Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
300 AM EST Fri Nov 21 2025

Valid 12Z Fri Nov 21 2025 - 12Z Sun Nov 23 2025

...Additional heavy rain and flash flooding threat for southern
California, western Arizona and southern Nevada today and Saturday...

...Record warmth to continue along the Gulf Coast, across the lower
Mississippi Valley and into the Southeast...

...Arctic air to remain absent from the Lower 48 over the next few days...

An active southern stream of the upper jet will continue over the next few
days, supporting a wet weather pattern from Southern California, portions
of the Desert Southwest, into the central and southern Plains,
mid-Mississippi Valley, Ohio Valley and Mid-Atlantic.  A low pressure
system developing over the central Plains early this morning continues to
support heavy rain and thunderstorms with threat of flash flooding mainly
across the Arklatex region.  This system will then track steadily eastward
through the eastern U.S. and off the Mid-Atlantic coast Saturday morning,
producing a swath of light to moderate rain stretching from the central
Plains through the Ohio Valley, central Appalachians and into the
Mid-Atlantic today through Saturday morning.  Portions of the Deep South
should also see a round of thunderstorms into the afternoon today but with
a minimal threat of flash flooding expected.  By Saturday, some widely
scattered showers and storms can be expected across the Southeast into
portions of the Mid-Atlantic.  The entire system including the trailing
cold front will clear the Southeast (except Florida) by Saturday night.

Meanwhile, across southern California into the Desert Southwest, two more
back-to-back low pressure systems will bring additional threat of heavy
rain and flash flooding  today and Saturday.  The first low has already
spread moderate to locally heavy rain into much of southern California
early this morning.  This lead system is forecast to quickly weaken as the
center reaches the coast near Los Angeles.  This heavy precipitation will
be falling across areas of southern California and the Southwest that
received heavy rains early in the week and this past weekend, posing
further risk of flash flooding, especially across burn scar and urbanized
regions.  A second system is forecast to develop quickly right on its
heels over the Pacific.  This system could even acquire some subtropical
characteristics under a cold upper low as it heads toward Baja California
Saturday morning.  The farther southward track of this second system
should keep the heaviest rainfall over Mexico on Saturday.  However by
later on Saturday, some bands of showers and embedded thunderstorms are
expected to sweep into Arizona, reaching into New Mexico by Sunday
morning.  Some wet snow can also be expected over the highest elevations. 
Meanwhile, the Pacific Northwest should see rain arriving early on Sunday
ahead of the next frontal system.

While the southern stream remains active over the next few days, the
northern stream will be characterized by mostly west to east flow at the
mid to upper levels.  This will keep arctic air absent from the Lower 48
over the next few days.  Most of the Lower 48 will subsequently have above
average temperatures late this week into this weekend.  The exceptions to
this will be across central to southern California into the Southwest
where cloud cover and the likelihood of rains will keep temperatures below
average.  Slightly below average temperatures also possible for the
Northeast and New England.  Record warmth will continue for areas along
the Gulf Coast, lower Mississippi Valley and Southeast over the next two
days.  Across these areas both much above average morning lows and
afternoon highs are expected.

Kong/Oravec


Graphics available at
https://www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php