766
FXUS66 KPQR 011742 AAA
AFDPQR

Area Forecast Discussion...UPDATED
National Weather Service Portland OR
1042 AM PDT Tue Jul 1 2025

Updated aviation discussion.

.SYNOPSIS...
Hot and dry weather continues today, though cooler than Monday.
Highs will still reach into the upper 80s to around 90 degrees
across the interior. Isolated thunderstorms remain possible
across the Lane and Linn County Cascades this afternoon and
evening. A cooling trend begins midweek, bringing more
seasonable conditions through the weekend. There are signs that
warmer temperatures may return early next week as upper level
ridging begins to rebuild.


&&

.DISCUSSION...Now through Monday...As of early this morning, skies
are mostly clear across northwest Oregon and southwest Washington,
with marine stratus confided to the immediate coast. The strong upper
ridge that brought Mondays peak heat is now beginning to shift
eastward as a weak trough approaches from the Pacific. Temperatures
today will still be warm but a few degrees lower than yesterday.
Inland highs are expected to top out in the upper 80s to near 90
degrees. The hottest locations on Monday reached the mid 90s,
but those values are not expected to repeat today.

There remains a 15-25% chance for isolated thunderstorms across
the Lane and Linn County Cascades this afternoon and evening. A
weak shortwave rotating around a cutoff low over California may
bring just enough lift and monsoonal moisture into central
Oregon to support convective development. Any storms that form
could produce lightning, gusty outflow winds, and small hail,
posing a hazard to recreation and outdoor activity in the
Cascades.

By tonight and into Wednesday, the upper ridge continues to
weaken and shift east as troughing takes hold across the Pacific
Northwest. This will bring cooler, more stable conditions with a
return to weak onshore flow. Expect inland highs in the low 80s
and coastal areas holding in the 60s to low 70s.

This cooler pattern appears likely to persist into the holiday
weekend, with ensemble guidance in strong agreement on broad
troughing through at least Saturday. Highs in the Willamette
Valley are expected to range from the upper 70s to low 80s,
which is near to slightly above early July climatological
norms. Persistent onshore flow may also promote morning marine
stratus, especially in low lying interior areas.

By Monday of next week, ensemble guidance begins to suggest a
transition toward zonal flow, with indications of upper level
ridging re-establishing over the western US. However, ensemble
clusters begin to diverge significantly beyond Sunday,
introducing forecast uncertainty for the early part of next
week. Inland temperatures may begin to rebound, potentially
returning to the upper 80s, though confidence in the magnitude
and timing of this warming is still limited. Surface winds are
expected to remain north to northwesterly both along the coast
and inland, which may help maintain marine influence in some
areas. ~Hall

&&

.AVIATION...Latest satellite imagery shows a continued narrow
strip of marine stratus resulting in IFR/LIFR cigs at KAST and
KONP. Coastal stratus coverage will diminish through the day,
however IFR cigs will remain favored at KONP while breakouts to
VFR are more likely to the north, including KAST. Inland, VFR
conditions will continue under mostly clear skies. Isolated
thunderstorms along and east of the Cascade crest later this
afternoon may result in high clouds associated with convective
debris, however cigs would remain VFR for inland terminals.
Diurnal winds out of the N to NW will increase to 15-20 kt gusting
to 25 kt along the coast, and to 10-15 kt with gusts reaching 20
kt along the Lower Columbia including KPDX this afternoon. Winds
will ease tonight.

PDX AND APPROACHES...VFR conditions will continue through 18z
Wednesday under mostly clear skies. Diurnal NW winds increase to
10-15 kt after 18-20z Tue, with gusts of 20-25 kt this afternoon
and evening from 21z Tue-04z Wed, before subsiding to 8-10 kt
after 06z Wed. -TK/Picard

&&

.MARINE...Persistent surface high pressure offshore will see
northerly to north-northwesterly winds persist across the waters
throughout the next week. Breeziest conditions are expected today,
with gusts up to 25 kt through this evening most likely south of
Cape Foulweather, easing to 15-18 kt or less by tomorrow. Small
Craft Advisories remain in effect through 5 PM this afternoon
north of Cape Falcon, and through 11 PM this evening from Cape
Falcon south to Florence. Choppy seas of 7-9 ft at 7-8 seconds
will continue through today, before subsiding to 3-6 ft tomorrow
through the weekend as winds weaken. -Picard

&&

.PQR WATCHES/WARNINGS/ADVISORIES...

OR...None.
WA...None.
PZ...Small Craft Advisory until 5 PM PDT this afternoon for PZZ251-
     271.

     Small Craft Advisory until 11 PM PDT this evening for
     PZZ252-253-272-273.
&&

$$

www.weather.gov/portland

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