055
FXUS66 KEKA 182246
AFDEKA

AREA FORECAST DISCUSSION
National Weather Service Eureka CA
346 PM PDT Wed Sep 18 2024

.SYNOPSIS...Weak showers will continue to dissipate over the next
couple of hours. Generally warming weather will build into the
weekend with strong northerly wind along shore helping to clear out
coastal stratus.


&&

.DISCUSSION...Today`s weather has been generally influenced by a
dynamic low pressure system gradually cloud south along the coast.
This system brought weak showers along the Mendocino Coast this
morning. That said any showers have been high based and have
struggled to produce more than a trace of rain. Instability and
moisture wrapping around the low has produced some isolated showers
this afternoon over high terrain in Trinity and Mendocino Counties.
Showers will mostly dissipate early this evening. Colder lows are
possible tonight but dewpoints solidly above 40 degrees will keep
temperatures from falling too low.

High pressure building over the eastern Pacific will gradually drift
inland through the weekend. Conditions will gradually warm with
above normal highs by Friday. The hottest valleys will approach near
100. Moderate heat risk is expected in Mendocino and Lake counties.
Much of this period of time the models are showing east to northeast
winds overnight and the ensemble clusters are in good agreement on
this. This combined with breezy winds in the afternoon along the
coast should keep coastal clouds to a minimum. The surface winds in
the afternoon looks to start diminishing late in the weekend or
early next week. This may allow coastal temperatures to warm into
70s.

The extended forecast is much more uncertain. Early next week is
likely to be the hottest days of the high pressure. Beyond next
Tuesday, 20% of models show continued high pressure, 50% of pressure
shows significantly weaker high pressure, and the remaining 30% show
a trough that may bring light wetting rain along the North Coast.
/JHW


&&

.AVIATION...A low pressure system and associated cold front
brought a plethora of cloud diversity to Northwest California
today. Impacts at the Taf sites were mostly of minor impacts.
Plenty of mid clouds and MVFR Cigs with meager amounts of rain and
showers fell at the air terminals. Post frontal system:
widespread marine low clouds were in/out and up/down mainly along
the Del Norte coast by late morning...then begin colliding along
the Humboldt and Mendocino Coasts in the afternoon; the result has
been IFR/LIFR impacting CIG/VIS at CEC and ACV. Into midday, VFR
cloudy conditions and an isolated shower or two prevailed across
the mountain interior. Thursday morning: LIFR/IFR conditions
expected at the coast. /TA


&&

.MARINE...Moderate northerly winds have started to build into the
outer waters this afternoon. Northerly winds will increase this
evening into Thursday with gusts possible (20% chance) above 35 kts
in the outer waters by early Thursday evening. Short period seas
will build in response with heights up to 9ft@7s in the far outer
waters. Most models keep the steepest waves out of the inner waters
except right around Cape Mendocino. Besides short period waves, the
sea state will be modified through Thursday by a minor northwest,
mid-period swell up to 5 feet. This complex sea state will create
conditions that are hazardous for smaller crafts.

With high pressure generally building over the northeastern Pacific,
moderate to strong northerlies will continue for the outer waters
through the week and likely into the weekend. The maximum wind
speeds are currently forecasted downwind of Cape Blanco off the
coast of Crescent City for the later part of this work week. The
chances of steep seas pushing into the inner waters will increase
Friday into Saturday as a passing shortwave pushes strong winds
closer to shore. /JHW


&&

.EKA WATCHES/WARNINGS/ADVISORIES...
CA...
None.
NORTHWEST CALIFORNIA COASTAL WATERS...
     Small Craft Advisory until 3 PM PDT Friday for PZZ470.

     Small Craft Advisory from 9 PM this evening to 3 PM PDT
     Friday for PZZ475.

&&

$$

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