or discuss
Office: MFR
FXUS66 KMFR 070529
AFDMFR
Area Forecast Discussion
National Weather Service Medford OR
929 PM PST Sat Dec 6 2025
.UPDATE...Aviation Discussion Updated.
&&
.AVIATION...07/06z TAFs...Mid and high clouds over the area tonight
with areas of IFR/LIFR conditions in low clouds in valleys west of
the Southern Oregon Cascades, including Medford and Grants Pass
areas. These conditions will persist through at least Sunday
morning. In the Umpqua valley, conditions are mainly VFR tonight
with MVFR/IFR expected to develop late tonight. Along the coast, a
front arrives late tonight and early Sunday morning, bringing rain
and a mix MVFR/IFR conditions.
Areas of rain and MVFR will spread inland from the coast into the
Umpqua Valley and into the Southern Oregon Cascades on Sunday. This
will bring lower ceilings (IFR/MFR) and mountain obscurations. Rain
with low ceilings (IFR and local LIFR) and areas of lowered
visibilities (IFR/MVFR) will continue Sunday evening for areas from
the Southern Oregon Cascades west, with VFR and local MVFR east of
the Cascades and across northern California.
On Sunday, moderate to strong winds aloft will result in mountain
wave turbulence along and east of the Cascades with stronger winds
near and at the ridges.
&&
.PREV DISCUSSION... /Issued 244 PM PST Sat Dec 6 2025/
DISCUSSION...While some subtle changes to the forecast have been
made, the main message remains the same for SW Oregon and northern
California. An upper ridge off the California coast will keep
most of the high-impact, heavy rainfall (and significant flood
risk) to our north through the middle part of next week.
The upper ridge will continue to deflect the main axis of
subtropical moisture associated with a strong atmospheric river
into NW Oregon, Washington and British Columbia. If you're headed
up there, prepare to get wet. Please refer to our colleagues to
the north (Portland and Seattle NWS) for the specifics on rain
amounts, but suffice it to say, it will be A LOT. They have flood
watches up from the Willamette Valley northward.
The frontal boundary that will supply all this moisture to the
PacNW will waver northward and southward multiple times through at
least Wednesday. This will bring bouts of moderate to perhaps
heavy rainfall to NW sections of our forecast area, primarily Coos
and Douglas counties (see Hydrologic Outlook for details), but
also Curry County. These areas could see 1-4 inches of rainfall.
South and east of the Rogue-Umpqua Divide, many folks will be left
wondering what all the hubbub is about and some areas in northern
California (eastern Siskiyou/Modoc counties) might not even get a
drop of rain.
We'll have a warm front move into the area late tonight and to
the north Sunday into Monday. This will renew the risk of
steadier precipitation across N&W sections of the CWA, but most,
if not all, precipitation stays to the north of the OR/CA border.
We don't currently predict any measurable rainfall here in
Medford during this time period, but there could be a 0.10-0.50 of
an inch from the coast to the Umpqua Divide/Cascades (perhaps a
little more in areas where terrain enhances lift). Snow levels
rise to 7000-8000 feet. Little or no precip is expected southeast
of Highway 97.
The main period in question is Monday night through Wednesday
when the frontal boundary jogs back to the south. Just how far the
front settles back southward is the main source of uncertainty.
This results in enhanced rain rates across NW sections, especially
Coos and Douglas Counties, but could also bring rain a little
farther south to around the OR/CA border. GEFS members are most
bullish with this outcome, but account for a lower % of the total
ensembles. ECMWF members prefer to keep the main moisture axis to
the north. If the farther south GEFS solutions pan out, this could
also mean another uptick in winds from the Cascades eastward
Tuesday night into Wednesday. 12Z deterministic GFS actually is
showing a strong 700MB jet of 65-70kt, which, if correct, could
bring wind headlines north of Highway 140. We have increased wind
speeds over the east side, but will adjust as new data become
available.
Model consensus is showing the frontal boundary lifting back to
the north late next week with the upper ridge re-amplifying along
the West Coast. This would likely result in a dry, mild period
for most, if not all, of the area into next weekend. CPC Week 2
outlook still calling for higher odds (50-70%) of above normal
temps and slightly favoring (33-40%) near to above normal precip.
Much of that will depend on the strength of the upper ridge.
-Spilde
MARINE...Updated 200 PM PST Saturday, December 6, 2025...Steep
seas diminish through this evening, then after a brief break tonight,
south winds increase through the day Sunday as another wet front
approaches the region. Gusty winds and steep seas north of Cape
Blanco on Sunday will spread to all of the southern Oregon waters
Monday, with Gales and/or very steep seas possible north of Cape
Arago. Conditions remain unsettled through the first part of next
week, with several fronts bringing periods of gusty south winds and
a likelihood of high and steep seas. -BPN/Petrucelli
&&
.MFR WATCHES/WARNINGS/ADVISORIES...
OR...CA...None.
PACIFIC COASTAL WATERS...Small Craft Advisory from 10 AM to 10 PM PST
Monday for PZZ356-376.
Small Craft Advisory from 7 AM Sunday to 10 AM PST Monday for
PZZ350-370.
Gale Watch from Monday morning through Monday evening for PZZ350-
370.
&&
$$
Office: PQR
FXUS66 KPQR 070551 AAB
AFDPQR
Area Forecast Discussion...UPDATED
National Weather Service Portland OR
951 PM PST Sat Dec 6 2025
Updated aviation discussion.
.SYNOPSIS...A prolonged wet pattern continues through early
next week as multiple frontal systems push inland. The most
notable period continues to focus on Monday through midweek,
when a prolonged atmospheric river may bring significant
rainfall and rising rivers across southwest Washington and
northwest Oregon. Today and Sunday bring lighter rainfall, while
Monday is expected to produce the highest totals across
southwest Washington and northwest Oregon.
&&
.Discussion...Now through Friday...Weather will remain active
through at least the middle of next week. Upper level zonal flow
will keep conditions dreary through Sunday with another
shortwave disturbance passing this evening and overnight. This
will bring a decent round of rain to the area as IVT values
increase to between 250-500 kg/ms. Rainfall with this system is
expected to be around 0.5-0.75 inches across the interior
lowlands, 0.75-1.5 inches along the coast, 1.5-3.0 inches along
the coast range and Cascades with the exception of the Lane
County Cascades which will be lower at 0.75-1.5 inches.
Widespread impacts are not anticipated through Sunday; however,
if rainfall rates sustain around 0.2 to 0.3 inches per hour for
several hours, a few faster-reponding basins, such as the Grays
at Rosburg and the Willapa River, could rise quickly. Breezy
southerly to southwesterly winds are expected at times with
gusts typically 30-40 mph, strongest near exposed coastal and
elevated terrain. This system will be a precursor to an active
few days where several inches of rain could fall across NW OR
and SW WA, increasing the potential for river and urban
flooding.
The synoptic set-up for the week starts with a ridge of high
pressure centered over the Pacific between Hawaii and southern
California. Clockwise circulation will advect sub-tropical moisture
northward toward the PacNW in several round between Monday and
Wednesday night. Mid level flow will predominantly be zonal as the
top of the ridge extends northward along the West Coast. At the same
time, several troughs will support surface lows and cold fronts that
will provide lift over the region. The first slug of AR moisture
enters the picture on Monday with IVT values along the coast peaking
above 750 kg/ms and values inland peaking between 500-750 kg/ms. The
heaviest rainfall with this first round is expected to fall between
Monday and Tuesday morning. 45% of NCEP Ensemble members show
rainfall totals between 4 pm Monday and 4 am Tuesday reaching or
exceeding the 10 year Average Return Interval for the Portland area.
This indicates that the expected rainfall totals during a 12 hour
period has a 10% chance of occurring in any given year. This is
notable given the expected widespread heavy precipitation and
potential urban flooding impacts. This round of rain will be
falling on already saturated soil which has prompted WPC to add
a Day 3 Slight/Marginal ERO risk over the CWA. The slight risk
covers all of SW WA, down the coast rang in OR and along the
Cascades down to around Santiam pass. rainfall totals from 4 am
Monday through 10 am Tuesday are expected to be 1.5-2.5 inches
across the interior lowlands, 3.0-5.0 inches along the coast and
coast range, and 3.0- 6.0 inches along the Cascades and Cascade
Foothills. Amounts may be slightly lower farther south, mainly
across Lane county. These rainfall amounts will lead to
significant rises on area rivers, especially in the coast range.
The second round of high IVT values is expected to impact the region
Tuesday night into Wednesday. IVT values are expected to be
slightly lower than the first wave, peaking around 500 kg/ms
both inland and along the coast. However, the duration of these
higher values is expected to be slightly longer. Rainfall
totals from late Tuesday through Wednesday night are expected to
be slightly lower across much of the area except for the
Cascades where totals are forecast to be slightly higher. As it
sits now, rainfall totals from early Monday through Wednesday
night will significant and impactful. While the chances for
widespread impacts are rather low, it is almost certain that
localized impacts will occur somewhere within the CWA.
Winds will be a concern Monday through Wednesday, with gusts up to
at least 30 mph inland and up to at least 40 mph at the coast. There
is a 10-20% chance for max wind gusts over 40 mph for inland areas,
and a 20-40% chance for gusts over 50 mph along beaches and
headlands. If wind gusts of this magnitude do materialize, expect
scattered downed trees and power outages.
Showery conditions will linger into Thursday and Friday as the flow
gradually weakens and dries. Snow levels are expected to remain high
(above 6000 ft) during this warm weather event, keeping most
precipitation as rain in the Cascades. Forecast confidence in exact
timing and magnitudes is still moderate given ensemble spread.
Overall, the Monday through Wednesday time period remains the
primary focus for potential high-impact hydrologic (see hydrology
section below for more details) and wind concerns. -19/12
&&
.AVIATION...A showery warm front will move over the area over the
next 24 hours. Showers continue within the vicinity of the area
with a mixture of flight categories. These showers will intensify
after 10Z Sunday causing CIGs to become widespread MVFR, and winds
to increase. The combination of wind and rain will cause
visibility to decrease, though how limited is unknown - ultimately
it will come down to rain rates. Given the south to southwesterly
winds amplifying, CIGs will hover right around the MVFR/VFR
threshold before decreasing to solid MVFR through the day. Wind
will ease towards the end of the forecast period.
Do want to note for those flight planning, a strong atmospheric
river system is going to move into the area on Monday. This system
will be accompanied by strong wind and very heavy rain.
KPDX AND APPROACHES...Exact timing is difficult for PDX as there
are a variety of factors that must come into play in order to get
any one cat level. Overall will see a trend towards MVFR after 10Z
Sun through at least 20Z. A diurnally driven weak easterly wind
will aid in clearing conditions temporarily. If they do clear, the
dewpoint depression will shrink and stratus may lower to IFR
levels. There is around a 20-30% chance of that occurring at some
point between 12-19Z Sun. With 30 kts of SSW wind at 2000 ft and
5-10 kt winds out of the SE to E at the surface, there will be a
period of modest low level wind shear values as we approach 18z
Sunday at KTTD and KPDX. Have included LLWS in the TAF at this
point but if the easterly winds at the surface shift to the south
then the risk will be far less. -27
&&
.MARINE...Seas will continue to slowly subside over the next
12-24 hours to less than 10 ft. A warm front will lift
northeastward across the area late tonight into Sunday morning
and result in southerly winds increasing across the waters. HREF
and NBM guidance suggest there is at least an 80% chance that
low end Gale Force wind gusts will occur across the waters south
of Cape Falcon. Seas will temporarily rise and become more wind
dominated due to these winds. Winds will then subside and
result in decreasing seas late Sunday before the next warm front
lifts northeastward across the waters. This suggests there is a
70% chance for stronger Gale Force winds to materialize across
the waters Monday. This will push seas into the mid teens Monday
afternoon with a 10-20% chance of seas climbing to at least
17-18 by 4pm Monday. Additional rounds of gusty southerly winds
are in store across the waters next week, but there is around
40-50% chance for brief Gale Force wind gusts across the waters
Tuesday and Wednesday. Southerly winds continue through the end
of next week, but there is 10% chance or less of Gale Force
winds materializing across the waters next Thursday, Friday and
Saturday.
&&
.HYDROLOGY...A series of frontal systems will keep conditions
very wet through the weekend and much of next week. The most
notable period will be late Monday through late Wednesday, when
a prolonged atmospheric river will bring significant rainfall
and the potential for widespread river flooding across southwest
Washington and northwest Oregon. Total rainfall amounts from
4am Monday to 4am Thursday (72 hour total) will most likely be
around 4 to 6 inches at the coast and interior lowlands, and 5.5
to 9.0 inches in the Coast Range and Cascades. Lane County
Cascades will be an exception, with 4-6.5 inches expected. There
is a 10% chance for rain amounts up to one foot in the Cascades
and Coast Range, up to 8-9 inches at the coast, and up to 7
inches in the Willamette Valley, Portland metro and Cowlitz
Valley. While rain amounts this high are unlikely to occur, they
represent a reasonable worst case scenario. This outcome would
result in widespread major flooding.
Although rain will likely become lighter Thursday into Friday,
the threat of flooding will linger along slow responding rivers.
Rivers draining the Coast Range and Willapa Hills have a 30-60%
chance of reaching moderate flood stage and a 20-40% chance of
reaching major flood stage. Additionally, many Willamette River
tributaries that drain from the Coast Range and Cascades have
anywhere from a 40-70% chance of reaching minor flood stage and
a 20-50% chance of reaching moderate flood stage. Flooding of
the Willamette mainstem rivers is unlikely to occur (less than
5%). Probabilities for specific river points can be found at the
National Water Prediction Service website.
There is also increasing confidence in the potential for
flooding along small creeks and streams as well as urban
flooding, including roadway flooding. Periods of heavy rain
will also increase the risk for landslides in areas of steep
terrain and debris flows over recently burned areas. People,
structures, and roads located below steep slopes, in canyons,
and near the mouths of canyons may be at serious risk from
rapidly moving landslides.
Considering the probabilities of flooding for rivers and urban
areas, a Flood Watch has been issued for all of southwest
Washington and northwest Oregon from 4 AM Monday to 4 AM Friday.
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...None.
WA...None.
PZ...Small Craft Advisory until 4 PM PST Sunday for PZZ210-251-271.
Gale Watch from Monday morning through Monday evening for
PZZ210-251>253-271>273.
Small Craft Advisory until 3 AM PST Sunday for PZZ252-253-272-
273.
Gale Warning from 3 AM to noon PST Sunday for PZZ252-253-272-
273.
&&
$$
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Office: PDT
FXUS66 KPDT 070543
AFDPDT
Area Forecast Discussion
National Weather Service Pendleton OR
943 PM PST Sat Dec 6 2025
.AVIATION...
Another period of rains ramps up across the area by sunrise. Lower
visibility would be found at KDLS as the HRRR shows the highest
precipitation hourly rates in that area from about 18z or so, and
into the afternoon. While higher rain rates are going to be right
along the Cascade Caps locations like Bend and Redmond are
unlikely to get sustained ceilings down in the IFR category
(70-90% confidence). Farther north, YKM, however has about a 50%
chance of seeing ceilings below 1000 ft after about 16z.. Overall
lighter rain rates are expected in the eastern terminals with
rain starting around 13z an ending around 21z. Russell/71
&&
.PREV DISCUSSION... /issued 240 PM PST Sat Dec 6 2025/
DISCUSSION...
Key Points:
1. Wet pattern continues through the weekend
2. Winds will return Monday night into Tuesday
3. Continued wet pattern with increasing temperatures
Winds are still a bit breezy across some areas across the CWA, but
remain below advisory criteria. Current radar shows some linger
showers continuing over the crests of the Cascades with little spill
over to the eastern slopes. Current satellite imagery shows the cast
majority of the area to be partly to mostly sunny. However, the
sunshine will be short lived as the next incoming round of
precipitation makes its way into the region tonight.
Tonight through Monday...Partly to mostly sunny skies will give away
to mostly cloudy and overcast as we continue to move through the
evening and into the overnight period. Precipitation will be pinned
to the Blues and the Cascades to start but will become widespread
this after 4AM. Models show QPF amounts to be elevated along the
higher elevations and along the eastern slopes before tapering of
slightly as we head towards the eastern portion of the CWA. Models
show rain to be continuous through Sunday with 24 hour precipitation
totals nearing wetting rain amounts of near 0.10-0.20 across
portions of the Basin, foothills of the N & S Blues and through
north central OR (70-90%). The eastern mountains, Highlands and
eastern slopes will see between 0.30 inches along the lower slopes
(60-80%) to near 1 inch around the crests (70-90%). Models are firm
agreement with yet another round of frontal systems impacting the
NW. Monday will be another soggy day with models showing even higher
amounts of precipitation, especially along the foothills of the
Blues and eastern slopes of the Cascades. 70-90% of the raw
ensembles show the crests of the Cascades could see nearly 2-3
inches of rainfall in 24 hours Monday. 30-50% for 0.90-1.20 inches
along the crests of the Blues and 70-90% for 0.10-0.20 inches
elsewhere.
Not only will Monday bring another round of wetting rains, but also
another round of breezy to windy conditions across the region Monday
night. Raw ensembles show the primary locations of sustained winds
of 30-35 to be along the Simcoe Highlands, foothills of the southern
Blues (40-60%) and the foothills of the N. Blues of WA (70-90%). The
associated gusts will be highest along the ridgetops of the
aforementioned areas with raw ensembles showing (70-90% confidence)
in the aforementioned areas seeing gusts of 40-45mph. This is below
wind advisory criteria at this time and will be closely monitored as
Monday draws nearer.
Tuesday onwards...Models continue to be in agreement with a
significant amount of rainfall expected over the course of the week.
NBM QPF amounts are relatively high, especially across the mountain
tops. Models even show the lower elevations could see near 0.15-0.25
inches of rain Tuesday (45-70%), (50-70%) again Wednesday before
tapering off to 0.05-0.1 inches Thursday. As for the mountains, raw
ensembles show (70-90%) for 1 inch or more Tuesday, (60-80%)
Wednesday and (50-70%) Thursday. Through the bulk of the next week,
snow levels are then forecast to remain high at mostly 5-8 kft with
periodic dips to 4.5 kft so much of the precipitation expected will
indeed fall as rain. With that in mind there are some concerns about
rises on area rivers. Current forecasts from the NWRFC in Portland
do place multiple rivers at action stage or minor flood stage by the
latter half of next week. 90
AVIATION...00Z TAFS...Mostly VFR conditions forecast through the
period. CIGs and vsby will stay VFR through late this evening and
early tonight, but an incoming system will bring lowering CIGS of
sct to ovc down to around 2kft to 6kft by tomorrow morning at all
sites. Precipitation associated with the incoming system will
start around 10Z for RDM/BDN/DLS but be fairly light at sites
RDM/BDN, and between 13Z-15Z for sites PDT/YKM/ALW/PSC. Heavier
precip at site DLS may reduce vsby to 3 to 5 miles. Precipitation
will last for several hours at each site with end times around 15Z
at sites RDM/BDN, and 18-20Z at sites DLS/PDT/YKM/PSC. Site ALW
will see light rain impacts persist after 18Z. Breezy winds will
continue into the early evening, then become 12kts or less
through the remainder of the period...except at sites BDN/ALW
where winds 12-17kts with gusts to around 25kts will redevelop
around or after 15Z(BDN) and 18Z(DLS). Lawhorn/82
&&
.PRELIMINARY POINT TEMPS/POPS...
PDT 41 54 43 58 / 30 90 60 80
ALW 42 51 45 57 / 40 90 70 90
PSC 42 56 44 59 / 20 80 30 70
YKM 36 53 37 55 / 30 80 30 80
HRI 42 56 43 60 / 20 90 40 70
ELN 34 47 34 49 / 40 80 40 80
RDM 33 55 37 57 / 30 50 40 50
LGD 35 45 38 49 / 60 90 80 90
GCD 34 48 38 52 / 40 90 50 70
DLS 46 56 47 60 / 80 100 80 90
&&
.PDT WATCHES/WARNINGS/ADVISORIES...
OR...None.
WA...None.
&&
$$
SHORT TERM...99
LONG TERM....99
AVIATION...71
