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AGUS76 KRSA 191331
HMDRSA

Hydrometeorological Discussion
National Weather Service / California Nevada RFC / Sacramento CA
630 AM PDT Sat Apr 19 2025

...WEAK SYSTEMS IMPACTING FAR NORTHERN AREAS SUN AND AGAIN TUE/WED...

.METEOROLOGICAL CONDITIONS (SAT AM - FRI AM)...

Dry conditions across the region this morning as a ridge travels
across the west. Up north, a shortwave is making its way through the
PacNW along with a surface front. Finally, an upper low continues to
pull away from srn CA/NV across AZ to the southeast. Observations
over the past 24 hrs report less than a tenth of an inch across
coastal srn CA with amounts up to 0.25" in the mountains. For today,
no precip expected for most areas as ridging passes overhead. The
shortwave currently over the PacNW will dip into nrn CA in the
afternoon potentially dropping a few light showers. A broader
troughing pattern will then take over on Sunday pushing in from
Canada and the Gulf of Alaska. This will bring some potential
showers to northern areas later Sunday. Drying again for Monday
before another trough digs into the PacNW on Tuesday morning
swinging inland the rest of the day. The southern edge of the trough
is expected to reach nrn CA/NV potentially again dropping a few
showers Tuesday/Wednesday. There is some disagreement on the timing
of the trough with the GFS quickly carrying it across nrn NV and out
of the area by Weds afternoon while the ECMWF is about a half a day
plus slower. Either way, no significant precipitation is expected.

A larger low is then progged to approach from the Gulf of Alaska/BC
towards the end of the week. Again disagreement on timing, path, and
general structure between the models but potential for additional
showers and cooler temperatures at the end of the week into the
weekend.

Temperatures near to about 10 deg F above normal through early next
week before troughing cools things down gradually from west to east
mid to late week.


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



AS

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