366
FXUS66 KEKA 202151
AFDEKA

AREA FORECAST DISCUSSION
National Weather Service Eureka CA
251 PM PDT Thu Jun 20 2024

.SYNOPSIS...Dry weather is expected for the foreseeable future.
Interior heat will build Friday through Saturday, followed by
slow moderation early to mid next week.

&&

.DISCUSSION...Visible satellite imagery clearly showed an
extensive field of stratus offshore over the coastal waters
this afternoon. A couple of clear areas have been opening up in
the lee of Cape Blanco and in the lee of Cape Mendocino. Stratus
has also been slowly eroding westward toward the shoreline with
the daytime heating and mixing. With such an extensive field of
low clouds offshore and a steady northerly influx of cool-damp
marine air underneath a solid inversion, clearer skies for
coastal sites north of Cape Mendocino will probably not last as
stratus regenerates by mid evening. This is a typical summer
pattern. This persistent stratus pattern will continue through
the weekend and probably into early next week until the inversion
lifts and/or weakens or stronger offshore flow develops. So far
there are no clear signals for either and will hedge the forecast
toward the climatology and persistence.

Otherwise, interior temperatures will continue to climb over the
next two days with 100F degree heat probable for the warmest
interior valleys. Saturday will most likely be the hottest day
with temperatures topping out around 98-104F in Lake, Trinity and
interior Mendocino counties. The heat is forecast to diminish on
Sunday, but it will still be hot with highs in the upper 90`s to
around 100F, mostly in Trinity county. NBM remains consistent with
temperatures trending down around mid next week as another trough
digs offshore over the NE Pacific and eventually approaches the
west coast. There are signs for stronger ridging from the SW with
500mb heights pumping up above 588DM early next week. Thus, the
downward trend of temperatures may end turning into another warm
up with high temps around 100F or more for out hot interior
valleys. By Thu, only about 6% of ensemble members support this
warmer scenario persisting past Wednesday. Otherwise, interior
temps will most likely remain well above normal next week. DB

&&

.AVIATION...The coastal marine stratus has continued to cling to
much of the coast today...with few breaks/streaks as
distinguished on Visual Satellite Imagery. Several pireps (pilot
reports) at the coast reported bases above 500 feet at CEC to
around 1000 feet by midday at ACV (or IFR-low MVFR). Mid-late
afternoon clearing or partial clearing can be expected along
sections of the coast...especially in the vicinity of ACV. Low
clouds will become persistent again in the evening at the
terminals and will continued into early Friday. The along-the-
coast pressure gradient remains meagerly tight resulting in a few
afternoon breezes from ACV-CEC. A weak upper level trough is
causing some higher clouds to advect across the inland areas. /TA

&&

.MARINE...Northerly winds are forecast to reach around 20 to 30
kts in the outer waters each afternoon through this weekend. Short
period waves are expected to propagate into the southern inner
waters from the stronger winds occurring in the lee of Cape
Mendocino. Localized Gale Force gusts are likely to return to the
outer waters Friday afternoon, primarily in the usual spots near Pt
St George and directly downwind of Cape Mendocino. Seas will remain
steep through the week due to the local winds, especially in the
outer waters. A couple minor swells below 2 ft move through over the
next few days, otherwise the sea state remains dominated by local
wind waves. Northerlies may weaken by mid next week. TDJ

&&

.EKA WATCHES/WARNINGS/ADVISORIES...
CA...
None.
NORTHWEST CALIFORNIA COASTAL WATERS...
     Small Craft Advisory until 3 AM PDT Friday for PZZ455-470-
     475.

&&

$$

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