Area Forecast Discussion
Issued by NWS Eureka, CA

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FXUS66 KEKA 282238

National Weather Service Eureka CA
338 PM PDT WED SEP 28 2016

.SYNOPSIS...A gradual cooling trend will continue through Friday as
an upper ridge drifts slowly east through the end of the week.
Some light rain is expected to develop on Saturday and increase in
coverage on Sunday. Slight chances for rain will continue into
early next week as multiple systems move through the region.


.DISCUSSION...Coastal stratus has expanded through the morning and
is now widespread. Light winds will limit mixing today and many
coastal areas will remain cloudy this afternoon through tonight. The
marine layer will deepen on Thursday as an upper trough advances
toward the Pacific Northwest, but once again mixing of the marine
boundary layer is not expected to be sufficient to dissipate the
cloud cover.

The approaching trough will bring increasing moisture to the region
beginning on Friday. A pinwheeling shortwave at the base of the
trough will move toward the Northwest California coast Friday night
into Saturday bringing isolated to scattered showers from primarily
the Eureka area and to the north. Rain with this first wave of
showers will remain light with totals between a few hundredths of an
inch near Eureka to around a quarter inch, possibly a little more,
in Del Norte County. Isolated showers may persist through Saturday
night as west-southwesterly flow impacts the coast.

The models have shifted significantly from yesterday with guidance
now converging on the most significant system occurring on Sunday,
rather than Monday, as a potent frontal system quickly moves through
the region. Widespread light to moderate rainfall is anticipated
beginning Sunday morning in the northern half of the area, expanding
south through the day. Total precipitation of a quarter to half inch
will be possible across much of the region while locally higher
amounts fall in the mountains. Snow levels will fall to near 5500
and 6000 feet resulting in some snow accumulations on the higher
mountain peaks but above any elevations requiring winter weather
products. Additionally, southerly winds ahead of this system remain
light and will likely have minimal impact.

West-northwesterly flow will persist on Monday into Tuesday which
will continue to bring the potential for isolated to scattered
showers to the region. /RPA


.AVIATION...LIFR stratus has been widespread and persistent along
the coast this afternoon, and while an hour or two of clearing
may occur before sunset, at this point it appears that both
terminals will remain socked in the rest of the day and through
the night. Stratus will surge farther inland again beginning in
the evening, and additional fog/mist vsby restrictions can be
expected overnight. While ceilings are expected to lift somewhat
tomorrow afternoon, coastal terminals can expect another day of
almost completely obscured IFR/LIFR skies. VFR conditions will
prevail at UKI for most of the period, although there will be a
window of opportunity very early tomorrow morning for low clouds
to drift into the the terminal from the south. /BRC


.MARINE...Strong northerly winds continue to blow across the outer
waters and near prominent capes and points this afternoon, resulting
in persistent steep seas that continue to propagate into near-shore
areas. Winds close to shore remain mostly light and southerly but
somewhat erratic due to typical eddies and flow reversals. This will
continue through the remainder of the evening, and no new changes
were made to current advisories. For mariners venturing into the
near-shore waters south of Cape Mendocino, while there are no
current advisories in this area, localized areas of strong
northerlies can be expected along the Lost Coast north of Shelter
Cove, and near Point Arena. Elevated but less steep seas and light
southerly winds can be expected elsewhere in this region.

Winds will begin to decrease overnight and early tomorrow morning as
an approaching frontal system weakens the pressure gradient. This
will allow seas to gradually settle, and will begin a period of
passing storm systems and erratic, but mostly moderate winds that
will last through early next week. While sharp changes in wind
direction and bursts of stronger winds can be expected, seas are not
likely to build to particularly large heights relative to our
waters. Mariners can also expect bouts of rain as fronts move
through as well. /BRC


.EKA Watches/Warnings/Advisories...
     Small Craft Advisory until 3 AM PDT Thursday for PZZ450.

     Small Craft Advisory until 9 AM PDT Thursday for PZZ470-475.



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