Area Forecast Discussion
Issued by NWS Eureka, CA

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FXUS66 KEKA 081030

National Weather Service Eureka CA
330 AM PDT Sat Aug 8 2020

.SYNOPSIS...Building heat is expected over the weekend and early
next week throughout inland areas, with mild but sunnier conditions
along the coast as well. Slight chances for thunderstorms exist
across interior mountains Monday.


.DISCUSSION...Main weather issues continue to be increasing
temperatures inland, shrinking marine layer, and potential isolated
thunderstorms across the eastern interior on Monday. Afternoon
temperatures will rise a few degrees today followed by another
notable rise on Sunday reaching between 100 and 104 degrees across
many interior valleys. Forecast models still indicating a weak
depression moving into the Bay Area which may promote thunderstorm
activity across northern CA and may bring afternoon storms to the
usual spots along the Yolla Bolly spine and Trinity Alps.  Along the
coast, mild conditions continue through the week, although a much
shallower and weaker marine later will allow for sunnier skies.
While some shallow stratus and fog may develop in places during the
overnight periods, particularly in the vicinity of Humboldt Bay,
marine clouds are likely to be less widespread and quicker to burn
off during the day bringing some nice weather back to the coast.


.AVIATION...Expect patches of stratus to develop around Humboldt
Bay by daybreak, with possible IFR/LIFR ceilings in the vicinity of
KACV through mid morning. Light mist has formed at KCEC, however
brisk northerlies offshore will likely result in rapid improvement
by 16Z. KUKI and other interior airfields should remain VFR through
the period.  Patches of stratus and mist will likely redevelop
around Humboldt Bay and the Eel Delta late tonight. Also, a
southerly wind reversal will advect central California fog and
stratus northward onto the Mendocino coast late tonight.


.MARINE...A tight pressure gradient between high pressure offshore
and a thermal trough along the northern California coast will result
in strong northerly winds through early next week. Gale force winds
are expected north of Cape Mendocino today through Sunday night,
primarily outside 20NM from shore. Low end gales with gusts to 35 kt
will also be possible south of Cape Mendocino outside 20NM. For now
will stay with a Hazardous Seas Warning for very steep short period
seas from 12 to 16 feet. Small Craft Advisory conditions will remain
present over the nearshore waters for the next several days, with
localized gale force gusts and larger steep seas found near Pt St
George and Cape Mendocino. Near Pt St George, gusts around 40 to 45
kt are expected this afternoon and evening. For Mendocino nearshore
waters, north winds should abate tonight and switch to light
southerly on Sunday south of Shelter Cove. Seas will likely remain
steep and hazardous through at least Sunday morning.

Winds look as though they will finally relax somewhat towards the
middle of next week as weak troughing develops over the West Coast.
Northerlies can be expected to persist for the foreseeable future.
Small scale eddies will likely spin up, resulting in localized
southerlies from time to time.


.FIRE WEATHER...Increasing temperatures and corresponding lower
RH values are expected through early next week. This combined with a
light but persistent offshore flow at night will also contribute to
a reduction in RH recoveries...especially along the upper slopes and
ridge tops. Afternoon temperatures are expected to reach near 100
degrees today across many interior low elevations, and will likely
peak at between 100 and 105 degrees Sunday and Monday. Daytime winds
will generally be driven by terrain backed by but a westerly
component. Some stronger overnight offshore gusts are also likely
across the ridges of Del Norte County through the weekend. In
addition, unstable conditions and deep mixing heights will also
likely develop each afternoon late in the weekend and early next
week. No thunderstorms are expected today and likely Sunday as well,
with slight chances returning to the area Monday. Uncertainty
remains high, and greater probabilities likely exist farther to the
east. Any storms that produce lighting may be initially dry.


NORTHWEST CALIFORNIA COASTAL WATERS...Small Craft Advisory until 11 PM PDT Sunday for PZZ450.

     Gale Warning until 3 AM PDT Monday for PZZ470.

     Small Craft Advisory until 9 AM PDT Sunday for PZZ455.

     Hazardous Seas Warning until 3 AM PDT Monday for PZZ475.



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