300
FXUS66 KPQR 120339 AAA
AFDPQR

Area Forecast Discussion...UPDATED
National Weather Service Portland OR
839 PM PDT Tue Jun 11 2024

Aviation Discussion Updated...

.SYNOPSIS...High pressure brings dry and warm conditions
Wednesday and Thursday. Friday through early next week,
troughing enters the region, resulting in increased
precipitation chances and cooler temperatures.

&&

.SHORT TERM...Now through Thursday Night...Clouds have given way
to sunny skies across the area this afternoon as a weak front
dissipates. Taking a look at visible satellite, a broken mid-
level stratocumulus deck persists from Pacific and Clatsop
Counties southwest into the adjacent coastal waters, with some
additional fair-weather cumulus lingering along the Cascades.
Expect a decrease cloud cover to continue to decrease with
lighter winds as high pressure rebuilds over the region tonight.
It`ll be a pretty cool night for June, with Wednesday morning
lows in the mid to upper 40s for lowlands and upper 30s for
higher terrain. Though we`ll start off Wednesday pretty cool,
the air mass will warm up later in the day with sunny skies so
afternoon highs should end up seasonable in the 70s.

High pressure will persist through Thursday, leading to another
cool night Wednesday night, but probably not quite as cold as
tonight. As the air mass continues to warm Thursday, it appears
likely Thursday afternoon will be a few degrees warmer than
mid June normals. Based on NBM guidance, it appears there is
around a 40% chance of the Portland Metro Area reaching 80 deg
F Thursday afternoon, while chances for the same in Eugene are
closer to 10-20%. -CB/Alviz

.LONG TERM...Friday through Tuesday...The upper ridge begins to
shift east of the forecast area on Friday as another trough near
the Gulf of Alaska dips southward toward the Pacific Northwest.
This will lead to a cooling trend and return of precipitation
chances. It currently looks like a weak front will brush the
coast and northern part of our CWA, so Friday`s PoPs are pretty
low (15-40% chance) and confined to the coast, Coast Range, and
southwest Washington.

Saturday, most ensemble members agree on troughing entering the
region with below-normal 500 mb heights. In this scenario, we
would see increasing chances for widespread precipitation and
below average temperatures. For now, the NBM`s 25-60% chance of
PoPs across northwest Oregon and southwest Washington at the end
of the week look reasonable. Sunday to Tuesday, the majority of
ensemble members (>85%) continue to show broad troughing over
the Pacific Northwest, maintaining a generally cool and
potentially wet start to next week. -Alviz

&&

.AVIATION...High pressure building in from the west this afternoon
as a front dissipates in the Cascades & Cascade foothills. VFR
conditions prevailing inland with cigs in the 3500 to 6000 ft
range, but predominantly MVFR at the coast where marine
stratocumulus remains. With the uptick of onshore flow, expect
breezy west winds in the mid/eastern Columbia Gorge, and over
higher terrain in Cascades through this evening. As high pressure
further builds inland through Wednesday, northerly low level flow
will bring drier conditions for clearing skies.

PDX AND APPROACHES...VFR expected to prevail through 00Z Thu. As
of 3 pm cigs between 4500-6000 ft in the area. CIGS will slowly
break part into the evening. Winds expected to become west to
northwest around 10 kt this evening with gust potential 15 to 20
kt. Winds then settle later in the evening. -mh/Rockey

&&

.MARINE...
High pressure will restrengthen over the offshore
waters tonight. As such, northerly winds will pick up again, but
mainly tonight and remain gusty at times through Wed evening. A
Small Craft Advisory continues on the waters with steep seas the
main hazard. Seas building to 9 to 12 ft with a period near 11
seconds this evening into early Wed am as fetch of swell moves
from northeast Pac into the waters.

High pressure will maintain northerly gradients through Thu,
though the north winds will be bit less, generally 10 to 20 kt,
with strongest wind gusting 25 kt in afternoons/evenings. Seas
settle to the 5 to 7 ft range, but remain choppy. Next front will
arrive later Fri, with flip back to W or SW winds of 10 to 15 kt
for late Fri into early Sun. -mh/Rockey

&&

.PQR WATCHES/WARNINGS/ADVISORIES...
OR...None.
WA...None.
PZ...Small Craft Advisory until 5 AM PDT Wednesday for PZZ210.
     Small Craft Advisory until 11 PM PDT Thursday for PZZ251>253-
     271>273.
&&

$$

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