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Hydrometeorological Discussion
National Weather Service / California Nevada RFC / Sacramento CA
830 AM PST Thu Feb 19 2026

...ACTIVE PERIOD TO CONTINUE AS LOW CURRENTLY SITS OVER THE SAC 
VALLEY AND COLD FRONT SWINGS THROUGH SOUTHERN CALIFORNIA...
...ADDITIONAL SYSTEM TO APPROACH THE NORTH COAST OVER THE WEEKEND...
...WARMING TEMPS WITH AR CONDITIONS AND PRECIP SUN INTO TUE...

.METEOROLOGICAL CONDITIONS (SHORT TERM: THU AM - SUN AM)...

Precipitation is spreading across much of California as a low 
pressure system currently sits over the Delta and it's cold front w/ 
PWATs nearing 1 inch makes it's way towards Point Conception. 
Currently, the heaviest precipitation sits along the northern 
portions of the low, up the sac valley where ~.25 inches has fallen 
in the past couple of hours and along the front where 2-hour 
rainfall rates have exceeded half an inch. 

The low pressure system is forecast to continue progressing eastward 
while the front will pivot around Point Conception and begin 
impacting much of the southern California Bight over the next 6 to 
18 hours. The heaviest precipitation over the next 24-hours 
currently targets much of the Sierra Nevada (1 to 2 inches; 2+ over 
the southern Sierra) and the higher elevations of the Big Sur Coast, 
Transverse, and Peninsular Ranges (Point Conception down to Mexican 
Border; 0.5 to 2 inches). The potential for convective activity over 
much of central and southern California will increase the 
possibility for hourly rain rates to approach and potentially exceed 
0.5 in/hr and could result in localized area of higher accumulations 
and flash flooding. 

Morning forecasts generally followed guidance from the NBM but 
worked in the HRRR and other higher resolution guidance in the near 
term to try and target the areas over southern California that favor 
orographic enhancement and may see convective activity. This 
brought the 24-hour totals over locations like Polomar Mountain and 
Mt. San Jacinto to over 2 inches.

A short lull in precipitation is forecast for Friday as this current 
system exits the region and before another systems brings 
atmospheric river conditions to the North Coast. 24-hour 
accumulations ending 12Z Sunday are primarily confined to north of 
the I-80 corridor with the heaviest amounts targeting Cape Mendocino 
where initial upslope flux with be strongest (~2 inches). Guidance 
continues to fluctuate on exact timing of this system and how 
quickly things retrograde into Monday. 

Freezing levels will remain relatively low through the first 2 days 
of the early window, staying below 3k feet across the north. Levels 
will begin to rise into Sunday under the WAA of the weekend storm to 
over 5k feet across the north and up to 12k feet across the far 
south. 

.METEOROLOGICAL CONDITIONS (LONG TERM: SUN AM - WED AM)...

A cold upr low will start the period over the northeast Pacific 
located along 140W somewhere between 40N and 50N. At the same 
time...an upr ridge will be situated over the interior of the 
western US. The offshore circulation will pinwheel a couple 
disturbances through the flow late Saturday into Sunday...bringing a 
frontal boundary along with an area of converging PW between 0.75- 
and 1.00-inch intersecting the northern CA coast. 19/00Z and 19/06Z 
models have pulled back the majority of the precip to mainly impact 
coastal areas from the Russian River basin northward and inland over 
the Shasta Lake drainage down through the Feather River basin. Look 
for the southern extent to reach near the I-80 corridor...but even 
this may be a bit aggressive given the latest trend of the models to 
keep the best forcing near the coast or offshore. For now...Sunday 
brings about 1.00- to 2.50-inches along the coast with the best 
totals over the King Range and Smith River basin...and then inland 
look for 1.00- to 2.00-inches above Shasta Dam and then about 0.50- 
to 1.00-inch across the Feather River basin. Freezing levels will 
generally start from 6000- to 7000-feet north of I-80 and slowly 
rise throughout the day as the region remains in the warmer sector.

Monday will be an interesting transition as the offshore upr low 
elongates toward the southwest and now looks to park itself outside 
of 140W between 30N and 40N. At the same time...high pressure will 
strengthen in the vicinity of southern Baja extending northward 
across the western US. This generates broad southwest flow aloft 
stretching from east of the Hawaiian Islands to the northeast aimed 
at much of the west coast. Also of note is a source pool of high 
moisture content air close to 20N/140W starting to advect out of the 
lower latitudes toward the northeast. PW values peak somewhere near 
1.75-inches within this channel of moisture with 1.00-inch PW values 
reaching the CA coast on Monday and then focusing and increasing 
closer to 1.50-inches on Tuesday over the SF Bay Area. As this 
warmer airmass reaches the west coast...look for freezing levels to 
bounce up in the range of 7000-feet near the CA/OR border...approx 
9000- to 10000-feet along I-80...11000- to 12000-feet across central 
CA and central NV...and over 12000- to 14000-feet for southern CA 
and southern NV. Under this WAA pattern...look for precip to mainly 
impact northern CA on Monday with the higher terrain seeing anywhere 
from 1.00- to 3.00-inches with the best totals between the Smith 
River basin to the north and Eel River basin to the south. 
Inland...look for 1.00- to 2.00-inches across the southern Cascades 
and northern Sierra down to about the American River basin. Still 
some questions about how far south and inland the precip will make 
it with discrepancies in the models...but this appears to be a 
reasonable compromise at this time. Into Tuesday...with the focus of 
the high moisture plume aimed at the SF Bay Area inland toward the 
central Sierra...this is where the best precip will fall with 
current amounts between 0.75- and 1.50-inches across coastal areas 
and 1.00- to 3.00-inches over the Sierra where orographics will 
enhance the precip totals. At this time...there doesn/t appear to be 
a strong forcing mechanism...so warm air advection/isentropic lift 
along with upslope orographic flow will be the primary driver of 
precip on Monday into Tuesday.


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.