…Wintry mix expected for portions of the central Appalachians, northern
Mid-Atlantic, southern New York and southern New England this evening and
overnight…
…Showers and thunderstorms with locally heavy rainfall possible across
the Ohio Valley through Monday…
…Modest atmospheric river activity to bring unsettled weather to the
Pacific Northwest and northern Rockies going through early this week,
including heavy rains for the coastal ranges and accumulating snow for the
higher elevations…
An upper-level disturbance will continue to cross through the central
Appalachians and into portions of southern New York and southern New
England going through this evening and overnight which will bring an area
of generally light precipitation. Sufficient cold air is in place at least
early on to facilitate areas of light snow along with some sleet and
freezing rain. Locally a few inches of snow will be possible across the
interior of the northern Mid-Atlantic, along with a glaze of ice before
temperatures warm up and allow for a changeover to rain later tonight and
early Monday morning. A chilly rain can be expected elsewhere tonight
across the Mid-Atlantic.
Meanwhile, farther to the west, a new storm system and an associated
frontal system will be ejecting across the Plains and Midwest by Monday.
This will drive a threat for areas of showers and a few thunderstorms
across much of the Ohio Valley later tonight and Monday as increasingly
moist and somewhat unstable air lifts north in close proximity to the
advancing cold front. Some of these showers and thunderstorms should
extend southwestward down into areas of the Lower Mississippi Valley.
Generally the rains are expected to be beneficial and not excessive with
locally 1 to 2 inches of rain anticipated through Monday. This storm
system will quickly lift across the Great Lakes region, and the trailing
cold front should then cross through much of the Mid-Atlantic and
Northeast by later Tuesday. Just ahead of the cold front should be the
pooling of much milder air, and temperatures across much of the eastern
half of the country should see high temperatures as much as 10 to 20
degrees above normal Monday and Tuesday. Much colder air though will be
arriving across the northern Plains and Upper Midwest on Tuesday behind an
Arctic cold front, and temperatures here will be trending back below
normal by the middle of the week.
A new round of modest atmospheric river activity associated with onshore
Pacific flow and the arrival of a couple of frontal systems will keep
areas of the Pacific Northwest and the northern Rockies unsettled going
through the early part of the week. Locally heavy rainfall can be expected
for the coastal ranges with locally a few inches of rain possible across
northwest Oregon and western Washington. Meanwhile, heavy accumulating
snow is expected for the higher elevations. This will include the
Cascades, Sawtooth, Bitterroots and Tetons where multi-day accumulations
through Tuesday of 1 to 2+ feet will be possible. Some lesser
accumulations will be possible across the northern Sierra Nevada as
moisture gradually settles farther south.
The remainder of the country including the Southwest and adjacent areas of
the southern U.S. should see generally dry weather through the first half
of the week with temperatures above normal.
Orrison
Graphics available at
https://www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php