823
FXUS66 KPQR 041305 AAA
AFDPQR

Area Forecast Discussion
National Weather Service Portland OR
604 AM PDT Wed Jun 4 2025

.UPDATE...Currently as of 6 AM Wednesday, a weak disturbance that
was expected to only bring drizzle to the coast has brought some
light rain/drizzle inland, specifically around the
Portland/Vancouver Metro. Expect any light rain or drizzle to
continue until 11 AM at the latest. So far, it looks like the Metro
has received 0.01 to 0.05 inches of rain over the past 6 hours and
should not receive much more.

.SYNOPSIS...
A stretch of warm, dry weather will continue across the Pacific
Northwest through early next week as high pressure remains the
dominant feature. Inland temperatures will steadily rise,
climbing into the 80s by Friday and potentially reaching the mid
to upper 90s by Sunday. Both Saturday and Sunday have a moderate
Heat Risk for interior valleys. Coastal areas will stay cooler,
but may still warm slightly over the weekend depending on wind
direction. Breezy afternoon winds each day may offer modest,
localized relief from the heat. Monday will likely stay hot as
well, though forecast confidence decreases slightly.

&&

.DISCUSSION...Now through Monday...A dry and stable pattern
remains in place across the Pacific Northwest through early next
week. Today will be the coolest day of the week, as a weak
disturbance and northwest flow keep highs near 70 degrees in the
interior valleys and cooler along the coast. Some morning cloud
cover and spotty drizzle remain possible, particularly along the
coast.

Warming becomes more noticeable Thursday as a ridge of high
pressure strengthens over the region. Inland temperatures will
likely exceed 80 degrees, with a 60-80% chance of reaching that
mark in the Willamette Valley. Coastal locations will remain
cooler, generally in the 60s to low 70s. By Friday, high
temperatures will trend further upward into the low to mid 80s
inland, setting the stage for the hottest stretch of the
forecast period.

Saturday appears warmer than earlier projections, with highs now
expected to reach the upper 80s for many interior locations. A
few warmer spots could briefly approach 90 degrees, but
confidence in any specific value remains moderate at this
range. Overnight lows into Sunday will also trend warmer,
providing a strong launching point for what may be the hottest
day of this upcoming period.

On Sunday, the NBM shows a 50-80% chance of the Willamette
Valley reaching or exceeding 90 degrees. A cooler scenario (10th
percentile) keeps highs in the mid to upper 80s if northwest
flow and marine influence persist. A warmer outcome (90th
percentile) driven by easterly or offshore winds, could push
highs toward the upper 90s to near 100 degrees. Portland may run
a few degrees warmer than surrounding areas due to urban heat
island effects. The NWS HeatRisk current shows moderate risk
cross much of the interior for both Saturday and Sunday. Coastal
areas will stay cooler overall, generally in the 70s, but
localized warming into the mid 70s is possible depending on wind
direction.

Monday is expected to remain hot, but with more uncertainty.
The NBM shows a broader range of highs from the mid 80s to upper
90s (25th to 75th percentile). As with Sunday, wind direction
will be key, where continued offshore flow would support another
day of widespread heat, while a shift toward marine air would
temper temperatures somewhat. Confidence remains lower for
Monday, and the situation should be monitored closely for the
potential of prolonged or intensified heat impacts. Winds each
afternoon this period will remain breezy, occasionally gusting
to 15-20 mph, though this may offer only modest relief in inland
areas.
~Hall

&&

.AVIATION...Northwesterly flow aloft continues today while a weak
disturbance deepens the marine layer, producing drizzle along the
coast and allowing stratus to push inland. An overcast marine
deck with predominately IFR CIGs is in place along the coast early
this morning. Periods of reduced visibility due to drizzle and
mist are also possible, potentially lowering conditions to LIFR
through 16z Wed. Expect conditions to gradually improve at coastal
terminals to primarily MVFR by 18-19z Wednesday. As the stratus
moves inland, expect predominately MVFR CIGs to persist through
Wednesday morning, lifting to VFR sometime around 21-23z.
Confidence in the exact timing is still low at this time. North to
northwest surface winds should remain relatively light this
morning, increasing to around 10 kt by the afternoon, with gusts
up to 20 kt near the central coast.

PDX AND APPROACHES...Low clouds with MVFR CIGs have developed
early this morning. Occasional mist/drizzle possible through the
morning hours. This cloud deck should gradually clear in the
afternoon hours with higher confidence in VFR CIGs after 23z
Wed. Northwest winds generally stay less than 8 kt today. /DH

&&

.MARINE...Not much change as a summer time pattern has settled in
with high pressure persisting offshore through the week, resulting
in persistent northerly winds. Northerly winds will be strongest
during the afternoon and evening hours each day this week,
especially over the central and southern waters where small craft
advisory level wind gusts up to 25 kt are likely to occur Thursday
and Friday.

The general sea state will continued to be dominated by northerly
wind waves and a fresh northwesterly swell through Sunday with
significant wave heights around 5 to 8 ft and a dominant wave
period around 8-10 seconds. Expect seas to remain steep and
choppy during the afternoon and evening hours when winds are
strongest. /DH

&&

.PQR WATCHES/WARNINGS/ADVISORIES...

OR...None.
WA...None.
PZ...None.

&&

$$

www.weather.gov/portland

Interact with us via social media:
www.facebook.com/NWSPortland
x.com/NWSPortland