Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
352 PM EDT Sat Mar 28 2026

Valid 12Z Tue Mar 31 2026 - 12Z Sat Apr 04 2026


...Wet pattern emerging for the east-central U.S. next
week/weekend...

...Overview...

Shortwave troughing moving across the northern tier Tuesday-
Wednesday should push a wavy frontal system ahead of it, bringing
precipitation for much of the central and eastern U.S. and cooling
temperatures in northern areas, though a Bermuda high to the south
will maintain warmth over the Southeast. More amplified troughing
is forecast to move into the Northwest by Thursday and eastward
into late week, continuing unsettled weather there, including
rain/mountain snow and strong winds. Additional moisture could
focus over the east-central U.S. later next week ahead of the
western troughing. Wintry weather including snow and ice are
possible on the northern side in parts of the Northeast.


...Guidance/Predictability Assessment...

Most of the latest deterministic/ensemble mean guidance remains
fairly agreeable on the broader pattern/evolution mid- to later
this upcoming week. The 00Z ECMWF/ECMWF AIFS and 06Z GFS are well
clustered depicting an initial upper-level shortwave in the
northern stream and accompanying surface low moving from the Great
Lakes region Tuesday to the Northeast on Wednesday, with a trailing
cold front slowing and stalling southwest through the Ohio Valley
to the southern Plains. This guidance also well captures an initial
leading shortwave in the southern stream ahead of a stronger
upper-trough digging into the western U.S., expected to emerge over
the Plains and the lingering wavy frontal boundary later Wednesday
into Thursday. However, more subtle differences in the progression
of the wave and subsequent northward extent of the warm sector and
orientation of the frontal boundary has led to more significant
uncertainty with respect to the axis of associated storms and
expected potential for heavy rainfall. For this latest update, the
axis of heaviest QPF from the NBM shifted from the Tennessee Valley
southwest through the Lower Mississippi Valley to the Ark-La-Tex
now to the northwest, aligned from the Middle Mississippi/Lower
Ohio Valleys southwest through the Ozarks and Ark-La-Tex. A deeper
wave in the northern stream, more southerly cold front progression,
and slower second wave left the CMC as an outlier in comparison to
the other guidance.

Thereafter, the other guidance begins to diverge more in handling
the evolution of the incoming stronger upper-trough over the West.
The ECMWF AIFS/GFS and ECens/GEFS means are more progressive in
bringing the trough out over the Plains late next week/early next
weekend faster compared to the ECMWF, which slows and digs in over
the West. The 12Z run of the ECMWF then came in more similar in
progression to the other guidance, though with some notable
differences still in the development/evolution of surface low
pressure over the Plains to Midwest. The updated WPC forecast used
a blend of the ECMWF/ECMWF AIFS/GFS with a small contribution from
the means for the early to mid-period as the guidance remained well
clustered handling the initial couple upper-waves. For the latter
part of the period, the contribution from the ECMWF is removed
given its noted outlier solution, and the contribution from the
ensemble means is increased to almost half the blend as differences
increase in the details of the deterministic guidance. The
combination of the ECMWF AIFS/GFS along with the ECens/GEFS means
to round out the forecast period also helps to maintain continuity
with the prior WPC forecast with respect to the progression of the
latter trough.


...Weather/Hazards Highlights...

A low pressure/frontal system tracking through the north-central
U.S. will begin to tap into Gulf moisture as it meanders eastward.
Precipitation is forecast across parts of the Midwest and Ohio
Valley and spreading into parts of the Northeast into Tuesday. The
moisture anomalies seem to maximize (with PWs over the 95th
percentile for this time of year) over the Lower Great Lakes
region, which may see multiple rounds of rain, and a Marginal Risk
in the Day 4/Tuesday ERO has been maintained for potential flooding
concerns focused over western New York. Some of this area also has
snow covered ground, so melting could exacerbate flooding.
Potential for flooding could be nonzero farther southwest along the
front in portions of the Ohio Valley to Mid-Mississippi Valley,
but the front may be moving fast enough to preclude any risk areas
at this time. Then by Wednesday, moist inflow into the cold front
should press south across the Mid-Atlantic, but move more slowly
with reloading moisture and instability across the Mid-South. Will
maintain a Marginal Risk across the Ark-La-Tex to Middle
Mississippi Valley and parts of the Lower Ohio/Tennessee Valleys
for flooding concerns, as high rain rates with possible training
could overcome the dry antecedent conditions. Additional rain and
thunderstorms are likely to persist across the eastern U.S.
Thursday before the focus returns back west from the Plains to
Mississippi Valley Friday into Saturday in response to the upper
trough making its way into the central U.S. pulling in additional
moisture. Initially on Tuesday, there are chances for snow and ice
across Maine, and then chillier air by later next week could lead
to wintry weather concerns for interior parts of Pennsylvania to
the Northeast on the northern side of the precipitation shield.

Across the West, unsettled weather will be common next week as
multiple rounds of troughing move through. Some enhanced QPF is
likely across the Pacific Northwest to northern California on
Wednesday, but the atmospheric river is forecast to remain too weak
to cause flooding issues. Multiple rounds of rain and mountain
snow are likely across the Intermountain West through the forecast
period. Gusty winds could be a concern across the Intermountain
West to Rockies and Plains with this troughy pattern.

Warmer than average temperatures will be common across much of the
U.S. into Tuesday, with the highest anomalies over the Ohio Valley
as temperatures reach into the 70s and 80s. However, the strong
cold front should bring temperatures back closer to average or
slightly below in the north-central U.S. Tuesday and Wednesday,
reaching the Mid-Atlantic and Northeast Thursday after a warm
midweek. Warmer than average temperatures could hang on across the
southern tier though, under the influence of a Bermuda high. The
West should see cooling temperatures as the week progresses given
the multiple rounds of troughing aloft.


Putnam/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