Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
300 AM EST Tue Dec 09 2025

Valid 12Z Tue Dec 09 2025 - 12Z Thu Dec 11 2025

...Atmospheric river to usher in several days of heavy rain into the
Pacific Northwest and snow into the northern Rockies...

...A clipper will bring a period of snow across the upper Midwest and the
Great Lakes through Tuesday...

...A stronger clipper is expected to bring the threat of heavy snow and
high winds across the upper Midwest on Tuesday then across the Great Lakes
on Wednesday...

A weather pattern that supports heavy rain across coastal Pacific
Northwest will transition to cold and snowy weather for the northern tier
states. This will be in stark contrast with dry and milder than normal
conditions across the Southwest. In the short-term, Arctic air in the wake
of an offshore low pressure center will cause temperatures to crash into
the teens this morning as far south as North Carolina, which will
challenge some low temperature records across the interior Mid-Atlantic to
southern New England.

Meanwhile, a prolonged atmospheric river event continues over the Pacific
Northwest, with radar and surface observations highlighting steady heavy
rainfall in the region. The arrival of widespread heavy rain today signals
the beginning of several days of heavy rainfall expected to impact western
Washington and northwestern Oregon. The potent trans-Pacific jet stream
will continue to transport sub-tropical moisture from the Pacific and dump
the moisture as heavy rain closer to the coast, and more than a foot of
new snow for the northern Rockies in northwestern Wyoming. Isolated to
scattered instances of flash flooding are possible near the coast and into
the Cascades through midweek, where a slew of Flood Watches are in effect.
Rainfall aside, parts of the Pacific Northwest, northern Rockies, and
northern Plains can also expect very gusty winds through the next couple
of days as the same Pacific jet develops a strong clipper system in the
Canadian Rockies. As this clipper system ejects eastward into the northern
Plains and upper Midwest late today, a swath of moderate to locally heavy
snow is expected develop along the northern flank of the low center.
Snowfall amounts of 4 to 8 inches can still be expected from northeastern
corner of North Dakota through the central Great Lakes. This clipper
system is forecast to quickly intensify, producing an expanding area of
very strong and gusty winds to accompany the snow. By tomorrow morning,
the maturing clipper migrates into the lower Great Lakes, spreading wintry
weather towards the Interior Northeast. The snow will be tapering off
across the northern Plains on Wednesday behind the storm but snow will be
expanding through the lower Great Lakes and into interior Northwest as the
storm center approaches.  Rain will be falling farther south across the
Ohio Valley on Wednesday, moving into the northern Mid-Atlantic later that
day.

Meanwhile, the central and southern Plains as well as the Deep South will
enjoy fine and dry weather with a warming trend especially for the Plains.
 The Southwest will remain dry and milder than normal while much milder
than normal conditions are forecast for the Northwest into the northern
High Plains along with the inclement weather. A gradual drying trend is
forecast for the Sunshine State as a cold front pulls out to sea.

Asherman/Kong


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