...TURNING COOLER WITH UNSETTLED CONDITIONS THROUGH THE WEEKEND...

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

As the upr low west of the northern CA coast continues to track
slowly eastward now within 130W...scattered showers and
thunderstorms are becoming more numerous over portions of northern
CA early this afternoon. The most concentrated cluster of cells are
moving northward over Trinity and northeast Humboldt counties and
making their way toward western Siskiyou county. Through the rest of
the afternoon and evening...look for convection to increase in
coverage as the SPC Day 1 Convective Outlook places a marginal risk
of severe thunderstorms over portions of coastal southern OR and
northern CA down to about the Eel River basin...while general
thunderstorms are possible over much of northern CA into northern NV
and down over portions of interior central CA.

Not much change in thinking with the initial upr low opening up and
increasing its forward speed to the CA coast later Friday...as a
deeper upr low dives southeast from the Gulf of Alaska. The best
precip on Friday will fall over northern/central CA...eventually
spreading over northwestern NV. Once again...convection will be an
issue on Friday with the SPC Day 2 Convective Outlook drawing a
broad area of general thunderstorms across northern CA into northern
NV and down across portions of interior central CA.

Then for Saturday...the deep upr low will move toward the northern
CA coast and shift inland on Sunday morning right near Point Arena.
This will provide another favorable day of precip production with
Saturday seeing the highest precip amounts for northern/central CA.
Coastal areas between the CA/OR border and Big Sur will range from
0.75- to 1.50-inches...while from the Shasta Lake drainage down the
length of the Sierra will primarily range from 1.00- to 2.00-inches
with some localized totals between the Feather and American River
basins approaching 2.50-inches.

Sunday will see the upr low moving inland while a compact
disturbance diving southward just off the west coast will move into
the flow and help dig the overall system toward southern CA. This
will help push some moderate amounts over coastal sections of
southern CA and eventually inland over all of NV.

Freezing levels will drop with each disturbance moving through the
area as cold air filters across the region. Currently looking at a
range of 8500-feet northwest to 12500-feet southeast...dropping down
to a range of 6500-feet northwest and 11000-feet southeast as the
first s/wv trof moves across on Saturday. Then with the cooler
system...look for freezing levels to bottom out late Sunday into
early Monday with 5000-feet for much of northern/central CA into
extreme western NV...and then 6000- to 7500-feet for the rest of NV
and southern CA.