016
FXUS66 KPQR 100958
AFDPQR

Area Forecast Discussion
National Weather Service Portland OR
256 AM PDT Wed Jul 10 2024

.SYNOPSIS...Finally, the heat has ended. Well, mostly. Will still
have a warm day across the interior, but highs mainly in the 80s to
middle 90s for the warmest spots. Lot cooler along the coast, where
low clouds and fog will keep it in the 50s to middle 60s today.
Overall, not much change through rest of the week, as high pressure
will maintain dry condition, with warm temperatures inland. But,
again, not as hot as recent days.
&&

.DISCUSSION...(Today through next Tuesday)...Finally, a long awaited
change in the weather pattern. Increasing southwest flow offshore
into the Pacific NW has pushed the pesky hot upper ridge east of the
region, with its axis now over Idaho southward over the Great Basin
states. With this shift, will also see an uptick in the onshore flow.
As of 2 am, marine low clouds and even fog blanketed the coastal
regions, with those clouds jamming up into the coastal river valleys
of the western Coast Range and Willapa Hills. That will keep the
coastal region cooler, with highs in the 50s to upper 60s.

But, onshore flow is not strong enough to push the clouds too far
inland. As such, will just have the moderating effect of high
humidity as that ocean air seeps inland. But, that, along with the
heart of the ridge to the east, will bring more manageable
temperatures to the interior. Overall, most areas inland will see
temperatures get into the middle 80s to middle 90s inland, with the
warmest being from Portland to Salem area, and towards the Hood River
valley.

Overall, not much pattern change through rest of the week into the
coming weekend, as will maintain warm southwest flow aloft. This will
keep inland areas warm, with highs in the 80s to lower 90s.
Interestingly, models still hinting that afternoon highs very well
could be around or just above 90. Model guidances suggests that there
is a 50-75% chance that temperatures will top out above 90. Best
chance of staying below 90 is Thursday, as least wise until next
week. This table shows the chance for high temperatures being above
90 deg for select spots across the region:

Chance of Daily MAX Temperature being above 90....
          WED    THU    FRI    SAT  SUN MONTUE
Kelso      15%     1%    10%    20%  10%  5% 1%
Portland      95%    40%    60%    75%  65% 45%25%
Salem     100%    45%    65%    90%  65% 60%30%
Eugene     100%    45%    65%    80%  60% 50%25%
Hood River   100%    80%    90%    95%  85% 60%30%

Finally, there is general agreement in the ensemble guidance that
core of the high pressure will shift from southern Nevada (WED/THU)
more towards the Four Corners region for FRI into this weekend. This
will open the door to monsoonal moisture working its way around the
high pressure. At this point, most ensemble guidance suggests the
moisture and thunderstorm chances will remain well south and east of
the region, but there is a 5-10% chance that the thunderstorm threat
impacts our Cascades by the end of the weekend.  Longer range shows
that will see uptick of onshore flow next week, with temperatures
across the region being more seasonal. That is, with 60s to lower 70s
on the coast, and lower to middle 80s inland. Ahh, welcome news for
those weary of the hot weather of the past 5 days.  /Rockey

&&

.AVIATION...High pressure over the region continues to slowly
move eastward this morning. VFR conditions will prevail for
inland locations. Coastal locations have developed low stratus/fog
as of 03-06Z Wednesday, with chances of these IFR/LIFR conditions
to persist around 70-80%, until 18-20Z Wednesday. Conditions may
improve to VFR thereafter (still a 30-40% probability of MVFR),
but conditions look to lower back to IFR by 02-04Z Thursday.
Light N/NW winds this morning, expected to increase to 5-10 kt
with gusts up to 20-25 kt by 19Z-21Z Wednesday.

PDX AND APPROACHES...High pressure will maintain VFR under clear
skies, with light onshore flow this morning. Winds will increase
to around 5-10 kt with gusts up to 20 kt by 19-21Z Wednesday.
-JH

&&

.MARINE...High pressure continues to move east, resulting in
gradually
decreasing pressure gradients. Seas will mainly be wind-driven,
between 3 to 5 feet. Pressure gradients tighten again Wednesday
evening, increasing winds into small craft advisory criteria.
Given confidence is high, a Small Craft Advisory has been issued
to go in effect from 5 PM Wednesday to 2 PM Thursday for all inner
and outer waters. Seas will remain between 5 to 7 ft through this
timeframe.
-JH
&&

.PQR WATCHES/WARNINGS/ADVISORIES...

OR...None.
WA...None.
PZ...Small Craft Advisory from 5 PM this afternoon to 2 PM PDT
     Thursday for PZZ251>253-271>273.
&&



$$

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