098
FXUS02 KWBC 250759
PMDEPD

Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
259 AM EST Tue Nov 25 2025

Valid 12Z Fri Nov 28 2025 - 12Z Tue Dec 02 2025

...Overview...

An exiting strong low pressure system and its associated trailing
cold front will usher in a steady stream of cold air and gusty
winds in its wake. Much colder conditions will arrive for the
eastern U.S. by the end of the week, with a sprawling Canadian
surface high enveloping areas from the Northern Plains to the
Southeast states, and heavy lake effect snows from Michigan to New
York state. Meanwhile, an upper level trough is expected to amplify
over the western states which may spin up a surface low across the
western High Plains and bring potentially heavy rainfall ahead of
it especially over the Lower Mississippi Valley. This trough should
also cause very cold temperatures in the northern/central High
Plains.


...Guidance/Predictability Assessment...

In general, the latest guidance depicts good agreement across the
country and utilized a multi-model blend as a start. This worked
well in regards to frontal depiction and associated pressures. As
previously noted, the NBM has persistently ran lighter for POPs and
QPF for the favored lake enhanced areas with this pattern.

Model spread increased rapidly by the weekend for the western half
of the nation as solutions show initial shortwave energy moving
through the Pacific Northwest and how strong it remains as it
tracks east along the northern tier will lead to sensible weather
differences like the potential for snow. Another round of energy
will plunge southward from Alaska. Previously the GFS was stronger
and faster then the rest of the guidance that resulted in a
stronger/farther west upper low separating into the southern stream
atop California/Nevada by Sunday compared to a phased solution in
other guidance. The ECMWF has started to trend toward the GFS
during the mid/late period with CMC remaining as a middle ground
solution. Continued to move quickly toward an ensemble- mean heavy
blend for the latter half of the period which provided run to run
continuity.


...Weather/Hazards Highlights...

Moderate to heavy Lake effect snow will be ongoing at the start of
the extended period and will slowly taper off through the weekend.
From Michigan to western New York some areas potentially may
received 6-12+ inches of snow accumulation. Into Friday, rain
could begin to emerge over eastern portions of the Plains into the
Mississippi Valley, but mainly light to moderate in intensity
initially. A fair amount of moisture return from the Gulf will help
enhance precipitation over the southern/central country for the
weekend and into next week. Showers and thunderstorms are expected
to increase in coverage and intensity from eastern Texas across
the Lower Mississippi Valley into to the Mid-South. A Day 5
Marginal Risk for excessive rainfall was raised for portions of
the western Gulf Coast and Lower Mississippi Valley. In addition,
moisture over- running the arctic airmass over the Northern Plains
could lead to more widespread snowfall chances across the north-
central Plains into the Midwest into Saturday, possibly spreading
into the Interior Northeast Sunday. Another round of snow is
possible in the northern/central High Plains on Saturday and
spreading east once again on Sunday. Meanwhile higher elevation
areas like the central Rockies could receive heavy snow. The
details are all highly dependent on uncertain model guidance
though, so continue to check updated forecasts.

A strong cold front ushers in a blast of cold air to the eastern
U.S. for the end of the week, dropping temperatures about 20
degrees for many areas by Friday. Temperatures in the East will
gradually raise closer to average into early next week. But
meanwhile a much colder arctic airmass then oozes southward across
Montana and much of the Dakotas by the weekend, with some subzero
overnight lows within the realm of possibility near the Canadian
border, along with highs in the teens.


Campbell/Tate


Additional 3-7 Day Hazard information can be found on the WPC
medium range hazards outlook chart at:
https://www.wpc.ncep.noaa.gov/threats/threats.php

WPC medium range 500mb heights, surface systems, weather grids,
quantitative precipitation forecast (QPF), excessive rainfall
outlook (ERO), winter weather outlook (WWO) probabilities, heat
indices, and Key Messages can be accessed from:

https://www.wpc.ncep.noaa.gov/medr/5dayfcst500_wbg.gif
https://www.wpc.ncep.noaa.gov/medr/5dayfcst_wbg_conus.gif
https://www.wpc.ncep.noaa.gov/5km_grids/5km_gridsbody.html
https://www.wpc.ncep.noaa.gov/qpf/day4-7.shtml
https://www.wpc.ncep.noaa.gov/#page=ero
https://www.wpc.ncep.noaa.gov/wwd/pwpf_d47/pwpf_medr.php?day=4
https://www.wpc.ncep.noaa.gov/heat_index.shtml
https://www.wpc.ncep.noaa.gov/#page=ovw




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