[ W WA | SW WA and W OR | SE WA and NE OR | NE WA and N ID ]

Western Washington

FXUS66 KSEW 240456

Area Forecast Discussion
National Weather Service Seattle WA
856 PM PST Sat Jan 23 2021

.SYNOPSIS...Clouds will increase tonight and a front will arrive 
Sunday. Another weather system will reach the West Coast Tuesday
night--with the heavier precipitation moving into California. The
snow level will be low through the week ahead for a chance of
spotty light snow at times in the lowlands. 


.UPDATE...Added mention of rain to the forecast this evening from
the South Sound southwest through Grays Harbor given the current 
radar trends. Will see leading edge of the precipitation continue 
to advance through the waters across the Olympic Peninsula this 
evening, before reaching the I-5 corridor early Sunday morning. 
Expect mostly rain at the lowest elevations with the snow level
around 500-1000 ft, though cool temperature profiles may support 
some snow mixing in at times. However, a southerly component to
winds and temperatures holding just above freezing should maintain
mostly rain. One exception may be in northern Whatcom County as 
light outflow winds and cooler air may lead to minor accumulating 
snow north of around Ferndale.                     Cullen


tonight and areas of precip should start by daybreak. The hills 
might pick up a little wet snow tomorrow morning, but 
accumulations should be mainly in the grass rather than the 
pavement. If dew points were lower starting out, and precipitation
was going to be heavier on Sunday--maybe I could get a little 
more excited about the prospect for lowland snow. Looking behind 
the front--as we get into Monday and Tuesday the air will be much 
colder aloft but the shower activity looks light and spotty. The 
next front will approach the coast Tuesday afternoon but precip 
Tuesday night does not look like much and the heavier precip will 
be well south of our area. 19

moist enough for shower activity at times--although California
looks a lot more interesting Wed and Thu. Another front or two
arrive late in the week--but it is too early to say much about 
that other than a low snow level is likely, but nothing yet looks
like a slam dunk for the lowlands. I think as time goes by, the
BLI-YWL gradient will look better--if by Thursday that is up
around -10mb and some genuine cold air is flowing down the Fraser,
that will make the forecast a lot easier for those areas that get
some colder air in place. 19


.AVIATION...The next frontal system will approach the region
tonight and move through the area Sunday. Current radar this 
evening already shows some light precipitation across portions of
the Southwest Interior this evening, with ceilings at area
terminals (KHQM and KOLM) already lowering down to MVFR. 
Current conditions at Puget Sound terminals remain VFR this 
evening, however expect MVFR ceilings and light rain to move in 
late tonight and overnight. Ceilings are likely to then lower to 
low- end MVFR /high- end IFR by Sunday morning and afternoon, 
with rain eventually turning to showers. Some snow may mix with 
rain or rain may change over to snow at times-the terminal most 
likely to experience this currently appears to be KBLI. Though, 
with southerly flow expected to increase across the area, this may
act to hold off any rain-to-snow chances for the terminal. Will 
need to continue to monitor trends over the next several hours. 
Winds out of the S today 5-10kts, increasing Sunday 8-12kts.

KSEA...Current conditions are VFR conditions this evening,
however except these to drop to MVFR overnight with light rain 
after midnight. Rain will taper to showers Sun morning, with 
ceilings continuing to fall to lower- end MVFR. Currently expect 
all precip to be rain through Sunday. Winds S 5-10 kts today, 
increasing to around 10kts Sunday.



.MARINE...The next frontal system is set to move through the area
tonight and Sunday. This will bring increasing winds to all area 
waters, with gale force winds likely over the Outer Coastal Waters
and Small Craft Advisories for all other waters except Puget 
Sound (which will be close). Based on latest guidance, have 
increased winds and headlines a bit earlier than previously 
forecast-with winds expected to pick up after midnight. Rain and 
low clouds will accompany the winds, making for a dreary day 
tomorrow. Winds will gradually ease through the afternoon and 
evening tomorrow, with swells increasing to between 10-15 ft 
across the near-shore coastal waters and 16-19 ft further offshore.
This will keep a SCA for all offshore waters and Grays Harbor Bar
through at least Monday afternoon. 

Unsettled (and colder) conditions will continue through next week, 
with periodic episodes of SCA winds and seas accompanying each 
frontal system. Another round of gale force winds appears possible 
on Tuesday for the offshore waters.



HYDROLOGY...No river flooding expected through the next 7 days.


PZ...Small Craft Advisory from 6 PM Sunday to 4 PM PST Monday for 
     Coastal Waters From Cape Flattery To James Island 10 To 60 
     Nm-Coastal Waters From James Island To Point Grenville 10 
     To 60 Nm-Coastal Waters From Point Grenville To Cape 
     Shoalwater 10 To 60 Nm.

     Gale Warning from 1 AM to 6 PM PST Sunday for Coastal Waters 
     From Cape Flattery To James Island 10 To 60 Nm-Coastal 
     Waters From James Island To Point Grenville 10 To 60 Nm-
     Coastal Waters From Point Grenville To Cape Shoalwater 10 
     To 60 Nm.

     Small Craft Advisory from 10 AM Sunday to 4 PM PST Monday for 
     Grays Harbor Bar.

     Small Craft Advisory from 1 AM Sunday to 4 PM PST Monday for 
     Coastal Waters From Cape Flattery To James Island Out 10 Nm-
     Coastal Waters From James Island To Point Grenville Out 10 
     Nm-Coastal Waters From Point Grenville To Cape Shoalwater 
     Out 10 Nm.

     Small Craft Advisory from 1 AM to 6 PM PST Sunday for Admiralty 
     Inlet-Central U.S. Waters Strait Of Juan De Fuca-East 
     Entrance U.S. Waters Strait Of Juan De Fuca-Northern Inland 
     Waters Including The San Juan Islands.

     Small Craft Advisory from 1 AM to 10 AM PST Sunday for West 
     Entrance U.S. Waters Strait Of Juan De Fuca.




[ W WA | SW WA and W OR | SE WA and NE OR | NE WA and N ID ]

Southwestern Washington and Western Oregon

FXUS66 KPQR 240540 AAA

Area Forecast Discussion
National Weather Service Portland OR
940 PM PST Sat Jan 23 2021

.SYNOPSIS...Mother nature continues to bring the region back to
'typical January' weather over the next few days, with cool
temperatures and low snow levels. Front arriving later tonight will
spread rain inland, with snow to a 1000 to 1500 ft range, though
could be a tad lower over Cowlitz Valley. Then, showery for Sun night
through Mon evening, with snow levels 800 to 1500 ft. A break in the
weather Monday night with dry conditions. Then another front arrives
Tue with rain and snow levels near 1500 feet. Seasonably cool and
unsettled weather continues through rest of next week.


.SHORT TERM...Tonight through Tuesday...No significant developments 
with a look at the early 00Z models and current observations. 
Satellite is showing good baroclinic leafing ahead of the 
approaching frontal system. This was expected as somewhat warmer 
southerly flow aloft gets lifted over the cooler surface air. 

Again, no 00Z Salem sounding data given communications issues 
occurring well beyond the control of this office, but don't feel 
like it would help much at this time as the front is still well 
offshore and approaching from the northwest. 

Did bring some very light snow accumulations down toward river level 
in the Longview/Kelso/Rainier area for late tonight/early Sunday 
morning. It's questionable as to how much, if any, will accumulate 
on roadways, but the non-paved surfaces may pick up less than a 1/2" 
by daybreak. That's about it for the lowest elevations across the 
region as southerly flow and relative higher pressure west of the 
Cascades will help keep temperatures just warm enough to prevent 
much interesting snow to occur below 700 feet for the next 36-48 
hours. Some flakes will mix in with the rain, perhaps even down to 
sea level at the coast through Monday evening. /JBonk

Remaining previous discussion follows: As of 1 pm, the next weather 
system was about 200 miles offshore, or just crossing long 130W. 
This front will bring increasing clouds this evening, with rain to 
the coast after midnight, and spreading inland late tonight into 
early Sunday morning. But, this timing will be problematic, thanks 
to the chilly air mass in place. Most of the low to mid-level flow 
will turn more southerly overnight, with air mass moderating just a 
enough to maintain rain for the interior lowlands below 1000 feet. 
Does seem that could see some snowflakes mixed with the rain as the 
precipitation starts, likely between 5 amd and 7 am well inland. 
But, any accumulation will stay at/above 1000 feet. 

But, areas to north of Portland could have some problems. Modeled
soundings suggesting that air mass will be just above freezing for
parts of southwestern interior of Washington. As precipitation
starts, air mass will cool a tad. But, soundings suggest that will
not take much to maintain a pro-snow environment down to the valley
floor. As such, think will see a period when the rain transitions
over to mostly snow for a time, roughly 6 am to 10 am, for good part
of the Cowlitz River Valley, and southward towards Ridgefield and
across northern Clark County, including Battle Ground. Ground will be
cold enough to support minor accumulations, generally less than an
inch and more likely a dusting to half inch. Still, could be enough
to make for potentially messy driving conditions at times. Do have
current Winter Weather Advisory for elevations above 1000 ft for
later tonight through Sunday morning. But, add to that the areas
above 500 feet for Cowlitz Lowlands, and above 700 feet in Clark and
North Willamette Valley for Sunday morning. 

Similar conditions expected in the eastern Columbia River Gorge, with
snow levels will be between river level and 500 feet. But, with onset
of precipitation being bit later in the morning, potential for low
elevation snow is less, thanks to temperatures being a tad warmer.
Snow will fall in the higher terrain of the Coast Range, Willapa
Hills and foothills of the Cascades. As such, with snow levels 1000
to 1500 feet, will maintain current Winter Weather Advisory for those
areas, as well as Cascades of Lane County. Total snowfall generally 2
to 6 inches, with 3 to 8 inches in Cascades.

Precipitation will become more showery in nature by afternoon, as the
front shifts farther inland and more unstable air mass shifts inland.
Overall, will maintain cool air mass, with snow levels 800 to 1200
feet inland for Sunday night and Monday morning. But, depending on
intensity of showers, could see snow levels lower bit lower under the
heavier showers, as the cold air aloft gets dragged downward,
allowing snowflakes to survive lower towards the ground. But, any
accumulations to the valley floor will be rather light, and very
hit-n-miss. Overall trend will be towards decreasing showers. 

Showers decreasing on later Monday into Monday night. This as the
main low upper trough shifts inland over the Pac NW. At moment, not a
lot of support for showers overnight Mon night. But, will keep 10-20
PoPs for the coast/coastal mtns, and dry inland. Will be chilly, with
overnight lows dropping into upper 20s to lower 30s.

Another front arrives on Tuesday. Though snow levels start low,
perhaps at 500 to 1000 feet in the morning. This could be another
challenging forecast, thanks to the snow potential as the front
arrives. Models continue to slow this front down a bit, with rain not
reaching coast until sometime Tue morning, with precipitation
spreading inland in the afternoon. If so, this could result in
slightly higher snow levels. For now, will keep formerly mentioned
trend, and let future shifts re-evaluate models/trends for evolving
Tue forecast. But, would not be surprised if this gets delay a bit,
allowing for temperatures inland to warm a bit as get tad more
southerly flow in advance of the front. 		     /Rockey

.LONG TERM..Tuesday night through Saturday...No big changes. Main
upper low/trough will sit just offshore for Tue night through Thu.
This will maintain unsettled weather, with some chance of showers.
Snow levels will stay in the 1000 to 1500 feet through that time,
with brief periods down to 500 to 1000 ft at times with any heavier
showers. Main story will be continued cool weather, with highs in the
lower to middle 40s and overnight lows in upper 20s to middle 30s.
That trough will shift inland later Thu night into Fri, with
decreasing showers. But, another system from the Gulf of Alaska will
drop southeast into the Pac NW next weekend, bring more precipitation
and chilly air. While snow levels look to stay in 1500 to 2000 range
on Saturday, there is some indication snow levels again drop back to
500 to 1500 feet by next Sunday. Lowlands snow lovers...stay tuned,
as it is that time of the year.   /Rockey


.AVIATION...Mid and high level clouds increasing across the area
with light showers at the coast. Cigs generally 035-050 inland
and 030-035 at the coast. Rain is expected to start along the 
coast between 09-10Z Sunday. Ceilings will deteriorate into MVFR
criteria in the valley after 12Z, possibly IFR at times 15Z- 21Z
per current CONSshort guidance. GFS and NAM relative humidity 
and condensation pressure deficit support the idea of IFR cigs. 
Snow levels will drop to around 1000 ft leading to a mixture of 
precipitatiion across the region. Low level southwesterly flow 
and cloud cover will keep overnight lows above freezing reducing 
any chances for freezing rain to develop. Low elevation areas 
north of KMMV and around KKLS will likely have lower snow levels 
so may see a rain-snow mix. 

For detailed regional Pac NW weather information, go online to: 

KPDX AND APPROACHES...Currently VFR with cigs around 045. 
Ceilings will lower into 1500-2000 ft late tonight with light 
rain. A rain-snow mix is likely around 15Z for a couple hours 
before transitioning back to rain but no accumulation is
expected. IFR cigs and visibilities possible 15-21Z. 
/mh -BPhillips


.MARINE...Fast moving cold front is expected to cross over the
waters late Saturday night into Sunday morning. The period of
southerly winds within the warm front will be brief and
transition to a northwesterly wind regime by 8 to 10 AM Sunday. 
The cold airmass being transported south from the Gulf of Alaska 
will assist in mixing down stronger winds aloft. A Gale Warning 
is in effect starting 10 AM Sunday. Wind gusts between 35-40 kt 
behind the cold front are likely to persist through Monday 
morning. Seas will build into the mid to upper teens Sunday
afternoon and stay above 15 ft through Monday afternoon.
Probabilistic wave guidance shows a 50-60% chance that PZZ270 
seas will reach between 18-20 ft. Winds will diminish to below 
SCA criteria Monday night. 

A weakening but still potent system will drop south Tuesday
bringing another round of high winds and building seas. The 
system will open up spreading gale and storm force winds across 
much of the NE Pacific. There is potential for storm force winds ahead
of the cold front which will swing across the coastal waters 
Tuesday afternoon but confidence is low at this time. Wave 
heights will continue to trend between 12-14 ft Tuesday through 
Wednesday. -BPhillips


OR...Winter Weather Advisory from 4 AM to 4 PM PST Sunday for 
     Central Coast Range of Western Oregon-Northern Oregon 
     Cascade Foothills.

     Winter Weather Advisory from 7 AM to 7 PM PST Sunday for 
     Cascade Foothills in Lane County-Cascades in Lane County.

     Winter Weather Advisory from 4 AM to noon PST Sunday for 
     Greater Portland Metro Area.

     Winter Weather Advisory from 4 AM to 1 PM PST Sunday for Lower 

     Winter Weather Advisory until noon PST Sunday for Coast Range 
     of Northwest Oregon.

WA...Winter Weather Advisory from 4 AM to noon PST Sunday for 
     Greater Vancouver Area.

     Winter Weather Advisory from 4 AM to 1 PM PST Sunday for I-5 
     Corridor in Cowlitz County-South Washington Cascade 

     Winter Weather Advisory until noon PST Sunday for Willapa Hills.

PZ...Gale Warning from 7 AM to 4 PM PST Sunday for coastal waters 
     from Cape Shoalwater WA to Florence OR from 10 to 60 NM.

     Small Craft Advisory from 10 AM Sunday to 10 AM PST Monday for 
     Columbia River Bar.

     Gale Warning from 10 AM to 4 PM PST Sunday for coastal waters 
     from Cape Shoalwater WA to Florence OR out 10 NM.



Interact with us via social media: 

[ W WA | SW WA and W OR | SE WA and NE OR | NE WA and N ID ]

Southeastern Washington and Northeastern Oregon

FXUS66 KPDT 240418

Area Forecast Discussion
National Weather Service Pendleton OR
818 PM PST Sat Jan 23 2021

.UPDATE...It has been a quiet evening with mostly clear skies, 
except for some local areas of mist or light fog near the 
surface. However, the vast majority of the forecast area is mostly
clear to clear with light winds. This is allowing for rapid 
radiational cooling. High thin clouds are now starting to move in 
over the central Washington Cascades from the northwest ahead of 
the next approaching weather system. The latest 00Z models are 
showing it to be cooler with this weather system, and they have 
increased snowfall amounts slightly. However, the weather system 
is still expected to stretch apart and weaken as it moves into the
Pacific Northwest on Sunday. It appears that the onset of 
precipitation will be slightly later than previously expected, 
but the difference is negligible. Precipitation type will be snow 
in all areas, including the Lower Columbia Basin. Only a few 
inches are expected in the Cascades and the northeast mountains, 
with up to an inch or so in the lower elevations. This system will
loose it's moisture as it stretches apart and weakens. Highlights
will not be needed with this system. There will be a break later 
Monday and Monday night into Tuesday morning, before the first in 
a long series of weak disturbances moves in by Tuesday evening, 
with unsettled weather for the remainder of the week. The models, 
as well as the ensembles are showing a slow warming through the 
latter half of the coming week with gradually increasing snow 
levels each day, resulting in more rain than snow for some areas
such as the Foothills of the Blue Mountains. In the Lower 
Columbia Basin and the Yakima/Kittitas Valleys precipitation type 
will be mainly snow or possibly a mix of precipitation as cold 
air will remain trapped in those areas against the Cascade east 
slopes. 88


.AVIATION...06Z TAFs...VFR conditions will prevail overnight,
except for possible brief periods of MVFR conditions due to
decreased visibility in mist or light fog. On Sunday, have backed
off on the onset of the expected snow a little, but when the snow
begins conditions will deteriorate to MVFR or possibly IFR at
times. Winds will remain light, and less than 10 kts at all 
terminals through the period. 88


.PREV DISCUSSION... /issued 252 PM PST Sat Jan 23 2021/ 

SHORT TERM...Tonight through Monday night...It will be a
relatively quiet night weather wise due to a shortwave ridge over
the region. Typically, a strengthening low level inversion would 
increase confidence of fog and low clouds for the Lower Columbia 
Basin and surrounding areas. However, increasing mid and high
level clouds will limit radiational fog development. Will keep
patchy freezing fog in the forecast but cannot rule out that dense
freezing fog is possible, particularly along the Blue Mtn

An upper level trough,currently between 140-150W, will approach
the coast early Sunday morning and will move onshore during the
afternoon. The trough will gradually migrate over WA/OR Sunday 
night and Monday, stretching and weakening east of the Cascades 
by Monday night. This trough is not very organized and has 
limited upper level support. No winter highlights are planned with
this approaching system. The main impact will be snow at almost 
all elevations. Snow levels will be around 1000-1500 feet during 
the day, therefore only a small portion of the forecast area will 
have a snow/rain mix. Overall, snow accumulations of 1-3 inches 
are forecast for the mountains (higher near the Cascade crest) and
up to 1 inch in the lower elevations. This ties closely with the
GEFS and ECMWF ensembles that have very low probabilities of 3+ 
inches across the forecast area. HREF members up to 12Z Monday are 
also showing similar amounts as in the forecast.

No wind concerns are anticipated during the short term forecast.
The Grande Ronde will likely have breezy winds Sunday but no 
significant winds. Wister

LONG TERM...Tuesday through Saturday...Ensembles show a persistent 
upper level trough just off the coast through the period. This will 
result in general southwest upper level flow across the area with an 
almost never-ending parade of weak disturbances moving through the 
Pacific Northwest. The best chance of precipitation will remain over 
the mountains.  However, the Columbia Basin could see some light 
snow Tuesday night before the lower atmosphere warms above freezing 
by late Wednesday. The warm air advection continues through the 
period with daytime highs warming slightly each day. The 
deterministic models show temperatures above normal by the weekend 
while the NBM slightly lags in this warmup. With the strong 
southwest flow, warmer temperatures seem a good bet and would not be 
surprised if the NBM starts to trend towards a warmer forecast. Snow 
levels will begin the period near the surface but warm to near 1500 
feet in the north to 3000 feet in the south by Saturday.  Earle 


PDT  25  35  28  38 /   0  20  40  10 
ALW  27  36  30  38 /   0  20  40  20 
PSC  26  36  30  39 /   0  20  40  10 
YKM  26  34  25  39 /   0  40  30  10 
HRI  27  37  29  41 /   0  20  40  10 
ELN  25  33  25  36 /   0  40  30  10 
RDM  21  38  21  37 /   0  50  40  10 
LGD  19  34  27  34 /   0  10  50  20 
GCD  21  40  25  36 /   0  20  50  20 
DLS  29  39  31  42 /   0  80  60  10 






[ W WA | SW WA and W OR | SE WA and NE OR | NE WA and N ID ]

Northeastern Washington and Northern Idaho

FXUS66 KOTX 240607

Area Forecast Discussion
National Weather Service Spokane WA
1007 PM PST Sat Jan 23 2021

Light snow will return to the Inland Northwest Sunday and linger
into Monday. Additional snow chances will come Tuesday night 
through the weekend. Most impacts to commutes will begin Wednesday
into the latter half of the week. 


Tonight: Today's incoming dry air will clear the region from the 
earlier cloud deck and bring another chilly evening ahead. After a 
cool day, low temperatures will drop into the single digits and 
teens in the northern mountains and down into the low 20s elsewhere. 

Sunday through Monday Night: A low to our north off the British 
Columbia coast is beginning to drop southward and by Monday, will be 
resting off the Pacific Northwest coastline. As this low lingers, 
there will be a light, prolonged snowfall across much of the region, 
especially in northeastern WA and northern Panhandle. The light 
snowfall totals, from mid-Sunday into Monday morning, is not looking 
to reach advisory levels. Most may only see an 1-2" over a 24-36 
hour time period. High elevations and northern mountainous terrain 
will receive closer to 2-5", which is light for the extended time 
period. Additionally, the most recent model runs have dropped the 
QPF values even lower to bring less snow than previous forecasts 
indicated. Snow totals may be fluctuating, but not by much and 
still keeping a light snow. 

This is not an out-of-season event, but caution should be taken in 
the Monday commute. Most snowfall will be overnight Sunday with 
temperatures remaining below freezing into the morning hours.

Temperatures on Sunday and Monday will remain near seasonal with 
highs into the upper 20s and mid-30s. Overnight lows will be a bit 
warmer, with the extended cloud coverage, compared to previous 
evenings only dropping into the teens and upper 20s. JS

Tuesday through Saturday: An active weather pattern is in store
next week. A messy longwave trough will set up off the West 
Coast, and multiple impulses will move through before a longwave 
ridge pushes the trough to the east at the beginning/middle of the
following week. This means several days with precipitation for 
the Inland Northwest and drier weather to follow.

After a lull Monday night into Tuesday morning, during which fog
and freezing fog may develop, precipitation chances return 
late Tuesday afternoon to the Cascades. By Wednesday morning, 
much of forecast area will be in or near snow showers. This 
continues Thursday but the precipitation won't be as widespread. 
Thursday night into Friday could bring a break from precip aside 
from residual mountain showers. Chances of precip increase again 
Friday night through Saturday.

Most of the precipitation this week is expected to be snow, and some
rain could mix in roughly along and south of the Snake River 
Valley in the afternoons. Regarding accumulations, light to
moderate (higher terrain) snow is expected each day, so there 
will be a few inches on the ground in many places by the time 
drier weather arrives next week. Overall, expect impacts to the 
morning and evening commutes multiple days this week starting 
Wednesday morning. RC


06Z TAFs: Ceilings of 1500-3000 feet will be associated with a
ragged stratus deck around Spokane, Coeur d'Alene, Sandpoint,
Colville and Omak through the night. Without much warm, moist
advection until after 12z, there will be holes in the low cloud
deck before becoming more widespread in the morning. Bands of
light snow will spread across the Cascades by mid day producing
visibility reductions around Wenatchee, Chelan, Omak and Moses
Lake. Light snow should arrive around Spokane and Coeur d'Alene
between 23z and 03z. Runway accumulations will be be light and
gradual with this weak system. /GKoch


Spokane        20  31  26  32  25  33 /  10  20  60  30  10  10 
Coeur d'Alene  18  33  26  33  24  33 /  10  20  50  30  10  10 
Pullman        22  34  26  32  24  34 /   0   0  50  30  10  10 
Lewiston       25  38  31  39  28  40 /   0   0  40  30  10  10 
Colville       14  28  22  32  22  32 /   0  20  50  20  10  10 
Sandpoint      18  29  25  31  25  31 /  10  30  50  30  20  10 
Kellogg        19  33  26  32  25  33 /   0   0  30  40  20  10 
Moses Lake     23  34  26  36  24  37 /   0  30  50  10   0  10 
Wenatchee      23  32  25  34  23  31 /   0  60  60  10  10  10 
Omak           20  29  26  34  25  33 /   0  40  60  10  10  10 





[ W WA | SW WA and W OR | SE WA and NE OR | NE WA and N ID ]

Back to U.W. Weather Page