Area Forecast Discussion
Issued by NWS Portland, OR

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FXUS66 KPQR 261616
AFDPQR

Area Forecast Discussion
National Weather Service Portland OR
915 AM PDT Fri May 26 2017

.SYNOPSIS...An upper level ridge of high pressure will build over
the region today bringing dry and warm conditions.  The ridge of
high pressure will maintain it`s presence over the region through
the Memorial Day holiday weekend. Afternoon high temperatures will
remain well above normal. High pressure shifts eastward early next
week ahead of the next approaching disturbance. Temperatures trend
gradually cooler with a return of rain chances during the second
half of next week as a disturbance tracks across the Pacific
Northwest.

&&

.SHORT TERM...Today through Sunday...An upper level ridge currently
offshore will continue to shift eastward today, with the ridge axis
near the coast by this evening and over the Pacific Northwest and
Great Basin over the weekend. With high pressure over the region,
temperatures in the Willamette Valley will be in the lower 80s today
and in the mid to upper 80s over the weekend.  NWP models show a
southerly wind reversal along the coast tonight bringing a weak
surge of marine stratus northward along the coast to around Pacific
City. This may keep Saturday`s temperatures a little bit cooler
along the central coast than the high pressure pattern might
otherwise suggest. Some uncertainty as to whether the marine air
will spill through the coastal gap into the southern Willamette
Valley later tonight. If so, the Eugene area could see low cloud
cover Sat morning and thus cooler afternoon temperatures. Will
evaluate further with 12z model runs. tw/Bowen

.LONG TERM...No Changes. Previous discussion follows...Sunday night
through Thursday. Little change to the overall pattern for the
Memorial Day holiday, with the upper level high pressure still
squarely positioned over western U.S. and temperatures remaining
around 20 degrees above seasonal normals, at least inland. However,
by Monday night into Tuesday, heights begin to lower ahead of the
next approaching disturbance. Some discrepancies among the models
with respect to timing and strength of this feature, so for now have
trended the forecast in line with a blend of models for Tuesday and
Wednesday. However, confidence in the forecast during the breakdown
of the ridge is a bit lower than average. Nonetheless, expect a
cooling trend back to near or perhaps slightly below normals for the
start of June. Tweaked the forecast in the extended period, but
overall the trend has remain consistent, even with the model
discrepancies. Bowen/Cullen

&&

.AVIATION...VFR conditions through the day today. Some IFR
stratus possible along the coast again tomorrow morning.

KPDX AND APPROACHES...VFR today and tonight. /Bentley
&&

.MARINE...Winds will remain below Small Craft Advisory criteria
well into next week, but there may be a few times with gusts near 20
kt in parts of the coastal waters such as this afternoon and
evening, late Sunday, and again Monday afternoon and evening.

Seas were very slow to come down below 10 ft, and have been running
around 2 ft above wave model guidance since early Thursday. Seas are
finally below 10 ft and are expected to continue to subside a couple
more feet as they remain below 10 ft well into next week. We do have
very strong ebbs right now and this will push the Columbia River Bar
to require a Small Craft Advisory for a Rough Columbia River Bar
during those times. pt

&&

.PQR WATCHES/WARNINGS/ADVISORIES...
OR...None.
WA...None.
PZ...Small Craft Advisory for Rough Columbia River Bar from 4 AM to
     9 AM PDT Saturday.

&&


$$

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


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