Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
300 AM EST Mon Nov 15 2021

Valid 12Z Mon Nov 15 2021 - 12Z Wed Nov 17 2021

...Heavy rain and mountain snow culminates today over the Pacific
Northwest before tapering off tonight....

...A rapidly intensifying low pressure system will bring high winds across
the northern Rockies today and through the northern Plains on Tuesday...

...Areas of rain/snow over the Northeast will gradually taper off as low
pressure system exits New England...

The latest round of heavy precipitation across northwestern Washington
state will reach peak intensity today as multiple frontal waves push
onshore and consolidate into a major low pressure system centered over
British Columbia.  Deep mild air ahead of the system will keep much of the
precipitation as heavy rain even up into the mountainous terrains, with
only the highest peaks seeing heavy snow.  A strong cold front will then
sweep across the Pacific Northwest later today through tonight as the low
pressure system intensifies.  Cold air rushing in behind the front will
change the heavy rain quickly to heavy snow across the higher elevations
along with high winds.  The system will likely reach peak intensity
tonight over Alberta Canada and slowly weakens as it tracks across the
Canadian prairies through Wednesday morning.  A widespread high wind event
is anticipated for the northern Rockies then spreading east through the
northern Plains to the upper Midwest for the next couple of days.  Only
modest snow amounts are forecast for the northern Rockies with this system
followed by little precipitation across the northern Plains given an
apparent lack of available moisture.  High temperatures will rise steeply
across the High Plains well into the 70s for the next couple of
afternoons, which are between 25-30 degrees above average for this time of
the year.  In contrast, colder than normal temperatures will surge into
the Pacific Northwest.

Meanwhile, an Alberta clipper with areas of rain/snow will begin to depart
the Northeast today.  Areas of rain/snow across the Great Lakes to New
England will slowly taper off through Tuesday.  Another weaker clipper
system will produce light rain/snow over the Northern Plains and Upper
Midwest tonight before dissipating. The downstream clipper will produce
light to moderate snowfall over the Lower Great Lakes, Central
Appalachians and Adirondacks through Monday. Generally 2-4 inches of snow
are expected with isolated higher amounts possible over the peaks of the
aforementioned mountains. This clipper will simultaneously produce
rainfall over coastal New England through Monday. Temperatures cool down
across the east in the wake of this system, with parts of the Ohio Valley
and Central Appalachians experiencing particularly cold high temperatures
between 15-25 degrees on Monday. A quieter period awaits the CONUS heading
into midweek.

Kong/Kebede


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