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AGUS76 KRSA 191412
HMDRSA

Hydrometeorological Discussion
National Weather Service / California Nevada RFC / Sacramento CA
615 AM PST Sun Jan 19 2025

...MAINLY DRY THROUGH THE WEEK...

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

Same story to start the day on this Sunday...a narrow upr ridge
continues to plant itself just off the west coast extending all the
way up into northwest BC and the Yukon...while downstream a broad
upr trof engulfs much of North America anchored to the Hudson Bay
low. Dry north to northwest flow aloft resides across CA and NV in
the middle of these two features. A polar continental s/wv trof is
diving south through this flow and is currently over southern BC on
its way toward the Great Basin and Sierra before starting to move
eastward as it reaches the lower Colorado River basin. In the wake
of this system...whatever moisture is currently available (PW values
near 0.33-inch along the coast and less than 0.25-inch over the
interior) will erode further with coastal areas dropping to PW
values near 0.25-inch and a broad area over the interior with less
than 0.10-inch PW on Monday through about midweek.

Another s/wv trof will ride up and over the upr ridge well to the
north and then make its way toward the northern Rockies for later
Monday into Tuesday with the next system then expected Thursday into
Friday from BC toward the Pacific Northwest. This feature looks to
displace the upr ridge just a bit to the west...which may allow the
Friday s/wv trof to drag some scattered light showers to the
northern fringe of the area with a few hundredths of an inch at best.

Models are a bit less excited about the potential for precip this
upcoming weekend. This overall pattern is just proving to be rather
tough to unstick.


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



Kozlowski

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