• Long Duration Winter Stor

    From Dumas Walker@21:1/175 to All on Mon Apr 1 08:43:00 2024
    FOUS11 KWBC 010835
    QPFHSD

    Probabilistic Heavy Snow and Icing Discussion
    NWS Weather Prediction Center College Park MD
    435 AM EDT Mon Apr 1 2024

    Valid 12Z Mon Apr 01 2024 - 12Z Thu Apr 04 2024

    ...Southwest/Central and Southern Rockies... Day 1...

    Light to moderate snow is expected to continue early in the period
    along the Mogollon Rim, and the southeastern Arizona and
    southwestern New Mexico mountains as a deep, positively-tilted
    upper trough advances across the region.

    Precipitation will begin to blossom further to the northeast, as a
    well-defined shortwave moving through the base of the broader-scale
    trough ejects out into the southern High Plains later today.
    Moisture focusing along a front sagging south in the wake of the
    departing low will fuel localized heavy snow accumulations from the
    Colorado Front Range to the Raton Mesa and Sangre de Cristos
    Mountains. WPC PWPF shows moderate (40 percent) or higher
    probabilities for accumulations of 8-inches or more in this areas.
    Models continue to indicate a mostly rain event for the lower
    elevations further east.

    ...Central Plains... Day 1...

    Ongoing precipitation across Kansas and Nebraska is expected to
    continue through the early part of the period as leading shortwave
    energy lifts out of the western U.S. trough. Light to moderate
    precipitation is expected to focus on the northwest side of an
    associated low-to-mid level low lifting from western Kansas into
    eastern Nebraska this morning. Models are not suggesting a
    widespread heavy snowfall event, with marginal temperatures and low
    SLRs contributing to a limited threat. However, there is some
    signal for banding to develop near the Nebraska-South Dakota border,
    which along with colder air sliding in from the north, may support
    some localized heavier totals. WPC PWPF shows slight (10 percent)
    or higher probabilities for accumulations of 4 inches or more
    centered mainly along and north of the central Nebraska-South
    Dakota border.

    ... Great Lakes into the Northeast... Days 2-3...

    ...The potential for a late season significant winter storm is
    increasing...

    Models continue to indicate that a late-season winter storm will
    likely develop mid week, producing widespread gusty winds and heavy
    snow portions of the Great Lakes and the interior Northeast.

    The previously noted shortwave emanating from the Southwest is
    forecast to lift northeast through the central Plains and mid
    Mississippi Valley, into the Great Lakes where it will begin to
    phase with an equally well-defined northern stream shortwave diving
    southeast out of central Canada. This will support a rapidly
    developing surface low that will track northeast from the mid
    Mississippi Valley on Tuesday morning into Michigan by the evening,
    where it will lift north and then retrograde as a deep upper low
    forms overhead. Models continue to show a track favorable for heavy
    snow developing across northern Lower Michigan, supported
    initially by low-to-mid level frontogenesis and favorable upper jet
    forcing centered across the region late Tuesday evening. Snow will
    begin to taper off as the low drops back to the southeast, but not
    before several inches of heavy snow fall across portions of the
    region. WPC PWPF shows moderate probabilities for accumulations of
    4 inches or more centered over interior northern Lower Michigan
    along with a slight chance for amounts exceeding 8 inches.

    As the upper low begins to move east across the Great Lakes,
    additional southern stream energy lifting out of the south will
    support the development of a triple-point low that will become the
    primary surface feature as it tracks from the Mid Atlantic to Long Island-southern New England late Wednesday into early Thursday.
    Overall, model timing has slowed a little with the overnight runs,
    but the overall consensus continues to show widespread moderate to heavy precipitation becoming likely across the Northeast by late
    Wednesday continuing into early Thursday. Rain or mixed
    precipitation at the onset will likely transition to all snow
    across much of eastern Upstate New York and central to northern New
    England, with several inches of heavy, wet snow appearing likely
    across the higher terrain. By early Thursday, WPC PWPF shows high
    probabilities (70 percent) for accumulations of 8 inches or more
    covering much or the Adirondacks, Green, and White mountains.
    Moderate probabilities extend as far south as the Catskills and
    east into central Maine.


    *** Key Messages for Early April Nor'easter ***

    ---Long duration winter storm becoming likely

    Confidence is increasing that a large storm system will produce gusty
    winds and late-season heavy snows across portions of the Great
    Lakes and the Northeast mid to late week.

    ---Widespread heavy snow.

    Heavy snow may develop across portions of the Great Lakes early
    Wednesday through early Thursday. Secondary low pressure
    development along the coast is likely to bring heavy snow and mixed
    freezing rain/sleet to the Northeast late Wednesday through Friday.

    ---Significant impacts from heavy snow and wind

    The combination of heavy snow rates and gusty winds will likely
    result in hazardous travel due to low visibility and snow-covered
    roads. Additionally, the heavy and wet snow could impact
    infrastructure.

    ---Forecast changes anticipated

    Uncertainty remains with the timing and location of the storm
    track, which will affect where the most significant impacts will
    occur. Keep up to date with the latest forecasts as this storm
    evolves.

    $$
    --- SBBSecho 3.20-Linux
    * Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (21:1/175)