564
FXUS02 KWBC 230739
PMDEPD

Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
339 AM EDT Fri Oct 23 2026

Valid 12Z Mon Oct 26 2026 - 12Z Fri Oct 30 2026


...Overview...

An upper low is forecast to swing into the Northwest early next
week while another shortwave moves from the central Rockies through
the Upper Midwest, bringing some rain and snow to these regions. An
upper ridge downstream will allow for warmer than average
temperatures to spread across much of the eastern half of the U.S.
The upper-level flow pattern should continue to flatten somewhat
for mid- to late week, though with the same general pattern, as
shortwave energy moves through the northern tier and subtropical
ridging reaches the Southeast. Rounds of rain and thunderstorms are
possible across the south-central U.S. with favorable flow aloft.
Overall, weather across the lower 48 does not appear widely
hazardous next week.


...Guidance/Predictability Assessment...

Model guidance is in reasonable agreement for the pattern at the
start of the medium range period Monday. GFS runs starting with the
18Z slowed down and look more like consensus for the upper low
moving into the Northwest. But model differences arise as early as
Tuesday as a round of energy moving through the northeast Pacific
shows spread that affects the downstream features. Namely, the 00Z
ECMWF indicates an upper low forming in the eastern Pacific well
west of Haida Gwaii Tuesday-Wednesday, which in turn means that
energy dropping southeast through western Canada digs farther east
of consensus (not combining with that upper low) and creates a
stronger trough in the north-central U.S. by Thursday. Other models
generally have energy dropping south through British Columbia
midweek to bring troughing into the Northwest by Thursday. The CMC,
AIGFS, and EC-AIFS seem to align best with the ensemble means,
while the 00Z GFS shows this pattern but takes the trough farther
east into the Great Basin by Thursday-Friday.

Thus the WPC forecast blend began with a multi-model blend of the
dynamical and AI models, but then did not prefer the ECMWF
depiction of the forecast, instead favoring the AIs, CMC, and the
ensemble means in increasing proportions as the forecast
progressed. Run-to-run continuity in the models is pretty low and
ensemble members indicate ample spread, so confidence for the
details of the forecast is pretty low as well, but at least the
less amplified pattern means the model differences are somewhat
less impactful than they could be.


...Weather/Hazards Highlights...

Multiple rounds of rain and higher elevation snow are forecast for
the Pacific Northwest across the northern Great Basin and Rockies
next week under a couple of upper troughs. Shortwaves in the
northern tier will also support precipitation in the north-central
U.S., and some snow could mix in at times even in lower elevations
of the northern Plains. Farther south, rain and thunderstorms are
possible in the southern/central Plains. Rain totals look to be
pretty modest there with some isolated higher totals possible,
though into later next week amounts may increase, depending on how
the pattern evolves. Additionally, showers and thunderstorms could
affect at least the east coast of Florida in easterly flow behind a
stalled front farther south.

Warmer than average temperatures are expected for portions of the
central and eastern U.S. from day to day under mean upper ridging.
Highs in the 70s are forecast as far north as the Mid-Mississippi
and Ohio Valleys. Temperatures should be near average to slightly
below average for highs in the western U.S. next week.


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, excessive rainfall outlook,
winter weather outlook probabilities, heat indices and Key Messages
are at:

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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