Hillsboro, Oregon 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

585
FXUS66 KPQR 161139 AAA
AFDPQR

Area Forecast Discussion...UPDATED
National Weather Service Portland OR
438 AM PDT Wed Jul 16 2025

...Updated aviation discussion...

.SYNOPSIS...
Hot and dry conditions persist through Wednesday, with inland
highs reaching the 90s to near 100 degrees. A Heat Advisory remains
in effect through Wednesday evening for the inland valleys of
northwest Oregon and southwest Washington. Conditions will remain
significantly cooler at the coast. Still warm on Thursday and Friday
with highs near 90 degrees for inland valleys. Upper level troughing
will bring more seasonable temperatures over the weekend with
increasing chances for coastal drizzle.

&&

.SHORT TERM...Wednesday through Friday night...Wednesday will remain
dry and should be the hottest day of this week for inland areas with
high temperatures ranging between 95 and 100 degrees over the
interior lowlands of northwest Oregon and southwest Washington. If
you must be outside during the hottest part of the day (1-6 PM), be
sure to stay hydrated and in the shade if possible to help avoid heat
exhaustion or heat stroke. Morning low temperatures will also be
rather warm with most locations only bottoming out between 64-68
degrees, except around 60 degrees in the Eugene-Springfield area.
Note the coast will remain much cooler with morning lows in the 50s
and high temps in the 70s. Also worth noting is areas of upper level
smoke and haze for locations south and east of Salem, mainly coming
from a large wildfire burning east of the Cascade crest between
Madras and Antelope; this fire is named the "Cram Fire." Not
expecting air quality to degrade much west of the Cascades given much
of the smoke will be above the surface. Also not expecting smoke to
be dense enough to noticeably impact surface temperatures.

Conditions will remain dry Thursday through Friday, however
temperatures will be less hot compared to Wednesday. That said,
temperatures will still be running several degrees above average with
highs in the upper 80s to lower 90s for inland valleys. Meanwhile,
the coast will stay in the 60s to around 70 degrees. Do expect any
lingering smoke and haze in the area to clear out from west to east
on Thursday given the return of onshore flow.      -TK

&&

.LONG TERM...Saturday through Tuesday night...Temperatures are
expected to return to near average for this time of year over the
upcoming weekend in response to an incoming upper level trough.
Models and their ensembles are in fairly good agreement this trough
will then remain in place into early next week, maintaining
seasonable temperatures. This pattern will also increase chances for
morning cloud cover for both inland and coastal areas.

This trough will also help deepen the marine layer, potentially
enough to result in morning drizzle at the coast this Saturday and/or
Sunday, with Sunday morning being the most likely timeframe.
ENS/GEFS/GEPS ensembles are in good agreement for light rain amounts
(a few hundredths of an inch or less) along the coast by Sunday
morning. Note the south WA/north OR coast has the best chance to
observe light drizzle, with lower chances from Newport to Florence.
Cannot completely rule out inland areas seeing patchy morning drizzle
Sunday morning, however the probability for this to occur is
currently less than 10%.

Uncertainty regarding rain chances/amounts increases significantly
early next week. This is when inland areas have a slightly better
shot of seeing measurable rain as the aforementioned upper level
trough evolves into a closed low, however this is far from certain at
this time. QPF plumes from the ENS/GEFS/GEPS highlight this
uncertainty well, with rain amounts ranging anywhere from nothing at
all to 0.5 inches in the Portland/Vancouver metro. Currently, around
70% of ensemble guidance suggests no rain at all for inland areas.
The remaining 30% generally suggests anywhere from 0.01-0.10 inches,
aside from a few outliers from the ENS that produce anywhere from
0.2-0.5 inches. Note these probabilities are similar over the entire
Willamette Valley as well. The NBM currently matches the most likely
outcome, producing no measurable rain. Regardless of whether or not
rain falls, it is clear there is no threat for extreme heat in the
long term forecast.      -TK

&&

.AVIATION...High pressure will maintain mostly VFR conditions with
clear skies across the region. An exception would be KONP, as
satellite imagery as of early Wednesday morning shows marine stratus
moving toward the central Oregon coast. There is a 30-50% chance
that KONP receives IFR/MVFR stratus between 12-16z Wed. Otherwise,
VFR conditions prevail throughout the day along the coast and across
the Willamette Valley. Expect light northerly to northeasterly winds
today, turning more westerly to northwesterly this evening. High
confidence (>80% chance) that IFR/MVFR marine stratus returns to the
coast by 03-06z Thu as onshore flow increases.

Will also note that wildfire smoke is forecast to spread into the
southern Willamette Valley from ongoing wildfires in central Oregon.
Therefore, smoke was added to the KEUG TAF for this afternoon.
Expect smoke to clear out in the evening when winds turn more
onshore.

PDX AND APPROACHES...VFR with clear skies through the TAF period.
Northeasterly winds under 10 kt today will turn more northwesterly
after 00z Thursday.     -Alviz

&&

.MARINE...High pressure over the Pacific will maintain northerly
winds through the week. The current Small Craft Advisory for the
outer waters (10-60 NM out) has been extended to 0500 Thursday for
the combination of breezy northerly winds with gusts up to 25 kt and
choppy seas of 8-9 ft at 8-9 seconds. The advisory for the inner
waters (out 10 NM) from Cape Falcon to Florence remains in effect
through 0200 Thursday. Winds weaken and seas subside heading into
the weekend.       -Alviz


&&

.PQR WATCHES/WARNINGS/ADVISORIES...

OR...Heat Advisory until 10 PM PDT this evening for ORZ108>122.

WA...Heat Advisory until 10 PM PDT this evening for WAZ204>207-209-
     210.

PZ...Small Craft Advisory until 2 AM PDT Thursday for PZZ252-253.

     Small Craft Advisory until 5 AM PDT Thursday for PZZ271>273.
&&

$$

www.weather.gov/portland

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