National Weather Service

Area Forecast Discussion
Issued by NWS Eureka, CA

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-- Discussion containing changed information from previous version are highlighted. --
992
FXUS66 KEKA 301224
AFDEKA

AREA FORECAST DISCUSSION
National Weather Service Eureka CA
524 AM PDT Thu May 30 2024

.SYNOPSIS...-- Changed Discussion --A warming trend will continue through this week with
the hottest inland valleys reaching the upper 90s by Friday. A
regular cycle of stratus and gusty afternoon onshore winds will
persist for the coast until Sunday. Monday shows rain arriving to
the northern counties in a quickly moving system with rain focused
on Del Norte County. Later next week, temperatures are going to
easily be above normal from the interior to the coast.-- End Changed Discussion --

.DISCUSSION...-- Changed Discussion --The current upper level ridge that been building
over Northern California looks to be stabilizing and should hold
steady through the end of the week. This will allow hot
temperatures to develop in the interior valleys with highs
possibly (~25%)reaching up to 95 degree highs in the very hottest
valleys of Lake and Trinity counties by Friday. Another impact of
this high pressure system is that it will also support a usual
cycle of nighttime marine stratus with gusty north winds pushing
on shore and mixing out these low clouds each afternoon. Onshore
coastal winds will be strongest this afternoon on the ridgetops.

Ensemble clusters indicate that a troughing pattern may set up late
in the weekend and into next week. The ECMWF Extreme Forecast Index
(EFI) indicates a decently high signal for more precipitation than
average from night Sunday through the morning on Monday. This
rain event likely will have minimal impacts within the region with
the National Blend of Models (NBM) indicating a 70% chance of
wetting rain (>0.1 inches) for Del Norte County and a 20-40%
chance in northern Humboldt County. Over the past few days,
confidence in this event has increased and should continue to do
so, especially when high resolution model guidance becomes
available for this time frame.

After this brief rain event, temperatures all over our area will be
on a steep rise. Interior temperatures are expected to be around 90
on Tuesday then bump up to just shy of 100 on Wednesday and
Thursday. Personally, I wouldn`t be surprised at all if we see
out first 100 degree days of the year in the middle of next week
as NBM is already showing a 60-70% chance of 100+ degrees for
Ukiah on Wednesday and Thursday. Winds during these days of
extreme heat are currently forecasted to peak on ridgetops at
around 20 mph. On the coast we have a chance of seeing unseasonably
warm temperatures as well. Eureka and Fort Bragg are both showing
temperatures in the mid- high 60s by the second half of next
week. This event is 6-7 days away, yet ensemble guidance is in
high agreement which is leading to the increased levels of
confidence in the forecast at this time. DS-- End Changed Discussion --

.AVIATION...-- Changed Discussion --.Weak high pressure is continuing to build over the area
this morning. This is bringing offshore flow which has kept stratus
out of most areas. The exception has been around Humboldt Bay and
southeast up the river valleys. Earlier in the night this made it
into KACV, but has since moved out. it is possible it could briefly
move in this morning, but for now am not expecting it to. This
afternoon gusty winds are expected again. These will likely be
similar to yesterday along the coast with gusts up to around 30 kt.
Tonight the offshore flow continues and the coastal areas look drier
so stratus is not expected to return in most areas. MKK-- End Changed Discussion --

.MARINE...-- Changed Discussion --High pressure is building in and winds are increasing this
morning. The waters north of Cape Mendocino have been slower to
increase than expected, but are finally starting to increase to
gales this morning. Steep waves are expanding as well. This
afternoon gale force gusts will get closer to the coast in zone
pzz450, but will mainly be limited to areas north of Trinidad. The hi-
resolution models are in good agreement on an area of weaker winds
off of Humboldt Bay. Tonight and Friday these stronger winds are
expected to push off the coast 5 to 10 miles.

For the weekend an upper level trough is expected to weaken the
winds on Saturday. The winds may even become briefly southerly in
the northern waters. Sunday a northwest swell around 10 seconds will
be the main wave. Initially it is expected to be around 3 feet, but
will build to around 6 feet at 10 seconds by Tuesday.

Sunday night or early Monday these winds are expected to switch back
to northerly once again. Monday and Tuesday it looks like the
northerly winds will increase some, but not get all that strong. Mid
to late in the week high pressure builds back in and northerly winds
will increase once again.-- End Changed Discussion --

.EKA WATCHES/WARNINGS/ADVISORIES...
-- Changed Discussion --CA...
None.
NORTHWEST CALIFORNIA COASTAL WATERS...
Small Craft Advisory until 3 AM PDT Saturday for PZZ450.

Gale Warning until 9 PM PDT this evening for PZZ455.

Gale Warning until 10 PM PDT Friday for PZZ470-475.-- End Changed Discussion --

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