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AGUS76 KRSA 242018
HMDRSA

Hydrometeorological Discussion
National Weather Service / California Nevada RFC / Sacramento CA
1220 PM PST Mon Nov 24 2025

...A SYSTEM MOVING IN TO THE PACNW ON THURS MAY BRING LIGHT SHOWERS
TO THE NORTH COAST...
...OTHERWISE DRY CONDITIONS THROUGH THANKSGIVING BEFORE POTENTIAL
FOR ADDITIONAL PRECIP NEXT WEEKEND, LOW CONFIDENCE...

.METEOROLOGICAL CONDITIONS (MON PM - SUN AM)...

Not much has changed since this morning. An upper ridge resides over
the eastern Pacific steering moisture well to our north and keeping
dry conditions over the region. A surface low moving into BC/WA on
Thursday may result in some light showers along the north coast and
over the srn OR Cascades. Amounts still look around 0.10" or less.
Models continue to disagree on the pattern after Thanksgiving with
the GFS insistent on a trough dropping in from the Gulf of Alaska
Friday before forming a closed low Saturday. This would bring
widespread showers to the area over the weekend. The ECMWF has a dry
weak embedded shortwave on the eastern side of the ridge offshore of
CA and a second trough sliding into the Four Corners through ID and
ne NV producing maybe a little bit of precip for ne NV. The
ensembles have trended a little drier in the 12z runs, the ECMWF
AIFS spread at Arcata is now down to 0 to 1.5" and the GFS spread
has dropped below an inch. Given that the same uncertainty remains
in place as before, no major changes to the QPF for the afternoon
update. Amounts went up over the Sierra by about 0.10" or so and
over the Ruby mountains in ne NV by 0.30". For all 6 days generally
looking at 0.10-0.25" for the Smith Basin, Cascades, and Sierra. For
coastal srn CA and the rest of the north coast and NV generally,
0.10" or less.



QPF graphics are available at www.cnrfc.noaa.gov/qpf.php



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