Valid 12Z Thu Nov 27 2025 - 12Z Sat Nov 29 2025
...Heavy lake effect snow continues from Michigan to New York through the
end of the week...
...Turning much colder for the eastern half of the country...
...Next major winter storm will affect the northern Plains and into the
Midwest Friday into Saturday...
An abrupt change to reality is underway across the Eastern U.S. in the
wake of a strong cold front currently exiting the East Coast. The
pleasantly mild weather that was experienced from the Southeast U.S. to
New England Wednesday will be replaced by a much colder airmass from
Canada in time for Thanksgiving Day and going into the upcoming weekend.
In fact, it will feel more like January for many of these same areas with
highs running 5 to 15 degrees below late November averages, and even more
in some cases. This colder weather pattern will also include heavy snow
downwind of the Great Lakes through Friday evening, with some areas
getting over a foot of accumulation in the more persistent lake effect
bands. This will severely affect travel from now into early Saturday, and
some roads could become impassable at times. Lake effect snow warnings are
in effect to the east of lakes Erie and Ontario, and blizzard warnings for
portions of the Upper Peninsula of Michigan, where winds will gust over 40
mph at times.
Out West, a compact and well organized low pressure system approaches the
Washington and Oregon coasts on the afternoon and evening of Thanksgiving
Day, and then moves inland across the Intermountain West and Rockies on
Friday. The onshore flow ahead of the low will produce widespread rain and
mountain snow to the Pacific Northwest, and increasing snowfall coverage
for the central and northern Rockies. A couple inches of rain is possible
for the windward terrain of Washington and Oregon, and 1-2 feet of snow
for the higher elevations of the Cascades and slightly lighter totals for
the Idaho and Montana mountains. Improving conditions return to this
region by early Saturday.
The next major winter storm starts developing across the northern Plains
on Friday as a surge of arctic air from Canada meets with the shortwave
energy aloft from the aforementioned Pacific storm system. Surface
cyclogenesis over the western High Plains Friday night in response to the
amplifying upper level trough will increase the influx of moisture
northward from the Dakotas to the Midwest states, over-running the arctic
airmass at the surface. Widespread moderate to heavy snow is forecast from
Montana to the western Great Lakes, and a wintry mix to the south of the
snowfall axis from Missouri to Indiana. The potential exists for 6 to 12
inches of snow accumulation for the most impacted areas, and the Weather
Prediction has issued Key Messages regarding this next event. Severe
travel disruptions are becoming likely for much of the northern Plains and
the Midwest late Friday into Saturday.
Hamrick
