Siletz, Oregon Weather Forecast Discussion

345
FXUS66 KPQR 012100
AFDPQR
Area Forecast Discussion
National Weather Service Portland OR
200 PM PDT Wed Oct 1 2025
.SYNOPSIS...Conditions will remain cool and showery through Thursday
as a low pressure system currently centered around 250 miles west of
Vancouver Island slowly moves southward and weakens. Friday and
Saturday will be seasonable with mainly dry conditions aside from a
few stray showers. Low-level offshore flow develops Sunday and
continues into early next week, bringing an extended period of dry
weather with high temperatures in the 70s for most inland valley
locations.
&&
.DISCUSSION...Now through Tuesday night...Radar, satellite and
surface weather observations from early Wednesday afternoon depicted
a band of light to moderate rain extending across the Willamette
Valley, Columbia River Gorge, and Cascades. This band of rain was
occurring along an occluded front that extended from a
vertically-stacked closed low pressure system centered around 250
miles west of Vancouver Island. Models are in general agreement this
low will gradually shift southward over the coastal waters through
Friday morning while weakening simultaneously. Until then, scattered
rain showers will remain in the area. Showers will be most prevalent
during the afternoon and evening hours Wednesday and Thursday, with
most showers dissipating during the overnight hours. The strongest
afternoon showers will have the potential to produce a flash or two
of lightning with brief gusty outflow winds and/or small hail under
the size of peas. That said, the probability for thunderstorms at any
given location is very low at 5-15%. The vast majority of the area
will not observe thunderstorms.
From Friday afternoon onward, the forecast is trending mainly dry
with northerly flow aloft. In addition, temperatures will become
noticeably warmer Sunday through Tuesday as low-level offshore
develops. Models and their ensembles depict minimal temperature
spread, suggesting confidence is high the warmer temperatures will
materialize. The NBM continues to suggest widespread highs in the 70s
across inland valleys on all three days, warmest on Tuesday when
highs are expected to rise into the mid to upper 70s.
The only other thing worth mentioning is overnight lows in the Upper
Hood River Valley near the Parkdale area. This area will likely see
morning lows near 40 degrees Thursday morning and upper 30s Friday
morning. Cannot completely rule out patchy frost Friday morning given
the clear skies and light winds in place, however the probability for
this to occur is at 20-40%. Probabilities drop to near 0% in Odell
and Hood River. Given the marginal temperatures in place and the fact
that temperatures will most likely stay above 36-37 degrees, have
decided not to issue a Frost Advisory for this zone. -TK
&&
.AVIATION...A frontal rain band extends across much of the
Willamette Valley to begin the period, with largely VFR vis/cigs
observed and brief reductions to MVFR levels possible before the
band exits eastward by 20z Wed and is replaced by a more showery
distribution of rain through this evening. Isolated thunderstorms
remain possible across much of the region, but confidence in their
occurrence has fallen below thresholds for PROB30 mention at all
sites except KAST; amendments will be issued as necessary for any
thunder that does develop. Southerly to southeasterly winds
continue at 5-10 kt inland and around 15 kt gusting to 20-30 kt
along the coast. Winds will ease as showers dissipate late this
evening, after 03-06z Thu.
KPDX AND APPROACHES...VFR conditions to persist through the
period as the frontal rain band transitions to scattered rain
showers after 20z Wed. MVFR cigs/vis are most likely during the
frontal passage, with other brief reductions possible but low
confidence in showers behind the boundary. Isolated thunder also
remains possible, most likely from 21z Wed through 03z Thu, but
confidence is low in timing and occurrence. Southerly to
southeasterly winds continue at 5-10 kt. -Picard
&&
.MARINE...A deep area of surface low pressure will linger west of
Vancouver Island, steadily weakening in place before moving
inland Friday into Friday night. The pressure gradient across the
waters will therefore slowly slacken through the workweek,
allowing winds to ease through the period. Gale Warnings remain in
effect this afternoon across the inner waters from Florence north
to Cape Shoalwater, as well as the outer waters north of Cape
Falcon, and will continue into this evening before wind gusts
fall below gale-force.
Seas also remain elevated with buoy observations of 15-18 ft
across the waters. As winds ease, seas will similarly subside,
finally falling below 10 ft by Thursday afternoon to evening. A
Hazardous Seas Warning will therefore be in effect until Thursday
morning, followed by a Small Craft Advisory until hazardous rough
seas and gusty winds end Thursday afternoon.
Afternoon and evening thunderstorms will continue to pose an
additional threat today, and less so on Thursday. Isolated storms
will be capable of producing severely limited visibility, gusty
and erratic winds, lightning, small hail, and even an isolated
water spout in their local area.
As a more seasonable pattern of offshore high pressure rebuilds
late in the week and through the weekend, winds will turn back out
of the north. -Picard
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...None.
WA...None.
PZ...Hazardous Seas Warning until 8 AM PDT Thursday for PZZ210-272-
     273.
Small Craft Advisory from 8 AM to 5 PM PDT Thursday for PZZ210-
     251>253-271>273.
Gale Warning until 11 PM PDT this evening for PZZ251>253.
Hazardous Seas Warning from 11 PM this evening to 8 AM PDT
     Thursday for PZZ251>253.
Gale Warning until 8 PM PDT this evening for PZZ271.
Hazardous Seas Warning from 8 PM this evening to 8 AM PDT
     Thursday for PZZ271.
&&
$$
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NWS PQR Office Area Forecast Discussion