Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
233 PM EST Wed Dec 22 2021

Valid 00Z Thu Dec 23 2021 - 00Z Sat Dec 25 2021

...Active weather with heavy mountain snow and lower elevation rain will
engulf much of the western U.S. over the next couple of days...

...Snow showers across Great Lakes through Thursday, then rain mixes in on
Friday; windy tonight across New England...

...Persistent warm and dry conditions over the central U.S. with fire
danger over the Front Range...

An active weather period has begun across the West, as a low pressure
system moves into the Pacific Northwest. Moderate to locally heavy
rainfall is likely tonight through Friday for the lower elevations of the
West, while heavy snowfall, currently impacting the Cascades and Northern
Rockies today, will expand into the Sierra and Central Rockies tomorrow
and Christmas Eve. There's a chance for isolated thunderstorms along the
West coast with this system, but the threat for severe weather remains
marginal. 1-3 feet of snow can be expected across the western mountains
with the highest elevations receiving isolated amounts of 4-6 feet,
especially over the Sierra. Rain moves into Southern California and the
Desert Southwest by Friday where a couple of inches of rain may cause
troublesome travel conditions.

A deep low pressure system will depart into the Canadian maritime this
evening leaving light snow showers and gusty winds across portions of the
Lower Great Lakes and interior Northeast in its wake. A Winter Storm
Warning remains in effect for northern Maine as a result. A
quasi-stationary boundary will form along the Great Lakes on Thursday and
will be the impetus for light snow across the region before a more dynamic
system arrives on Christmas Eve. Rain will mix in over parts of the Lakes
and Ohio Valley while freezing rain remains a possibility for parts of the
Upper Midwest and North Dakota on Friday.

An upper-ridge will move across the southern tier states over the next few
days. This area of high pressure will cause temperatures across the Plains
and Mississippi Valley to rise significantly heading into the weekend.
Temperatures will be anomalously warm with highs between 25-35F degrees
above average for many areas by Friday. This translates into upper-60s to
mid-80 degree days for much of this region. A Critical Risk of Fire
Weather remains in effect for parts of the Front Range (southeastern
Wyoming into northwestern Nebraska) tonight, due to increased winds and
dry conditions beneath the area of low pressure moving across southern
Canada. Meanwhile, temperatures will begin to drop along the Northern
Rocky foothills on Friday as the cold front associated with the
aforementioned Canadian system swings through the region.

Kebede


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