Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
257 AM EST Wed Dec 08 2021

Valid 12Z Wed Dec 08 2021 - 12Z Fri Dec 10 2021

...Developing winter storm to produce the first widespread and significant
snow of the season across parts of the Sierra Nevada, Intermountain West,
Central Rockies, and central High Plains on Thursday and Friday...

...Light snow possible across the Northeast today and Upper Great Lakes on
Thursday...

...Potentially record-breaking warm temperatures to build across the
south-central United States...

The most widespread and impactful system to affect the Nation through the
end of the week will be located between the Intermountain West and central
High Plains as a potent upper-level trough and cold front enter the region
later today. Moderate snow is expected out breakout tonight into early
Thursday across portions of the Sierra Nevada and Intermountain West, with
snow also falling into the lower elevations and potentially impacting the
Thursday AM commute in central/northern Nevada. Throughout the day on
Thursday, snow is forecast to steadily spread eastward and into the
Central Rockies before reaching parts of the central High Plains by
Thursday night. Snowfall amounts greater than 6 inches are likely across
the Sierra Nevada and higher terrain of the Intermountain West, with 3-6
inches likely across the lower terrain. Over a foot of snow is expected
across the Central Rockies of Utah, western Colorado, and far southern
Wyoming. Meanwhile, heavy snow is also forecast to create hazardous
driving conditions throughout southeast Wyoming and western Nebraska into
Friday morning, where widespread 6-12 inches of snow is possible.
Residents in these locations are advised to plan ahead as difficult travel
conditions are increasingly likely with this first significant snow of the
season. Winter Weather Advisories and Winter Storm Watches have been
issued. Periods of heavy snow are also possible across the Cascades and
Northern Rockies, thanks to a persistent onshore flow ushering in Pacific
moisture to the region. Over a foot of snow is forecast through Friday
morning across the Cascades, Olympics, and mountainous terrain of northern
Idaho and northwest Montana. Winter Weather Advisories and Winter Storm
Warnings have been issued here. Finally, it is worth noting that this
active weather pattern along the West Coast will likely lead to
much-needed rainfall spreading into central and southern California on
Thursday, but amounts are currently expected to remain under a quarter of
an inch.

For the eastern U.S., an area of low pressure located along a stalled
frontal boundary draped across the Southeast is expected to move northeast
and rapidly strengthen off the New England coastline tonight. While this
system is forecast to remain well offshore, light snow is still possible
across parts of the Northeast and New England. Snow showers are also a
possibility throughout the northern Mid-Atlantic, with little-to-no
accumulation expected. Farther south, a cold front exiting the Southeast
by this afternoon may spark a few thunderstorms over southern Georgia and
the eastern Carolinas. Light precipitation is also expected to sweep into
the Upper Midwest/Great Lakes on Thursday in the form of snow as a warm
front lifts near the region. A few inches of snow could fall across the
U.P. of Michigan.

Elsewhere, a warming trend is on the way for the central United States as
anomalous upper-level ridging builds downstream of the western trough.
Highs are expected to reach into the 70s and 80s by Thursday, with 60s
extending into the middle Mississippi Valley. Daily high temperature
records are likely to be topped through Oklahoma and Texas on Thursday,
with even more December warmth on the way to end the week.

Snell

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