350
FXUS66 KPQR 051808 AAA
AFDPQR

Area Forecast Discussion...UPDATED
National Weather Service Portland OR
1107 AM PDT Thu Jun 5 2025

...Updated aviation discussion...

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 low 80s for today, mid 80s by Friday, upper
80s to low 90s by Saturday, then low to mid 90s by Sunday.
Saturday, Sunday, and Monday 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.

&&

.DISCUSSION...Now through Tuesday night...Temperatures are on
the rise today as strong upper level ridging builds over the
Pacific Northwest. Inland highs will warm into the upper 70s to
low 80s this afternoon, while coastal areas remain cooler,
generally topping out in the mid 60s to near 70. Morning stratus
inland and along the coast will continue to break up through the
afternoon.

The warming trend will continue Friday through the weekend as
the ridge strengthens and expands. Friday will likely see
widespread highs in the mid 80s across the interior, then the
upper 80s to low 90s on Saturday. Temperatures will likely peak
on Sunday, with inland areas - especially across the Willamette
Valley - reaching the low to mid 90s. In the Portland/Vancouver
metro area, the latest NBM indicates a 70-90% chance of
exceeding 90 degrees and a 50-80% chance of exceeding 95
degrees. In a warmer outcome (90th percentile), highs could
approach 100 degrees, particularly in urban locations where the
heat island effect may amplify temperatures.

Overnight lows will stay in the 50s for most locations, but
Saturday and Sunday nights could remain in the low 60s,
particularly in urban areas. These warmer overnight
temperatures, combined with persistent daytime heat, contribute
to a moderate HeatRisk for much of the interior Saturday through
Monday. While not extreme, the prolonged heat may still pose
health risks to sensitive populations. Coastal areas will remain
cooler with highs mostly in the low to mid 70s, though some
locations could briefly reach the upper 70s depending on wind
direction.

Breezy afternoon winds are expected daily, occasionally gusting
to 15-20 mph in the valleys. These winds could provide modest,
localized relief from the heat but will not significantly affect
overall warming.

By Monday and Tuesday, ensemble and cluster guidance suggest a
gradual transition to a more zonal flow pattern. This will allow
for a slight moderation in temperatures, though inland areas are
still expected to remain above seasonal norms. Mondays highs
will likely remain in the mid to upper 80s, maybe up to 90
degrees in urban areas, followed by a drop into the low 80s
Tuesday. Coastal temperatures are expected to hold steady
through early next week.
~Hall

&&

.AVIATION...Satellite imagery as of 1745z Thu depicts MVFR stratus
clouds across northwest Oregon gradually dissipating. Skies have
begun to clear across the Coast Range and Cascades, and parts of the
coast. Expect the stratus deck across the Willamette Valley and
north Oregon coast to break out by 19-21z as daytime heating
progresses, returning VFR conditions. High pressure will lead to
sunny skies for inland terminals. There is more uncertainty among
guidance with whether or not VFR conditions return along the central
Oregon coast this afternoon. Could see a mix of MVFR/VFR CIGs
between 21z Thu to 03z Fri around KONP as marine stratus lingers
just offshore. North-northwesterly winds across the region will
generally be around 10 kt or less, except along the coast and
southern Willamette Valley where tighter pressure gradients will
lead to 10-15 kt winds with gusts up to 20 kt.

PDX AND APPROACHES...MVFR stratus expected to lift by 19-20z Thu.
Conditions improve to VFR with sunny skies this afternoon. High
clouds return tonight. Northwest winds around 10 kt or less through
this evening, weakening overnight.        -Alviz

&&

.MARINE...Very little change as high pressure persists offshore
through the weekend. This will maintain breezy northerly winds
across the coastal waters, strongest in the afternoon and evening
hours. The thermally induced low pressure trough over the south
Oregon coast strengthens again later this afternoon. This will
tighten pressure gradients across the waters, with gusts up to 25 kt
becoming more widespread. Have included the inner coastal waters
south of Cape Falcon in the Small Craft Advisory for this afternoon
through tonight. With similar conditions continuing through Friday,
have also extended the advisory for the outer waters through Friday
evening.

The general sea state will continued to be dominated by northerly
wind waves and northwesterly swell through Sunday with significant
wave heights around 5 to 8 ft and a dominant wave period around 8-11
seconds. Seas will be steep and choppy during the afternoon and
evening hours when winds are strongest. /DH

&&

.PQR WATCHES/WARNINGS/ADVISORIES...

OR...None.
WA...None.
PZ...Small Craft Advisory from 2 PM this afternoon to 5 AM PDT
     Friday for PZZ252-253-271.

     Small Craft Advisory until 11 PM PDT Friday for PZZ272-273.
&&

$$

www.weather.gov/portland

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