748
FXUS66 KEKA 072150
AFDEKA

AREA FORECAST DISCUSSION
National Weather Service Eureka CA
250 PM PDT Tue May 7 2024

.SYNOPSIS...A significant pattern change from the cool, wet, winter-
like conditions is currently underway. A building expansive Pacific
ridge of high pressure will bring quickly warming temperatures and
strengthening N to NE winds. This combination of elements will allow
for unseasonably warm temperatures closer to the coast.


&&

.DISCUSSION...With increasing subsidence from the strengthening
high pressure offshore,the clearing of skies will continue to trend
and will promote more frost development overnight. The expansive
Pacific ridge will continue amplifying today, and will persist
through late in the week. Outside of the immediate coast,
temperatures will be noticeably warmer today for most. Northerly
winds will be increasing today, and by the afternoon, gusts of 25
to 35 mph are forecast for the exposed coastal areas. Interior
ridgetop northeasterly winds will ramp up tonight, and will become
strong (gusts over 50 mph) from southern Trinity southward,
particularly over the highest ridges of Lake County through
Thursday morning.

The northerly breezes will be of similar strength on Wednesday as
the high further amplifies and an upper trough cuts off and
retrogrades west into the Great Basin. This will strengthen
offshore winds on Thursday/Friday when the warmest temperatures
are expected to the coast. Ensembles guidance holds near record to
record highs in the mid to upper 70s to the coast Thursday and
likely Friday. Interior valleys will rise to the upper 80s to low
90s. Given the setup and models` difficult ability to resolve the
far westward push of warmth from the offshore winds, leaned toward
the 75th percentile on Thursday for coastal highs when the most
pronounced offshore flow will develop. This will be quite a swing
from the below average temperatures of recent days, allowing
little time for acclimation. Ensembles generally hold the ridge
through the extended, with varying phases of amplification. /JJW
/EYS

&&

.AVIATION...By mid-morning Sky and Vis became VFR. Any aviation
concern today has been "ramping-up" northerly winds near the
coast; the cause will be developing offshore high pressure and
inland (inverted) low pressure trofing interacting. Therefore, the
at/near the coast pressure gradient will tighten; the result will
be gusty coastal winds through evening. Windy conditions will
result in the lack of coastal stratus into Wednesday. Late
Wednesday morning, elevated offshore winds could possibly, and
briefly become the catalyst for LLWS at CEC. Inland weather today
and through Wednesday is expected to stay inconsequential. /TA

&&


.MARINE...A northerly wind regime will become strong and dominant as
synoptic ridging sets up over the Western US. Winds will increase to
gale force by this evening. These northerly gales are expected to
last through Thursday. Gusts above 35 kts in all area waters are
forecast with some gusts in the northern outer waters reaching 45
kts by late Wednesday night. Wind waves out of the NW will be steep
at 9 to 10 feet in height and as many seconds in period. Seas are
anticipated to peak over 15 ft at 10-11 seconds out of the north by
Wednesday night. The thermal trough will build toward the coast late
in the week resulting in a weakening pressure gradient over the
waters and likely some weak southerly return flow near the immediate
coast.


&&

.EKA WATCHES/WARNINGS/ADVISORIES...
CA...
     Frost Advisory from 3 AM to 10 AM PDT Wednesday for CAZ102-
     105>108-110-111-114.

NORTHWEST CALIFORNIA COASTAL WATERS...
     Small Craft Advisory until 9 PM PDT this evening for PZZ450-
     470.

     Gale Warning from 9 PM this evening to 3 AM PDT Thursday
     for PZZ450-470.

     Small Craft Advisory until 3 PM PDT this afternoon for
     PZZ455-475.

     Gale Warning until 3 AM PDT Thursday for PZZ455-475.

&&

$$

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