...ANTICIPATED A SHIFT TO COOLER AND WETTER LATER WED THROUGH SUN...

.METEOROLOGICAL CONDITIONS (TUE PM - MON AM)...

Dry conditions continue this afternoon as an upr ridge along the
west coast slides inland. An area of low pressure has moved within
140W as it slowly tracks toward the CA coast basically along 38N.
Ahead of this feature...a convergent area of moisture has advected
northward and become entrained into the circulation with a broad
area of PW values near 1.00-inch.

For Wednesday...the higher moisture content air will reach the CA
coast while the upr low remains just outside 130W. With increasing
diffluent flow over portions of northern CA...scattered precip will
begin to develop during the afternoon hours in a line from Cape
Mendocino over to Oroville and Susanville along with points north.
SPC continues to paint an area of general thunderstorms over the
interior of northern CA during this period.

The upr low continues to slowly track to the east on
Thursday...moving within 130W. With better forcing over northern
CA...precip is expected to increase with the best totals along
coastal sections from the Eel River basin northward...and then
inland over the Shasta Lake drainage down through the
northern/central Sierra. Overall totals will range from 0.25- to
0.50-inch.

Finally by Friday and Saturday...a secondary disturbance dropping
southeast from the Gulf of Alaska will kick the initial upr low
parallel to the central and southern CA coast before swinging inland
(slightly farther north in the 07/12Z GFS and EC...more south closer
to the CA/MX border in the 07/12Z CMC). This will bring the best
precip to central and southern CA. Also...as the secondary
disturbance is moving closer to the northern CA coast...precip
should continue across northern CA. It should be said...at this time
there continues to be a lower confidence with the secondary system
as the trajectory of the system varies quite a bit with the most
recent models. As a result...the Sunday (Day 6) forecast trends
closer to the latest WPC QPF and NBM.

Freezing levels will start elevated on Wednesday...9000-feet
northwest to 13000-feet southeast. Then as each of the systems move
toward the region...freezing levels will drop to 4000-feet
northwest...about 5000-feet along I-80...and 5500- to 7000-feet over
central sections...and 7500- to 9000-feet south.

Afternoon update changes resulted in increases for northern CA in
the range of 0.10- to 0.33-inch on average...relatively unchanged in
central CA (except southern Sierra increases 0.10- to 0.33-inch) and
similar to slightly down for coastal southern CA. Over
NV...northwest portions of the state remained similar...with an area
of plus 0.10-inch for south-central NV.