FXUS66 KPQR 192200
AFDPQR

Area Forecast Discussion
National Weather Service Portland OR
300 PM PDT Tue May 19 2026

.SYNOPSIS...Dry and benign weather is expected across the 
region through much of the next week with high pressure
remaining in place over the Northeast Pacific. Weak systems 
aloft may bring enhanced cloud cover on some days, but rain 
chances are minimal. Uncertainty in the forecast increases 
Sunday into Monday as chances for precipitation return.

&&

.DISCUSSION...Now through Monday night...Broad upper-level
ridging continues to build over the Northeast Pacific with
persistent northwesterly flow streaming onshore from the Gulf of
Alaska. This pattern will remain largely the same through
Wednesday, with weak upper shortwaves bringing marine air inland
and allowing pockets of mist or drizzle along the coast through
the overnight and early morning hours. Temperatures will remain
seasonable, around 60 degrees on the coast and near 70 degrees
along the I-5 corridor. As offshore ridging shifts east late in
the week, temperatures will trend warmer, reaching the 60s to 
near 70 degrees on the coast and upper 70s to mid 80s inland. 
This will support widespread Minor HeatRisk excepting only the 
immediate coast and high Cascade crest. Chances for Moderate
HeatRisk are 20-35% in Portland and the adjacent northern
Willamette Valley, 5-20% in Salem and Albany/Corvallis, and 5%
or less elsewhere. Concerns for hazardous weather otherwise
remain low.

Friday through the holiday weekend, uncertainty in the evolution
and possible break-down of the upper-level ridge yields growing
uncertainty in forecast temperatures and precipitation. In 
general, as the ridge deamplifies, temperatures are more likely 
to trend cooler through the period, especially by Monday. The
80%-confidence envelope (the difference between the 10th and 
90th percentiles) in temperature widens from 8-13 degrees on
Friday and Saturday to 13-19 degrees on Sunday and Monday along
the I-5 corridor, with warmer scenarios resulting from a more
persistent ridge and cooler scenarios from a more rapid break 
down. There continues to be greater consensus of an upper-level 
trough digging over the Northeast Pacific on Monday, supporting 
much cooler temperatures and 30-60% chances for rain across the 
region, with the highest chances to the north of US-20 and in 
areas of higher terrain. -36 

&&

.AVIATION...An upper level ridge offshore will maintain
northwesterly flow across the airspace. Current satellite and 
surface observations (as of 16Z Tue) show generally VFR 
conditions with pockets of MVFR for inland locations and mostly 
VFR conditions with MVFR/IFR conditions for locations north of 
KONP. These conditions are expected to persist through the 
majority of the TAF period. It should be noted that guidance is 
showing a very weak, upper level disturbance, around 09Z-12Z Wed
that could result in lowered flight conditions (IFR/LIFR) along
the coast as well as some MVFR conditions backbuilding along 
the Cascades and pushing eastward into the Willamette Valley. 
This is resulting in a 45-65% chance for IFR conditions along 
the coast, a 25-35% chance for LIFR and a 35-55% chance for MVFR
conditions for inland locations. If these conditions manifest, 
improvement in overall flight conditions across the airspace 
should start towards the very end of the TAF period. 

North/northwest winds 6-10 kt persist through the TAF period
with gusts up to 20 kt possible along the coast starting 
around 20Z-22Z Tue through around 04Z Wed.

KPDX AND APPROACHES...Predominately VFR conditions expected 
through the majority of the TAF period. Guidance shows 
backbuilding clouds along the Cascades pushing eastward starting 
around 09Z Wed. This is resulting in a 35-55% chance for MVFR 
conditions developing and impacting the terminal. If these 
conditions manifest, improvement towards VFR starting around 18Z
Wed. North/northwest winds 6-10 kt persist through the TAF 
period. -42

&&

.MARINE...Northerlies are expected to persist through much of 
the week as the summer-like pattern settles in. Strongest winds 
are expected during the afternoon and evening periods as a 
surface thermal trough strengthens over the region. Therefore, 
have updated the current suite of Small Craft Advisories as 
gusts up to 25 kt are expected across all zones with the 
exception of PZZ251, this afternoon and Wednesday afternoon. 
Seas 6 to 9 feet are expected through the week as well. Chances 
increase on Thursday and Friday for widespread wind gusts for 
all marine zones.

Small Craft Advisories are in place for the Columbia River Bar 
Wednesday morning due to strong/very strong ebb currents which 
will produce conditions hazardous to small craft. Strong/very
strong ebb currents are possible during the morning hours each 
day this week. -42/DH

&&

.PQR WATCHES/WARNINGS/ADVISORIES...

OR...None.

WA...None.

PZ...Small Craft Advisory from 6 AM to 10 AM PDT Wednesday for 
     PZZ210.

     Small Craft Advisory until 2 AM PDT Wednesday for PZZ252-253-
     271-272.

     Small Craft Advisory from 4 PM to 9 PM PDT Wednesday for 
     PZZ252-271-272.

     Small Craft Advisory from 1 PM to 9 PM PDT Wednesday for 
     PZZ253.

     Small Craft Advisory until 9 PM PDT Wednesday for PZZ273.

&&

$$

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