National Weather Service Area Forecast Discussion for Long Beach, WA USA

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Area Forecast Discussion
National Weather Service Portland, OR or
149 pm pdt sat jun 13 2026

.synopsis...the upper level ridge is building over the region
which will lead to a few days of hot temperatures, warm
overnight lows, low humidity, and breezy winds. peak heating
days will be sunday and monday with minimal overnight
temperature relief. extreme heat warning in effect for the
greater portland-vancouver metro and columbia river gorge sunday
through tuesday. heat advisory in effect elsewhere, with the
coast only being on sunday. breezy easterly winds through the
columbia river gorge on this afternoon and sunday will ease on
monday. warm conditions remain through the week though will be
at least 10 degrees cooler for inland locations.

&&

.short term...now through monday night...the ridge is beginning
to build in and we are already starting to see impacts. as the
ridge amplifies, we will see winds and temperatures increase,
and humidity drop. there has been minimal change in the overall
forecast and all appears to be on track based on current
observations. the easterly winds have begun to increase within
the columbia river gorge and the portland-vancouver metro area.
within an hour, we saw the temperature spike by 87 degrees f,
and the humidity drop to 19%. these easterly winds will aid in
increasing temperatures this we still cannot rule out
high temperatures of 100 degrees f on both sunday and monday.
afternoon as they mix down warmer air aloft and warm the
surface for inland valleys. we will also see conditions along
the coast warm up as those same easterly winds aloft rise up and
over the coast range, and thus downslope warm air aloft into
the coastal cities. tillamook is a site most known for seeing
this effect.

on sunday and monday we will see temperatures increase a few
degrees each day. we are expecting the warmest day along the
coast on sunday, while the hottest day inland will be on monday
(though only by one or two degrees). ultimately the pattern will
remain generally unchanged on sunday and monday. lets dive into
the numbers! there is high confidence that we will see inland
highs of 95 degrees f or more but we cannot rule out high
temperatures of 100 degrees f or more on both days. on sunday,
the chances are highest in the central willamette valley and
along the 99w corridor through tigard into northplains. the
probabilities are a bit more scattered, but in general there is
around a 30-40% chance of highs of 100 degrees or more on
sunday. monday on the other had sees much more widespread
probability. one reason for this is that the overnight
temperature on sunday into monday morning will remain elevated
and thus, the daytime temperatures will have a leg up for
becoming excessively hot for the region. the latest nbm shows
probability ranging from 80-90% within clackamas and washington
counties, around 30-50% chance in the portland-vancouver metro,
and around 60-70% chance in the central willamette valley. due
to more of a northerly wind pattern, the southern willamette
valley and associated cascade foothills will see lower
probabilities. one thing to consider though is topography. in
areas that are east-west aligned, they will see more of that gap
flow and warming from the easterly winds. therefore, they could
be slightly warmer.

as previously mentioned, the overnight lows are a very
influential component of the forecast as they set the stage for
the daytime outcomes. overall, there is around a 30% chance of
low temperatures of 70 degrees or greater sunday into monday for
the east slopes of the coast range and the i-5 corridor.
conditions will be slightly cooler on monday night into tuesday
where those probabilities are less than 10% everywhere except
the far southern willamette valley. the combination of the
overnight and daytime temperatures is what determines the
heatrisk for the region. on sunday there has been an expansion
of the major heatrisk, likely due to the overnight temperatures.
on monday, major heatrisk remains just for the greater
portland-vancouver metro area. elsewhere, moderate heatrisk. a
number of heat related hazards have been issued.

because heat is one of the leading cause of weather related
deaths, it is critical that you protect yourself, loved ones,
pets and community members. be sure to drink ample water, find
cool places to spend your days, and check on your neighbors. in
addition, natural water bodies remain quite cold so if you`re
planning on hitting lakes and rivers to cool down keep that in
mind. cold water shock can hit quickly and sometimes without
signs.

in addition to the heat, the tightening surface pressure
gradients associated with the surface thermal trough will lead
to breezy offshore winds today and sunday, especially within the
central and southern willamette valley in the afternoon and
evening hours and the columbia river gorge and western cascade
gaps in the evening and overnight hours. additionally, as
daytime temperatures increase, relative humidities will also
decrease to near critical levels. this is producing some fire
weather concerns in areas with cured grasses and finer fuels
saturday into monday due to hot, dry, and breezy conditions.
based on feedback from area partners, fuels are not quite cured
enough to consider any red flag warnings at this point, but
there is uncertainty on how the fuels will be impacted by the
continuous days of dry and hot conditions. be aware of
potential ignition sources such as vehicle chains dragging on
the pavement, hot vehicle components, sparks created by power
tools, and cigarette butts as all of these could easily result
in the ignition of cured grasses and dry, fine fuels. live
vegetation and larger fuels may not have enough time to dry out
prior to the dry and breezy conditions, but this is a variable
that is being closely monitored by our state and federal fire
partners. -27/03

.long term...tuesday through saturday...models are coming into
better agreement that the ridge will hold into tuesday and the
trough that was displayed earlier in the week is no longer going
to have significant influence. it will still cause the ridge to
flatten slightly, but we are not necessarily expecting straight
zonal flow. instead, we will see a slight northwesterly wind
which will keep the northern portions of the area cooler than
the southern areas. with this in mind though, heat remains a
concern though the daytime highs continue to remain below
critical levels. while the extreme heat warning and heat
advisories remain in effect through tuesday, we will continue to
evaluate on whether they remain a significant threat. an area
that will maintain at least moderate heatrisk on tuesday is the
greater portland-vancouver metro area and other urban centers.
this is likely due to the urban heat island effect.

come wednesday we will have transitioned out of the heat wave
but 500 mb ensemble models continue to show general ridging over
the region. this means that we will continue to see dry, clear,
and warm conditions. overall, high temperatures will be in the
60s along the coast, in the 80s inland, and in the 60s-70s along
the cascades. the pattern remains fairly stable with minimal
changes in the sensible weather. ultimately it just comes down
to the numbers and how much uncertainty we experience. as we
move into later on the week (thu-fri), confidence decreases in
exact temperature values. right now there is anywhere from a
6-10 degree spread in potential high temperatures each day.
ultimately prepare for a week of dry and warm conditions.
-27

&&

.aviation...l confidence in this pattern change is low at this
time. -03

&&

.climate...high pressure will maintain vfr conditions with clear
skies through the taf period across all terminals. north to
northeasterly winds expected, except northwesterly at the coast.
surface pressure gradients tighten this afternoon supporting gusty
winds up to 20-25 kt at any given terminal. after 03-04z sunday,
winds should gradually weaken as pressure gradients ease and winds
turn back offshore at the coast.

in addition, temperatures between 90 to 100 degrees are forecast
across the willamette valley saturday through monday. be aware of
high density altitude which may reduce aircraft performance.

kpdx and approaches...vfr with clear skies through the taf period.
northeasterly winds with gusts up to 20 kt are expected through
the afternoon. winds weaken later in the evening after 03-04z
sunday. -dh

&&

.marine...high pressure offshore will maintain the summertime
pattern this weekend and through much of next week. a
strengthening thermal trough along the coast will increase
pressure gradients over the coastal waters today. as such,
northerly winds will increase to around 15-25 kt with gusts up to
25-30 kt south of cape falcon, while gusts up to 25 kt will be
possible northward toward cape disappointment. winds ease by
sunday morning, but are expected to increase again as diurnally
driven northerlies peak each afternoon and evening through next
week. seas around 4 to 8 ft at 7-10 seconds are expected to
persist, driven primarily by the northerly wind chop. -dh


&&

.pqr watches/warnings/advisories...
or...heat advisory from 11 am to 11 pm pdt sunday for orz101>103.
     heat advisory from 11 am sunday to 11 pm pdt tuesday for
     orz104>108-113>119-121>125.
     extreme heat warning from 11 am sunday to 11 pm pdt tuesday
     for orz109>112-120.
wa...heat advisory from 11 am to 11 pm pdt sunday for waz201.
     heat advisory from 11 am sunday to 11 pm pdt tuesday for
     waz202>205-208-210.
     extreme heat warning from 11 am sunday to 11 pm pdt tuesday
     for waz206-207-209.
pz...small craft advisory until 2 am pdt sunday for pzz251-271.
     small craft advisory until 5 am pdt monday for pzz252-253-272-
     273.
&&

$$

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