Area Forecast Discussion
Issued by NWS Eureka, CA

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FXUS66 KEKA 172242

National Weather Service Eureka CA
342 PM PDT Mon Jun 17 2019

.SYNOPSIS...Hot and sunny weather will continue into mid week
across inland northwest California, before an upper level trough
brings somewhat cooler temperatures for Thursday and Friday.
Coastal areas will see areas of morning clouds with afternoon
sunshine accompanied by a brisk northerly breeze.


.DISCUSSION...After several days of persistent low clouds, the
coast has finally cleared completely this afternoon, with
widespread sunshine across all of northwest California. This is
due in part to drier northerly flow, which will continue through
most of the rest of this week into the upcoming weekend. Some
cumulus has popped up over the higher mountains of the Mendocino
National Forest, but as an upper-level ridge continues to build
aloft, this cumulus has shown very limited vertical development.
More mid- level moisture, along with better instability and some
disturbances tracking through have helped trigger scattered
thunderstorms over the Sierra. All of that support for convection
will continue shifting to the south and east of our area, so we
have virtually no chance of precipitation this week in northwest
California. The aforementioned upper-level ridge will crest
across northern California on Tuesday, resulting in the hottest
day of the week. Inland high temperatures might be a few degrees
higher than this afternoon, likely breaking 100 degrees in the
hottest valley locations like Ukiah, Covelo and Weaverville. The
ridge will begin to give way on Wednesday, but high temps will
only back off into the mid to upper 90s in those hot spots.
Thursday and Friday will see more appreciable cooling, as a more
substantial upper-level trough drops southward from the Pacific
Northwest, bringing high temps back closer to normal readings for
mid to late June. The airmass with this trough will be even drier
than the current one, keeping inland areas dry with mostly sunny

Meanwhile, at the coast, areas of low clouds and some fog will
redevelop each night and linger into the morning hours, followed
by afternoon sunshine and gusty northerly winds. The clouds will
be most persistent between Ferndale and Trinidad, but even that
section should at least see afternoon sunshine every day this
week. Much of the Mendocino and Del Norte coasts should stay clear
even during the overnight, thanks to northerly offshore flow off
Cape Blanco and Cape Mendocino. The surface pressure gradient will
remain onshore during the daytime, at least enough to keep coastal
areas seasonably cool. Additionally, with strong high pressure
persisting through the weekend, northerly winds will remain quite
strong during the midday, afternoon, and evening hours. These
winds will be strongest at the usual exposed headland locations,
but with breezy conditions even around Humboldt Bay once the
morning clouds clear. Otherwise, sensible weather will not change
much at the coast through the weekend. With the upper-level
trough passing by late this week, the marine layer will likely
deepen, perhaps shifting low clouds into the coastal hills, but
clearing is still likely each afternoon for the entire region.


.AVIATION...A shallow marine layer persisted along the Coast this
morning. The layer was less extensive. Today`s sounding data
averaged tops 1200- 1500 feet. Stratus cleared out early at CEC as
NNW flow increased. Clearing continued south with ACV clearing
around 12 Noon. Satellite Imagery showed a few lingering low
clouds over the Eel Delta and Humboldt/Arcata Bay this afternoon.
Breezy to gusty winds were sustained along the coast and will
continue through early to mid evening...especially at CEC.
Expecting mostly clear skies to continue at CEC through Tuesday
morning. Continuity showing some uncertainty for ACV as lower
clouds will redevelop and most likely spread over the airport
overnight/early morning. VFR conditions should continue at UKI. A
"southerly push" moved to the Mendocino and Sonoma border this
morning. Expect another push overnight, but do not expected low
Cigs to move into UKI. /TA


.MARINE...A large area of high pressure over the NERN PAC
combined with low pressure over CNTRL CA and the Great Basin will
yield gale force northerlies over the outer waters through at least
midweek, and perhaps through late week. In addition, localized gusts
from 25 to 35 kt will be probable in the vicinity of Point Saint
George and Cape Mendocino. Otherwise, steep hazardous seas from 10
to 14 feet are expected across all coastal waters, including the
inner waters.


     until 5 AM PDT Tuesday for PZZ450-455.

     Gale Warning until 3 AM PDT Thursday for PZZ470.

     Gale Warning until 11 PM PDT Tuesday for PZZ475.



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