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Hydrometeorological Discussion
National Weather Service / California-Nevada RFC / Sacramento CA
630 AM PDT Wed Aug 26 2026

...CHANCES OF SHOWERS/T-STORMS IN THE AFT/EVE THROUGH SAT, MAINLY SE 
CA, THE SIERRA, AND NV...
...ABOVE NORMAL TEMPERATURES FOR MUCH OF CA/NV THE NEXT COUPLE DAYS 
WITH MORE WIDESPREAD NEAR TO BELOW NORMAL CONDITIONS FRI ONWARD...

.METEOROLOGICAL CONDITIONS (WED AM - TUE AM)...

CA and NV remain between strong high pressure over the Four 
Corners/TX and low pressure/troughing offshore of the PacNW. This 
will keep near to below normal temperatures over nw CA through 
tomorrow with near to +10 deg F or so above normal temperatures 
across the rest of the region. Cooling will then kick off on Friday 
as troughing expands further southward offshore. Additional systems 
rotating in from the Gulf of Alaska should keep this pattern in tact 
throughout the rest of the forecast window resulting in widespread 
near to below normal conditions across the region. 

As far as precip, models continue to show mid level moisture and 
instability rotating in occasionally around the ridge to the east. 
This will result in some chances of scattered showers and 
thunderstorms in the afternoons/evenings over se CA, the Sierra, and 
NV into the weekend. These chances will vary in exact location each 
day. Additionally, remnant moisture from what is currently Tropical 
Storm Iselle looks to get caught up in the flow pattern migrating 
through central CA and into ne CA/nrn NV later Thursday into Friday. 
Models are now showing better chances of more widespread shower 
activity Friday to Saturday morning across the Sierra and into 
nrn/cntrl NV. The majority of ensemble members from the GEFS and 
ECMWF AI runs are showing some showers that fall outside the typical 
monsoonal convective pattern. For the moment, QPF totals for that 24 
hour period may exceed 0.25" over some of the higher terrain but 
generally 0.10-0.25" or less. That moisture looks to move out of the 
area Saturday morning, but mid level moisture and instability from 
the ridge may still bring chances of showers/thunderstorms before 
being pushed out by drier air coming in from offshore on Sunday.


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.