492
FXUS01 KWBC 240639
PMDSPD

Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
138 AM EST Wed Dec 24 2025

Valid 12Z Wed Dec 24 2025 - 12Z Fri Dec 26 2025

...There is a High Risk of excessive rainfall over parts of
Southern California on Wednesday...

...Moderate to heavy snow over the Northeast and Sierra Nevada
Mountains...

...Rain/freezing rain possible over the Pennsylvania and Great
Lakes...

A system moving off the Northeast Coast by Wednesday morning will
have a front lingering across the Southeast through Friday.
Moisture streaming northward out of the Gulf will aid in
developing rain over parts of the Ohio/Tennessee Valleys through
Wednesday afternoon.

A wave of low pressure will develop over parts of the Middle
Mississippi Valley and move eastward into the Ohio Valley/Central
Appalachians by Thursday morning. The system will usher in rain
over parts of the Mid-Atlantic by Christmas morning. Along the
northern edge of the precipitation shield, pockets of
rain/freezing rain will develop over parts of the Great Lakes and
Northern Mid-Atlantic overnight Christmas Eve into Christmas Day.
In addition, as the low moves away from New England, moderate to
heavy snow will develop over New England through Wednesday
Afternoon. Snow will continue over the Northeast on Christmas.

On Wednesday, moisture and upper-level impulses from the Pacific
will stream eastward over the Pacific Northwest/Northern
California, as a front moves inland over the West Coast. The
system will produce rain and higher-elevation snow over parts of
the Pacific Northwest and the Northern Intermountain Region.

Also, a broad plume of moisture will move over California, with
rain moving into California and the Great Basin. A stream of
moisture-laden air will produce heavy rain over California on
Wednesday, with very heavy rain developing over parts of Southern
California. Therefore, the WPC has issued a High Risk (level 4/4)
of excessive rainfall over Southern California through Thursday
morning.  Severe, widespread flash flooding is expected. In
addition, areas that normally do not experience flash flooding
will flood. Furthermore, lives and property are in great danger.
Additionally, a Slight Risk of excessive rainfall will develop
over Northern/Central California and into parts of Southern Nevada
on Wednesday.

Heavy snow will develop over the Sierra Nevada Mountains through
Friday. Rain and snow at the highest elevations will develop over
the Great Basin and the Southwest through Friday.

In addition, the heavy rain will continue over California on
Christmas. Therefore, the WPC has issued a Moderate Risk (level
3/4) of excessive rainfall over parts of Southern California from
Thursday into Friday morning. Numerous flash flooding events are
possible. In addition, many streams may flood, potentially
affecting larger rivers. The flooding may include debris flows in
or near recently burned areas.


Ziegenfelder


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

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