or discuss
Office: MFR
FXUS66 KMFR 190533
AFDMFR
Area Forecast Discussion
National Weather Service Medford OR
933 PM PST Tue Nov 18 2025
.DISCUSSION...Updated Aviation Section...
&&
.AVIATION...19/12Z TAFs...Ceilings have persisted into this evening
for many valleys west of the Cascades, including most areas south
and east of the Rogue-Umpqua Divide, including Medford and
Montague/Yreka. Ceilings are around 3000 feet (borderline MVFR) and
could last through much of tonight. There is a chance ceilings lift
or even scatter out for a time by morning, and if they do, those
same valleys are likely to fog in under IFR/LIFR conditions.
With high pressure building in and plenty of low-level moisture, we
expect areas of valley fog and low clouds to redevelop this evening
and fill in again overnight into Wednesday morning. This will bring
widespread valley IFR/LIFR and to most TAF sites. Offshore flow
could prevent the fog/low clouds at North Bend, so a VFR forecast is
indicated there through Wednesday morning. Most areas should clear
to VFR by late morning or early afternoon, but some locations may
not fully clear at all. The end of the TAFs show the incoming
rainfall for sites as the next front moves inland. -Spilde/BPN
&&
.PREV DISCUSSION... /Issued 220 PM PST Tue Nov 18 2025/
DISCUSSION...Satellite image shows a lower cloud deck persisting in
the Rogue, Illinois, Applegate, and Shasta Valleys and the clouds
have been slow to erode over the past few hours. Meanwhile, lower
clouds in some of the valleys east of the Cascades, in particular
Lake County have also been slow to burn off. iIt's possible these
areas may not break out at all or at the very least late in the
afternoon.
Guidance tonight is in pretty good agreement for low clouds and
patchy to areas of fog to form for the interior westside valleys
again later tonight into Wednesday morning, and the valleys east of
the Cascades. For the westside valleys, this should be enough to
keep temperatures from dropping near or below freezing as the cloud
layer and fog will slow down the amount of cooling tonight.
The pattern overall will remain rather quiet for the rest of the
week into next weekend. The exception will be Wednesday night into
Thursday as an upper trough will move into the area bringing
precipitation, but much like the last couple of times, the low will
split from the main flow and push south into northern Cal. This will
limit the amount of precipitation we get in our area. Snow is
expected to be confined to the mountains. Even then 24 hour snowfall
accumulation will be an inch or less along the Cascades and around
Mount Ashland and the higher terrain east of the Cascades. Meanwhile
snowfall amounts will be higher at Mount Shasta Ski area.
As the upper low splits and weakens, precipitation during the day
Thursday will diminish, but will tend to linger longer in Northern
California.
The upper low will move south into California Thursday night with
dry weather likely. However, low level moisture from Wednesday night
and Thursday morning precipitation will be high, thus setting the
table for low clouds and fog again for the interior valleys.
Friday through the weekend is likely to be dry as upper ridging
nudges in from the west as the cutoff low moves towards southern
California. The upper flow will likely remain westerly with the
ridge remaining over the area Saturday through Sunday. This will
likely keep the storm track farther north, this keeping our area
dry. There's good agreement among the operational models with the
overall pattern this weekend. The operational models, the majority
of the individual ECMWF (88 percent), and all of the GFS ensemble
means show no precipitation in our area Sunday. Additionally, the
clusters are also in good agreement into Sunday with upper ridging
over our area and the storm track farther north. As is typical, the
NBM solution for the weekend is too high, too far south, and inland,
especially given the above mentioned. So while we have a slight
chance to chance pops in the forecast for some locations Sunday, the
reality is we'll end up dry.
Now it won't be until late Sunday night into Monday where a weak
upper trough will swing north of the area and this will send a
weakening front into our area early Monday morning. The front will
weaken as it moves through the area Monday, therefore it's possible
most of the precipitation (and it will be light) will be in the
morning with most areas dry Monday afternoon.
A cooler and drier airmass will follow Monday night into Tuesday
which the operational models show, but this is not locked in stone
with some the individual ensemble members hinting at more upper
troughing which could bring cooler and possibly unsettled weather.
-Petrucelli
MARINE...Updated 200 PM PST Tuesday, November 18, 2025...North
winds and northwest swell will gradually subside tonight with
conditions improving from north to south into Wednesday. Then,
another frontal system is expected Wednesday afternoon and night
with steep wind-driven seas. After the front passes and winds
diminish, large longer period swell arrives Thursday into Friday.
Guidance is showing the swell peaking in the 16-19 foot range at
15 seconds Thursday evening. A somewhat active pattern then
continues through the weekend, with persistent elevated seas of
slightly higher than 10 feet. -Spilde
BEACH HAZARDS/HIGH SURF...Updated 200 PM PST Tuesday, November
18, 2025...Guidance is showing a long period swell arriving Thursday
morning and persisting through Friday morning. With swells peaking
in the 16-19 foot range (15 sec period) Thursday evening, this will
result in 20-24 foot breaking waves in the surf zone. A high surf
advisory has been issued. -Spilde
&&
.MFR WATCHES/WARNINGS/ADVISORIES...
OR...High Surf Advisory from 10 AM Thursday to 4 AM PST Friday for
ORZ021-022.
CA...None.
PACIFIC COASTAL WATERS...Small Craft Advisory until 10 PM PST this
evening for PZZ356-376.
Small Craft Advisory from 1 PM Wednesday to 10 AM PST Thursday
for PZZ350-356-370-376.
Hazardous Seas Watch from Thursday morning through late Thursday
night for PZZ350-356-370-376.
&&
$$
Office: PQR
FXUS66 KPQR 190600
AFDPQR
Area Forecast Discussion
National Weather Service Portland OR
1000 PM PST Tue Nov 18 2025
.UPDATED AVIATION DISCUSSION...
.SYNOPSIS...A weakening frontal band is sliding slowly eastward
through the forecast area this afternoon, producing widespread
mid-level cloud cover and virga. Precipitation reaching the
ground has been extremely limited, and dry conditions will
prevail for most locations. After a brief interruption Wednesday
night into Thursday with a weak front brushing the region, a
broader transition toward a wetter, more active pattern takes
shape over the weekend and into early next week.
&&
.SHORT TERM...Now through Thursday Night...The frontal zone
draped from the north Oregon Coast toward southwest Washington
continues to drift inland. There continues to be little to no
precipitation from this frontal band as most of the moisture
continues to evaporate within the sub-cloud layer. The trailing
edge of the band now stretches from roughly Tillamook northeast
to Kelso, and this feature will exit over the Cascades by late
this evening.
Temperatures will hold near seasonal norms through this
afternoon, but the combination of clearing tendencies and a
drier air mass tonight favors stronger radiational cooling.
Early this morning, a brief period of freezing fog developed in
the Eugene area, and the pattern tonight points to a
similar a similar risk for the southern Willamette Valley. Fog
potential overall is higher tonight than last night, especially
for Salem southward. Could see pockets of dense fog elsewhere
in interior valleys before sunrise Wednesday morning. Easterly
winds within the Columbia River Gorge and along the coast will
likely keep fog out of nearby terminals, although fog being
advected within the Columbia River Gorge towards Troutdale and
Portland is not out of the question.
Wednesday will remain largely quiet, with temperatures a few
degrees warmer than today. The next system arrives late
Wednesday as a modest shortwave and surface front approach from
the Northeast Pacific. Model consensus continues to show the
upper trough splitting, but with the main closed low
heading northeastward towards Juneau AK and a small shortwave
trough that may form a small closed surface low drifts eastward
towards the Pacific Northwest. Uncertainty remains regarding the
location of the shortwave trough as it moves towards the PNW, as
models suggest that it will move into either Washington or
Oregon. This system will bring around 0.20 to 0.40 inches of
rain to the coast and Coast Range, 0.10 to 0.20 inches within
the interior valley, and 0.10 to 0.30 inches along the Cascades
and Cascade foothills, with the higher amounts expected along
the central Oregon Coast and Coast Range. Snow levels will stay
above 5000 feet, keeping travel over the Cascade passes largely
unaffected.
.LONG TERM...Friday through Tuesday Morning...The end of the
workweek begins under a broad but low-amplitude ridge, keeping
the primary storm track pointed into British Columbia on Friday,
focusing the better rain chances over western Washington and
brushing only the far northern portions of our region. Farther
south, shower chances remain lower but not zero as weak
disturbances pass along the periphery of the ridge.
Over the weekend, the ridge axis shifts inland and gradually
breaks down as a series of Pacific waves drop southward.
Ensemble guidance has grown more aligned in showing the storm
track dipping south into Oregon by Sunday, introducing a
steadily increasing probability of widespread rain. Confidence
is higher for a more organized system late Sunday into Monday,
which could deliver meaningful precipitation to the lowlands and
accumulating snow to the Cascades. Cooling aloft within the
approaching trough supports falling snow levels, and current
probabilities show a 25-35% chance for at least 6 inches of new
snow at the Cascade passes from late Sunday into early Tuesday
morning.
~12
&&
.AVIATION...Tonight high pressure will maintain calm winds and
mostly clear skies setting the stage for widespread fog and low
cloud development resulting in degraded flight conditions through
much of Tuesday morning. Currently as of ~05-06z, CIGs/VIS have
already begun to lower across the central and southern Willamette
valley with more localized pockets of fog elsewhere into the
Portland Metro and in coast range/Cascade valleys. High confidence
(70-90%)in the continuation of this trend towards IFR/LIFR
conditions for most inland sites by 08-11z, including KPDX. The
REFS which has captured fog development well thus far projects a
~70-80% chance for <0.5 mile VIS for all inland terminals
excluding KTTD by 12z. It's this latter site (KTTD) and coastal
sites outside of well protected valleys (KONP, and to some extent
KAST) where forecast confidence is lower due to the development of
easterly flow as the night goes on which would limit fog/low
stratus formation where it can surface. Still, would give KTTD a
40-50% chance for IFR to LIFR conditions between 09-13z before
those east winds become more prominent. It's also worth noting
temperatures will be right around 32 degrees at KEUG by sunrise,
meaning freezing fog is possible.
East flow and added mixing as the morning goes on will chip away
at the fog/low stratus largely N to S through the Willamette
Valley but will struggle to scour out the airmass KSLE to KEUG.
Forecast confidence regarding the timing of any categorical
improvement through Wednesday morning into the afternoon is low.
That said, expect breezy east wind with gusts up 20-30 knots to
develop at KTTD by 16-18z.
KPDX AND APPROACHES...Fog is currently attempting to develop
around the terminal late this evening as confidence grows in a
drop to IFR/LIFR conditions around 08-10z with a probabilities
peaking at 75% for <0.5mile vis around 12-13z Wednesday.
Confidence is still rather low as to exactly when fog and low
stratus will scour out at the KPDX terminal, as the terminal
will be near the edge of the stratus/fog deck. The end time
depends solely on when easterly winds reach the KPDX terminal.
Current guidance suggests the earliest this occurs would be
around ~15z Wednesday but they tend to progress too quickly in
these scenarios. Higher confidence in a return to VFR by
18-21z.
&&
.MARINE...
Buoy observations from Tuesday afternoon showed seas
ranging between 6 to 8 ft at 11 to 12 seconds, with light north to
northeast winds around 10 kt. Winds are still expected to become
easterly for a brief period of time Wednesday morning as offshore
flow develops. East winds should generally stay at or under 10
kt, but may be locally stronger downwind of coastal gaps. Winds
veer to the south and increase Wednesday afternoon as another
frontal system approaches the waters, with wind gusts peaking
between 25 and 30 kt Wednesday evening through Wednesday night as
the front moves through. Small Craft Advisories have been issued
to cover this threat.
Winds weaken significantly on Thursday behind the frontal passage,
however a long period westerly swell will be rapidly increasing.
Forecast seas have increased with today's forecast update, and are
now expected to peak between 17-19 ft Thursday afternoon and
evening with a dominant wave period of 14-15 seconds. There is a
10% chance seas will peak at or slightly above 20 ft. Given
increasing confidence for steep and hazardous seas on Thursday, a
Hazardous Seas Watch has been issued for the inner and outer
waters late Thursday morning through Thursday night.
Seas are then expected to slowly subside to 10-13 ft Friday
morning and afternoon, and then remain within that range through
the upcoming weekend. Winds look to stay under 20 kt Friday
through the weekend as well. -23
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...None.
WA...None.
PZ...Small Craft Advisory from 7 PM Wednesday to 10 AM PST Thursday
for PZZ251>253.
Hazardous Seas Watch from Thursday morning through late
Thursday night for PZZ251>253-271>273.
Small Craft Advisory from 2 PM Wednesday to 10 AM PST Thursday
for PZZ271>273.
&&
$$
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Office: PDT
FXUS66 KPDT 191034
AFDPDT
Area Forecast Discussion
National Weather Service Pendleton OR
234 AM PST Wed Nov 19 2025
Updated Aviation Discussion
.DISCUSSION...Skies are clearing across much of the forecast area
early this morning as a ridge of high pressure accompanied by
cold and dry air slides into the PacNW. Low clouds are lingering
(and even building) across some of our elevated valleys in central
and eastern Oregon, but otherwise much of the Basin and mountain
foothills are seeing clear skies. Could see patchy fog develop
across some of our usual fog-prone areas along river valleys, but
given the lack of a temperature inversion present across obs,
thinking is that this morning will just be cold, with much of the
forecast area seeing below-freezing temps. As of this discussion's
writing, the Freeze Warning in the Columbia River Gorge is
flirting with verification with temps in the mid to upper 30s, and
as long as low stratus does not form via light easterly winds,
the last of our freeze-eligible zones should finally fall.
Looking ahead, Wednesday will be dry before our forecast area is
clipped by the next system - a low diving to our south and east
before settling over southern California. The trajectory of this
system is not favorable for widespread precip, so as of now, the
forecast for late Wednesday into Thursday looks to be that of light
mountain snow generally less than an inch above primarily 4500-5000
ft, with perhaps a stray shower impacting the Basin (15-30%) via
wraparound moisture from the low as it digs to our south. But with
most of this system's moisture landing to our west, impacts are
overall anticipated to be minimal.
We enter another relatively benign pattern Friday through Sunday as
ridging, slightly dirty in nature, prevails over the region.
Guidance favors persistent shower chances across primarily the WA
Cascades over the weekend, but QPF is once again minuscule. Ensemble
guidance starts to diverge Monday onward, but some members do depict
an upper-level wave moving down from the ridge upon us early Monday
morning, which would provide for the next-best chance for area-wide
precip. But beyond that, forecast confidence weakens (30-40%) as
ensemble solutions diverge in light of a relatively progressive
synoptic pattern. 74
.AVIATION...12Z TAFs...Mostly VFR conditions forecast through the
period. Chances of fog developing at any site tonight is 15% or
less, though that said a few pockets are beginning to develop
around site PDT per satellite. Will continue to monitor for
potential impacts. Otherwise, a system arriving to the region will
increase mid level cloud cover to bkn-ovc between 5kft to 12kft
AGL around or after 03Z at all sites, with a potential for a
rain/snow mix and MVFR or lower CIGS/vsby developing at sites
RDM/BDN around 09Z tomorrow. Winds will remain light, 12kts or
less, through the period. Lawhorn/82
&&
.PRELIMINARY POINT TEMPS/POPS...
PDT 48 32 47 32 / 0 20 30 0
ALW 48 35 46 36 / 0 20 40 10
PSC 49 32 49 30 / 0 10 10 0
YKM 48 32 50 29 / 0 20 10 0
HRI 48 34 48 31 / 0 20 20 0
ELN 45 29 48 29 / 0 20 10 10
RDM 50 28 47 23 / 0 60 20 0
LGD 50 34 50 30 / 0 20 50 10
GCD 53 35 49 29 / 0 30 40 0
DLS 50 39 52 36 / 0 60 40 10
&&
.PDT WATCHES/WARNINGS/ADVISORIES...
OR...Freeze Warning until 10 AM PST this morning for ORZ041.
WA...Freeze Warning until 10 AM PST this morning for WAZ024.
&&
$$
DISCUSSION...74
AVIATION...82
FXUS66 KPDT 191040 CCA
AFDPDT
Area Forecast Discussion
National Weather Service Pendleton OR
240 AM PST Wed Nov 19 2025
Updated Aviation Discussion
.DISCUSSION...Skies are clearing across much of the forecast area
early this morning as a ridge of high pressure accompanied by
cold and dry air slides into the PacNW. Low clouds are lingering
(and even building) across some of our elevated valleys in central
and eastern Oregon, but otherwise much of the Basin and mountain
foothills are seeing clear skies. Could see patchy fog develop
across some of our usual fog-prone areas along river valleys, but
given the lack of a temperature inversion present across obs,
thinking is that this morning will just be cold, with much of the
forecast area seeing below-freezing temps. As of this discussion's
writing, the Freeze Warning in the Columbia River Gorge is
flirting with verification with temps in the mid to upper 30s, and
as long as low stratus does not form via light easterly winds,
the last of our freeze-eligible zones should finally fall.
Looking ahead, Wednesday will be dry before our forecast area is
clipped by the next system - a low diving to our south and east
before settling over southern California. The trajectory of this
system is not favorable for widespread precip, so as of now, the
forecast for late Wednesday into Thursday looks to be that of light
mountain snow generally less than an inch above primarily 4500-5000
ft, with perhaps a stray shower impacting the Basin (15-30%) via
wraparound moisture from the low as it digs to our south. But with
most of this system's moisture landing to our west, impacts are
overall anticipated to be minimal.
We enter another relatively benign pattern Friday through Sunday as
ridging, slightly dirty in nature, prevails over the region.
Guidance favors persistent shower chances across primarily the WA
Cascades over the weekend, but QPF is once again minuscule. Ensemble
guidance starts to diverge Monday onward, but some members do depict
an upper-level wave moving down from the ridge upon us early Monday
morning, which would provide for the next-best chance for area-wide
precip. But beyond that, forecast confidence weakens (30-40%) as
ensemble solutions diverge in light of a relatively progressive
synoptic pattern. 74
.AVIATION...12Z TAFs...Mostly VFR conditions forecast through the
period. Chances of fog/low stratus developing at any site tonight is
15% or less, though that said a few decks of stratus are beginning
to develop around site PDT per satellite. Will continue to monitor
for potential impacts. Otherwise, a system arriving to the region
will increase mid level cloud cover to bkn-ovc between 5kft to 12kft
AGL around or after 03Z at all sites, with a potential for a
rain/snow mix and MVFR or lower CIGS/vsby developing at sites
RDM/BDN around 09Z tomorrow. Winds will remain light, 12kts or less,
through the period. Lawhorn/82
&&
.PRELIMINARY POINT TEMPS/POPS...
PDT 48 32 47 32 / 0 20 30 0
ALW 48 35 46 36 / 0 20 40 10
PSC 49 32 49 30 / 0 10 10 0
YKM 48 32 50 29 / 0 20 10 0
HRI 48 34 48 31 / 0 20 20 0
ELN 45 29 48 29 / 0 20 10 10
RDM 50 28 47 23 / 0 60 20 0
LGD 50 34 50 30 / 0 20 50 10
GCD 53 35 49 29 / 0 30 40 0
DLS 50 39 52 36 / 0 60 40 10
&&
.PDT WATCHES/WARNINGS/ADVISORIES...
OR...Freeze Warning until 10 AM PST this morning for ORZ041.
WA...Freeze Warning until 10 AM PST this morning for WAZ024.
&&
$$
DISCUSSION...74
AVIATION...82
