Area Forecast Discussion
Issued by NWS Portland, OR

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29
000
FXUS66 KPQR 260355
AFDPQR

Area Forecast Discussion
National Weather Service Portland OR
855 PM PDT Thu Aug 25 2016

.SYNOPSIS...Warm temperatures will continue across the region Friday
as high pressure remains over the region, with a thermal trough
of low pressure over the Willamette Valley. The thermal trough will
shift east late Friday, signaling a return to onshore winds Friday
night and Saturday. A persistent upper level trough will maintain
onshore flow along with more seasonably normal temperatures for at
least the first half of next week. Periods of light rain are also
possible at times next week across the northern part of the area.

&&

.SHORT TERM...(Tonight through Sunday)...After a very hot day
across the region today, temperatures remain hot inland this evening.
Numerous record maximum temperatures were set both at the coast
(Astoria and Newport), as well as across the Willamette Valley
(Portland airport, Troutdale, Hillsboro, Salem, and Eugene). Latest
surface analysis depicts the thermal trough centered over the I-5
corridor through the Willamette Valley this evening. Clear skies
continue tonight, and temperatures remain quite warm overnight with
lows across the Willamette Valley only around 60 to 65. Forecast for
tomorrow remains on track, with overall temperatures very similar
inland to today`s readings. However, expect the coast to begin to
warm quickly in the morning, but cool off a bit with the the flow
turning onshore as the thermal trough slides eastward.

The thermal trough axis will move east of the Cascades Friday night
and bring relief from the heat as onshore flow increases across the
region.  Additionally, a southerly stratus surge will bring a return
of fog and low clouds to the coast Saturday.  Temperatures  will be
cooler inland Saturday will be about 10 degrees cooler, but still a
few degrees above seasonal normals. However, bigger change in store
for the start of next week as a weak disturbance drops south from
British Columbia into the region, starting a cooling trend into next
week.Cullen

.LONG TERM...(Sunday night through Wednesday)...Seasonable
weather will arrive for the long term period as a long wave trough
develops across the PacNW and remains through the week. There is
still some model certainty regarding the southern progression of the
energy which will impact how much precipitation our area sees.
Currently the best chance for showers is in far NW Oregon and SW
Washington on Sunday night and Monday. Have kept PoPs in the 20-30
range Tue-Thu as showers look possible each day, but uncertainty
precedes any higher PoP mention. /Bentley

&&

.AVIATION...Generally VFR conditions tonight and Fri.

KPDX AND APPROACHES...VFR tonight and Fri. pt

&&

.MARINE...High pressure will remain over the northeast Pacific
through Friday, with thermal low pressure near the coast and over
northern California. This will keep moderately brisk north winds
over the coastal waters. The strongest winds are likely to be
over the southern waters this evening, where peak gusts are
expected to reach 20 to 25 kt. Otherwise expect winds to remain 20
kt or less through Fri as winds turn a little more onshore later
Friday. As a low swings through southern B.C. Friday night and
Saturday, winds will turn more onshore but remain below Small
Craft Advisory thresholds. A series of troughs off the B.C. and
Washington coasts will keep winds on the lighter side well into
next week.

Seas will stay well below 10 ft into next week. pt

&&

.PQR WATCHES/WARNINGS/ADVISORIES...
OR...Red Flag Warning from 11 AM to 9 PM PDT Friday for Central
     Oregon Cascade Foothills-East Slopes of the Central Oregon
     Coast Range-Mt. Hood National Forest  -West of Cascade
     Crest-North Oregon Cascade Foothills-North Oregon Coast
     Range-Willamette National Forest-Willamette Valley.

     Heat Advisory until 8 PM PDT Friday for Cascade Foothills in
     Lane County-Central Coast Range of Western Oregon-Central
     Columbia River Gorge-Central Willamette Valley-Coast Range
     of Northwest Oregon-Greater Portland Metro Area-Lower
     Columbia-Northern Oregon Cascade Foothills-South
     Willamette Valley-Upper Hood River Valley-Western Columbia
     River Gorge.

WA...Red Flag Warning from 11 AM to 9 PM PDT Friday for Clark County
     Lowlands-East Willapa Hills-Extreme South Washington
     Cascades.

     Heat Advisory until 8 PM PDT Friday for Central Columbia River
     Gorge-Greater Vancouver Area-I-5 Corridor in Cowlitz
     County-South Washington Cascade Foothills-Western Columbia
     River Gorge-Willapa Hills.

PZ...Small Craft Advisory for winds until 3 AM PDT Friday for Waters
     from Cascade Head to Florence OR from 10 to 60 nm.

&&

$$

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.



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