988
FXUS66 KPQR 302213
AFDPQR

Area Forecast Discussion
National Weather Service Portland OR
313 PM 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 Tuesday afternoon. Conditions cool to near to slightly
above normal for early July for midweek into the weekend.

&&

.DISCUSSION...Monday afternoon through Sunday...Observed
temperatures at 3pm Monday are in the low 90s for locations east
of the Coast Range, though marine stratus lingering right along
the coast is keeping coastal temperatures in the upper 50s to
low 60s. Inland temperatures are on track to peak in the mid-90s
late this afternoon as high pressure over the Desert Southwest
builds northwest into Oregon and Washington. Temperatures on
Tuesday are expected to be around 5 degrees lower than today,
peaking in the upper 80s to around 90 degrees. Thunderstorm
chances for the Lane County Cascades have diminished for tonight
as latest guidance keeps the main forcing and moisture south of
the county, though a few showers could still form between 5 PM
tonight through 5 AM Tuesday. Latest guidance indicates a
shortwave along the cutoff low pressure system over California
will move just north enough tomorrow afternoon to bring enough
monsoonal moisture north into central Oregon as well as
providing enough lift for a 15-25% chance of thunderstorms over
the Lane and Linn County Cascades tomorrow afternoon.

Weak troughing moving into the PacNW Tuesday night into
Wednesday pushes the high pressure back to the east, allowing
daytime temperatures to fall into the low 80s. Ensemble guidance
is in good agreement that weak longwave troughing will linger
over the region through the end of the week and into the holiday
weekend, bringing the return of onshore flow and near-seasonal
temperatures for early July. Daily normal high temperatures are
around 78-81 degrees across the Willamette Valley from July 1-6.
High temperatures are forecast around 79-82 degrees across the
Willamette Valley Wednesday through Sunday with little spread in
the ensemble data. With the return of onshore flow, could also
see the return of more widespread morning stratus across inland
areas, as well. -HEC

&&

.AVIATION...Satellite imagery as of early Monday afternoon depicts
lingering stratus along the coast with persistent LIFR/IFR
conditions at KONP. High pressure will maintain VFR conditions
with mostly clear skies for Willamette Valley terminals through
the TAF period. Will see some increasing high clouds tonight from
the south, in addition to a return of LIFR/IFR marine stratus.
Surface pressure gradients tighten this afternoon, strengthening
north/northwest winds across the area with gusts up to 25 kt at
any given terminal. Winds gradually ease after 03-06z Tue.

PDX AND APPROACHES...VFR with mostly clear skies through the TAF
period. Some high clouds this evening. Northwesterly winds 10-15
kt with gusts up to 25 kt this afternoon/evening.      -Alviz

&&

.MARINE...High pressure will maintain northerly winds across the
waters through the week, breeziest today and Tuesday. Small Craft
Advisories remain in effect across all marine zones through 1700
Tuesday, with northerly winds forecast to gust up to 30 kt. An
exception is the Columbia River Bar, where the Small Craft
Advisory ends 2300 Monday due to winds easing below 20 kt. The
strongest winds over the waters are forecast south of Cape Falcon,
where pressure gradients are tightest. Expect steep and choppy seas
8 to 10 ft at 7-8 seconds through Tuesday. Seas subside to around
4-6 ft mid-week onward as winds weaken.        -Alviz

&&

.PQR WATCHES/WARNINGS/ADVISORIES...
OR...None.
WA...None.
PZ...Small Craft Advisory until 11 PM PDT this evening for PZZ210.
     Small Craft Advisory until 5 PM PDT Tuesday for PZZ251>253-
     271>273.

&&

$$

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