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Hydrometeorological Discussion
National Weather Service / California Nevada RFC / Sacramento CA
630 AM PDT Fri May 15 2026

...PRECIP CHANCES INCREASE OVER NORTHERN/EASTERN NV ON SUN...
...COOLER TEMPS THIS WEEKEND WARM TO ABOVE NORMAL BY NEXT WED-THU...

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

Zonal onshore flow is generally focused between 40N and 50N this 
morning with a s/wv trof along 135W making its way toward the 
Pacific Northwest and southwest BC. A flattened upr ridge resides 
off the CA coast pretty much along 140W. Through today...the pattern 
will begin to start to buckle as the s/wv trof shifts inland with 
the opportunity for some light precip making its way down to the 
crest of the southern OR Cascades. For this weekend...look for this 
overall system to dig over the interior on its way toward the Great 
Basin...bringing an area of mainly light precip to northern and 
eastern NV on Sunday. Amounts will generally remain near or less 
than 0.25-inch. 

Given this flow regime on Sunday...dry northerly flow will develop 
across CA as the area is sandwiched between the digging s/wv trof 
over the Great Basin and a building upr ridge offshore between 130W 
and 140W. Into next work week...the general troffing over the 
interior will shift farther to the east...while the offshore upr 
ridge becomes quite broad and stretches over much of the eastern 
Pacific and the western US. This will allow temperatures to rebound 
from being mainly below normal this weekend to anywhere from plus 5- 
to plus 15-degF over seasonal normals by Wednesday into Thursday.

Freezing levels currently range from 8000- to 11000-feet over the 
northern portion of the region to 12000- to 14000-feet across the 
southern half. As the system digs from the Pacific Northwest to the 
Great Basin...the freezing level gradient becomes more northeast to 
southwest oriented with a range of 6000- to 7000-feet over the 
Humboldt River basin to 13000- to 14000-feet along the southern CA 
coast. These will become a bit more uniform by the middle of next 
week under high pressure with 12500- to 13500-feet throughout the 
area.


Please Note: This product may NOT be routinely updated.
Please refer to the following product issued by the CNRFC
www.cnrfc.noaa.gov/Daily-Briefing for a graphical summary of
weather and hydrologic conditions.