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

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

...Heavy rain and mountain snow culminate 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 then 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 will begin to depart the Northeast today. 
Areas of rain/snow associated with this system over the Great Lakes to New
England will slowly taper off through Tuesday.  Another weaker clipper
system will produce light rain/snow across the northern Plains to the
Midwest through tonight before dissipating.  Temperatures will be colder
than normal across the East today in the wake of the Alberta clipper, with
morning lows dropping to near freezing as far south as the interior
Southeast.  However, a steady warm up is anticipated as the very mild air
across the mid-section of the country heads progressively towards the
eastern U.S. through midweek.

Kong


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