Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
259 PM EST Wed Jan 14 2026

Valid 12Z Sat Jan 17 2026 - 12Z Wed Jan 21 2026

...The high wind event late this week in the Northern & Central
Plains and nearby Colorado and Wyoming Rockies could last into
Sunday...

20Z Update: The 12Z model guidance suite is in excellent synoptic
scale agreement with the amplified upper level flow pattern that
will be in place, particularly through Monday before some
differences start becoming more evident. The main thing to watch
going into the upcoming weekend will be the evolution of a
potential coastal low pressure system that could bring impactful
winter weather to parts of the East Coast. There has been a more
westward trend in the latest guidance with the low off the coast of
the Carolinas on Sunday and the inland extent of the precipitation
shield, with the GFS indicating a more pronounced trend towards a
winter storm from the eastern Carolinas to southern New England,
whereas the non-NCEP guidance features a solution with
precipitation confined closer to the coast. Interests across the
East Coast should continue to closely monitor future forecasts
since changes are likely going forward. In addition to the coastal
low, lake effect snow will continue to make weather headlines for
most of this forecast period, and QPF was raised and blended with
GFS/ECMWF/CMC guidance to better depict mesoscale banding features
that is not well accounted for in the NBM. The previous forecast
discussion is appended below for reference. /Hamrick
-----------------------

...Guidance/Predictability Assessment...
The 00z model guidance remains generally agreeable on the broader
pattern through the medium range period, with a slow
broadening/breakdown of the ridge/trough couplet across the Lower
48.  The greatest differences are related to embedded short- wave
timing within the upper-trough and associated system development at
the surface. The largest difference in the guidance compared to
this time yesterday is a stronger shortwave rounding the base of
the Eastern Trough, which leads to cyclogenesis at some distance
offshore the Southeast/Carolinas on Sunday. The 00z GFS/00z UKMET
are the sharpest, which don't befit the breadth of the upper level
trough. 

The blend for the pressures, fronts, and 500 hPa heights is one
composed of even amounts of the deterministic guidance early
before inclusion of the 12z ECMWF/00z NAEFS means was used for the
detail issues later on. The 01z NBM QPF appeared too limited due to
its low bias with the light/moderate precipitation expected, so
included some of the 13/12z ECMWF and 13/18z GFS QPF to help deal
with the issue, both broadly around the Great Lakes and eventually
for the Pacific Northwest next Wednesday. It's possible later NBM
cycles and future WPC forecasts get wetter across portions of the
Mid- Atlantic and New England states around the Sunday time frame.


...Weather/Hazards Highlights...
This remains a relatively dry pattern with generally offshore flow
from the continent and downslope winds from the Rockies, so no
excessive rainfall outlook areas were necessary for Saturday and
Sunday. Lake effect/enhanced snowfall will remain a fixture near
and downwind of the Great Lakes as a series of shortwaves
aloft/clipper systems move within and through the broad troughing
over the Plains, Great Lakes, and East. Snow will also be possible
for the Northern Plains, Midwest, and Appalachians/Northeast.
Portions of the Southwest and Gulf coast late should see sufficient
moisture intrusion for rain, at times.

The new fly in the ointment is a new-to-the-forecast cyclone that
forms at some distance offshore the Carolinas/Southeast, which then
moves northeast from Sunday onward. The 00z GFS/00z UKMET are much
closer to the coast with the surface low/sharper aloft than the
00z Canadian/00z ECMWF. Used a compromise of the available
guidance here as a starting point, which will likely need
adjustments in future cycles, along with QPF near the East Coast.
There is some chance for accumulating snow from the Southern
Appalachians through the southern/central Mid- Atlantic States into
southern New England from late Saturday into early Monday; bears
watching to see if the guidance can converge further with this
feature and possible snow and near and offshore wind impacts.

Below average temperatures are expected for the eastern portion of
the Lower 48, while much of the West and High Plains will have
above average temperatures. There is significant potential for high
winds for portions of the Northern/Central Plains, portions of the
Front Range of CO, and some of the mountains bordering central WY
from Friday into Sunday, with gusts up to 70 mph possible Saturday
and Sunday. Additionally, is also some indication for enhanced
offshore wind potential for central and northern California Sunday
onward due to enhanced high pressure across the Great Basin.


Roth/Putnam


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