…An Atmospheric River will bring a couple rounds of heavy, lower
elevation rain and high elevation mountain snow to the Pacific Northwest
and northern California…
…Lingering precipitation chances for the Northeast and Carolinas Monday
with some locally heavier rainfall along the central Gulf Coast…
…Above average temperatures continue for much of the country, more
seasonable temperatures for the Northeast and the West on Tuesday…
A pair of Pacific storm systems will help to usher in waves of moisture
into the Pacific Northwest and northern California in an active
Atmospheric River pattern over the next couple of days. Moderate to heavy
coastal rain and high elevation mountain snow is already ongoing over the
Pacific Northwest this morning and will continue to spread inland as well
as into northern California throughout the day Monday. A moderate lower
elevation rain/wintry mix and higher elevation snow will also spread into
portions of the northern Rockies and Great Basin by Monday evening. Some
locally heavier snowfall totals of 8-12″+ will be possible for the
Cascades with more moderate totals elsewhere. Precipitation will linger
into Tuesday for the Pacific Northwest and northern Rockies/Great Basin as
well as spread into the central Rockies as this system continues inland.
Then, on Tuesday evening, a second system will approach the Pacific
Northwest bringing the next wave of moisture inland. Showers and even some
thunderstorms along the coast and upslope portions of the Coastal Ranges
will lead to some heavier rainfall totals late Tuesday into early
Wednesday, with an isolated threat for flooding. Additional heavy snowfall
is also expected for the Cascades.
Some showers and thunderstorms will linger in the Carolinas and along the
central Gulf Coast ahead of a cold front pushing off the East Coast
through the day Monday. Higher moisture along the Gulf could lead to some
locally heavier downpours. A secondary cold front to the northwest will
also bring some additional light to moderate showers to the interior
Northeast, which may include a wintry mix by Monday evening. Elsewhere,
some isolated showers and storms will be possible across the
central/northern Plains and Mississippi Valley late Tuesday/early
Wednesday morning as the first storm system over the West reaches the
region.
Forecast high temperatures Monday continue to remain above average by
around 5-15 degrees for much of the country. Some of the most unseasonably
warm highs will be throughout New England, with highs in the 50s and 60s,
and the Mid-Atlantic, with highs into the 60s and 70s. Otherwise,
temperatures range from the 40s and 50s in the northern Plains/Midwest;
the 50s and 60s for the Pacific Northwest, northern Rockies, Great Basin,
and California; the 50s for the central Plains and Ohio Valley; and the
70s and 80s for the Desert Southwest, Texas, and the Southeast. A cold
front passing through the Northeast will bring much cooler, more
seasonable temperatures Tuesday, as highs fall into the 40s and 50s. The
Pacific system passing through the West will also bring some more
seasonable temperatures Tuesday, with highs falling into the 40s for the
Great Basin/northern Rockies and the 60s and 70s in the Desert Southwest.
Putnam
Graphics available at
https://www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php