Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
209 AM EDT Sun Apr 19 2026

Valid 12Z Wed Apr 22 2026 - 12Z Sun Apr 26 2026

...Overview...

Unsettled weather will persist through the period as a Pacific
mid/upper-level low moves inland over northern California and the
Pacific Northwest before ejecting eastward into the Northern
Plains. This system will bring strong winds and widespread
precipitation, including the potential for moderate to heavy rain
and mountain snow. As the trough and surface low interacts with
Gulf moisture, the system will strengthen, producing heavy rain and
severe weather across central U.S. by late week. Expect a
temperature swing with rapid cooling as the frontal passage moves
eastward bringing below normal temperatures across much of the West
into Northern/Central Plains and Midwest by the weekend.


...Guidance/Predictability Assessment...

Models continue to show relatively good agreement on the large
scale features of a ridge over central U.S. moving eastward through
the period, while the upper low/trough continues to move into
central U.S. Model uncertainty focuses mostly on the smaller scale
features of the low/trough over the West and the progression and
evolution of the system as it moves eastward. The GFS and CMC
seems to show agreement on some of the shortwave features compared
to the ECMWF. Later in the period, the GFS continues to show
another shortwave trough developing while CMC and ECMWF starts to
align. Although the deterministic models seemed to show differences
that can affect surface low and sensible weather, the ensemble
means seem to smooth out some of the differences. Therefore, a even
model blend was initially used within the forecast, but shifted
towards more of the ECMWF and CMC, with their respected ensemble
means towards the later portion of the period.


...Weather/Hazards Highlights...

The Pacific frontal system will continue to push east into central
U.S. on Thursday, resulting in increasing precipitation chances
across Kansas, Missouri, and Iowa. Moderate rainfall are expected,
with locally heavy rainfall possible in eastern Kansas and
east/northeastern Missouri. Sufficient instability and susceptible
flooding conditions from an increase in soil moisture could lead
to isolated flooding concerns. This flood threat is also
represented by a Marginal Risk of excessive rainfall for portions
of Kansas and Missouri in the Day 5/Thursday ERO.

The Pacific system and amplified trough over western U.S. will
support unsettled conditions from California into the Great Basin
and Central Rockies on Wednesday. Multiple embedded shortwaves
rotating the base of the trough will bring periods of widespread
lower-elevation rain and mountain snow, with locally heavy
precipitation possible along favored terrain. By late week, the
trough continues to eject eastward, sending a more organized
surface system into the Plains by Thursday. This strengthening
surface low and frontal boundary is likely to lead to increasing
chances for organized convection and severe weather across the
Plains into the Mississippi Valley. Moisture return from the Gulf
will support the potential for locally heavy rainfall, especially
where frontal boundaries slow or become quasi- stationary. Although
there may be uncertainty on details surrounding the system, there
is a signal for enhanced precipitation that could lead to
localized flood risk. In addition, strong gusty winds are expected
to build as the system moves across the Intermountain West into the
Plains and Mississippi Valley through the week.

Accumulating mountain snow will be possible across portions of the
central and northern Rockies and into the northern Plains. While
impacts should be mainly confined to higher elevations, some travel
impacts may be possible. Lower elevation rain may be moderate to
heavy at times, particularly along favored upslope regions.

By midweek, some isolated showers and storms may be possible for
South Florida and southeast Texas near a stalled frontal boundary.
In addition, the relatively weak cold front will continue to push
through the Ohio Valley, Mid- Atlantic, Northeast Wednesday into
Thursday, bringing chances for isolated to scattered showers.
Otherwise, much of the Desert Southwest and Southeast will be
mainly dry next week, before the cold front drops into the Southern
Plains/Mississippi Valley by Friday. As the front pushes eastward,
showers and thunderstorms may develop Friday into the weekend.

Below normal temperatures over western U.S. will continue through
the period with temperatures dropping 10-15 degrees below average
across California on Wednesday behind the cold front. Ahead of the
system, temperatures 20-30 degrees above average will persist over
central U.S. on Wednesday. As the cold front pushes into the Plains
by Friday, above normal temperatures gradually move eastward by the
end of the week, while below normal temperatures will spread into
Northern/Central Plains and Midwest by the weekend. Over into the
West, temperatures will begin to moderate late in the period.


Oudit


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