Hopland, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

193
FXUS66 KEKA 191208
AFDEKA

AREA FORECAST DISCUSSION
National Weather Service Eureka CA
508 AM PDT Thu Sep 19 2024

.SYNOPSIS...High pressure is building over the area. This will
strengthen through the weekend and into early next week bringing
above normal temperatures. Some of the warmer valleys may see
temperatures around 100 Sunday and Monday. Offshore flow
strengthens over the weekend bringing sunny skies and warm
temperatures to the coast.

&&

.DISCUSSION...High pressure is building over the area as the upper
level pushes to the southeast. The marine layer is already shallow
this morning, only around 1500 feet or so. This will likely clear
out by this afternoon, but models indicate it may take it`s time
and it may not occur until early afternoon.This afternoon inland
temperatures are expected to warm by nearly 10 degrees over
yesterday with highs in the upper 80s expected.

Friday and Saturday most inland areas continue to see some warming
with highs getting into the low to mid 90s by Saturday. Northeast
winds overnight will help keep much of the coastal areas clear.
Breezy northwest winds each afternoon will likely keep
temperatures from warming much more than the mid 60s. Sunday and
Monday inland temperatures continue to warm with the warmer
valleys seeing temperatures near 100. The winds at the coast may
be slightly weaker and this could allow temperatures to warm into
the 70s, although confidence is low on this.

The main area of uncertainty in this forecast is how quickly the
ridge breaks down. Tuesday most of the models agree that the ridge
axis will have just moved onshore. This will likely change the
wind patterns enough to bring a return of stratus and fog to the
coast. The ensemble clusters struggle more with how quickly the
ridge will break down. One of the clusters keeps a strong ridge
over the area while others start to break it down. One cluster has
a trough moving onshore by Wednesday afternoon and bringing some
rain as early as Thursday. Needless to say this would also bring
some differences in temperatures. MKK

&&

.AVIATION...A substantial layer of low ceiling, foggy marine stratus
has established itself all along the NW California coast and coastal
river valleys. Visibilities and ceilings are showing LIFR conditions
at the coastal terminals and should remain as such for most of the
morning. NBM Model guidance currently is showing a drop in the
probability of stratus <500ft AGL & <1000ft AGL near KACV from
75%(<500ft AGL)& 90%(<1000ft AGL) at 1800Z to 25%(<500ft AGL) & 50%
(<1000ft AGL) at 1900Z. These probabilities tell that the low
stratus will mostly likely rise up above LIFR conditions, yet is not
necessarily going to dissipate entirely from the terminal space
during the day. This evening, overcast skies/fog and its associated
LIFR conditions are forecasted to return to the coastal terminals.
In addition, a southerly wind reversal could lead to some wind shear
at the marine layer/free atmosphere boundary.

KUKI shows its similar pattern of daytime winds from the W/NW before
dying off at or around sunset (0330Z). Some extremely high-
resolution models suggest breezy winds along the mountain ridges
inland, which could possibly mix down into the terminal space, but
confidence remains low on this occurring. No cloud layers are
forecast to develop over the inland areas, besides in the coastal
river valleys, leading to VFR conditions inland.


&&

.MARINE...Strong northerly winds (>20kts) are forecast to remain in
the outer waters today. These winds are creating steep wind waves
and conditions that warrant a small craft advisory in the outer
waters at least through tomorrow at 3pm. However, tomorrow
afternoon/evening there is substantially model guidance agreement of
a strong low-level jet (winds at 925mb 40-50kts) building over our
waters from tomorrow evening through Saturday afternoon. These LLJ
winds have a good chance to mix down to the ocean surface with high-
resolution models showing sustained northerly winds speeds reaching
just under 35kts & gusts possible up to 40kts. Wind waves in the
outer waters for this time period are forecast to ramp up as well
due to surface winds with certain areas currently forecasted to max
out around 14ft@10s. These windy and wavy conditions could warrant
an extended, or even upgraded, marine hazard statement for Friday
evening into the weekend. More confidence on these details will be
available within the next 24hrs as more models initialize and extend
through this time period of interest.

&&

.Fire Weather...Offshore flow (NE Winds) is ongoing this morning
and is expected to continue for the next several days. It looks
like it will be the strongest on Saturday morning with winds of 15
to 25 mph and gusts to 35 mph on the most exposed areas of Del
Norte county. Winds will be lighter farther south and east,
although there is some uncertainty on how much lighter. This will
also bring drier air to the coastal mountains and recoveries are
only expected to be around 40 percent on the higher terrain. This
combination will bring elevated fire weather conditions so will
add a headline to the fire weather forecast for this in zones 203
and 204. Late in the weekend and early next week it looks like
winds will diminish some, although RH recoveries will remain poor.
MKK

&&

.EKA WATCHES/WARNINGS/ADVISORIES...
CA...
None.
NORTHWEST CALIFORNIA COASTAL WATERS...
     Small Craft Advisory until 3 PM PDT Friday for PZZ470-475.

&&

$$

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https://www.weather.gov/images/eka/zonemap.png