Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
127 PM EST Sat Dec 25 2021

Valid 00Z Sun Dec 26 2021 - 00Z Tue Dec 28 2021

...Significant snowfall for portions of West Coast mountain ranges;
freezing rain threat for parts of interior Northeast tonight into Sunday
morning...

...Anomalously warm temperatures continue for most of the central and
eastern U.S. while cold airmass expands across Northwest; records
possible...

...Dynamic system to bring rain, snow and a wintry mix from the Northern
Plains to the Mid-Atlantic Sunday...

The seemingly endless upper level troughing pattern in the West is
forecast to stick around through the remainder of the holiday weekend.
Anomalously cold conditions and a barrage of Pacific moisture results in
prolonged periods of mountain snow and coastal/valley rain, some of which
may fall heavy at times. Enough cold air is in place for even metropolitan
areas of the Northwest to receive measurable snowfall. Winter Storm
Warnings have been issued from Portland, Oregon and the Willamette Valley
on south to the Sierra Nevada and the Transverse Range in Southern
California through Sunday. Through the remainder of the weekend, the
heaviest snowfall totals are expected to occur in the northern and central
Sierras, where 2 to 4 feet of snow (locally higher amounts possible) are
expected. The Portland metro area may receive 2 to 5 inches of snow and
the Seattle metro (under a Winter Weather Advisory through Sunday
afternoon) could receive a few inches of snow. A little farther east, the
next upper level disturbance slams into the West Coast on Sunday,
delivering another round of moderate-to-heavy snowfall to the
Intermountain West. Snow totals, from the Sawtooths, the Tetons, Wasatch,
and central Rockies can anticipate roughly 1 to 2 feet of snow by the end
of the weekend. Travel will be treacherous, to at times impossible, from
the Sierras to the central Rockies this weekend due to whiteout conditions
and drifting snow.

The other weather story of the weekend will be the continued much above
normal warmth for most of the central and eastern U.S. Record-tying and
record-breaking high temperatures are likely from the Southern Plains to
the Mid-Atlantic. A passing cold front drops temperatures to more
seasonally warm levels in the Ohio Valley on Sunday, but much of the South
remains remarkably warm as highs soar into the 80s once again in Texas and
Oklahoma. The warmest average temperatures for Sunday will stretch from
northern Texas into southern Kansas where temperatures will be 25-35
degrees above average. Winds will also increase ahead of a cold front
across the High Plains on Sunday. The combination of windy, dry, and
continued warm conditions have resulted in a Critical Risk of fire weather
issued by the Storm Prediction Center for southwest Kansas, southeast
Colorado, and portions of both the Oklahoma and northern Texas Panhandles.
One exception to the anomalous warmth (aside from the cooler, stormy setup
along the West Coast) is the Northern Plains where frigid Canadian air
will pool behind a strong cold front. Morning lows are forecast to be
sub-zero in the High Plains of Montana and North Dakota with daytime highs
struggling to get out of the single digits. This cold airmass will expand
back into the West coast on Sunday and eastward by Monday.

Elsewhere, scattered light to moderate rain showers along a frontal system
will move across the Northeast tonight. A wintry mix of freezing rain and
snow is forecast in the cooler air on the north side of the front across
upstate New York and New England. A glaze to moderate freezing rain is
expected for Upstate New York and western New England, with accumulations
of around a tenth to a quarter of an inch possible in the Hudson and
Connecticut River Valleys. Snow showers are likely for the higher terrain
of western New England and Maine. Winter Weather Advisories are in effect
for these areas. By Sunday afternoon, snow will begin to increase in
coverage across the Northern Plains and Upper Midwest as an emerging storm
system strengthens and approaches from the West. Latest forecast guidance
indicated anywhere from 6 to 12 inches of snow possible in eastern North
Dakota Sunday night and into early Monday morning. Parts of northern
Minnesota may also pick up as much as 6 inches Sunday night, while
isolated parts of Minnesota's Lake Superior coast may see over a foot of
snow on Monday. A glaze of ice accumulation is also possible in the Upper
Mississippi Valley and the central Great Lakes Sunday night into early
Monday morning.

Kebede/Mullinax


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