315
FXUS01 KWBC 220800
PMDSPD

Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
259 AM EST Fri Nov 22 2024

Valid 12Z Fri Nov 22 2024 - 12Z Sun Nov 24 2024

...Atmospheric river will produce one last round of heavy
rain/mountain snow and strong wind gusts across the Pacific
Northwest today...

...Moderate to heavy snow for portions of the Central Appalachians
today...

...Above average temperatures expand across the Central U.S. this
weekend...


Anomalous moisture supported by a deep low pressure system will
continue impacting the Pacific Northwest today. Life threatening
flooding is likely across portions of northern California, where
additional amounts of 3-5" are expected, mainly over coastal
areas. As much as 4-10" of rain are possible for the northern
Sierra Nevada. Dangerous flooding, rock slides and debris flows
remain likely today. A Moderate Risk of Flash Flooding is in
effect for upslope portions of the northern Sierra below 5000`.
The flooding risk will decrease from north to south by later today
and into tonight. Heavy mountain snow is expected over the
Washington Cascades and Northern Rockies through Saturday.
Multiple feet of snow are likely to accumulate over portions of
the northern Sierra (above 7000`) by Saturday evening. Strong
winds will continue across coastal areas of northwest California
into western Washington, and over south-central Oregon. These
winds may blow down trees and power lines, and additional power
outages are possible.

A deep upper low will pivot over the Northeast and reinforce a
cooler airmass along with a relatively shallow bit of moisture
into the region today. Some rain and snow showers are expected
across much of the Northeast/northern Mid-Atlantic as a result.
Heavier snow will likely remain confined to the higher terrain of
the Central Appalachians, where between 6-12 inches are expected
with locally higher amounts possible. Snow chances diminish as the
day progresses and temperatures rise. Upper ridging over the
Intermountain West and Rockies will shift eastward into the
Central U.S. this weekend where above average temperatures are
likely to follow.


Kebede


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