950
FXUS66 KEKA 052220
AFDEKA

AREA FORECAST DISCUSSION
National Weather Service Eureka CA
320 PM PDT Wed Jun 5 2024

.SYNOPSIS...High pressure and hot interior temperatures will
continue through Thursday. This pattern will bring major heat
risk to interior valleys, especially in Lake County. Otherwise
typical summer weather will continue into the weekend.

&&

.DISCUSSION...High pressure will remain over the area through
Thursday, bringing hot temperatures to the interior. Heat risk
will be greatest in Lake County and NE Trinity where the strong
inversion will help keep overnight low temps in the lower to mid
70s. Such prolonged heat will be sufficient to pose a risk to
anyone without effective cooling and/or adequate hydration. Thus,
a heat advisory remains in effect for Lake County through Thursday
evening. The heat will begin to moderate on Friday, but high
temperatures will remain above early June averages; 80-84F.

Model soundings continue to indicate inverted-V profiles and
high amounts of buoyant energy and deep adiabatic lapse rates
associated with strong diurnal heating on Thursday. Convective
inhibition diminishes on Thu, but a strong mid level cap will
probably keep this energy from being realized. LFC`s are expected
to be quite high, 7-10kft, and any storms that develop will be
tied to the highest terrain of NE Trinity late in the afternoon
and early evening.

Interior temperatures will moderate over the weekend as the marine
layer deepens in response to a splitting 500mb trough. Interior
temperatures will most likely remain above early June normals for
interior Mendocino, Trinity and Lake. Average high temps are
80-84F for the warmest interior valleys. Interior heat is then
forecast to return early next week as 500mb heights and anomalies
increase again. There is still a great deal variability with the
evolution of the weekend trough. The southern branch of the split
may develop into a cut-off and pump higher PWATs into the area
from the south. Interior storms are not 100% out of the question
this weekend and early next week, but at this point there are no
definitive signs for storms and for now will lean heavily toward
the National Blend of Models (NBM) guidance. DB

&&

.AVIATION...Scattered coastal stratus is lingering downwind of
Trinidad to the north point of Cape Mendocino as northerly winds
increase offshore. Remaining low ceilings expected to scatter out
for mostly VFR conditions along the north coast this afternoon
with scattered haze/mist possible, especially at ACV. CEC will be
most exposed to 15-20 knot gusts forecast to further pick up late
this afternoon. HREF is indicating a swift return to IFR ceilings
late tonight with the development of a southerly wind reversal
beginning around Humboldt Bay. ACV will likely experience reduced
ceilings as early as midnight as marine stratus pushes onshore.
Model guidance indicates higher probabilities of IFR visibility`s
<1SM beginning before sunrise and persisting through late morning,
while CEC is less likely to become inundated for more than a few
hours around 6- 7am. A similar pattern expected to ensue, wherein
increasing northerlies and daytime heating scatter coastal stratus
and break the marine inversion in the afternoon. JMM

&&

.MARINE...As high pressure continues to build into the west coast,
narrow expansion fans extending lee of southern OR and Cape
Mendocino are expected to produce near-gale force wind gusts this
afternoon into Thursday, beginning in the southern waters before
expanding into the northern outer waters.

Although gale criteria remains fairly marginal and localized, the
addition of a large long period NW swell is already elevating wave
heights to 12-14 feet at 15 seconds across area waters. Combined
wave heights will continue to exceed 14-16 feet at 15 seconds early
Thursday in the southern waters and the northern outer waters as
locally generated wind waves persist. Current guidance indicates
gale gusts becoming concentrated in the far northern outer waters
early Friday before quickly diminishing. All zones are expected to
subside to sub-10 foot wave heights by late this week and early
weekend as the swell subsides. JMM

&&

.EKA WATCHES/WARNINGS/ADVISORIES...
CA...
     Beach Hazards Statement through Thursday morning for CAZ101-
     103-104-109.

     Heat Advisory until 8 PM PDT Thursday for CAZ114-115.

NORTHWEST CALIFORNIA COASTAL WATERS...
     Hazardous Seas Warning until 3 PM PDT Thursday for PZZ450-
     470.

     Gale Warning until 9 AM PDT Thursday for PZZ455-475.

&&

$$

Visit us at https://www.weather.gov/eureka

Follow us on Facebook and Twitter at:
https://www.facebook.com/NWSEureka
https://www.twitter.com/NWSEureka

For forecast zone information
see the forecast zone map online:
https://www.weather.gov/images/eka/zonemap.png