Area Forecast Discussion
Issued by NWS Portland, OR

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531
FXUS66 KPQR 182150
AFDPQR

Area Forecast Discussion
National Weather Service Portland OR
250 PM PDT Thu Oct 18 2018

.SYNOPSIS...High pressure over the region will continue to produce
mild days, cool nights and mostly clear skies before a more active
storm track brings periods of rain next week.

&&

.SHORT TERM...Today through Sunday...Not a whole lot in the way of
forecast changes in the short term. There continues to be an area of
upper level high pressure centered over the eastern Pacific. Models
are in a good agreement it will expand northward before traversing
eastward across the Pacific Northwest over the weekend. This will
result in a continuation of the warm days, cool nights and mostly
clear skies through the weekend across the interior.

Along the coast it will be a different story, though. This morning`s
stratus clouds have generally temporarily retreated to just the
beaches this afternoon but will come back to the entire coast quickly
this evening and into Friday again. This will greatly reduce high
temperatures along the coast when compared to the past few days. With
that said, thermal low pressure will temporarily shift towards the
coast Friday night, which should result clearing Friday night into
Saturday before possibly returning Sunday.

For those tired of the east winds near the mouth of the Columbia
River Gorge, the good news is that they`re done for now with
Troutdale reporting light and variable winds this afternoon. However,
the respite in the east winds will be brief as they should return as
early as Friday and linger through the weekend, although they won`t
be as strong as they were earlier this week.

The weekend looks like more of the same as the upper high finally
moves directly over the local area and then begins to push east.
Expect light offshore or dry northerly winds, becoming more light and
variable Sunday ahead of an actual upper trough arriving early next
week. Overall, continued mild and dry throughout the short term
period.

.LONG TERM...Sunday night through Thursday...The persistent upper
level high pressure over the region through the short-term period is
modeled to finally push east of the Cascades early next week. Expect
one more warm and dry day for most of the area on Monday. However,
it appears that a southerly marine surge will be working its way up
the coast Sun night into Mon, which should keep the coast mostly
cloudy and cool. The fcst models are then in good agreement that a
frontal boundary will move onshore during the day Tue and push
through the region Tue night. There does not appear to be very
impressive forcing aloft once the front moves onshore, with the
models suggesting that moisture will be rather shallow with
precipitation remaining generally light east of the Coast Range. The
Tue front appears to usher in a much more progressive and typical
late-October pattern, with additional systems to bring precipitation
chances at times through the remainder of the week. Expect generally
cool and cloudy weather to persist from Tue through the end of next
week. Pyle

&&

.AVIATION...VFR SKC inland through this evening. VFR conditions
along the coast look to continue until the evening. Look for a
return to IFR conditions this evening along the coast, and will
continue into Friday morning. Patchy fog is possible for the
interior valleys after 09Z Fri.

KPDX AND APPROACHES...VFR SKC through the overnight hours. Patchy
fog is possible during the late night to early Friday morning
hours.

&&

.MARINE...High pressure continues to be the dominate feature off
the coastal waters, and will continue to be the dominate feature
through the weekend. Models are in agreement that as this high
pushes on land, expect to see wind speeds. First in the southern
outer waters, followed by the northern outer waters. As a result
have put out a small craft advisory for winds during this period
of time.

Models in the extended time period continue to be in agreement,
that a deep low coming from the Gulf of Alaska, could bring Gale
Force winds to our waters by the middle of next week.

Seas will continue to hold around 6 to 7 feet through Friday, but
will start to ease to around 4 to 5 feet during the weekend. Then
building back to 10 feet by the middle of next week.

&&

.PQR WATCHES/WARNINGS/ADVISORIES...
OR...None.
WA...None.
PZ...Small Craft Advisory for winds from 2 AM Saturday to midnight
     PDT Saturday night for Waters from Cape Shoalwater WA to
     Cascade Head OR from 10 to 60 NM.

     Small Craft Advisory for winds from 3 PM Friday to midnight PDT
     Saturday night for Waters from Cascade Head to Florence OR
     from 10 to 60 NM.

&&

$$

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This discussion is for Northwest Oregon and Southwest Washington
from the Cascade crest to 60 nautical miles offshore. This area is
commonly referred to as the CWA or forecast area.



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