079
FXUS66 KEKA 262215
AFDEKA

AREA FORECAST DISCUSSION
National Weather Service Eureka CA
315 PM PDT Fri Jul 26 2024

.SYNOPSIS...Temperatures will diminish below average in the
interior this weekend, followed by slow warming next week.
Coastal areas will remain cool with occasional low overcast and
patchy fog.

&&

.DISCUSSION...Visible satellite imagery showed an area of stratus
locked onto portions of the coast this afternoon. The depth of
the marine layer appeared to be shallow based the rate of inland
clearing and KACV profiler; no more than 1500 feet. Marine layer
will most likely deepen tonight. Stratus clouds will probably
cover much of the coast for the remainder of the weekend, though
some afternoon clearing will certainly be possible a few miles
away from the shoreline. Thicker stratus should also yield some
patches of light misty drizzle, though confidence is not high
there will any measurable amounts.

Temperatures in the interior will begin to "cool" below normal
on Saturday with highs mostly in the 80s for the warmest valleys.
Most of Trinity county is forecast to remain in the 90`s. Trough
aloft with below normal 850mb temperatures will remain over the
area for the remainder of the weekend and early next week. Also,
a 500mb vort max will move across the area this afternoon and
evening, however showers and thunderstorms are not expected due to
very limited moisture and low available buoyant energy.

A deeper push of moist air associated with a decaying front and
transient 500mb shortwave trough may bring some measurable precip
(most likely drizzle) to the North Coast region early next week,
specifically Monday night or Tue. RAW and uncalibrated ensemble
probability for a tenth or more in 24 hours from the ECMWF ENS is
10-30% for Del Norte and far northern Humboldt. Some light
measurable precip, most likely drizzle, appears possible (10-20%
chance) even though NBM 6 hourly probabilities are silent (10% or
less). Granted July is the driest month of the year on average and
odds for 0.10 or more are not good with strong downstream ridging
dominating. Ensemble means indicate a building 500mb ridge and
above normal 850mb temperatures for the latter portion of next
week. NBM probabilities for 100F or more increase to 50% or more
for the typically hot interior valley locations in the interior
late next week. Thus, after a break from the heat this weekend and
early next week, it does appear likely that summer heat will
return late next week. DB

&&

.AVIATION...Stratus has clung to the immediate coast today, driving
IFR to LIFR ceilings at KCEC and KACV. Brief clearing is possible at
the terminals lat this afternoon, although confidence is low as to
whether or not this will actually occur at the terminals, and if it
does, should only be for a few hours at most. Stratus rebuilds this
evening and overnight tonight. VFR is forecast to continue for the
interior through the TAF period. TDJ

&&

.MARINE...Northerlies are forecast to slowly weaken over the next
few days as an upper low moves in from the SW. This will weaken the
land-sea pressure gradient over the next couple of days causing
winds and seas to calm down significantly. This wind shut down is
currently forecasted to hold steady through the weekend into early
next week, then the usual thermal trof pattern returns by mid week,
generating northerlies of 10 to 15 kts. TDJ

&&

.FIRE WEATHER...Elevated to locally critical fire weather conditions
due to gusty diurnally driven winds and very low RH`s from 10-20%
are expected through this afternoon and evening, primarily across
Lake, Trinity and interior Mendocino counties. Overnight RH
recoveries have been generally good to moderate, except for some
exposed ridges of Mendocino and Lake Counties. A deeper marine is
forecast to develop tonight and persist through this weekend as a
trough aloft develops over the area. Humidities are expected to
increase as temperatures decrease below average this weekend.
Afternoon winds are also forecast to be lighter this weekend.
Also, a mid level vort max will progress over the area this
evening and generate slight instability into Saturday afternoon.
Some cumulus will build, however deep layer moisture and buoyant
energy appears insufficient to warrant thunderstorms. A slow and
moderate warming trend is expected mid next week with 100F degree
heat most likely returning late next week. Chance for wetting
rain, based on the NBM, is near zero for the next 7 days. DB

&&

.EKA WATCHES/WARNINGS/ADVISORIES...
CA...
None.
NORTHWEST CALIFORNIA COASTAL WATERS...
     Small Craft Advisory until 4 AM PDT Saturday for PZZ450-455.

     Small Craft Advisory until 10 AM PDT Saturday for PZZ470-
     475.

&&

$$

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