439
FXUS66 KEKA 272201
AFDEKA

AREA FORECAST DISCUSSION
National Weather Service Eureka CA
301 PM PDT Thu Jun 27 2024

.SYNOPSIS...Relatively clear skies and mild temps continue this
afternoon. Lower daytime RHs and slightly elevated winds expected
in interior Trinity, Mendocino and Lake County. Warming and drying
trend returns Friday, potentially becoming more intense next week.


&&

.DISCUSSION...Coastal stratus has eroded this afternoon while high
cloud streams over southern Humboldt and Trinity counties. Skies are
expected to clear inland as this high cloud continues to progress
eastward this evening. Stratus is expected to redevelop tonight
primarily in Humboldt county, with drizzle possible along the coast
late tonight between Eureka and Ferndale. Seasonable temps continue
across the interior this afternoon, with some sites seeing NW wind
gusts in the 15 to 20 mph range, primarily in eastern Trinity,
Mendocino and Lake counties.

Broad, weak ridging is expected build into the region Friday,
driving interior temperatures back into the 90s. NBM exhibits high
probabilities of interior valleys >90 degrees on Friday, aligning
with short range deterministic models. With increasing temperatures,
min daytime RH values can be expected to drop into the mid teens and
low 20`s in Lake, interior Mendocino, and Trinity counties. Moist
NW flow will sustain marine influence for coastal counties through
this weekend. Additional upper shortwaves will provide similar
disturbances this weekend before potential for substantially warmer
and drier conditions next week. Long-range models indicate
anomalous warm ridging building into the eastern Pacific, coupled
with potential for min RHs in the teens and single digits by mid-
week. Stay tuned for updates on potentially elevated fire weather
conditions and heat risk.


&&

.AVIATION...A plethora of low clouds continued over the Del Norte Coast (mostly
LIFR/IFR stratus)...and MVFR clouds nearly over all of Humboldt
County this morning. By late morning, all the stratus had scoured
out of CEC. Notably: the marine layer was much shallower today with
MVFR Cigs over ACV which scattered before 10 AM. Tops of the marine
clouds over Humboldt were about 1000 feet lower than yesterday.
Winds at the coast will "rev up" today due to increasing interaction
between offshore building high pressure and the inland thermal low
pressure. Agree with previous discussion that short-term model
guidance is indicating stratus redeveloping along areas of the North
Coast... particularly Humboldt Bay to ACV. /TA


&&

.MARINE...Northerlies strengthen and spread from south to north
across the coastal waters this afternoon into Friday, with the
strongest winds across the southern outer waters and downwind of
Cape Mendocino. Wind driven seas will generate steep short period
NW seas around 6 to 9 feet across the southern waters today. Winds
are forecast to ramp up on Friday with near gale with localized
gale force gusts across the outer waters and in the fan of Cape
Mendocino on Friday. Short period seas will pick up to around 8 to
10 feet at 8 to 9 seconds Friday afternoon as result. Winds
slightly diminish from north to south throughout the weekend as
another upper level trough moves over the area. However, elevated
northerly winds and steep seas will persist over the southern
waters.


&&

.FIRE WEATHER...Gusty NW winds combined with 15-25% minimum
daytime RH values may pose a brief increased fire weather threat
this afternoon and evening, especially in Lake County. Greatest
threat to fine fuels in areas below 2000 feet.


&&

.EKA WATCHES/WARNINGS/ADVISORIES...
CA...
None.
NORTHWEST CALIFORNIA COASTAL WATERS...
     Small Craft Advisory until 9 PM PDT Saturday for PZZ455-475.

     Small Craft Advisory from 11 PM this evening to 3 PM PDT
     Saturday for PZZ470.

&&

$$

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