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

Western Washington


250 
FXUS66 KSEW 111518
AFDSEW

Area Forecast Discussion
National Weather Service Seattle WA
815 AM PDT Sun Apr 11 2021

.SYNOPSIS...An upper ridge will build over British Columbia through 
the week ahead as an upper low develops over the Great Basin. A weak 
upper trough might touch off some showers over the Cascades Monday 
afternoon. Otherwise, Western Washington will have dry weather with 
a warming trend in the week ahead.

&&

.SHORT TERM /TODAY THROUGH TUESDAY/...Chilly at daybreak and again 
Monday morning, but skies are mostly clear and Western Washington 
will see a warming trend in the week ahead. High temps today will 
still be cool--in the 50s. There is a little upper trough that will 
drop south out of British Columbia on Monday so our warming trend 
starts out pretty slow. Highs will probably struggle to see 60 on 
Monday and a few showers could develop over the Cascades in the 
afternoon. I think the sunny forecast for Monday in the Cascades 
will probably need to be adjusted for some clouds and a chance of 
showers in the afternoon. That trough moves south through Oregon 
Monday night and then heights start to rise as an upper ridge begins 
to build into British Columbia. Even as a large upper low develops 
over the Great Basin in the week ahead, upper ridging over B.C. and 
Alberta will allow high temps to warm to the upper 50s to mid 60s on 
Tuesday and then even warmer after that. 19

.LONG TERM /WEDNESDAY THROUGH SATURDAY/...Dry weather expected to
continue through the long term with upper level ridging offshore 
and an upper level low to the southeast of the region centered 
over eastern Oregon/Idaho. A rex block pattern then looks to 
develop late in week as the upper level high amplifies over 
Canada and the low remains situated to the southeast of the region.
High temperatures will gradually continue to warm throughout the 
week, topping out in the upper 60s to low 70s by Friday and 
Saturday. Overnight lows will be in the upper 30s to mid 40s. 14

&&

.AVIATION...Norther to northwest flow aloft will continue through
tonight with an upper ridge offshore. At the surface, offshore
flow will develop today and continue to night with a trough near
the coast and higher pressure east of the Cascades. The air mass
will be stable. Skies will be mostly clear after patchy low 
clouds burn off this morning.

KSEA...Mostly clear. There will be some patchy low clouds in the 
area this morning but they are not expected to affect the 
terminal. Light southeast wind will become north 6-12 knots this 
afternoon. Schneider

&&

.MARINE...Offshore flow will develop today and continue through
much of the upcoming week. 

West swell 10-12 feet over the Coastal Waters will subside below
10 feet later today. There will be small craft advisory strength
north to northwest winds over the Coastal Waters at times the next
few days, mainly late afternoon and evening hours. There will 
also be small craft advisory strength northerly winds for much of 
the inland waters Monday afternoon and evening. Schneider


&&

.HYDROLOGY...River flooding not expected over the next 7 days.

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...None.
PZ...Small Craft Advisory until 2 PM PDT this afternoon 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 until 11 AM PDT this morning 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-Grays Harbor Bar.

&&

$$

www.weather.gov/seattle

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

Southwestern Washington and Western Oregon


845 
FXUS66 KPQR 111657
AFDPQR

Area Forecast Discussion
National Weather Service Portland OR 
956 AM PDT Sun Apr 11 2021


Updated aviation and marine discussions...


.SYNOPSIS...After a chilly and frosty start, will see a sunny day
today, with plenty of sunshine. Overall, high pressure over the
region will maintain dry sunny days and somewhat cool nights for the
coming week. The combination of high pressure over the inland Pac NW
and weak thermal trough along the coast will result in light to
moderate offshore flow from time to time. 


&&


.SHORT TERM...Today through Tuesday...Rather chilly air mass across
the region this morning, with 2 am temperatures in the lower to
middle 30s. Will see temperatures drop to the upper 20s to lower 30s
through 6 am, with quite a bit of frost. Fortunately, not too many
temperature sensitive plants have been planted in gardens yet. 

But, after chilly start, will see temperatures bound well into the
50s today under sunny skies. High pressure over the inland Pac NW
will move little over next several days. Upper trough digging
southward over the northern Rockies will contribute to maintaining
the high, along with somewhat cooler air mass. Overall, expect cool
nights again tonight, and possibly Monday night. But, will not be as
cold as this am. So, will keep frost patchy for tonight, mainly owing
to bit warmer temperatures and bit more wind for Sun night. 

Thermal trough will build north along the Oregon coast today into
tonight. This thermal trough will not move much through Tue. This
pattern will promote light to moderate offshore flow over the region
from time to time, with east to northeast winds 10 to 20 mph with
gusts to 30 mph along the coast and higher terrain of the coastal
mountains. Will see bit more way of northerly winds for the interior
in the afternoons, mainly Mon again on Tue. 

Overall, this pattern will bring mild days, and cool nights for next
several days.						  /Rockey


.LONG TERM...Wednesday through Saturday...Deterministic and ensemble 
guidance agree that the long term forecast will remain dry throughout
the period. Upper low pressure over eastern Oregon on Tue will sink
slowly southward into the Great Basin for Wed and Thu. Overall,
expect dry conditions, with slow warming trend for later in the week.
Still moderate potential of interior locations reaching into the 70s
maybe Thu, but more likely for Fri and Sat.	

	     
&&


.AVIATION...High pressure over Canada and thermally induced lower
pressure along the northern California and southern Oregon coast
will lead to VFR conditions areawide through 18z Monday. Expect
north to northwesterly wind gusts of 15 to 25 kt to develop at
many taf sites between 21z Sunday and 03z Monday, particularly
along the coast and in the southern Willamette Valley.

For detailed regional Pac NW aviation weather information, go 
online to: https://weather.gov/zse

KPDX AND APPROACHES...High pressure over Canada and thermally
induced lower pressure along the northern California and 
southern Oregon coast will lead to predominantly VFR conditions 
through 18z Monday. Expect north to northwesterly winds of 10 to
15 kt to develop between ~00-05z Monday. /Neuman


&&


.MARINE...High pressure currently over the northeast Pacific is 
expected to remain nearly stationary through at least the middle
of next week. Thermally induced lower pressure along the 
southern Oregon coast will gradually spread northward today and 
Monday, which will produce a summer-like gusty northerly wind 
pattern across the coastal waters. The pressure gradient is 
expected to decrease across the waters Wednesday with wind speeds
generally falling below Small Craft Advisory criteria at that
time.

Seas are currently hovering in the 11 to 13 ft range this morning
and remain a couple feet above model guidance. Nonetheless, 
seas should gradually lower below 10 ft today as the incoming 
fresh swell dissipates. With that said, the fall should be 
somewhat gradual as northerly winds strengthen today and bring 
an increasing wind wave component to the seas this afternoon and 
evening. Seas may become particularly steep and hazardous as 
dominant wave periods fall into the 7 to 10 second range. 

Wind gusts should peak around 30 kt across the waters off the
central coast of Oregon late this afternoon and evening. High 
resolution models do suggest there is a chance wind gusts could 
peak closer to 35 kt, but past history would suggest this is 
unlikely except perhaps in the waters directly off Florence. As a
result, will keep a Small Craft Advisory in place and hold off on
any Gale products. Expect similarly windy conditions to redevelop
Monday afternoon and evening across the waters. Winds should end
up a few knots less on Tuesday and then drop more dramatically 
by Wednesday. 

Stronger offshore flow will be possible late in the week, which 
could produce some gusty winds near the gaps in the Coast Range, 
but whether or not these will be strong enough to meet Small 
Craft Advisory thresholds remains uncertain at this point. High 
pressure looks to more or less persist across the northeast 
Pacific through next weekend so not expecting too many wind and 
seas concerns through that time. There is a chance a southerly 
wind reversal could bring a brief bout of gusty southerly winds 
and fog to the waters towards next weekend, but plenty of 
uncertainty exists at this point in when that will occur and how 
pronounced it will be. /Neuman 


&&


.PQR WATCHES/WARNINGS/ADVISORIES...
OR...None.
WA...None.
PZ...Small Craft Advisory until 9 PM PDT Monday for Coastal waters 
     from Cascade Head to Florence OR out 10 NM-coastal waters 
     from Cape Shoalwater WA to Florence OR from 10 to 60 NM.

     Small Craft Advisory until midnight PDT tonight for Coastal 
     waters from Cape Shoalwater WA to Cascade Head OR out 10 
     NM.

     Small Craft Advisory until 9 PM PDT this evening for Columbia 
     River Bar.

&&


$$

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

Southeastern Washington and Northeastern Oregon


650 
FXUS66 KPDT 111634
AFDPDT

Area Forecast Discussion
National Weather Service Pendleton OR
934 AM PDT Sun Apr 11 2021

.AVIATION...18Z TAFs...Clearing stratocu this morning at BDN/RDM.
Otherwise few afternoon cumulus buildups today with winds 10kts or
less. Some passing this cirrus tonight into tomorrow morning with
light winds. A front swinging through later tomorrow will bring 
north to northeast winds 10-15kts with higher gusts and increasing
mid level clouds tomorrow afternoon.

&&

.PREV DISCUSSION... /issued 410 AM PDT Sun Apr 11 2021/ 

SHORT TERM...TODAY THROUGH TUESDAY...An upper level ridge is off 
the coast while an upper level trough is over the northern Rockies 
and Plains. This will keep the forecast area under a dry northwest 
flow today with mostly clear skies and light winds. There will be 
some stratus clouds this morning over central Oregon that will 
slowly dissipate. On Monday a dry shortwave over western Canada will 
drop into the Pacific Northwest and begin to form a closed low that 
slowly drops south and over southern Oregon on Tuesday. Since this 
system originated over western Canada there will not be much 
moisture associated with it so just expecting some partly cloudy 
conditions but no Precipitation. The biggest impact from this system 
will be some increasing winds from the northeast late Monday that 
will peak on Tuesday and then linger into Wednesday. This pattern 
will keep temperatures a little cooler than normal for mid April 
with chilly below freezing nights including in the Columbia Basin.  

LONG TERM...Wednesday through Sunday...A large closed low will have 
several waves rotating around it across the western half of the U.S. 
on Wednesday. Any precipitation will be on the southern periphery of 
the low south of the forecast area.  The closed low will gradually 
fill and flatten in response to a strengthening ridge over western 
Canada.  While most of the forecast area will be under a dry 
easterly flow aloft on Thursday, there may be a few light snow 
showers over the Wallowas.  Friday through Sunday's forecast remains 
dry and warm, although there are model differences on the details of 
the decaying low and the ridge to the north.  The differences are 
relatively minor in terms of the overall forecast. A large upper low 
developing west of 140W this coming weekend will likely play a role 
in the weather across the PacNW early next week.  

No major weather concerns are anticipated during the long term 
period.  Breezy NNE winds on Wednesday will not be as strong as 
Tuesday.  The temperatures climbing into the mid 60s to mid 70 at 
the end of the week are about 10 degrees above seasonal average. 
This will enhance snow melt from the higher elevations that 
currently are around 95-120 percent of average snowpack. River and 
stream rises are likely but minimal chance for flooding. Wister/85

&&

.PRELIMINARY POINT TEMPS/POPS...
PDT  54  29  58  37 /   0   0   0   0 
ALW  56  32  61  38 /   0   0   0   0 
PSC  59  32  64  41 /   0   0   0   0 
YKM  58  30  61  36 /   0   0   0   0 
HRI  59  29  63  39 /   0   0   0   0 
ELN  54  29  58  35 /   0   0   0   0 
RDM  56  22  59  27 /   0   0   0   0 
LGD  49  27  53  31 /   0   0   0   0 
GCD  53  28  57  31 /   0   0   0   0 
DLS  61  35  64  41 /   0   0   0   0 

&&

.PDT WATCHES/WARNINGS/ADVISORIES...
OR...None.
WA...None.
&&

$$

SHORT TERM...91
LONG TERM....85
AVIATION.....84

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

Northeastern Washington and Northern Idaho


932 
FXUS66 KOTX 111847
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
1147 AM PDT Sun Apr 11 2021

.SYNOPSIS...
Today will feature light winds and cool, sunny conditions. A 
pattern shift Monday through Wednesday will bring gusty north and 
northeast winds and little to no rainfall. The strongest winds 
look to arrive Tuesday. Temperatures are expected to warm into the
60s to 70s towards the end of the week.

&&

.DISCUSSION...
Clear skies across most of Washington this morning, and clearing
skies as clouds lift and move east out of northern Idaho. On
visible satellite the snow in the Cascades and the Olympic
mountains shows up quite nicely. Some fair-weather clouds are
beginning to develop along the terrain in the northeast mountains
and Okanogan Highlands. Winds are much calmer this morning and
clear skies overnight allowed many areas to radiate out and cool
down into the low to mid 20s. 

..STRONG NORTHEAST WINDS TUESDAY...

Today should be a nice day for any outdoor plans before the week
begins and we have what may seem like a repetitive pattern of
breezy to windy conditions throughout most of the week. Each
weather disturbance that moves through will be moisture starved
but will bring about breezy to gusty winds. The first will begin
to develop Monday night and shift the winds out of the northeast,
more of a back-door cold front, which will amplify the east-
northeast wind gradient as an upper level low slides south into
the Great Basin. Through the week ahead, this Low will park itself
in the Great Basin keeping us here in the Inland Northwest in a
northerly flow pattern and mostly dry. /Dewey

&&





AVIATION... 
18Z TAFS: Weak pressure gradient and a dry trending airmass will
leave VFR skies with light winds for the next 24-hours for all
airfields in the area. /Dewey

&&

.PRELIMINARY POINT TEMPS/POPS...
Spokane        50  27  55  33  55  33 /   0   0   0   0   0   0 
Coeur d'Alene  49  26  53  31  53  30 /   0   0   0   0   0   0 
Pullman        47  27  53  32  53  30 /   0   0   0   0   0   0 
Lewiston       54  31  59  36  59  35 /   0   0   0   0   0   0 
Colville       53  25  56  29  58  30 /   0   0   0   0   0   0 
Sandpoint      47  27  52  32  52  32 /  10  10  10   0   0   0 
Kellogg        44  28  48  32  48  31 /  10  10   0   0   0   0 
Moses Lake     57  28  62  37  62  36 /   0   0   0   0   0   0 
Wenatchee      54  33  58  37  60  38 /   0   0   0   0   0   0 
Omak           57  30  60  33  63  34 /   0   0   0   0   0   0 

&&

.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.

&&

$$

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