• DAY1 3/5 Risk Areas Poste

    From Mike Powell@618:250/1 to All on Wed Apr 30 07:59:00 2025
    ACUS01 KWNS 301238
    SWODY1
    SPC AC 301236

    Day 1 Convective Outlook
    NWS Storm Prediction Center Norman OK
    0736 AM CDT Wed Apr 30 2025

    Valid 301300Z - 011200Z

    ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM NORTHEAST
    TX INTO SOUTHWEST OK AND THE ARKLATEX...

    ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM WEST-CENTRAL
    MO ACROSS SOUTHERN IL INTO SOUTHERN IN...

    ...SUMMARY...
    Scattered severe thunderstorms are possible on later today into this
    evening from the southern Plains into the Lower Ohio Valley, with
    the greatest risk expected across north-central Texas into the
    ArkLaTex region. Large to very large hail, damaging winds, and
    tornadoes are all possible, with some strong-tornado potential.

    ...Synopsis...
    Early morning satellite imagery shows a mature convective complex
    over western OK and northwest TX, another decaying convective
    complex over southern MO, and a shortwave trough moving across the
    Southwest. Recent surface analysis shows a mesolow associated with
    western OK/northwest TX MCS over the SPS vicinity, with another,
    more substantial low back southwest near SNK. An outflow boundary
    from prior convection extends from south-central OK through
    southeastern OK before becoming more diffuse and merging with the
    stationary front over central AR.

    The ongoing MCS is forecast to continue eastward/northeastward
    throughout the day while the Southwest shortwave progresses into the
    southern High Plains. Farther east, the stationary front that
    extends from AR into the Mid-Atlantic is expected to begin
    translating back northward as a warm front.

    ...North TX/Southern OK into the Arklatex and Mid-South...
    The well-organized MCS currently tracking across southwest OK and
    northwest TX is forecast to continue east-northeastward throughout
    much of the period. The northern portion of this system will likely
    remain progressive, moving through southern OK and north TX.
    Damaging gusts and occasional hail will be possible with this system
    throughout much of its lifecycle. Buoyancy decreases with eastern
    extent, so the system should begin to lose intensity, but its
    organized character limits the predictability of where that will
    occur. Not only that, but downstream destabilization could lead to
    potential reintensification/redevelopment along the outflow during
    the late afternoon. Vertical shear will be modest, suggesting
    reorganization into a severe convective line appears unlikely.

    The southwestern portion of this MCS is expected to trail behind the
    more forward-progression portion as it becomes more parallel to the
    deep-layer shear vector. This orientation would likely keep deep
    convection out of central/northeast TX before this afternoon. Storm
    development appears probable across central TX as the surface low
    and associated dryline shifts eastward ahead of the Southwest
    shortwave trough. Development is possible ahead of this dryline
    within the destabilized warm sector over northeast TX as well. Lapse
    rates will be modest, but ample low-level moisture will still result
    in moderate to strong buoyancy during the afternoon. Additionally, a
    belt of stronger low-level flow is anticipated to persist,
    supporting strong low-level shear and veering low-level hodographs.
    The conditions support the potential for supercells capable of all
    severe hazards, including tornadoes.

    Eventual storm clustering could lead to development of a nocturnal
    MCS that could eventually approach parts of the lower MS Valley,
    with at least an isolated severe threat.

    ...West TX into Northwest TX/Southwest OK...
    Additional strong to severe storms will be possible across parts of
    west TX, in closer proximity to shortwave trough moving across the
    southern High Plains. Cold temperatures aloft and steep lapse rates
    will support a threat of hail and localized severe gusts, even
    though deep-layer flow/shear will be more modest within this regime.
    These storms may eventually spread toward southwest OK/northwest TX
    before weakening.

    ...Parts of MS/OH Valleys...
    Afternoon thunderstorm development is anticipated amid modest
    low-level moisture advection in the wake of the convective cluster
    currently moving through southwest MO. Modest buoyancy and shear
    across the region suggest there is some potential for at least
    transient storm organization in the vicinity of the frontal zone,
    with an attendant threat for hail, locally damaging wind, and
    possibly a tornado.

    ...Southern VA/northern NC...
    Scattered storm development will be possible near the front across
    parts of VA/NC. Deep-layer flow/shear will generally be weak, but
    steep low-level lapse rates could support locally damaging outflow
    winds with the strongest storms.

    ..Mosier/Jewell.. 04/30/2025

    $$
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  • From Mike Powell@618:250/1 to All on Sat May 17 08:52:00 2025
    ACUS01 KWNS 171249
    SWODY1
    SPC AC 171248

    Day 1 Convective Outlook
    NWS Storm Prediction Center Norman OK
    0748 AM CDT Sat May 17 2025

    Valid 171300Z - 181200Z

    ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS NORTH
    TEXAS AND SOUTHERN OKLAHOMA...

    ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER PORTIONS OF
    UPSTATE NEW YORK AND WESTERN NEW ENGLAND...

    ...SUMMARY...
    Severe thunderstorms producing large to very large hail, damaging
    gusts and a couple of tornadoes are expected across the southern
    Plains. Additional severe storms are possible across the Northeast.

    ...Southern Plains Region...
    Water vapor imagery depicts a pronounced southern stream upper-level
    trough over the Baja Peninsula this morning, with evidence of a lead
    impulse approaching southwest TX. This leading impulse will
    contribute to ascent in the vicinity of a sharpening dryline across
    Western North Texas/Oklahoma by early afternoon. To the east of the
    dryline, extreme instability (MLCAPE in excess of 4000 J/kg) is
    expected to develop given the moist low-level air mass and
    relatively cool mid-level thermal profiles. With negligible CINH by
    early/mid afternoon, thunderstorms are expected to develop along the
    dryline and move east/northeast into North Texas and southern
    Oklahoma. Supercells will be the dominant mode initially, with a
    risk for very large hail (in excess of 3.5 inches), and damaging
    gusts. Although low-level shear is not especially strong, some
    tornado risk will exist given the magnitude of instability and
    potential for storm-scale interactions. Eventual upscale growth into
    a severe MCS is expected as storms continue to move across North
    TX/southern OK this evening. Severe wind probabilities have been
    increased across the Enhanced Risk area for the expectation of a
    more concentrated corridor of damaging wind potential.

    Across central/northwest OK, a narrowing plume of instability will
    be present east of the dryline and south of an east-west oriented
    frontal boundary. Within this moist sector, strong to extreme
    instability and around 50 kts of deep-layer shear will support at
    least isolated supercell storm development this afternoon over
    central OK. Very large hail (3 inches or greater) will be possible,
    in addition to damaging gusts. Tornado risk will be dependent on
    storm interactions. Thunderstorm development over northwest OK is
    more uncertain, however should a storm develop a supercell mode will
    be favored with all hazards possible.

    ...Northeast...
    Strong mid-level height falls will spread across much of the
    northeastern U.S. today in response to the approaching Great Lakes
    upper low. Large-scale ascent will increase with as the left-exit
    region of the 500mb jet translates across PA. Scattered
    thunderstorms, including supercells, are expected to develop
    along/ahead of the synoptic cold front across upstate NY, with
    subsequent movement expected into western New England. Multiple
    rounds of thunderstorms are likely, with severe hail and winds as
    the primary risks. A tornado or two cannot be ruled out with any
    stronger and semi-discrete supercell. Please refer to Mesoscale
    Discussion 836 for additional details on short-term expectations.

    ...Northern Utah Vicinity...
    A Marginal Risk has been introduced across northern UT and vicinity
    given expected higher concentration of storms within a deeply-mixed
    boundary layer. Strong/severe gusts will be the primary severe risk.

    ...Lower Mississippi Valley/Southeast...
    Thunderstorms continue from central MS into the western Carolinas at
    13z, with occasional pulses of strong/severe cells. Isolated
    stronger storms will remain possible as diurnal
    heating/destabilization takes place in the presence of ample shear
    for organized storms. However, with the line of convection oriented
    generally parallel to the shear vector, any severe risk should be
    isolated. Strong gusts will be the primary hazard.

    ..Bunting/Marsh.. 05/17/2025

    $$
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  • From Mike Powell@618:250/1 to All on Fri Jun 6 08:57:00 2025
    ACUS01 KWNS 061216
    SWODY1
    SPC AC 061214

    Day 1 Convective Outlook
    NWS Storm Prediction Center Norman OK
    0714 AM CDT Fri Jun 06 2025

    Valid 061300Z - 071200Z

    ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON
    AND EVENING OVER PARTS OF THE CENTRAL AND SOUTHERN HIGH PLAINS...

    ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER PORTIONS OF
    THE MID MS AND TN VALLEYS...AND OVER SOUTHERN NEW ENGLAND....

    ...SUMMARY...
    Scattered severe thunderstorms are expected across portions of the
    central and southern High Plains. Very large hail, damaging winds,
    and a tornado threat is anticipated. Isolated severe thunderstorms
    are also possible extending into the Tennessee/Ohio Valleys, and
    over parts of southern New England. Damaging winds are the primary
    concern in these areas.

    ...Mid MS and TN Valleys...
    Morning radar loop shows a mature quasi-linear MCS over eastern OK
    tracking into western AR. This system has produced sporadic severe
    wind reports overnight, and may continue to pose that risk for a few
    more hours. Some weakening is expected through late morning, with
    eventual rejuvenation of storms as they spread across parts of KY/TN
    and vicinity. Model guidance varies on extent of severe storm
    coverage. However, favorable westerly flow aloft, dewpoints in the
    70s, and pockets of strong daytime heating will encourage intense
    thunderstorm re-development.

    ...High Plains...
    The forecast scenario for today is similar to yesterday, with two
    areas of focus for severe thunderstorm activity. One is along the
    CO foothills, where moist/southeasterly low-level winds and
    moderately steep mid-level lapse rates will yield afternoon MLCAPE
    of 1000-2000 J/kg. Storms are expected to intensify by mid-late
    afternoon along the foothills and spread southeastward into the
    adjacent plains. Forecast soundings show generally straight-line
    hodographs, which will promote splitting supercells capable of very
    large hail and a few tornadoes. Activity may organize upscale
    during the evening over southwest KS and spread across OK overnight.

    Farther south, yesterday's and last night's convection has
    reinforced a surface outflow boundary which will extend across west
    TX. Similar to yesterday, intense supercells are expected to form
    in vicinity of this boundary during the late afternoon, posing
    another risk of very large hail and a few tornadoes.

    ..Southern New England...
    A plume of seasonally high PW values extends across the OH Valley
    into southern New England. Modest air mass destabilization is
    expected by mid day with an axis of 1000-2000 J/kg SBCAPE expected
    to extend across southern New England by 18z. While deep layer shear
    is not forecast to be that strong, adequate flow should exist for at
    least some organization. Locally damaging winds are the primary
    concern with storms that form along this instability axis.

    ..Hart/Bentley.. 06/06/2025

    $$
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