• Nor'Easter develops today

    From Dumas Walker@21:1/175 to All on Sunday, February 22, 2026 09:50:51
    FOUS11 KWBC 220932
    QPFHSD

    Probabilistic Heavy Snow and Icing Discussion
    NWS Weather Prediction Center College Park MD
    432 AM EST Sun Feb 22 2026

    Valid 12Z Sun Feb 22 2026 - 12Z Wed Feb 25 2026

    ...Central Appalachians, Mid-Atlantic, through Northeast... Days 1-2...

    *** Nor'Easter rapidly develops today as it slowly shifts north just
    off the Mid-Atlantic Coast. Heavy snow and blizzard conditions
    are expected for the Delmarva through the Northeast Urban Corridor
    through eastern New England through Monday. ***

    Northern stream mid-level trough axis is over St. Louis while
    a southern stream wave in the right entrance region of the SWly
    jet is allowing surface cyclogenesis over the Carolina Coast. These
    features phase this morning, the jet shifts east, bringing the
    surface low into the left exit of the jet stream, promoting rapid
    low development north of Cape Hatteras. 1050mb surface high
    pressure approaches Ontario tonight, setting up a great pressure
    gradient across the Great Lakes and Northeast. By this afternoon,
    the deepening low off the Delmarva begins drawing cold air in from
    the NW with low level fgen banding allowing snow accum across the
    Mid-Atlantic (from the morning rain to higher elevation snow). Snow
    rates really increase this evening over the Delmarva/NJ and NYC
    from the combo of further low development and nocturnal trends with
    00Z HREF mean snow rates of 1"/hr over this area by 00Z with
    localized 2"/hr rates in NJ by midnight. Late night snow rates
    further increase, exceeding 2.5"/hr over Long Island before
    shifting to southeast New England by 09Z. Day 1 snow probs for >12"
    are 70-90% from the MD part of the Delmarva through southeast
    Mass. Day 1 snow probs for >24% are 50% for the central Jersey
    Shore. Probs for >6" greater than 50% are over the Blue Ridge,
    north/east of the Potomac River in central/southern Maryland,
    across eastern PA and the Hudson Valley.

    Event peak snow rates per the HREF are 3"/hr early Monday, though
    the very high winds (with gusts potentially to 70mph) will limit
    the SLR, so that may not be realized, but it'll be quite impactful
    snow banding with oceanic enhancement. The low then pivots to
    Nova Scotia with rates of 1-2"/hr through Monday afternoon. Monday
    evening north flow from the Gulf of Maine should allow a pivoting
    band of ocean enhanced snow into southeast Mass/Cape Cod further
    adding to the historic snow. Day 2 snow probs for >12" are 50-70%
    over eastern Mass and just off the Maine coast with 50% probs for
    6" from southern NH through eastern Maine and down through eastern CT.

    Upslope snow through the central Apps begins this afternoon,
    continuing through Monday evening. Snow rates generally stay below
    1"/hr, but the prolonged duration leads to some significant snow
    fall. Day 1 snow probs for >8" are 50-80% from the Laurels of PA
    through the Allegheny Plateau of central WV.

    ...Cascades and Northern Rockies... Days 1-3...

    Sprawling deep low lingers well off the WA coast today which
    directs Pacific moisture across the Northwest CONUS. This low then
    shears into a zonally oriented trough Monday which directs an
    atmospheric river (AR) into OR later Monday before shunting south
    through northern CA Monday night/Tuesday.

    Snow levels rise today to 3500ft in the WA Cascades, 5000-6000ft
    in OR, and 6500ft in far northern CA. Day 1 snow probs for >6" are
    40-80% in the WA Cascades (above pass level) and the highest OR/CA Cascades.

    A tighter baroclinic zone sets up Monday with snow levels dropping
    to around 2500ft at Snoqualmie Pass WA and to around 4000ft in
    northwest MT while rising above 7000/8000ft in the core of the AR
    in OR. Day 2 snow probs for >6" are 50% at pass level in the WA
    Cascades and for the ranges of northwest MT.

    The southward shift in the AR through Tuesday brings heavy precip
    to northern portions of CA and the Great Basin with CA snow levels
    over 9000ft with no snow impacts. Snow levels are closer to 7000ft
    in NW WY and central ID where Day 3 snow probs are 50-80%.

    ...Great Lakes... Days 1/2...

    Inverted trough extending northwest from low over Lake Huron
    maintains NNWly flow and strong cold air advection over Lakes
    Superior and Michigan today. This expands east across Lake Erie
    tonight into Monday as the Nor'easter develops off the Mid-
    Atlantic coast. Day 1 snow probs for >4" are 40-70% over the
    Porcupine and Huron Mtns as well as over far SW MI and northern IN.
    Day 1.5 snow probs for >4" are 40-70% southeast of Lake Erie in
    northeast OH, Erie Co PA, and Chautauqua Co NY.

    Day 3...

    An Alberta Clipper shift ESE from northern MN through MI Tuesday
    before reaching Upstate NY Tuesday night. Warm air advection ahead
    of the surface low will be into an Arctic airmass with plenty of
    DGZ available for snow crystal growth. Moderate snow rates from
    Lake Michigan enhancement can be expected in the eastern U.P. where
    Day 3 snow probs for >6" are 40-60%. LES begins on the back side of
    the clipper Tuesday night off Lake Superior, spreading across the
    Great Lakes then Wednesday.

    Jackson

    ...Winter Storm Key Messages are in effect and linked below...

    https://www.wpc.ncep.noaa.gov/key_messages/LatestKeyMessage_1.png

    $$
    --- SBBSecho 3.28-Linux
    * Origin: Capitol City Online (21:1/175)