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000
FXUS66 KOTX 261157
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
457 AM PDT THU MAY 26 2016

.SYNOPSIS...
Expect mild weather with isolated mountain showers again today.
The arrival of a cold front tonight will bring cooler
temperatures for the Memorial Day weekend, along with a good
chance for showers over the Idaho Panhandle and the mountainous
portions of Washington. Expect breezy conditions as well. Look for
a gradual warming trend after the Memorial Day weekend, with upper
60s to mid 70s by early next week.

&&

.DISCUSSION...

Today through Friday Night: One wave is exiting this morning which
brought rain to portions of northeast WA and north ID overnight.
Another wave will move west to east through the day ahead of the
closed low approaching the area. Expect clouds to increase through
the day ahead of the cold front set to move across the area this
evening and overnight. Afternoon showers are possible across
northern WA and north ID. The moisture isn`t great with the front
moving through tonight. A Chance of showers exists across
northeast WA and north ID, but the best chance will be in Ferry
and Stevens Counties. Winds will increase this morning across the
east slopes. Southwest winds 10-15mph will spread into the Basin,
Spokane and Palouse later this afternoon. The winds in the east
slopes into the Wenatchee and Waterville Plateau will peak late
this afternoon/early this evening. Northwest winds 15-20 mph with
gusts to 30 mph is possible. Friday showers will continue across
the region, mainly impacting northern WA and ID. 500mb temps in
the afternoon approach -26C along with some decent cape and
lingering mid level moisture will prompt the possibility of
thunderstorms north of a line from Republic to Sandpoint. Chance
of precipitation wanes through the night. Temperatures today will
be around average-mid 60s to mid 70s. Friday we drop below average
with temperatures in the upper 50s to upper 60s. Overnight lows
will be in the 40s. Friday night some of the usual colder
locations could drop down into the mid 30s. /Nisbet

Saturday through Thursday: The most notable difference in model
guidance for the mid and extended range fcst was the much slower
and deeper GFS solution with the Sunday frontal passage, and
especially the upper trough. The Nam and Ecmwf were in much better
agreement with bringing this Memorial Day weekend trough through
the Pac Nw quicker in the faster steering flow. That said, the
entire weekend has a chance of showers and isolated thunderstorms
for nearly all mtn zones, with an isolated shower threat for the
lower elevation zones...including the Spokane/ Coeur d`Alene areas
and south into the Palouse and central Idaho Panhandle mtns. Windy
conditions across the Upper Columbia Basin and the Wenatchee
region seems likely Sunday following the frontal passage. Tues
through Thurs may turn out to be warmer and dry if the favored
Ecmwf keeps its run- to- run consistency.bz

&&

.AVIATION...
12Z TAFS: Another wave moves in today ahead of the primary low.
The low level SW flow ahead of it may produce some MVFR stratus
toward 14-18Z, from PUW-COE. But confidence is very low. Showers
are expected this afternoon mainly near the mtns, maybe sprinkles
near COE. As for winds: as afternoon mixing increases widespread
gusts to 20kts expected at most TAF locations with gusts up to
30kt at EAT by 00Z. Winds will remain elevated through the night,
but not be as gusty.

&&

.PRELIMINARY POINT TEMPS/POPS...
Spokane        68  46  60  43  61  45 /   0  10  20  10  30  20
Coeur d`Alene  68  45  59  41  60  43 /  10  10  30  10  40  30
Pullman        65  44  57  41  60  43 /   0   0   0   0  20  20
Lewiston       71  49  64  47  67  49 /   0   0   0   0  20  20
Colville       71  45  62  41  64  43 /  20  40  60  50  60  30
Sandpoint      67  44  58  38  58  41 /  20  20  50  40  50  30
Kellogg        63  41  53  38  55  41 /  20  20  30  10  60  30
Moses Lake     75  46  68  45  70  47 /   0   0   0   0  10  10
Wenatchee      73  49  67  49  69  50 /   0   0   0   0  20  10
Omak           75  46  68  43  69  46 /  10  10  20  10  20  20

&&

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

$$




000
FXUS66 KOTX 260939
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
239 AM PDT THU MAY 26 2016

.SYNOPSIS...
Expect mild weather with isolated mountain showers again today.
The arrival of a cold front tonight will bring cooler
temperatures for the Memorial Day weekend, along with a good
chance for showers over the Idaho Panhandle and the mountainous
portions of Washington. Expect breezy conditions as well. Look for
a gradual warming trend after the Memorial Day weekend, with upper
60s to mid 70s by early next week.

&&

.DISCUSSION...

Today through Friday Night: One wave is exiting this morning which
brought rain to portions of northeast WA and north ID overnight.
Another wave will move west to east through the day ahead of the
closed low approaching the area. Expect clouds to increase through
the day ahead of the cold front set to move across the area this
evening and overnight. Afternoon showers are possible across
northern WA and north ID. The moisture isn`t great with the front
moving through tonight. A Chance of showers exists across
northeast WA and north ID, but the best chance will be in Ferry
and Stevens Counties. Winds will increase this morning across the
east slopes. Southwest winds 10-15mph will spread into the Basin,
Spokane and Palouse later this afternoon. The winds in the east
slopes into the Wenatchee and Waterville Plateau will peak late
this afternoon/early this evening. Northwest winds 15-20 mph with
gusts to 30 mph is possible. Friday showers will continue across
the region, mainly impacting northern WA and ID. 500mb temps in
the afternoon approach -26C along with some decent cape and
lingering mid level moisture will prompt the possibility of
thunderstorms north of a line from Republic to Sandpoint. Chance
of precipitation wanes through the night. Temperatures today will
be around average-mid 60s to mid 70s. Friday we drop below average
with temperatures in the upper 50s to upper 60s. Overnight lows
will be in the 40s. Friday night some of the usual colder
locations could drop down into the mid 30s. /Nisbet

Saturday through Thursday: The most notable difference in model
guidance for the mid and extended range fcst was the much slower
and deeper GFS solution with the Sunday frontal passage, and
especially the upper trough. The Nam and Ecmwf were in much better
agreement with bringing this Memorial Day weekend trough through
the Pac Nw quicker in the faster steering flow. That said, the
entire weekend has a chance of showers and isolated thunderstorms
for nearly all mtn zones, with an isolated shower threat for the
lower elevation zones...including the Spokane/ Coeur d`Alene areas
and south into the Palouse and central Idaho Panhandle mtns. Windy
conditions across the Upper Columbia Basin and the Wenatchee
region seems likely Sunday following the frontal passage. Tues
through Thurs may turn out to be warmer and dry if the favored
Ecmwf keeps its run- to- run consistency.bz

&&

.AVIATION...
06Z TAFS: A shortwave crossing east WA/north ID tonight/early
THU will produce some isold/sct -shra. Main risk toward NE WA/north
ID, only a slight risk fm GEG-COE. Secondary wave moves in Thursday,
ahead of the primary low. The low level SW flow ahead of it may
produce some MVFR stratus toward 10-14Z, from PUW-GEG-COE. But
confidence is very low. Some showers are possible again Thursday
afternoon mainly near the mtns, maybe sprinkles near GEG-COE-SFF-
PUW. As for winds: tonight surface speeds abate, esp. away from
the Cascades. Yet 1.5-2kft AGL winds speeds are between 20-35kts.
This brings thoughts of LLWS overnight/early THU, esp. near
EAT/MWH/PUW. Yet there isn`t much directional difference. Will be
monitored. THU PM mixing increases, bringing gust near 20kts,
local to 35kt near EAT late. /J. Cote`

&&

.PRELIMINARY POINT TEMPS/POPS...
Spokane        68  46  60  43  61  45 /   0  10  20  10  30  20
Coeur d`Alene  68  45  59  41  60  43 /  10  10  30  10  40  30
Pullman        65  44  57  41  60  43 /   0   0   0   0  20  20
Lewiston       71  49  64  47  67  49 /   0   0   0   0  20  20
Colville       71  45  62  41  64  43 /  20  40  60  50  60  30
Sandpoint      67  44  58  38  58  41 /  20  20  50  40  50  30
Kellogg        63  41  53  38  55  41 /  20  20  30  10  60  30
Moses Lake     75  46  68  45  70  47 /   0   0   0   0  10  10
Wenatchee      73  49  67  49  69  50 /   0   0   0   0  20  10
Omak           75  46  68  43  69  46 /  10  10  20  10  20  20

&&

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

$$




000
FXUS66 KOTX 260556
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
1056 PM PDT WED MAY 25 2016

.SYNOPSIS...
Expect mild weather with isolated mountain showers and
thunderstorms again on Thursday. The arrival of a cold front
Thursday night will bring cooler temperatures Friday and Saturday,
along with a good chance for showers over the Idaho Panhandle and
the mountainous portions of Washington. Look for a gradual warming
trend after the Memorial Day weekend, with upper 60s to mid 70s by
early next week.


&&

.DISCUSSION...
Evening update: minor updates for tonight into tomorrow morning. I
increased cloud cover in the east and extended the shower threat
through the night and reduced the cloud cover in the west. By
morning the main threat is painted across the northern Panhandle
expanded, near the ID/MT border and near the Cascades. The main
potential shower maker is a mid-level disturbance shifting across
that region tonight, weakening going into the morning. The next
disturbance starts to move in tomorrow, just ahead of the main
low. This will make for a breezy day tomorrow, with the main
shower threat around the mountains in the afternoon. I can`t rule
out some sprinkles or stray shower over the eastern Columbia Basin
in the afternoon too with that second disturbance, but the risk is
too low to mention otherwise. Temperatures look on track. Given
the sky cover at this hour, I`m not expecting a repeat of the
sheltered valley fog that occurred this morning, but if there is
any clearing this will have to be reexamined. /J. Cote`

&&

.AVIATION...
06Z TAFS: A shortwave crossing east WA/north ID tonight/early
THU will produce some isold/sct -shra. Main risk toward NE WA/north
ID, only a slight risk fm GEG-COE. Secondary wave moves in Thursday,
ahead of the primary low. The low level SW flow ahead of it may
produce some MVFR stratus toward 10-14Z, from PUW-GEG-COE. But
confidence is very low. Some showers are possible again Thursday
afternoon mainly nr the mtns, maybe sprinkles nr GEG-COE-SFF-PUW.
As for winds: tonight surface speeds abate, esp. away from the
Cascades. Yet 1.5-2kft AGL winds speeds are between 20-35kts.
This brings thoughts of LLWS overnight/early THU, esp. near
EAT/MWH/PUW. Yet there isn`t much directional difference. Will be
monitored. THU PM mixing increases, bringing gust near 20kts,
local to 35kt near EAT late. /J. Cote`


&&

.PRELIMINARY POINT TEMPS/POPS...
Spokane        47  68  44  60  42  61 /  10   0  10  20  20  30
Coeur d`Alene  48  67  43  59  40  60 /  20  10  10  30  20  40
Pullman        45  65  43  57  41  60 /  10   0  10  10  10  20
Lewiston       51  70  48  64  47  67 /  10   0  10  10  10  20
Colville       46  71  45  61  42  64 /  20  20  30  60  50  60
Sandpoint      46  67  43  57  38  58 /  20  20  20  40  40  60
Kellogg        44  65  41  53  39  55 /  20  20  20  30  20  60
Moses Lake     52  74  46  68  44  70 /   0   0  10   0  10  10
Wenatchee      52  73  48  67  48  69 /   0   0  10  10  10  20
Omak           47  74  45  67  44  69 /  10  10  10  20  10  20

&&

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

$$




000
FXUS66 KOTX 260005
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
505 PM PDT WED MAY 25 2016

.SYNOPSIS...
Expect mild weather with isolated mountain showers and
thunderstorms again on Thursday. The arrival of a cold front
Thursday night will bring cooler temperatures Friday and Saturday
along with a good chance for showers over the Idaho Panhandle and
the mountainous portions of Washington. Look for a gradual warming
trend after the Memorial Day weekend with upper 60s to mid 70s
by early next week.


&&

.DISCUSSION...
Tonight and Thursday: Under the weak ridge aloft and light winds,
shallow instability is leading to cumulus field blooming across
the mountains and isolated showers forming on the ridge tops this
afternoon. With the mid level winds from the northwest, most of
these showers should move off the ridges and bring light showers
to the valleys this evening. A few cells have the potential of
occasional lightning and small hail, but these cells would be
short lived, especially across the Okanogan Highlands and
northeast Washington. Although with the loss of daytime heating,
these cells will dissipate quickly. Breezy winds will persist
across the Columbia Basin to the Spokane area and the Palouse
through early evening, then the gusty downslope winds will
increase in the lee side Cascade valleys. The ridge will break
down on Thursday as an area of low pressure drops down from BC and
cold front sweeping toward the US/Canadian border late in the
afternoon. Anticipate increasing clouds through the day with
convection focused ahead of the front in the northern mountains.
Gusty southwest-west winds will increase Thursday afternoon with
gusts to 20 to 25 mph. More mild temperatures can be expected with
highs in the upper 60s to mid 70s. /rfox.

Thursday night through Friday night...Model agreement is quite
good that parts of the Inland Northwest will be impacted by yet
another upper level low and cold front dropping southeast via BC.
It appears the influence of the trough will be felt in the
Cascades and possibly the northern Washington mountains on
Thursday night before the threat of precipitation and the cold
front spreads into the Idaho Panhandle Friday morning. The
instability ahead of the cold front will support showers, but it
is likely too shallow for nocturnal thunderstorms. The front is
expected to shift into Montana by Friday afternoon with the upper
level cold pool remaining fixed over the far NE corner of
Washington and the northern Idaho Panhandle. Diurnal heating will
likely be sufficient to trigger some post frontal showers and
possibly a few thunderstorms. Model soundings suggest if we see
any thunderstorms form they will only be weak pulse type storms.
The threat of precipitation will likely plummet rapidly from north
to south across the forecast area given the positioning of the
upper level jet. Looks like locations south of Highway 2/I90 will
remain free from precipitation save the central Idaho Panhandle
while most of the precipitaiton will occur north of here. The
threat of precipitation is expected to taper off overnight. fx

Saturday through Monday...the all important holiday weekend forecast
is beginning to come into focus and while it is not looking like a
stellar weekend for outdoor activities...neither will it be a
dreary wash-out. The GFS and EC models are in reasonable agreement.
A progressive flow regime will prevail through the weekend with an
overall troffy pattern...but previous forecasts of a vigorous
upper low directly transiting the region have been tempered to
suggest a series of weaker disturbances...an ill defined one on
Saturday and Sunday and a slightly stronger one on Monday. This
suggests that while scattered afternoon and evening showers and a
few thunderstorms are still likely...these storms should be of a
hit-and-miss nature with substantial dry breaks between them. The
best chance of showers and storms will be over the Idaho Panhandle
and northern mountains each afternoon and evening. The deep basin
will probably remain dry as downslope flow produces a rain shadow
effect...with the eastern and northern margins of the basin
subject to isolated showers and a stray thunderstorm each day
Saturday through Monday. Temperatures will run 5 to 7 degrees
below normal...generally in the 60s while overnight lows should
remain around normal in the mid 40s. So...for barbequers and
campers outside of the deep basin zones preparations should be
made for generally dry and cooler than normal conditions
interspersed with an occasional brief shower in the afternoons and
evenings.

Tuesday and Wednesday...A drying and warming trend is expected to
develop during this period with both main modes suggesting at
least a weak upper level ridge rebounding over the forecast area
in the wake of Monday`s disturbance. Breezy northerly winds are
possible as some drier Canadian continental air filters into the
region. Temperatures should recover into the solidly normal
territory on Tuesday and a bit above normal by Wednesday. /Fugazzi

&&

.AVIATION...
00Z TAFS: A weak shortwave disturbance pushes in from the west
tonight into early Thursday, before weakening. Expect SCT-BKN
cloud cover over NE WA/N ID and maybe a stray shower near the
north WA and ID. There could also be some isolated thunderstorms.
The risk of anything at a TAF sites is limited. Winds will abate
away from the Cascades. However stronger winds are expected near
the Cascades through the evening, before these decrease going into
early Thursday AM. We will watch for some LLWS around MWH to PUW.
A second disurbance approaches later Thursday in advance of a
deeper low, with more clouds and mainly mountain shower chances,
and more breezy winds. Potential areas where the forecast may
veer from current thinking is around the sheltered valleys and
perhaps the higher palouse, where stratus/patchy fog may develop
overnight/early Thursday morning. Confidence is low. /J. Cote`

&&

.PRELIMINARY POINT TEMPS/POPS...
Spokane        47  68  44  60  42  61 /  10   0  10  20  20  30
Coeur d`Alene  48  67  43  59  40  60 /  20  10  10  30  20  40
Pullman        45  65  43  57  41  60 /   0   0  10  10  10  20
Lewiston       51  70  48  64  47  67 /   0   0  10  10  10  20
Colville       46  71  45  61  42  64 /  20  20  30  60  50  60
Sandpoint      46  67  43  57  38  58 /  20  20  20  40  40  60
Kellogg        44  65  41  53  39  55 /  20  20  20  30  20  60
Moses Lake     52  74  46  68  44  70 /   0   0  10   0  10  10
Wenatchee      52  73  48  67  48  69 /   0   0  10  10  10  20
Omak           47  74  45  67  44  69 /   0  10  10  20  10  20

&&

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

$$




000
FXUS66 KOTX 251746
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
1046 AM PDT WED MAY 25 2016

.SYNOPSIS...
Expect warmer weather with isolated mountain showers and
thunderstorms during the afternoon and evening hours today and
Thursday. The arrival of a cold front Thursday night will bring
cooler temperatures Friday and Saturday along with a good chance
for showers over the Idaho Panhandle and the mountainous portions
of Washington. Look for a gradual warming trend over the Memorial
Day weekend with upper 60s to mid 70s Sunday and Monday.

&&

.DISCUSSION...
Updated the forecast to adjust some weather elements this morning.
Patchy morning fog has eroded from the valleys of northeast
Washington and north Idaho. Under the weak area of high pressure
aloft, a low pressure trough resides across central Washington.
Weak northerly flow aloft will keep a steam of mid level clouds
spreading in from BC, although surface based instability will
increase afternoon midday and help cumulus to develop especially
across northeast Washington and the northern panhandle. Anticipate
light showers to develop over the ridge tops through the
afternoon, especially near the surface trough axis. There is a
small chance of thunderstorms over mainly north Idaho where the
best instability will lie. Any storms that do develop will be
short lived with occasional lightning, small hail and gusty winds.
The coverage of convection will wane quickly in the evening.
Meanwhile, gusty southwest winds will develop across the southern
Columbia Basin into the Spokane area and Palouse with gusts to 25
mph. West to northwest winds will increase this evening across the
lee side Cascade valleys as the surface trough waffles to the east
and allowing the downslope winds to funnel into eastern
Washington. Could see wind gusts of 30 mph this evening. /rfox.

&&

.AVIATION...
18Z TAFS: Fog has lifted although some local MVFR cigs will linger
near KCOE and surrounding valleys through midday. Cumulus will be
developing through the afternoon especially over the mountains
with isolated showers. There is enough instability to support a
chance of thunderstorms over north Idaho this afternoon and early
evening. Gusty southwest winds will develop near KGEG-KCOE this
afternoon, while gusty northwest gap winds will develop near KEAT
this evening and overnight. May see some occasional gustiness near
KPUW toward morning. Otherwise lighter winds and VFR conditions
are anticipated by Thursday morning. /rfox.

&&

.PRELIMINARY POINT TEMPS/POPS...
Spokane        71  47  68  44  60  41 /  20  10   0  20  30  20
Coeur d`Alene  70  48  68  44  59  40 /  20  20  10  20  30  20
Pullman        67  45  65  42  58  40 /  10  10   0  10  10  10
Lewiston       74  51  70  47  65  46 /  10  10   0   0  10  10
Colville       74  46  70  46  60  40 /  30  20  20  40  60  30
Sandpoint      69  46  67  44  56  39 /  20  20  20  30  50  30
Kellogg        64  44  65  41  54  38 /  20  20  20  20  30  20
Moses Lake     78  52  73  47  69  45 /  10   0   0  10  10  10
Wenatchee      76  52  73  47  67  48 /  10   0   0  10  10  10
Omak           78  47  73  46  66  44 /  20  10  10  30  30  20

&&

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

$$




000
FXUS66 KOTX 250532
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
1032 PM PDT TUE MAY 24 2016

.SYNOPSIS...

Clouds will continue to dissipate tonight, with only slight shower
chances lingering east. Wednesday will be the warmest day of the
week, with temperatures in the 70s and the potential for a few
showers or thunderstorms in Idaho and northeast Washington. The
Memorial Day weekend will likely be chilly and showery with the
arrival of another slow moving low. More unsettled spring time
weather is likely through early next week.


&&

.DISCUSSION...
Evening update: things are quieting down on the radar, with the
smattering of showers around the region falling apart with the
loss of the daytime heating. The main shortwave slipping by
eastern WA. Another will skim by the ID Panhandle later this
evening and early overnight, keeping some slight shower threat
alive. But for the most part the region is drying out. I made
some adjustments to reduce sky cover and lower overnight lows
a degree or two in spots. Otherwise the forecast is on
track. /J. Cote`

&&

.AVIATION...
06Z TAFS: The threat of showers will continue to wane, while
clouds thin as drier air spread in behind a couple weak
disturbances. A threat of showers/t-storms develops again
Wednesday afternoon toward the NE WA/ID Panhandle mountains, but
the risk is small around TAF sites. A cold front approaches from
the west late Wednesday into Wednesday night, allowing for some
breezy conditions in the afternoon and evening. Some of the
strongest winds are expected near EAT, with possible gusts
between 20-30kts. Wednesday evening the surface may decouple from
the winds aloft with that passing front, perhaps allowing for
some LLWS about 1-2kft AGL, with possible speeds around 30kts.
Confidence is low at this time but it will be monitored,
especially near MWH/PUW. /J. Cote`


&&

.PRELIMINARY POINT TEMPS/POPS...
Spokane        48  70  48  67  44  60 /  20  20  10  10  20  50
Coeur d`Alene  45  68  48  66  44  59 /  20  30  20  10  20  50
Pullman        45  66  45  64  43  58 /  30  20  10  10  10  30
Lewiston       51  73  51  70  48  65 /  20  20  10  10  10  20
Colville       46  73  46  70  45  62 /  20  40  20  20  40  80
Sandpoint      43  67  47  64  43  58 /  20  40  20  20  30  50
Kellogg        43  63  44  59  40  55 /  30  40  20  20  20  50
Moses Lake     48  77  49  74  47  68 /  10  10   0  10  20  30
Wenatchee      53  76  52  72  49  65 /  10   0   0  10  20  30
Omak           47  76  49  74  47  65 /  10  10  10  20  30  60

&&

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

$$



  [top]

000
FXUS66 KSEW 250331
AFDSEW

Area Forecast Discussion
National Weather Service Seattle WA
831 PM PDT TUE MAY 24 2016

.SYNOPSIS...Mostly cloudy skies will continue through Wednesday
with onshore flow. An upper low will bring an increasing chance of
showers Thursday through Saturday. Another upper level trough will
reach the area Sunday night or Monday.

&&

.SHORT TERM...Weak high pressure aloft and low level onshore flow
will produce mostly cloudy and generally dry weather tonight and
Wednesday. An upper low will drop down from the northwest
Thursday and bring some showers...mainly from Thursday afternoon
through Friday. A Puget Sound convergence zone seems likely at
times during this period. The onshore flow pattern will maintain
mostly cloudy skies and highs will be a few degrees below normal.
Schneider

.LONG TERM...Previous discussion...By Saturday morning the low is
opening up to more of a trough and is near the Idaho Panhandle--
but some PSCZ precip could still be going over Western WA. The 12z
GFS has a second trough arriving around daybreak Monday for
another round of shower activity. Camping this holiday weekend may
require blue tarps in the mountains and in the PSCZ, but might not
be too bad overall in the lowlands.

&&

.AVIATION...A long wave trough continues to linger over the West
as the associated upper level low spins over the MT/Saskatchewan
border. The air mass over western WA is stable. The flow aloft is
northerly with low level onshore flow at the surface. Low level
stratus clouds increasing over the area although cigs remain
VFR...except HQM at the time of this writing. Could see some
locations with cigs dropping down into MVFR very late tonight or Wed
morning. As has been the pattern...should see cigs lift and cloud
cover break up some by Wed afternoon. 33/SMR

KSEA...VFR conditions through this evening. Light N winds expected
to shift back to S between 09-12Z tonight. Ceilings near 2000 ft
early Wednesday morning. 33/SMR

&&

.MARINE...Onshore flow will prevail this week with high pressure
over the NE Pacific. Inherited Small Craft Advisory looks to be on
track. Given the weather pattern...can expect to see Small Craft
Advisory winds in the Central and East Strait of Juan de Fuca during
the afternoon and evening hours each day. 33/SMR

&&

.SEW Watches/Warnings/Advisories...
WA...None.
PZ...Small Craft Advisory until 5 AM PDT Wednesday for Central U.S.
     Waters Strait Of Juan De Fuca-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-East
     Entrance U.S. Waters Strait Of Juan De Fuca-Northern Inland
     Waters Including The San Juan Islands.

&&

$$

www.weather.gov/seattle

You can see an illustrated version of this discussion at
www.weather.gov/seattle/gafd/latest_webafd.html




000
FXUS66 KSEW 242141
AFDSEW

Area Forecast Discussion
National Weather Service Seattle WA
240 PM PDT TUE MAY 24 2016

.SYNOPSIS...Clouds might break up a bit late this afternoon and evening
but then they will fill back in overnight into Wednesday. An upper low
will bring an increasing chance of showers Thursday through Saturday.
Another upper level trough will reach the area Sunday night or Monday.

&&

.SHORT TERM...After some sunbreaks later this afternoon and evening
the clouds will fill back in overnight. Onshore flow will increase
Wednesday in response to an upper level low digging south along the
British Columbia coast. The increasing onshore flow will limit the
amount of afternoon sunshine on Wednesday and give slightly cooler
max temps. As the upper level low sags south Thursday and Friday
there will be an increasing chance of showers with stronger onshore
flow.

.LONG TERM...The 12z gfs takes the center of the low from the
central B.C. coast on Thursday and drops it SE into Eastern
Washington Friday morning. That track keeps the best chance of
showers over Western WA in the mountains and perhaps a PSCZ but also
suggests a chance for some wrap around rain in the north Cascades at
first. By Saturday morning the low is opening up to more of a trough
and is near the Idaho Panhandle--but some PSCZ precip could still
be going over Western WA. The 12z GFS has a second trough arriving
around daybreak Monday for another round of shower activity.
Camping this holiday weekend may require blue tarps in the mountains
and in the PSCZ, but might not be too bad overall in the lowlands.

&&

.AVIATION...A long wave trough will remain over the West tonight while
an upper level low spins over MT. The air mass over western WA is
stable. The flow aloft is northerly with low level onshore flow at
the surface. Low level stratus clouds cover much of western WA but
ceilings are mainly VFR. The stratus may break up late this
afternoon then reform overnight. MVFR ceilings are possible early
Wednesday morning. 33

KSEA...VFR conditions through this evening. Light N winds
developing 00-03Z then flipping back to S 09-12Z tonight. Ceilings
near 2000 ft early Wednesday morning. 33

&&

.MARINE...Onshore flow will prevail this week with high pressure
over the NE Pacific. Small Craft Advisory winds are likely in the
Central and East Strait of Juan de Fuca during the afternoon and
evening hours each day. 33

&&

.SEW Watches/Warnings/Advisories...
WA...None.
PZ...Small Craft Advisory until 5 AM PDT Wednesday for Central U.S.
     Waters Strait Of Juan De Fuca-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-East
     Entrance U.S. Waters Strait Of Juan De Fuca-Northern Inland
     Waters Including The San Juan Islands.

&&

$$

www.weather.gov/seattle

You can see an illustrated version of this discussion at
www.weather.gov/seattle/gafd/latest_webafd.html




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