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fxus66 keka 182201 
afdeka

Area forecast discussion
National Weather Service Eureka California
201 PM PST Sat Nov 18 2017

Synopsis...a cool dry air mass will persist across the region
through tonight. Thereafter, a front will approach northwest
California Sunday night into Monday resulting in the development
of moderate rain and gusty winds. Wet and unsettled weather will
likely continue through the middle of next week.

&&

Discussion...stable high pressure was located over northwest
California and the adjacent coastal waters Saturday afternoon. The
high signals the potential for another night of enhanced
radiational cooling over interior portions of the region, which
could yield frost development. Near the coast, the combination of
increasing high level cloudiness combined with the encroachment
of slightly higher marine layer moisture values is expected to
preclude frost development.

Otherwise...model guidance continues to show the development of
an atmospheric river (ar) Sunday into Monday. However, the
strongest ivt values associated with the Arkansas are forecast to mainly
impact coastal or, WA, and British Columbia. Nevertheless, a round of moderate
rainfall occurring in association with strengthening low-level
warm air advection/moist isentropic upglide appears likely late Sunday night into
Monday, with the highest precipitation totals occurring over del
Norte County.

By Monday night, model guidance shows the primary shield of rain
lifting north of CA, with redevelopment occurring Tuesday night as
a narrow Arkansas filament spreads across northwestern California. With this second
period of rain, multi-day precipitation totals are forecast to
range from 2-4 inches over del Norte County to around a half inch
over southern Mendocino County.

&&

Aviation...VFR conditions mostly prevailed across the region
overnight through Saturday afternoon under a ridge of high
pressure. A few local interior valleys again and very briefly
reported low vis and cigs this morning...including uki. High
pressure will remain the prevailing feature through Sunday
afternoon resulting in no significant changes or impacts at area
airports. However on Sunday, increasing clouds will continued to
stream across the region ahead of an approaching weather system
expected late Sunday night. In the morning, local patchy clouds
and fog possible along sections of the north coast, but expect
inland valleys such as uki, to have a lesser chance of any fog/low
cig development. /Ta

&&

Marine...low seas and variable winds will persist through
tonight. Southerly winds and steepening seas will then develop
during Sunday, with winds strengthening to near gale force Sunday
night into Monday over the northern outer waters. Elsewhere, small
craft speeds will be probable over the southern outer waters.

Beyond Monday...southerly winds will remain elevated through at
least mid week as additional weather systems move across the
northeastern Pacific. Furthermore, steep southerly wind waves
combined with a westerly swell will yield a confused and
potentially hazardous sea state.

&&

Eka watches/warnings/advisories...
California...frost advisory from 11 PM this evening to 10 am PST Sunday for
caz102>106-109-112.

Northwest California coastal waters...gale watch from Sunday
afternoon through Monday morning for pzz470.

Small Craft Advisory from 11 PM Sunday to 4 PM PST Tuesday for
pzz475.

&&

$$

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