340
FXUS66 KPQR 301015
AFDPQR

Area Forecast Discussion
National Weather Service Portland OR
315 AM PDT Mon Jun 30 2025

.SYNOPSIS...
Hot weather continues today and Tuesday, with today shaping up
to be the hottest day of the week. Expect widespread highs in
the low to mid 90s across the interior valleys. A few isolated
thunderstorms are possible over the Lane County Cascades this
evening and again Tuesday. Cooler conditions return by midweek,
although temperatures will still stay a bit above normal for
early July.

&&

.DISCUSSION...Now through Friday...
As of early this morning, skies remain mostly clear inland
across northwest Oregon and southwest Washington. High pressure
extending from the Desert Southwest continues to strengthen over
the region, setting the stage for a hot day ahead.

Inland areas - particularly the Willamette Valley - are expected
to reach the low to mid 90s today. Based on the latest data,
there is a 70-90% chance of temperatures hitting at least 95
degrees for communities north of Corvallis, and a 50-70% chance
for areas to the south. Additionally, there is a 30-50% chance
of reaching 100 degrees in a corridor stretching from Salem to
Tualatin, and a 5-10% chance for most other inland locations.
Overnight lows have stayed relatively mild in most places,
cooling into the upper 50s to low 60s. However, areas like the
Columbia River Gorge have stayed warmer, with lows only in the
low 70s - enough to push HeatRisk into Major for today.

While this stretch of heat is not long enough to meet official
heat advisory criteria, it can still pose risks - especially for
those without air conditioning or spending prolonged time
outdoors. Please take precautions and check on vulnerable
individuals.

Looking at thunderstorm potential: high pressure is helping to
pull some monsoonal moisture northward from the Desert
Southwest. Most of this moisture will likely remain south and
east of our region, but there is a 10-20% chance that a few
storms could develop over the Lane County Cascades later today
into tonight, and again Tuesday afternoon and evening. If storms
develop, lightning and gusty winds would be the main concerns.

Relief is on the way by Wednesday, as the high pressure system
shifts east and a weak trough starts to influence our weather.
This will bring cooler air and a return of weak onshore flow.
Expect highs in the low to mid 80s inland and 60s to low 70s
along the coast through the end of the workweek. While not
dramatically cooler, this pattern will be more comfortable
compared to the early-week heat.
~Hall

&&

.AVIATION...Widespread VFR conditions expected to dominate inland
locations throughout the period under mostly clear skies. However,
satellite and land based observations are showing a strip of
marine clouds just off the coast. This is resulting in IFR/LIFR
conditions along the coast through around 17Z-19Z Monday.
Northerly winds have fallen to around 6 to 10 kt or less, but
expect gusty winds to return around 17Z-19Z Monday. Expect gusts
up to 30 kts along the coast and up to 25 kts inland through at
least 04Z-06Z Tuesday.

PDX AND APPROACHES...VFR with northerly winds. Gusts up to 20 kt
return around 17Z Monday through around 06Z Tuesday. /42

&&

.MARINE...Broad high pressure over the area is resulting in a
typical summer time wind pattern. Northerly winds will persist
through at least Tuesday morning with gusts up to 30 kt expected.
Higher gusts are expected in zones PZZ273, PZZ272, PZZ253, PZZ252.
Gusts up to 25 kt expected elsewhere. These wind speeds may not
be observed by the local buoys. General seas slowly building
towards 7 to 9 feet through early Tuesday. Seas and winds
expected to subside below Small Craft conditions starting around
Wednesday as the broad high pressure system starts to weaken and a
low pressure system starts to move inland Wednesday/Thursday near
the OR/CA border.

Given this information, have maintained the current suite of
Small Craft Advisories across all waters to include the Columbia
River Bar. Also, with a wind dominated pattern, expect conditions
to be steep and choppy at times. Current guidance does have
conditions improving along and near the Columbia River Bar
this evening, while all other locations will maintain Small Craft
Conditions. /42

&&

.PQR WATCHES/WARNINGS/ADVISORIES...

OR...None.
WA...None.
PZ...Small Craft Advisory until 11 PM PDT this evening for PZZ210.

     Small Craft Advisory until 8 AM PDT Tuesday for PZZ251>253-
     271>273.
&&

$$

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