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000
FXUS66 KPQR 301634
AFDPQR

Area Forecast Discussion
National Weather Service Portland OR
933 AM PDT Mon May 30 2016

.SYNOPSIS...An upper level ridge will build into the Pacific
Northwest today, bringing clearing skies and drying weather to
southwest Washington and northwest Oregon. The ridge will produce
warming temperatures over the next couple of days with light offshore
flow pushing inland temps close to 90 on Tuesday. Onshore flow will
start to develop Wednesday to take the edge off the heat. Though
daytime temperatures will be slightly cooler the latter half of next
week, they will remain well above normal.

&&

.SHORT TERM...(Today through Thursday)...The upper ridge of high
pressure seen in water vapor pictures along 130W early this morning
is expected to shift east to the coast by the end of the day, and
then inland over the Pacific NW by Tue. The classic cycle of a
thermal trough is the result, with models showing the trough of
thermally induced low pressure along the S Oregon coast building
north up the coast today and tonight, then shifting inland into the
Coast Range during the day Tuesday. With the resulting turn to
offshore flow, dry and mostly sunny weather is expected for the
region today and Tuesday. Temperatures will quickly warm well above
normal both today and Tuesday. Models continue to depict 850 mb
temperatures over the region climbing to around 18 degrees C by
Tuesday afternoon. This, in combination with offshore flow, will push
temperatures inland to around 90 degrees. Meanwhile, temperatures at
the coast will likely reach into the 70s relatively early in the day,
before flow turns onshore in the afternoon and the marine air will
prevent additional heating in the later afternoon hours.

The upper ridge continues to advance inland Tuesday night and
Wednesday and flattens out a bit, and the low-level flow will turn
more onshore as the surface trough pushes east of the Cascades.
Expect low stratus or fog to return to the coast Tuesday night as the
cooler marine air returns. This should noticeably modify temperatures
Wednesday along the coast, but temperatures inland will remain well
above normal and only cool a few degrees. The remnants of a weak
shortwave passing well to the north could bring some light showers
across the far northern and coastal portions of the area late
Wednesday through Thursday. Heights continue to fall just a bit, but
expect temperatures to remain around 80 inland on Thursday.   /Cullen

.LONG TERM...(Thursday night through Sunday)...The models have come
to the consensus that upper level ridging will persist through at
least Saturday. This will keep dry weather and warm temperatures over
the region, with afternoon highs at the coast in the upper 60s to
lower 70s. The interior will likely see highs stay in the 80s. With
overnight lows in the upper 50s to mid 60s and light winds expected
late next week we could be in for some unpleasant nights. However, a
slight onshore gradient should keep temperatures from getting out of
hand. Another weak shortwave on Sunday could bring a slight chance of
thunderstorms to the Oregon Cascades, but confidence remains low. /64

&&

.AVIATION...VFR conditions at all TAF sites through Monday night.
Gusty northwesterly winds at KAST and KONP this afternoon and
evening.

PDX AND APPROACHES...VFR conditions expected through Monday night.
 /Bentley

&&

.MARINE...High pressure in the northern Pacific will shift
northward Monday with a thermally induced low developing across
northern California and southern Oregon. This combination will
lead to gusty north winds this afternoon through Tuesday then
weakening on Wednesday. A small craft advisory in effect for all
waters through 12Z Tuesday and continues for the outer waters
through Tuesday evening. There will probably be small craft
advisory winds for the nearshore waters Tuesday afternoon and
evening.

Seas between 4 and 5 feet today and should become choppy
especially during the afternoon and evening with the stronger
diurnal winds. Seas will increase slightly due to a gusty
northerly fetch for the first half of the week, do not expect
this rise to be more than a couple of feet. /Bentley

&&

.PQR WATCHES/WARNINGS/ADVISORIES...
OR...None.
WA...None.
PZ...Small Craft Advisory for winds from 2 PM this afternoon to 11
     PM PDT Tuesday for Waters from Cape Shoalwater WA to
     Florence OR from 10 to 60 nm.

     Small Craft Advisory for winds from 2 PM this afternoon to 5 AM
     PDT Tuesday for Coastal Waters from Cape Shoalwater WA to
     Florence OR out 10 nm.

&&

$$

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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.





000
FXUS66 KPQR 290909
AFDPQR

Area Forecast Discussion
National Weather Service Portland OR
210 am PDT Sun May 29 2016

.SYNOPSIS...An upper level low pressure system over southern British
Columbia will persist today, bringing onshore flow to southwest
Washington and parts of northwest Oregon. This will keep a small
chance for some precipitation across the northern and coastal parts
of the forecast area. Upper level ridging will start to build Sunday
night, then strengthen Memorial Day and Tuesday, resulting in much
warmer and drier conditions. Daytime temperatures are expected to
cool a bit late in the week.
&&

.SHORT TERM...(Tonight through Tuesday)...A shortwave trough in
water vapor pictures was off the WA coast early Sun morning near
128w, rotating around the base of the BC upper level trough. Low
level flow was generally onshore across the forecast area, with a
fairly solid area of low clouds banked up against the coast and
coast range, and to a lesser extent the n part of the Cascades.
Surface observations and radar indicated scattered showers were
mainly over western WA and off the WA coast. As the shortwave moves
e across the Pacific NW today, will keep in some low pops for light
rain or drizzle this morning, mainly for areas where clouds had
already filled in. Will also hang on to a slight chance of showers
across the n this afternoon. Pops drop off quickly by evening as the
upper trough pushes off to the east, and ridging aloft begins to
build in from the west. With the trough brushing across and onshore
flow, may see high temps today a couple degrees cooler than Sat.

Mon and Tue models agree on the upper ridge shifting inland over the
Pacific NW. Low level flow turns more northerly, and eventually
offshore for most areas by Tue morning as a thermally induced
surface trough builds n up the Oregon coast. The trough appears
likely to move inland into the Coast Range by Tue afternoon, turning
flow back onshore on the coast. Dry weather and warming temps will
be the result, with inland high temps approaching 90 Tue afternoon
as model h8 temps rise to near 18 deg c. Should still be warm on the
coast Tue morning, before onshore flow brings cooling marine air in
the afternoon.

.LONG TERM...Tuesday night through Saturday...The upper level ridge
will persist over the Pac NW through Wednesday keeping temps on the
warmer side of things. Models continue to show 850mb temps near 20C.
With the thermal trough shifting inland slightly on Wednesday this
should allow temps in the interior to warm significantly, with
widespread afternoon highs around 90F likely. SW flow aloft through
the end of the week likely to keep the region dry. Although still
warmer than normal through the end of the week under ridging aloft,
onshore flow should provide some moderation in temps late in the
week.
&&

.AVIATION...Weak front over far northwest Oregon this am is
maintaining onshore flow. Mix of MVFR and VFR along the coast this
am, along with patchy drizzle. These clouds continue to work
inland up the Columbia River and over the Coast Ranges this am.
Still think will see these most inland extent of the MVFR clouds
may reach KPDX/KTTD by 13Z.

Other area of clouds over the Cascades continue to backbuild, with
that deck around 4000 ft. This deck will gradually break apart
between 18z and 20z, with scattered clouds inland after 21z.

PDX AND APPROACHES...A 4000 ft cloud deck will remain through 20z,
then break apart and scatter by 22z. While not likely, there is
small chance that will see scattered to broken clouds of 2000 ft
between 12z and 16z.                       TAFcaster...rockey.
&&

.MARINE...High pressure over the northeast Pacific will build
today and Monday. Meanwhile, thermal low pressure over NW
California will build north along SW Oregon coast. This will
bring typical early summer of gusty north to northwesterly winds,
with the strongest winds to south of Cascade Head. While may see a
few gusts 20 to 25 kt around Florence southward later today. But,
it appears strongest winds will be Mon and Tue
afternoons/evenings, where winds 15 to 25 kt to south of Cascade
Head. To north of Cascade head, may see a few gusts reach 25 kt,
but think will be few and far between. Northerly winds continue
for Wed to Fri, but appears gradients will be weaker, with winds
only 10 to 20 kt.

Seas hovering at 3 to 5 ft trough Monday am, but as winds pick up
so will the short period wind waves. will see seas 5 to 8 ft for
late Mon through Wed, with higher seas south of Cascade Head.

&&

.PQR WATCHES/WARNINGS/ADVISORIES...
OR...None.
WA...None.
PZ...None.
&&

$$

Interact with us via social media:
www.facebook.com/NWSPortland
www.twitter.com/NWSPortland

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.





000
FXUS66 KPQR 290358
AFDPQR

Area Forecast Discussion
National Weather Service Portland OR
858 PM PDT Sat May 28 2016

.SYNOPSIS...An upper level low pressure system over southern British
Columbia will persist through Sunday, bringing onshore flow to
southwest Washington and parts of northwest Oregon. This will keep a
chance for some precipitation across the northern parts of the
forecast area. Upper level ridging will start to build Sunday night,
then strengthen Memorial Day and Tuesday, resulting in much warmer
and drier conditions. Daytime temperatures are expected to cool a bit
late in the week.
&&

.SHORT TERM...(Tonight through Tuesday)...The models continue to show
a weak frontal zone will drag across the southwest Washington and
parts of northwest Oregon tonight and Sunday morning, bringing
areas of light rain or drizzle to the area. The best chances will be
along the north coast, with the next best areas in the north
interior areas such as Portland and Kelso as well as the central
Oregon coast, with the lowest chance in the south Willamette Valley.

After a nice day over most of the inland areas today with temps
climbing into the lower 70s, tonight and a good part of Sunday will
be cloudier with temps down about 5 or so degrees Sunday as compared
to today. The models show the clouds lifting some Sunday afternoon
and perhaps trying to thin, but the best clearing will take place
overnight Sunday night as an upper level ridge builds in.

The clearing Sunday night will lead to good radiational conditions
that will let temps cool off well down into the 40s most lower
elevation areas, as well as allow some patchy fog to form especially
near the coast but at some of our typical inland fog prone areas.

The upper ridge will bring warming and plenty of sunshine on Memorial
Day after any brief patchy morning fog or low clouds. Look for temps
inland to rebound well into the 70s on Monday.

Warm dry weather will continue into Tuesday with a thermal trough
building up the coast Monday night and moving over much of western
Oregon Tuesday. Per 850 mb temps, inland temps will push well up
into the 80s Tuesday, and even approach 80 at the coast before the
sea breeze kicks in.

Little change to the forecast tonight. Tolleson

.LONG TERM...No Changes. Previous discussion follows...
Tuesday night through Saturday...The upper level ridge will persist
over the Pac NW through Wednesday keeping temps on the warmer side of
things. Models continue to show 850mb temps near 20C. With the
thermal trough shifting inland slightly on Wednesday this should
allow temps in the interior to warm significantly, with widespread
afternoon highs around 90F likely. Models continue to diverge beyond
Thursday with little consistency among the various runs so confidence
remains extremely low. Have decided to trend the current forecast to
the more progressive 28/12Z GFS solution on Thursday which brings a
more pronounced onshore flow pattern to the region. Have also added a
slight chance of thunderstorms to the Cascades on Thursday due to the
GFS bringing some mid and upper level moisture to the region.
Otherwise, only minor changes were made to the forecast from Friday
onward using a blend of the GFS and ECMWF. /64
&&

.AVIATION...VFR conditions expected everywhere except for the coastal
TAF sites. Marine clouds have moved in along the coast and will lower
to MVFR in the next few hours. Already observing cigs between 700 and
1300 feet at KHQM for the last few hours. Expect these cigs to
moderate somewhat at KAST, but still expect a period of lower sub
1500 foot MVFR cigs at KAST later tonight after a weak front moves
through. In addition, showers and occasional drizzle will be possible
along the coast through the early morning hours Sunday. Inland areas
will remain predominantly VFR overnight although some MVFR cigs are
possible, especially in southwest Washington and the northern
Willamette Valley.

PDX AND APPROACHES...VFR conditions in control through this evening.
Lower cigs will move in after 07Z, but are expected to remain mostly
VFR. /Bentley
&&

.MARINE...As expected, northern marine waters saw a brief period of
20 to 25 knot gusts this afternoon ahead of a weak front which is
sweeping through the waters this evening. These winds have since
subsided and will continue to weaken and become more northerly
overnight and into tomorrow. Attention is now turning towards the
thermal low development on Monday and into Monday night which will
bring small craft winds to at least central Oregon waters and likely
into northern waters as well. This pattern will continue through at
least Tuesday before the gradient shifts further offshore on
Wednesday as the thermal low builds north.

Seas will remain in the 3 to 5 foot range tonight and into the first
part of the week. Fresh swell will begin to develop on Tuesday with
the extended northerly fetch, but seas are only expected to rise to ~
6 feet. With short ~7 second periods, will need to watch for square
seas if seas rise higher than expected. /Bentley
&&

.PQR WATCHES/WARNINGS/ADVISORIES...
OR...None.
WA...None.
PZ...None.
&&

$$

Interact with us via social media:
www.facebook.com/NWSPortland
www.twitter.com/NWSPortland

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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