Area Forecast Discussion
Issued by NWS Portland, OR

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FXUS66 KPQR 231002

Area Forecast Discussion
National Weather Service Portland OR
215 AM PDT Wed Aug 23 2017

.SYNOPSIS...A weak storm system will bring cooler temperatures and a
chance for some very light rain late tonight and Thursday. Hot
weather will return over the weekend and linger into early next week.


.SHORT TERM...Tonight through Saturday...Fog product reveals marine
clouds entrenched along the coast early this morning. Marine clouds
should continue to filter inland, particularly across the northern
Willamette Valley. A shortwave trough sliding eastward into Canada
today will drag a front currently offshore into the region tonight.
This should spread even more clouds inland overnight and result
temperatures cooling further on Thursday. In addition, some light
rain certainly appears possible late tonight and Thursday morning,
particularly along the coast and Cascade foothills.

Shortwave ridging slowly pushing eastward into the Pacific Northwest
should warm temperatures closer to average for the date on Friday
before temperatures rise into at least the mid-upper 80s on Saturday
in the Willamette Valley. /Neuman

.LONG TERM...Saturday night through Wednesday...Shortwave ridging
over the Pacific Northwest will bring hot weather back to the
region. Several days of 90F+ temperatures appear likely for the
Willamette Valley...with Sunday and Monday appearing the hottest.
This upcoming hot stretch will likely produce a multi-day period of
critical fire weather conditions as well. East to northeasterly
winds should allow smoke to filter back into the region Sunday and
Monday. The flow aloft may turn southerly enough early next week
that there is an outside chance of elevated thunderstorms developing
at some point, but for now, models suggest it won`t happen so have
kept PoPs below mentionable thresholds for now. /Neuman


.AVIATION...IFR fog and stratus along the coast is starting to
move inland with stratus as close as the north side of Vancouver
up the Columbia and to near Alma near Eugene. Lowered cigs from
MVFR to IFR shortly after stratus development for the valley
based on upstream obs from KKLS.

KPDX AND APPROACHES...Expect MVFR conditions at the terminal in
the next few hours eventually lowering to IFR for a period this
morning before clearing to VFR by late morning. /Bentley


.MARINE...Benign marine weather conditions persist with winds
less than 10 knots and seas less than 4 feet. A weak cold front
will move through our waters late Wednesday into Wednesday Night.
Post frontal northerly winds on Thursday morning may approach
small craft advisory strength, but given the short duration of
strongest winds and borderline 21-22 kt gusts expected, elected
not to issue any products. Otherwise, winds will remain less than
20 knots until Friday afternoon into the weekend when the thermal
trough builds north and strengthens northerlies across southern
waters. A small craft advisory will likely be needed during this
timeframe. Without any storms to generate a swell, seas will
remain small through the weekend and into next week. /Bentley





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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 forecast area. is the U.S. government's official web portal to all federal, state and local government web resources and services.