...COOLER AND UNSETTLED WEATHER THROUGH THE WEEKEND...

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

The upr low off the CA coast has slowly continued its track to the
east this morning...reaching 130W just below 40N. The broad area of
1.00-inch PW ahead of the primary circulation made its way to
coastal areas yesterday with the KOAK ROABs over the past several
launches indicating a PW value of 0.92-inch at 08/12Z followed by
1.04-inch at 09/00Z and 0.91-inch at 09/12Z. Through today...look
for the upr low to move within 130W with a the best area of
diffluent flow aloft spreading the northern half of the region. The
SPC Day 1 Convective Outlook now targets an area of coastal southern
OR down through northern CA with a marginal risk of severe
thunderstorms and a broader area of general thunderstorms across the
rest of northern CA into northern NV...down through the interior of
central CA.

For Friday...a secondary area of low pressure will drop southeast
from the Gulf of Alaska and reach to a location just west of the
northern CA coast on Saturday. This feature will act to kick the
initial upr low inland across northern/central CA as it becomes an
open wave. Compared to the thinking a couple days ago...the trend of
the models has been to be a bit more shallow with this disturbance
as it moves inland...bringing less of an impact to southern CA. Once
again...SPC is drawing a broad area of general thunderstorms across
northern CA into northern NV along with a smaller portion of central
CA. Best precip totals will fall in similar areas.

Saturday will see the initial disturbance quickly moving inland
across the Great Basin...while the secondary upr low will reach its
southern extent just below 40N and start to track to the east before
reaching the CA coast in the vicinity of Point Arena late Saturday
or early Sunday. Precip will be quite widespread with 1.00-inch or
higher expected along coastal areas between the CA/OR border and Big
Sur...while inland from the Shasta Lake drainage down the length of
the Sierra will see the potential for amounts reaching 2.00-inches.
Amounts then taper off across northwest NV and southern CA.

The upr low will slowly track inland across northern CA on Sunday
while a compact disturbance dropping southward just off the west
coast will help to dig the overall system southward as well. This
will bring widespread precip with the best totals along the length
of the Sierra and down to coastal southern CA from Los Angeles to
San Diego. Also...look for precip to spread across much of the state
of NV. Then into the beginning of the next work week...Monday and
Tuesday will see conditions drying out as the overall system moves
inland. Light precip will be possible from the Sierra crest eastward
over portions of NV.

Freezing levels are currently still elevated ahead of the initial
upr low...running from 9000-feet northwest to 13000-feet southeast.
Through Friday...look for these to drop as the upr low approaches
coastal areas and then shifts inland on Saturday reaching down to
about 6000- to 7500-feet for northern/central CA and inland over NV
down to about 8000- to 9000-feet. Southern CA will range from 9000-
to 10000-feet. The coldest air will move overhead late Sunday into
early Monday as the stronger upr low from the Gulf of Alaska moves
across the region. Look for 5000- to 6000-feet for northern/central
CA into western NV. The rest of NV down to southern CA will range
from 6000- to 7500-feet.

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.