Area Forecast Discussion
Issued by NWS Eureka, CA

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000
FXUS66 KEKA 151338
AFDEKA

AREA FORECAST DISCUSSION
National Weather Service Eureka CA
538 AM PST Fri Feb 15 2019

.SYNOPSIS...Widespread rain showers and mountain snow will
continue into the weekend as a series of systems move through the
region. Showers may contain small hail. A few thunderstorms will
also be possible. Snow levels will hover around 2500 feet through
Saturday and possibly lower a bit more on Sunday. High pressure
will briefly settle in early next week.

&&

.DISCUSSION...Widespread showers continue across the region this
morning as a deep upper level trough descends upon the Pacific
Northwest and northern California. Cold advection aloft has served
to increase mid level lapse rates and bolster convective
activity, with a handful of lightning strikes observed overnight
along the CA coast. Snow levels have dropped to approximately 2000
to 2500 feet across the area, with heavy snow impacting the
interior mountains.

The broad showery regime will persist for the next 24 to 36 hours
as the trough continues to advance to the east, with a trailing
shortwave once again enhancing shower coverage and intensity
overnight tonight into Saturday morning. This will continue to
yield widespread showers and heavy mountain snow through Saturday
monring, with the modest instability being generated by the cold
advection aloft also sufficient to support the chance for a few
thunderstorms and the the threat for accumulating small hail along
the coast.

Another upper trough will then provide a reinforcing shot of cold
air on Sunday, possibly bringing snow levels as low as 1000 feet
Sunday morning. Showers should also be diminishing in coverage
and intensity by this time though, helping to limit any snow
accumulations after Saturday afternoon. High pressure then looks
to build over the eastern Pacific by Monday, providing at least a
brief respite from the recent stormy conditions early next week.
/CB


&&

.AVIATION...Showers will continue through Friday, with another
trough focusing shower activity later this afternoon and early
this evening. Briefly heavy downpours and small hail will be
possible with many showers today, but the best chance will likely
occur as that trough passes. Ceilings and VSBY at the three TAF
sites will be VFR most of today, but MVFR during the periods of
heavier showers. Winds will be strong and gusty at times again
over portions of northwest CA, particularly along the coast. Winds are
already gusting to 30 kt this hour at CEC, and should continue to
be around that range, increasing at ACV as well from the south
heading into this afternoon. Winds will shift toward the west as
the trough passes by this evening, then will tend toward the west
and northwest into Saturday. /AAD

&&

.MARINE...Only change to the forecast was to the near-term, as
steep seas around 8 to 10 feet around 8 seconds from the southwest
and west were a bit larger than expected, and into Hazardous Seas
Warning criteria. This warning will continue for all the coastal
waters through Saturday morning, even while the steeper waves will
begin to subside a bit. A large swell has yet to show up at the
nearshore buoys(though the forerunners have), but should arrive
around 6 AM around 20 ft at 16 seconds. This will peak tonight
between 20 and 25 ft across the waters, then decay on Saturday.
Winds will be moderately strong, with some local gusts approaching
35 kt at times today as another trough swings through. These winds
will veer to the west and northwest tonight into Saturday, and
remain northerly into next week. Winds will then ease somewhat
later Saturday into Sunday, but are expected to pick up for next
week as high pressure builds offshore. As the aforementioned swell
decays, seas will become more dominated by the shorter period and
more locally-generated waves Sunday into early next week. /AAD

&&

.HYDROLOGY...Water levels on area rivers are beginning to recede
this morning, and this trend is expected to continue through the
weekend within a broad showery pattern. The Eel River at
Fernbridge and the Mad River at Arcata remain in monitor stage as
of early Friday morning, but both rivers are forecast to drop
below monitor stage by Saturday, with no additional flooding
impacts expected. /CB



&&

.BEACH HAZARDS/COASTAL FLOODING...A W-NW swell arriving early
this morning at 20-23 ft will bring high surf, with breakers
from 21-25 feet on west-northwest facing beaches today into
Saturday morning. A High Surf Advisory continues. High tide is
forecast to occur around 7am this morning, and assuming that swell
shows up on time, some waves may wash over portions of New Navy
Base Road on Samoa. Either way, there will be some minor flooding
around the usual spots in King Salmon and the Arcata Bottoms. We
have a Coastal Flood Advisory in effect for those spots, and will
likely need one for Saturday morning`s high tide as well. The
threat for hazardous surf will gradually subside later on
Saturday, but astronomical tides will continue to rise this
weekend into early next week. There may continue to be a threat of
minor coastal flooding around Tuesday and Wednesday with the
highest tide levels, though with northerly winds the anomaly on
top of the the high tide will likely be reduced. /AAD


&&

.EKA WATCHES/WARNINGS/ADVISORIES...
CA...High Surf Advisory until 9 AM PST Saturday for CAZ101-103-104-
     109.

     Winter Storm Warning until 10 AM PST Saturday for CAZ102-105>108-
     111.

     Coastal Flood Advisory until 9 AM PST this morning for CAZ103.

NORTHWEST CALIFORNIA COASTAL WATERS...Hazardous Seas Warning
  until 9 AM PST Saturday for PZZ450-455-470-475.

&&

$$

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