432
FXUS66 KPQR 100945
AFDPQR

Area Forecast Discussion
National Weather Service Portland OR
245 AM PDT Tue Jun 10 2025

.SYNOPSIS...A pattern change aloft will see a steady transition
to cooler weather through the week as onshore flow strengthens.
Largely dry conditions continue into the weekend, with the next
chance for widespread rain not expected until next week.

&&

.SHORT TERM...Now through Friday Night...One final day of warm
to hot temperatures is in store across inland portions of the
region as the upper-level ridge of recent days continues to
shift eastward toward the Central Plains while upper-level
troughing begins to develop over the Pacific Northwest. Cooler
air will steadily push into the region on strengthening onshore
flow, yielding afternoon high temperatures trending downward
through Friday. Temperatures today will still reach afternoon
highs in the mid to upper 80s across inland valleys today, some
15-20 degrees above normal, while areas of higher terrain see
70s and the coast remains in the upper 50s to mid 60s. The
hottest temperatures around 90 degrees are expected along the
central Columbia Gorge to around Hood River, where locally
Moderate HeatRisk may still present hazardous conditions for
those without effective cooling and/or adequate hydration. Those
seeking relief from the heat in area lakes and rivers should
continue to be aware that water temperatures remain cold and
hypothermia can occur despite hot air temperatures.

The risk of hazardous heat quickly drops through the workweek as
afternoon highs across inland valleys fall by about 4-8 degrees
each day, reaching seasonable values in the low 70s by Friday.
Overnight lows similarly trend downward by 2-3 degrees each
night from upper 40s to low 50s tonight to low to mid 40s on
Friday night. Elsewhere, temperatures similarly trend cooler
albeit at a slower rate. Largely dry weather is expected aside
from areas of mist or drizzle possible along the coast. Stronger
onshore flow may also yield periods of breezier conditions with
westerly to northwesterly gusts reaching 20-30 mph in Coast
Range gaps and the central Columbia Gorge. -Picard


.LONG TERM...Saturday through Monday...There is a growing
consensus among long-range ensembles that a closed upper low
will track to the southeast from south-central Alaska toward the
Haida Gwaii this weekend. Repeated shortwave impulses on the
southern flank of the low may bring chances for light rain to
the region this weekend, but few ensemble members suggest much
in the way of accumulations until early next week when a more
robust shortwave could bring the best chance for widespread
accumulating rain in almost two weeks. -Picard

&&

.AVIATION...Clear skies and VFR conditions across most of the
region continue as high pressure lingers throughout the airspace.
The coast will differ, with mostly MVFR/IFR conditions through
the TAF period, specifically before 18Z Tuesday and after 02Z
Wednesday. Probabilistically, both KAST and KONP have a 50-70%
chance of MVFR conditions during the aforementioned times.
However, both terminals differ in terms of IFR and LIFR chances,
with a 10-20% chance of IFR and less than 10% chance of LIFR at
KAST, and a 30-50% chance of IFR and a 10-20% chance of LIFR at
KONP.

Otherwise, expect light northwesterly winds around 5 kt to
increase to 5-10 kt around 22Z Tuesday and persist until 04-06Z
Wednesday. KONP may experience slightly stronger winds, around
8-13 kt with gusts up to 21 kt.

PDX AND APPROACHES...VFR conditions and clear skies through the
TAF period. Light northwesterly winds around 3-5 kt becoming 7-9
kt with gusts up to 15 kt possible between 22Z Tuesday and 06Z
Wednesday. ~Hall

&&

.MARINE...Little change in the forecast as surface high pressure
centered well offshore maintains a northerly wind regime through
the end of the week. Current observations show winds gusting to
20-25 kt over the coastal waters, with seas running 8-9 ft due
to a combination of short period wind waves and building
northwest swell. These conditions will maintain Small Craft
Advisories through at least Wednesday and possibly beyond as
combined seas generally remain in the 7-9 ft range for the next
several days. Additionally, the Columbia River Bar will have
strong ebb chop this morning until 8 AM so have issued a Small
Craft Advisory. Another Small Craft Advisory may be needed for
tomorrow morning between 2 AM and 8 AM as strong ebb chop will
return. ~Hall/CB

&&

.PQR WATCHES/WARNINGS/ADVISORIES...

OR...None.
WA...None.
PZ...Small Craft Advisory until 8 AM PDT this morning for PZZ210.
     Small Craft Advisory until 11 PM PDT this evening for
     PZZ251>253.
     Small Craft Advisory until 5 PM PDT Wednesday for PZZ271>273.

&&

$$

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