574
FXUS02 KWBC 311928
PMDEPD

Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
328 PM EDT Sat Oct 31 2026

Valid 12Z Tue Nov 03 2026 - 12Z Sat Nov 07 2026


...A slowly progressive storm system will bring heavy
rains/thunderstorms across the Central U.S. through midweek and
into the eastern U.S. later next week...


...Overview...

An active weather pattern continues across central and eastern U.S.
for next week, as the upper trough and associated frontal system
supports widespread showers and thunderstorms along/ahead of a main
frontal boundary. Locally heavy rainfall will be possible across
portions of the the Mississippi Valley, Southeast, and
Ohio/Tennessee Valley as the system moves eastward. Gusty winds may
develop across the Plains as the frontal boundary pushes eastward
on Tuesday. Meanwhile, additional Pacific disturbances broaching the
West later next week may bring uncertain precipitation chances.

...Guidance/Predictability Assessment...

Latest model guidance generally supports the eastward progression
of a broad upper-level trough across central U.S. into eastern U.S.
through next week. Model agreement increases in regard to the
development of surface cyclogenesis across the Plains and the
eastward progression of an associated frontal boundary. Ample
differences remain regarding the timing and amplitude of the upper
trough and the eventual progression of the frontal boundary
through eastern U.S. due to quite varied from cycle to cycle stream
phasing/system interactions. These differences impact the
timing/focus of heavy precipitation, as well as the extent of
instability available for thunderstorm development. Additionally,
models show agreement of another Pacific energy moving into the
West, but uncertainty remains on the some of the shortwave features
and timing of the inland progression. For Tuesday/Wednesday, a
multi-model blend incorporating the GFS/ECMWF/CMC/UKMET solutions
appears appropriate, but favor a composite of best clustered
GEFS/ECMWF/Canadian ensemble means and machine learning guidance in
a highly uncertain period from Thursday-next Saturday to navigate.


...Weather/Hazards Highlights...

The primary weather feature during the beginning of next week will
be the eastward progression of the amplified upper trough and
associated surface low/frontal system. Stronger southerly flow
ahead of the system will transport Gulf moisture northward,
supporting widespread showers and thunderstorms along the
frontal boundary over the Mississippi Valley and portions of the
Great Lakes and Southeast. Periods of moderate to locally heavy
rainfall will be possible, particularly where stronger forcing
overlaps with deep moisture and low-level convergence. Some
thunderstorms could produce locally excessive rainfall, especially
where repeated storms occurs. WPC continues the Marginal Risk for
Excessive Rainfall for portions of mid to lower Mississippi Valley
and Southeast for Tuesday.

Behind the cold front, strengthening pressure gradients may
produce gusty winds across portions of the High Plains on Tuesday.
As the system progresses into eastern U.S., showers and
thunderstorms will develop across portions of the Southeast, Mid-
Atlantic, Great Lakes, and Northeast on Wednesday. As the Gulf
moisture continues to pool along the boundary, chances for heavy
rainfall increases. WPC has placed a Marginal Risk for Excessive
Rainfall for portions of the Southeast into Tennessee/Ohio Valley
and Mid-Atlantic for Wednesday. The storms will advance northeast
by late next week. The forecast becomes quite tricky by later next
week as guidance flow evolutions remain incredibly sensitive from
cycle to cycle related to northern and southern stream system
interactions and phasing uncertainties. It does broadly look to be
an increasingly wet period into the East, but most likely from the
Mid-Atlantic to the Northeast with upper support and moisture from
moderate western Atlantic coastal low genesis. Expect overall
cooler and drier conditions in the wake of the main frontal system.

Across the west, quite uncertain additional Pacific shortwave
energies will approach the West Coast during the mid to late week,
which will support increased precipitation across the Pacific
Northwest and eventually portions of the the Intermountain West and
California. The highest precipitation probabilities will initially
favor coastal and mountain areas.

Oudit/Schichtel


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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