Lebanon, Oregon 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

602
FXUS66 KPQR 072217
AFDPQR

Area Forecast Discussion
National Weather Service Portland OR
317 PM PDT Sun Jun 7 2026

.SYNOPSIS...Monday will be a cool and rainy day as steady stratiform
rain spreads over the area with an incoming surface low. Expect
persistent rain from near sunrise to near sunset before stratiform
rain transitions to off-and-on showers towards 8 PM Monday. Showers
will then linger into Tuesday and Wednesday, maintaining cooler than
normal temperatures. Breezy south to southwest winds will also occur
Monday afternoon through Tuesday afternoon with wind gusts as high as
30-35 mph. High pressure arrives on Thursday, bringing dry weather
with highs in the 70s, except 60s at the coast. Attention then turns
to a multi-day heat wave beginning next weekend and extending into
early next week. Highs in the 90s are likely (65-85% chance) for
inland valleys during this heat event, with a 10-30% chance for highs
at or above 100 degrees June 14-15 for inland valleys.

&&

.SHORT TERM...Now through Wednesday night...The short term forecast
is highlighted by cool and wet conditions. Beginning Monday morning,
a ~998 mb closed surfaced low will track over the south WA/north OR
coastal waters towards the Long Beach Peninsula by the late
afternoon. A large swath of steady stratiform rain ahead of the
surface low will spread from west to east across western WA/OR around
sunrise and linger through the day, resulting in a cool and wet day.
By sunset, steady stratiform rain will transition to off-and-on
post-frontal rain showers. Beyond Monday, models and their ensembles
remain in good agreement for broad upper level troughing over the
region with west to northwest flow aloft Tuesday through Wednesday.
This will maintain a cool and showery weather pattern through
mid-week with high temperatures mainly in the 60s, however NBM PoPs
suggest showers should dissipate by Wednesday afternoon at the latest
for most locations.

The vast majority of precipitation will fall between 5 AM PDT Monday
and 5 AM PDT Wednesday. QPF amounts from the deterministic NBM during
this 48-hour period range generally between 0.5-1.0" over inland
valley, around 1" at the coast, and 1-2" in the Coast Range, Willapa
Hills, and Cascades. Probabilities for over 0.5" of rain have
increased to 85-95%, and probabilities for 1" of rain or more have
increased to 25-50% over the Willamette Valley and Portland metro,
and 75-95% along the coast, Coast Range, Willapa Hills, and Cascades.
-23

.LONG TERM...Thursday through Saturday night...The long term forecast
is highlighted by a prolonged stretch of dry conditions with a
multi-day heat wave beginning next weekend. Before the heat kicks in,
expect pleasant weather on Thursday with mostly sunny skies and high
temperatures in the 70s, except 60s at the coast. From Friday onward
into early next week, models and their ensembles show an upper level
ridge amplifying over the far northeast Pacific, with some
uncertainty regarding exactly how far east the ridge axis will move.
Despite the uncertainty with the location of the ridge axis,
confidence is high temperatures will be heating up significantly June
13-15. This is when the LREF mean shows 500 mb heights near the
climatological 97-98th percentile and the NBM shows a 65-85% chance
for high temperatures above 90 degrees for inland valleys and less
than a 10% chance at the coast. In fact, there is a 10-30% chance for
highs at or above 100 degrees June 14-15 for inland valleys,
suggesting a major heat wave is within the realm of possibilities. In
addition, overnight lows in the mid or even upper 60s will offer
minimal overnight relief. As such, probabilities for a Moderate
HeatRisk or higher peak near 75-90% June 14-15, with a 20-50% chance
for a Major HeatRisk or higher. Note the highest probabilities are
over the greater Portland/Vancouver metro. Anyone who is sensitive to
heat or those who have outdoor plans should pay attention to the
forecast over the coming days and be prepared for potential extreme
heat. Those planning on swimming in rivers or lakes to cool off
should be mindful of cold water temperatures and swift currents,
which can become life threatening. -23

&&

.AVIATION...Largely VFR flying conditions are expected through
the period with high cloud coverage continuing to increase ahead
of an approaching frontal system. West to northwest winds at 5-10
kt along the coast and north winds near 5 kt inland will ease
below tonight. Cigs trend lower tonight before rain arrives from
the west by 12-15z Mon, with southerly winds rising to 5-10 kt
ahead of the frontal boundary. Chances for MVFR cigs will increase
to 50-75% along the coast and 35-555% at inland terminals after
15-18z Mon.

KPDX AND APPROACHES...VFR conditions expected throughout the
period. High cloud coverage will increase from the west, followed
by rain beginning by 13-15z Mon. North to northwest winds around
5 kt today will ease overnight, then rise out of the south near 5
kt Monday morning ahead of the frontal boundary. Chances for MVFR
cigs increase to 25% by 18z Mon, and to 50% by 18z Mon. -36

&&

.MARINE...An active and progressive pattern continues with periods
of rain and elevated wind through midweek. A first frontal system
arrives tonight into Monday morning, bringing widespread rain and
strengthening southerly winds. The strongest winds reach 20-25 kt
with gusts as high as 30-32 kt through much of the day on Monday,
with isolated gale-force gusts as high as 35 kt most likely
between 1-6 PM PDT within 20 NM south of Cape Foulweather. Seas
will build from 4-5 ft this afternoon to 7-9 ft at 8 seconds by
Monday afternoon with a continued dominant westerly swell. Small
Craft Advisories remain in effect beginning at 11 PM PDT this
evening beyond 10 NM and at 5 AM PDT Monday within 10 NM, and
continuing through at least Tuesday afternoon. While southerly
winds will subside behind the frontal passage, west-northwesterly
winds is its wake are also expected to gust near 20-25 kt while
seas remain relatively steep, so Small Craft Advisories may need
to be extended further.

West-northwest winds on Wednesday will steadily turn out of the
north as high pressure builds offshore. Strengthening northerlies
will see diurnal peaks in the afternoon each day Thursday through
at least Saturday, periods which could necessitate additional
Small Craft Advisories for gusts near 25 kt. Seas through this
period look to remain near 5-7 ft with a west-northwest swell at
9-11 seconds. -36

&&

.PQR WATCHES/WARNINGS/ADVISORIES...

OR...None.

WA...None.

PZ...Small Craft Advisory from 5 AM Monday to 2 PM PDT Tuesday for
     PZZ251>253.

     Small Craft Advisory from 11 PM this evening to 2 PM PDT
     Tuesday for PZZ271>273.

&&

$$

www.weather.gov/portland

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