Area Forecast Discussion
Issued by NWS Eureka, CA

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19
FXUS66 KEKA 221142

National Weather Service Eureka CA
442 AM PDT SAT OCT 22 2016

Today will be dry. A weak cold front will bring a chance of rain to
locations west of a Ukiah to Weaverville line for Sunday. The
weather pattern will stay active through the weekend, as a series of
systems brings wet weather to all of northern California.


One more dry day is in store for the region, before the weather
pattern becomes much more active. A mid-level low located offshore
from Washington will send a cold front across the area on Sunday.
Rain will develop along this front, spreading southeastward as we
progress through the afternoon and evening. Another and somewhat
stronger cold front will pass through the region on Monday, with
rainfall increasing in coverage and intensity. Cooler air aloft will
also allow snow levels to drop to just below 7000 feet across the
Trinity Alps, with some snow accumulation possible.

The forecast becomes more challenging for the middle to end of the
week, as divergence in the model solutions increases. The Monday
front will basically washout by Tuesday, as the first in a series of
systems approaches the state. This is where the model continuity
decreases, as the GFS shows vort maxes riding the ejecting northeast
ahead of a trough axis with somewhat of an atmospheric river
signature. Meanwhile, the ECMWF shows a closed mid-level low and
associated surface low slowly lifting northeast. This is a
significant difference, as they both show another surface low
lifting northeast towards our region by the end of the week or
weekend, with just timing and low pressure strength being the issue.
This will play a role in the synoptic pattern for the end of the
week, which could affect the end of the week system in terms of
strength and precipitation amounts, depending how the pattern

In any event, a prolonged period of rainfall potential looks to be
in store for much of the upcoming week, with most guidance
indicating widespread amounts of 2 to 5 inches possible (locally
higher. Obviously this is several days out and things will likely
change to some extent, but the overall "theme" of a wet week has
been consistent for several model runs now with high confidence in
this developing. /PD


Areas of ground fog are present around the interior
valleys this morning...kuki alternating between mvfr and ifr early
this morning but should give way to vfr by mid morning. An
approaching front will produce a gradual wind shift to the south
throughout the day.  Although wind speeds will be light the
directional change should promote improved cigs and vsbys for all
the coastal terminals through mid morning on.


A cold front will move across the region today with
a gradual wind increase along the front tonight and Saturday. A
westerly swell will propagate across the waters as well and persist
through early next week. Small craft advisories will remain in
effect across all the waters through late evening due to elevated
seas. Winds and seas will decrease Sunday. A stronger cold front
will move through the region Monday increasing the winds and seas.
Small craft advisories may be necessary across the outer waters
Sunday night and Monday due to an increase in the winds and seas.


.EKA Watches/Warnings/Advisories...
NORTHWEST CALIFORNIA COASTAL WATERS...Small Craft Advisory until 9 PM PDT this evening for PZZ450-455-



Visit us at

Follow us on Facebook and Twitter at:

For forecast zone information
see the forecast zone map online: is the U.S. government's official web portal to all federal, state and local government web resources and services.