Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
307 PM EST Fri Dec 24 2021

Valid 00Z Sat Dec 25 2021 - 00Z Mon Dec 27 2021

...Heavy mountain snow, moderate lowland snow, and rain through the
Holiday Weekend for the West...

...Anomalously warm temperatures continue for most of the central and
eastern U.S., with record highs possible from the Southern Plains to
Mid-Atlantic...

...Scattered rain showers and a wintry mix forecast along a frontal system
moving across the Great Lakes and Northeast...

Heavy mountain snow and rain in the West and record warmth for the central
and eastern U.S. are the focus of the short-term forecast period (Friday
evening through Sunday). In the West, a series of storm systems will
continue to bring heavy mountain snow, moderate lowland snow, and rain to
the West Coast and the Rockies through the Holiday Weekend. Another foot
of snow is likely for the Cascades in the Pacific Northwest and Sierra
Nevada in California, with locally higher totals over several feet
possible for northern portions of the Sierra Nevada. Totals of around 6-12
inches, with locally higher amounts, are also forecast for portions of the
northern and central Rocky Mountains. Widespread Winter Storm Warnings and
Winter Weather Advisories remain in effect for the mountain ranges across
the region due to both the forecast heavy snow and high winds resulting in
blowing snow and dangerous travel conditions. Meanwhile, cooler air
continues to move in across the Pacific Northwest as a series of cold
fronts moves through and an upper-level trough begins to dig further south
over the region. Widespread highs in the 30s are likely both Saturday and
Sunday. Due to the cooler temperatures, snow levels will continue to lower
to sea level, with snow forecast for both Seattle and Portland. The
greatest chance of accumulation will be for Portland and the Willamette
Valley in Oregon, where 1-6 inches of snow is possible. Meanwhile, rain
showers will continue for the West Coast and portions of the desert
Southwest. A Slight Risk of Excessive Rainfall remains in effect through
Saturday morning for the greater San Diego area and surrounding mountain
ranges, with a Marginal Risk for central Arizona. Rain should taper off
first for southern California but rainfall rates of around 0.5 inches per
hour will continue to lead to the threat for flooding across burn scars in
Arizona.

The other major weather story of the weekend will be the continued much
above normal warmth for most of the central and eastern U.S., with
record-tying and record-breaking high temperatures forecast from the
Southern Plains to the Mid-Atlantic. Highs Saturday will range from the
40s and 50s across the Central Plains, Midwest, and northern Mid-Atlantic;
the 60s and 70s for the Ohio Valley, southern Mid-Atlantic, and South; and
into the 80s for Texas. Temperatures will cool a bit further east on
Sunday while increasing for the Central and Southern Plains. Winds will
also increase ahead of a cold front across the High Plains on Sunday.The
windy, dry, and continued warm conditions have resulted in a Critical Risk
of fire weather issued by the Storm Prediction Center for southwest
Kansas, the Oklahoma Panhandle, and the northern Texas Panhandle. One
exception to the anomalous warmth will be in the Northern Plains where
frigid Canadian air will remain in place on the north side of a generally
stationary front. Highs in Montana and North Dakota will be in the single
digits and teens.

Elsewhere, scattered light to moderate rain showers are forecast along a
frontal system moving across the Great Lakes and Northeast on Saturday. 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
of freezing rain is expected for Upstate New York and western New England,
with accumulations of around 0.1 inches possible in the Hudson and
Connecticut River Valleys. Snow showers are likely for the higher terrain
of western New England and Maine. A light wintry mix is also forecast on
the backside of the system across the Great Lakes on Sunday. Later in the
day Sunday, snow will begin to increase for the Northern Plains and Upper
Midwest as another storm system begins to strengthen and approach the
region. However, heavier totals should hold off until the overnight.

Putnam


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