320/107)
  • From COD Weather Processor @1:2320/107 to All on Thu Oct 15 08:21:36 2026
    ACUS48 KWNS 150821
    SWOD48
    SPC AC 150818

    Day 4-8 Convective Outlook
    NWS Storm Prediction Center Norman OK
    0318 AM CDT Thu Oct 15 2026

    Valid 181200Z - 231200Z

    ...DISCUSSION...
    The primary upper-air feature of interest is an amplifying trough,
    which will evolve into a closed low along the West Coast Monday
    night into Tuesday/Days 5 and 6. Thereafter, 00Z deterministic and
    ensemble guidance indicates the midlevel system will shift east into
    the Great Basin and lower Colorado Valley with an associated belt of
    stronger southwesterly flow overspreading the southern Rockies and
    potentially central and southern High Plains by Thursday/Day 8. In
    the low levels, surface ridging is forecast to persist from the
    Northeast into the southern Plains into at least early next week,
    which will slow the return of moisture from off the Gulf into the
    Great Plains.

    ...Days 4 through 6/Sunday through Tuesday...

    A few strong thunderstorms appear possible across portions of the
    lower Colorado Valley into the Four Corners and southern Rockies,
    especially on Tuesday. However, instability currently appears too
    weak to support a severe weather threat.


    ...Days 7 and 8/Wednesday through Thursday...

    While particular details regarding location and intensity of the
    midlevel trough/low remain uncertain, there is some ensemble signal
    that a favorable overlap of stronger vertical shear and at least
    modest instability could materialize over the southern Rockies,
    where a few strong to severe storms may occur. At least an isolated
    severe weather threat could spread from the southern Rockies into
    the adjacent High Plains by Thursday on the condition that
    sufficient low-level moistening/destabilization occurs along and to
    the east of a surface lee trough.

    ..Mead.. 10/15/2026
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    --- scorpsmtpd
    * Origin: capitolcityonline.net * KY, USA (1:2320/107)
  • From COD Weather Processor @1:2320/107 to All on Fri Oct 16 07:54:42 2026
    ACUS48 KWNS 160754
    SWOD48
    SPC AC 160752

    Day 4-8 Convective Outlook
    NWS Storm Prediction Center Norman OK
    0252 AM CDT Fri Oct 16 2026

    Valid 191200Z - 241200Z

    ...DISCUSSION...
    A rather stagnant upper-air pattern will be in place across the
    CONUS into early next week, with an upper ridge continuing over the
    central U.S. as a mid-level cut-off low meanders along the Atlantic
    coastline and an upper trough gradually amplifies along the West
    Coast. By the middle to end of next week, the West Coast upper
    trough will advance eastward toward the Rockies, encouraging surface
    lee troughing and subsequent low-level moisture return (albeit
    modest) across the Great Plains states. Thunderstorm development is
    possible, especially across portions of the southern High Plains
    Days 6-7 (next Wednesday-Thursday). However, deterministic guidance
    suggests that little overlap of meaningful buoyancy and vertical
    wind shear will take place over the southern High Plains next Wednesday-Thursday, with calibrated ML/AI guidance only hinting at a
    severe threat that will be isolated at best. Therefore, severe
    probabilities have been withheld this outlook.

    ..Squitieri.. 10/16/2026
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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 17 07:49:42 2026
    ACUS48 KWNS 170749
    SWOD48
    SPC AC 170747

    Day 4-8 Convective Outlook
    NWS Storm Prediction Center Norman OK
    0247 AM CDT Sat Oct 17 2026

    Valid 201200Z - 251200Z

    ...DISCUSSION...
    An upper trough will gradually approach the Rockies into the middle
    of next week, encouraging surface lee troughing and accompanying
    modest low-level moisture return. As this occurs, cooler
    temperatures and stronger flow aloft will overspread this low-level
    moisture, resulting in increased potential for thunderstorm
    development. There are some indications of enough buoyancy/shear
    overlap in the Desert Southwest to Great Plains states during the
    Days 5-7 (Wednesday-Friday) time frame to support an isolated severe
    threat. Calibrated AI/ML guidance supports this potential, with
    guidance trends showing gradually increasing probabilities. However,
    given anticipated low buoyancy, the severe threat still appears
    quite isolated and localized.

    ..Squitieri.. 10/17/2026
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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 18 07:57:48 2026
    ACUS48 KWNS 180757
    SWOD48
    SPC AC 180755

    Day 4-8 Convective Outlook
    NWS Storm Prediction Center Norman OK
    0255 AM CDT Sun Oct 18 2026

    Valid 211200Z - 261200Z

    ...DISCUSSION...
    A mid-level trough will amplify while traversing the Interior West Wednesday-Friday, before ejecting into the central and northern
    Plains by the weekend. As the upper trough traverses the Interior
    West, modest low-level moisture will advect ahead of it across the
    Desert Southwest to the High Plains late next week into the weekend.
    Despite strong forcing accompanying the upper trough, deterministic
    guidance still shows relatively weak buoyancy across the warm sector
    over the Southwest to the High Plains, with only occasional
    favorable overlaps with stronger vertical wind shear. Such setups
    would typically favor strong to isolated severe storms, as also
    indicated by a consensus of available ML/AI calibrated guidance.

    ..Squitieri.. 10/18/2026
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    --- scorpsmtpd
    * Origin: capitolcityonline.net * KY, USA (1:2320/107)
  • From COD Weather Processor @1:2320/107 to All on Mon Oct 19 08:32:26 2026
    ACUS48 KWNS 190832
    SWOD48
    SPC AC 190830

    Day 4-8 Convective Outlook
    NWS Storm Prediction Center Norman OK
    0330 AM CDT Mon Oct 19 2026

    Valid 221200Z - 271200Z

    ...DISCUSSION...
    A mid-level trough will progress across the Rockies late this week
    and eject into the central and northern Plains states this weekend.
    Thereafter, a more zonal, progressive upper-air pattern will become
    established across the CONUS, with stronger flow aloft relegated to
    the northern CONUS, and multiple mid-level impulses poised to
    traverse this flow into early next week. At the moment, the best
    chance for any severe potential (albeit isolated) will be across the
    Desert Southwest on Day 4 (Thursday) and across the High Plains on
    Day 5 (Friday). In the Days 4-5 period, along the eastern portion of
    the upper trough, a belt of 50-60 kt mid-level flow will overspread
    the Desert Southwest into the southern and central High Plains, atop
    modest low-level moisture. Marginal instability and strong vertical
    wind shear should overlap across the Desert Southwest on Thursday
    and over the southern to central High Plains on Friday to support
    scattered strong thunderstorms, a couple of which may briefly reach
    severe limits. Given the anticipated isolated nature of the severe
    threat, as also suggested by ML/AI guidance, severe probabilities
    were not introduced this outlook.

    ..Squitieri.. 10/19/2026
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    --- scorpsmtpd
    * Origin: capitolcityonline.net * KY, USA (1:2320/107)
  • From COD Weather Processor @1:2320/107 to All on Tue Oct 20 07:59:36 2026
    ACUS48 KWNS 200759
    SWOD48
    SPC AC 200757

    Day 4-8 Convective Outlook
    NWS Storm Prediction Center Norman OK
    0257 AM CDT Tue Oct 20 2026

    Valid 231200Z - 281200Z

    ...DISCUSSION...
    A mid-level trough will gradually de-amplify while ejecting into the
    central and northern Plains this weekend. Thunderstorms will be
    likely this weekend into early next week from the Desert Southwest
    into the Plains states. The best chance for isolated severe
    thunderstorms will be Days 4-5 (Friday-Saturday), when stronger
    forcing for ascent will coincide with better moisture/instability
    over the Desert Southwest. Thereafter, buoyancy and upper support
    will become increasingly decoupled with mid-level trough ejection
    into the Plains.

    Through much of next week, increasingly positively tilted upper
    troughing over the eastern CONUS will yield a northwesterly upper
    flow regime across most of the CONUS east of the Rockies. A
    relatively cool and/or stable airmass will overspread most of the
    CONUS, with no clear signal of an organized severe threat, as also
    supported by ML/AI guidance consensus.

    ..Squitieri.. 10/20/2026
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    --- scorpsmtpd
    * Origin: capitolcityonline.net * KY, USA (1:2320/107)
  • From COD Weather Processor @1:2320/107 to All on Wed Oct 21 08:02:56 2026
    ACUS48 KWNS 210802
    SWOD48
    SPC AC 210800

    Day 4-8 Convective Outlook
    NWS Storm Prediction Center Norman OK
    0300 AM CDT Wed Oct 21 2026

    Valid 241200Z - 291200Z

    ...DISCUSSION...
    A mid-level trough gradually progressing across the Rockies this
    weekend will eject into the Plains, with the prevailing mid-level
    flow pattern becoming more zonal and progressive through next week.
    Surface high pressure and attendant subsidence will overspread most
    of the CONUS east of the Rockies, limiting thunderstorm development
    through at least early next week. The best chance for any severe
    weather (albeit sparse) would be across the southern Rockies Day 4
    (Saturday), where a buoyant airmass will reside ahead of the upper
    trough prior to ejection.

    Medium range guidance depicts the eastward progression and
    amplification of another upper trough toward the middle of next
    week, which should encourage strong surface troughing and the
    progression of a cold front across the central U.S. The southern
    extent of the front may interact with a potentially buoyant airmass
    over the southern Plains, most likely around Day 8 (Wednesday) or
    beyond. While at least isolated severe storms are possible,
    questions regarding the placement and timing of the front, and lack
    of consistency among guidance precludes severe probabilities this
    outlook.

    ..Squitieri.. 10/21/2026
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    --- scorpsmtpd
    * Origin: capitolcityonline.net * KY, USA (1:2320/107)
  • From COD Weather Processor @1:2320/107 to All on Thu Oct 22 07:57:12 2026
    ACUS48 KWNS 220756
    SWOD48
    SPC AC 220755

    Day 4-8 Convective Outlook
    NWS Storm Prediction Center Norman OK
    0255 AM CDT Thu Oct 22 2026

    Valid 251200Z - 301200Z

    ...DISCUSSION...
    A progressive upper-air pattern is expected through much of next
    week, with multiple mid-level troughs expected to traverse the
    central and northern CONUS through the extended period. Surface
    troughing will accompany several of these passing upper waves,
    encouraging the development of at least scattered showers and
    thunderstorms. However, deterministic medium-range guidance shows
    minimal convective instability associated with these surface
    troughs, which should limit the potential for severe thunderstorms
    into next week.

    ..Squitieri.. 10/22/2026
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    --- scorpsmtpd
    * Origin: capitolcityonline.net * KY, USA (1:2320/107)