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Hydrometeorological Discussion
National Weather Service / California Nevada RFC / Sacramento CA
640 AM PDT Mon May 11 2026

...HIGH PRESSURE RIDGE PEAKS TODAY INTO EARLY TUESDAY...
...LIGHT PRECIP NEAR THE CA/OR BORDER AND FAR NRN NV LATE TUE-WED...
...SEASONABLY WARM AND DRY INTO THE WEEKEND...

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

High pressure ridge is expected to settle and strengthen over the 
Four Corners region today and tomorrow...bringing dry conditions and 
increasing temperatures across CA and NV. Afternoon high temperature 
anomalies will peak anywhere from plus 10- to plus 25-degF over 
seasonal normals. However...this heat is expected to be short-lived 
as a s/wv trof currently approaching 140W off the Pacific Northwest 
and northern CA coast moves eastward will reach the west coast 
Tuesday afternoon or evening. This will displace the upr ridge 
farther downstream of the region with the potential for some light 
precip moving across areas near the CA/OR border and far northern NV 
later Tuesday through Wednesday. There are some model differences in 
terms of the trajectory and timing the system as it moves inland 
through the middle of the week...but overall are all showing this 
transition in the overall pattern. Total precip will generally range 
from 0.25- to 0.50-inch over the Smith River basin up to the crest 
of the southern OR Cascades...while elsewhere expect 0.10-inch or 
less.

For the end of the week...Thursday will see weak upr ridging sliding 
across the region with some warming anticipated. Then for Friday 
into Saturday...a couple disturbances moving across the Pacific 
Northwest will lower heights across the region...but at this time 
any precip should remain north of the area.

Freezing levels are currently ranging from 13000-feet northwest to 
15500-feet close to the CA/MX border...currently very near the peak 
for this heat event. As the s/wv trof reaches the coast later 
tomorrow into Wednesday...look for freezing levels to drop with the 
most pronounced fall over northwest CA and the upper Klamath River 
basin...down to about 6500- to 9000-feet...while elsewhere will be 
from 10000- to 14500-feet from northwest to southeast. For later 
Wednesday into early Friday...a persistent pattern of 10000- to 
14000-feet is anticipated before dropping again with the systems 
moving toward the Pacific Northwest with a sharp gradient of about 
5000-feet far north to 14500-feet far south.


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.