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000
FXUS66 KPQR 200501 AAA
AFDPQR

Area Forecast Discussion...UPDATED
National Weather Service Portland OR
1000 PM PDT Fri Apr 19 2024

Updated aviation discussion...

&&

.SYNOPSIS...High pressure holding steady over the region
through tonight, with east to northeast winds on the west slopes
of the Cascades and to some degree, the Coast Range. Cooler for
Saturday, as a front moves across the region. This could result
in spotty light rain into Saturday night. Dry and mild
conditions return by the start of the upcoming week, with cooler
showery weather returning by the middle of next week.

&&

.SHORT TERM...TONIGHT THROUGH SUNDAY NIGHT...A pattern change
is on deck as a weak frontal system is expected to cross over
the region starting late tonight/early Saturday morning. This
will bring cooler daytime highs Saturday and Sunday. Offshore
flow will slowly weaken and become onshore through the overnight
hours, which will enable cooler marine air to infiltrate across
the region. Models have slowed the front, and current guidance
have light rain starting along the coast Saturday morning and
arriving inland by the afternoon. At this time current guidance
has this being a typical spring high PoP/low QPF event with the
coast having around 0.10 to 0.20 inches, inland areas having
0.05 to 0.10 inches and the Cascades having 0.15 to 0.25 inches.
Also, with the onshore flow a.k.a. the air conditioning and
clouds, expect daytime highs in the mid 50s to mid 60s on
Saturday and low 50s to low 60s on Sunday. The pattern changes
again Sunday/Monday as high pressure offshore will start
building inland. This will end the shower potential, with
morning marine clouds giving way to mixture of sunshine and
clouds for the start of the upcoming week. -42


.LONG TERM...MONDAY THROUGH THURSDAY...The early part of next
week will be characterized by a short wave ridge across the West
Coast. Dry and mild conditions are expected under mostly sunny
to partly cloudy skies. Temperatures across the interior valleys
will reach into the upper 60s to near 70 with a bump into the
low 70s on Tuesday. A series of disturbances will approach the
PNW toward the middle/end of next week. The first disturbance
looks like it will be on the weaker side but could bring
increasing clouds, cooler temps, and very light rain. The second
disturbance will follow quickly on the heels of the first later
in the week and could bring a better shot of rain to the area.
Model guidance varies at this point regarding timing and
strength so changes should be monitored in the coming days.
-Batz


&&

.AVIATION...Predominately VFR thresholds prevail tonight as high
pressure slowly shifts eastward. Expect increasing high level clouds
as the next system approaches the Pacific Northwest. Winds will
generally be variable and around 5 kt or less tonight. After 16-18z
Sat, cigs across the region will fall to low-end VFR as the front
moves closer.

Expect the front to reach the coast around 18-21z Sat, and push
inland into the Willamette Valley around 21z Sat-00z Sun. The latest
model guidance suggests a 60-80% chance that cigs fall to MVFR along
the coast during the frontal passage, and a 20-30% chance for the
Willamette Valley. This system will bring light rain that is not
expected to impact visibility. Expect winds to turn westerly/
southwesterly after 18z Sat with the frontal passage, and strengthen
to around 10-15 kt with gusts to 20-25 kt at any given terminal
through the afternoon.

Notes: Wind at KHIO will be unavailable overnight between 04Z and
13Z. The ASOS at KTTD is only available via the dial in option. The
AWOS at KMMV is still out of commission. As it is not maintained
locally by the National Weather Service, there is no estimated time
of repair.

PDX AND APPROACHES...Predominately VFR thresholds through the TAF
period, with cigs lowering to low-end VFR late morning/early
afternoon Saturday. East winds around 8-12 kt continue through 18z
Sat, then shift southwesterly in the afternoon with the frontal
passage. Southwest winds Saturday afternoon could gust between 20-25
kt. Latest guidance suggests a 20-30% chance of MVFR cigs between
21z Sat-00z Sun.     -Alviz

&&

.MARINE...High pressure dissipates tonight and a weak front moves
inland Saturday. Main impact will be increasing winds which has
initiated a Small Craft Advisory through Sunday morning. Winds
become northerly and will persist through mid-week. -Muessle

&&

.PQR WATCHES/WARNINGS/ADVISORIES...
OR...None.
WA...None.
PZ...Small Craft Advisory from 11 AM Saturday to 2 AM PDT Sunday
     for PZZ251>253-271>273.
&&

$$

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