Hydrometeorological Discussion
Issued by NWS California-Nevada RFC

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AGUS76 KRSA 232135
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Hydrometeorological Discussion
National Weather Service / California Nevada RFC / Sacramento CA
930 AM PST Thu Feb 23 2017

...COOLER WEATHER WITH LIGHT SHOWERS NEXT SEVERAL DAYS...

.24 HOUR PRECIPITATION TOTALS (ENDING FEB 23 AT 400 AM PST)...

A weak system moving across northern CA and northern NV brought
widespread light to moderate precip. Amounts were greatest along the
north coast from Cape Mendocino northward and extreme northern NV
with totals from 0.25- to 0.75-inch (local 1.00- to 1.25-inches.
Totals over the higher terrain of the upper Klamath River basin down
through northeast CA and the northern/central Sierra crest saw
totals in the range of 0.25- to 0.50-inch. Elsewhere...amounts were
generally less than 0.10-inch.


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

Expect a few light showers continue today over portions of nrn
CA/srn OR and nrn/cntrl NV under nly/nwly flow across the region.
Expect this activity to wind down tonight before a trough drops in
from the north and brings additional light showers Fri through Sat
night.  Expect freezing levels 1000-4000 ft across the nrn two
thirds of the area and higher across srn CA.


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

Overall evolution of the pattern is similar between the EC and
GFS...but there are some timing differences initially with the s/wv
trof moving through central and southern CA. The GFS is a bit faster
with the EC lagging on the timing. At 26/12Z...the GFS has the
disturbance over western AZ...while the EC is back along the central
CA coast. Then later in the day...another reinforcing s/wv trof will
dive in from the north and rotate through the northern half of the
region...while a weak s/wv trof over the eastern Pacific moves
toward northern Baja. A little better agreement between the GFS and
EC with these two disturbances. Then late in the period...an upr
ridge will pump up over the far eastern Pacific...bringing dry
conditions for the middle of the week.


.HYDROLOGICAL CONDITIONS...

High flow/stages are expected remain on mainstem rivers for the next
five days.

On the Upper Sacramento River high flow releases from Shasta will
keep stages high.  Expect flood stages at Tehama, Vina and Ord Ferry.

On the San Joaquin River, high releases on the Tuolumne and Merced
rivers will keep high flows going for the foreseeable future. The
Tuolumne River at Modesto is expected to remain near 59 feet.
Vernalis is about 1 foot above danger stage.

Other streams are generally receding under dry conditions.


More information on the CNRFC website at http://www.cnrfc.noaa.gov

DRK/KL/DRK/KL

$$



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