Area Forecast Discussion
Issued by NWS Eureka, CA

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000
FXUS66 KEKA 222359
AFDEKA

AREA FORECAST DISCUSSION
National Weather Service Eureka CA
359 PM PST Wed Feb 22 2017

.SYNOPSIS...
A series of upper waves are forecast to move south and east across
the northeastern Pacific during the week. This will aid in
occasional shower development and the maintenance of low snow levels
over northwest California.

&&

.DISCUSSION...
.SHORT TERM...
(Tonight and Thursday)

Abundant showers and cloud cover helped keep temperatures in check,
which was aided by colder than anticipated air aloft, which dropped
snow levels to near 1400 feet across the northern half of the area
based on the latest spotter and profiler reports. Area web cams also
showed snow accumulation on hwy 299 near Berry Summit. The latest hi-
resolution model runs show these showers/snow showers maintaining
greater coverage and intensity through the next several hours, and
this lines up well with the current Doppler radar loops.

As a result, we issued a Winter Weather Advisory on the fly for
interior Del Norte, southwestern and eastern Humboldt, and all of
Trinity county. Here, snow levels will be maintained near their
current levels through tomorrow morning, where 1 to 4 inches of snow
are anticipated. For elevations below that level, numerous reports
of hail, up to 1/4 of an inch in size, has been reported. This may
continue through the evening for a few locations, but a downward
trend in hail reports have been noticed over since 2 PM, precluding
the need of including this in the forecast.

.LONG TERM...
(Thursday night through next Tuesday)

Several disturbances in the flow aloft will bring periods of
showers/snow showers to the region through early next week. These
will cross the region as a pair of short-0wave troughs drop
southeast across the area, with one trough crossing in the Friday
night through Saturday morning time frame. Colder air will continue
to filter into the region through the weekend, with snow levels
remaining in the 1000 to 2000 feet range, mainly along and north of
highway 3600 feet.

As precipitation increases with this incoming trough, snow amounts
of 1 to 3 inches (locally higher) may develop at some of the passes,
and a Winter Weather Advisory may need to be issued in the next 24
hours should the numerical models continue to show this. Another
trough crossing the region Sunday night into Monday will also signal
another increase in precipitation coverage and amounts, with POPs
having been increased during both periods. /PD

&&

.AVIATION...
Scattered showers will continue to move across the
Redwood Coast overnight with occasional reductions to MVFR, mainly
at KACV. Most of the showers are forecast to end around KUKI over
the next couple of hours. Winds will be diminishing this evening.
/SEC

&&

.MARINE...
Borderline small craft advisories remain in effect until
0300 UTC this evening as the westerly swell gradually subsides. High
pressure will then take control of the forecast which will allow
winds and waves to primarily come from the north. Conditions are
forecast to improve through Friday and into Saturday before the next
system arrives to our waters. Winds and wave heights will start to
trend upwards Saturday into Sunday with 10 foot waves returning to
the forecast on Monday. Small craft advisories will likely be needed
starting late Sunday night or early Monday morning. /KAR

&&

.EKA WATCHES/WARNINGS/ADVISORIES...
CA...Winter Weather Advisory until 4 AM PST Thursday for CAZ102-
     104>108.

NORTHWEST CALIFORNIA COASTAL WATERS...Small Craft Advisory until 7 PM PST this evening for PZZ450-455-
     470-475.

&&

$$

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