040
FXUS01 KWBC 310757
PMDSPD

Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
255 AM EST Fri Jan 31 2025

Valid 12Z Fri Jan 31 2025 - 12Z Sun Feb 02 2025

...Precipitation returns to the West Coast, with atmospheric river
activity expected to bring heavy rain and flooding concerns to
portions of central and northern California...

...Much needed rainfall expected across the Upper Tennessee
Valley, Southern Appalachians and Mid-Atlantic, with light wintry
precipitation expected for New England...

...Above average temperatures are expected across large sections
of the country going into the weekend with exception to the
Northwest and the Northeast where temperatures will be trending
gradually below normal...

After several weeks of no precipitation along large portions of
the West Coast, a considerably more active West Coast weather
pattern will unfold over the next few days which will include the
arrival of multiple Pacific frontal systems. This will include the
arrival again of well-defined atmospheric river activity also into
especially central and northern California. Much of the rain and
higher elevation snowfall will be welcomed across the Pacific
Northwest, but for California, the concern especially by Saturday
and Sunday will be heavy to excessive rainfall that will lead to
flooding concerns. This will include the Bay Area and interior
areas of the Sacramento Valley and also the foothills of the
Sierra Nevada. A Slight Risk (level 2 of 4) of excessive rainfall
has been depicted by the Weather Prediction Center across these
areas, and while there will be certainly benefits to the rainfall,
the expectation is that a front will stall out across central
California and foster a persistence of atmospheric river
conditions and heavy rains that will drive flooding concerns.
Temperatures across the West will initially be above normal for
many locations, but the passage of the frontal activity over the
Pacific Northwest should allow temperatures here to trend
gradually below normal, and this will also allow for lowering snow
levels in time.

Meanwhile, a storm system crossing through the Ohio and Tennessee
Valleys will be advancing across the central and southern
Appalachians and the Mid-Atlantic states today through tonight
which will bring moderate to locally heavy rainfall. Generally
these rains will be quite beneficial, but there may be sufficient
rainfall in conjunction with snowmelt over the higher terrain of
the central Appalachians to bring a threat of flooding. A Slight
Risk (level 2 of 4) of excessive rainfall has been depicted across
the higher terrain of West Virginia. A portion of this storm
system will also bring heavy to potentially excessive rainfall
today across areas of northern Illinois. However, the northern
edge of the precipitation shield as it lifts off to the northeast
into parts of New York and New England will encounter a sufficient
amount of cold air for some light snowfall and also locally some
concerns for sleet and freezing rain. This storm system will exit
the region by early this weekend, with colder temperatures
arriving in its wake and especially across the Northeast.

By Sunday, a new storm system related to the unsettled weather
impacting the West Coast will begin to eject east out across the
northern Plains, and this will bring a threat for several inches
of accumulating snow to the Upper Midwest. Colder temperatures
will begin to settle south from Canada in the wake of this system
across the northern High Plains. However, above average
temperatures though are expected in general across much of the
country outside of the Northwest and the Northeast, and in some
cases across the Plains and Midwest, the temperatures this weekend
will be as much as 15 to 20 degrees above normal. Many areas of
the Southeast and the Southwest will also be warmer than normal
with highs as much as average 5 to 10+ degrees above average.

Orrison

Graphics available at
https://www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php
$$