Thursday, April27, 2017 L-36.com


Marine Weather and Tides
Winthrop, WA

Version 3.4
What's New / NOTES
5/19/2016 - There were issues with the 3 day airport observation history. I switched to another data source. Let me know if you see any issues with the data feeds.
3/12/2015 - Added section for Gulf current for users in the GMZ marine zones.
This was requested by a user. If you have requests, please let me know.

Sunrise 5:47AMSunset 8:10PM Thursday April 27, 2017 7:21 PM PDT (02:21 UTC) Moonrise 6:01AMMoonset 8:52PM Illumination 4% Phase: Waxing Crescent; Moon at 2 days in cycle
NOTE: Some of the data on this page has not been verified and should be used with that in mind. It may and occasionally will, be wrong. The tide reports are by xtide and are NOT FOR NAVIGATION.
Marine Forecasts
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7 Day Forecast for Marine Location Near Winthrop, WA
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location: 48.47, -120.18     debug


Area Discussion for - Spokane, WA
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Fxus66 kotx 280002
afdotx
area forecast discussion
national weather service spokane wa
502 pm pdt Thu apr 27 2017

Synopsis
Expect cool, breezy, and showery weather for tonight and Friday.

Mountain passes could see a couple inches of snow overnight
tonight into Friday. A ridge of high pressure moves in Saturday
delivering a brief dry period before more unsettled weather moves
in Sunday and into early next week. A warm drying trend returns
Wednesday and Thursday delivering dry weather and good chance for
temperatures in the 60s and 70s.

Discussion
Tonight... A weak shortwave evident on water vapor imagery is
currently moving through our forecast area and has lead to a build
up of cumulus and scattered to numerous showers across eastern
washington and the idaho panhandle. These showers are expected to
continue into the evening hours before constricting to mainly the
idaho panhandle mountains overnight. As the gradient slackens
behind this system, breezy west and southwest winds ,currently
ongoing this afternoon, will diminish gradually overnight. Low
temperatures will remain generally in the mid 30s to low 40s with
some wet snowfall again possible at areas like lookout pass.

/kalin
Friday through Saturday... A broad upper level trough is digging
into the central united states while a broad ridge is forming
over the eastern pacific today. This will place the forecast area
under a northwest flow sandwiched between these two features. One
weak wave in this flow is bringing some shower activity
today... And on Friday another weaker wave will descend through the
region with another chance of showers... Mainly concentrated over
the idaho panhandle and the mountains of eastern
washington... With a few isolated and weak showers wandering about
the eastern basin as well. This will not be a big event, more of a
hit-and-miss nuisance with stability parameters suggesting no
significant threat of thunder.

Conditions will improve Friday night and at least through Saturday
morning for mainly dry and clear to partly cloudy conditions
during a break period as the offshore ridge asserts it's
stabilizing influence over the region. By Saturday afternoon
clouds will increase as the ridge gets flattened by an incoming
wave of moisture. Showers may develop by Saturday afternoon over
the cascades as the moisture deepens.

With the forecast area residing on the cool side of the polar jet,
temperatures will run a bit below normal for the next two days
with highs only reaching the mid to upper 50s at most valley
locations and maybe breaking into the low 60s at the lowest
elevation locations. Snow levels will vary from 4000 to 5000 feet
during the day and drop to near valley floors at night although
any snow Friday morning and evening will be light and quickly
melted as things warm up during the day. /fugazzi
Saturday night through Tuesday morning: a ridge of high pressure
amplifying over the ERN pac will attempt to build inland but be
suppressed by a pair of shortwaves over-topping it. This will
delay our chances for warm and dry weather until later in the week
keeping the region under a low amplitude northwest jet. Each of
the shortwaves denting the ridge will usher a weak frontal system
through the inland NW delivering periods of light rain. The first
wave of moisture arrives Saturday night and departs Sunday
afternoon with a second to follow Monday night and depart early
Tuesday. Each system will tap into a decent plume of moisture but
the quick timing, antecedent dry boundary layer, and westerly
trajectory will limit rainfall to around a quarter of an inch or
less for nearly all locations. The idaho panhandle will stand the
best shot for achieving a quarter of an inch of rainfall with each
of the systems while the columbia basin (especially west) will
see very little to no precipitation from this pattern due to
cascade shadowing. Sunday will be quite breezy across the columbia
basin and into the palouse. This system will feature a more
pronounced surface low resulting in tighter gradients and cold
advection vs Monday. Similar to what was experienced on Wednesday,
winds will be strongest across the lower columbia basin, palouse,
and blue mtns where speeds of 15 to 25 mph will be possible
coupled with gusts near 30 mph.

Tuesday afternoon through Thursday: it is my pleasure to inform you
that warm and dry weather is on tap for the middle to end of the
upcoming week! The pattern change comes courtesy of a ridge of
high pressure which is able to finally amplify over the western
us. Be sure to take advantage of the mild temperatures and
abundance of sunshine for it will not last into the weekend.

Nearly all guidance is indicating a break down of the ridge and
transition to a cooler, trough by the weekend. It is conceivable
that we see a good deal of wind or thunderstorms as the ridge
breaks down but at this point, these details are far from certain
and will become more apparent heading into the next week. So back
to the nice weather, is this warm up unusual? Certainty not. The
return interval via the naefs for incoming ridge heights and
midlevel temperatures are roughly every 1-3 years. As a matter of
fact, spokane hit 82f just last year on may 3rd. So despite the
580 decameter 500mb heights and 850mb temperatures of 15c... This
is not uncommon for early may but in regards to how 2017 has
started out, it will feel like quite the change as temps warm into
the 70s. /sb

Aviation
00z tafs: showers produced by a weather disturbance moving
through the aviation area will gradually diminish this evening
but some will result in MVFR conditions this evening. Winds
should diminish this evening as well overnight. More afternoon
and evening showers are expected tomorrow. /pelatti

Preliminary point temps/pops
Spokane 37 55 37 57 43 58 / 30 20 10 10 30 40
coeur d'alene 35 53 36 57 40 56 / 60 30 20 10 50 60
pullman 37 53 37 57 43 57 / 40 30 10 10 40 50
lewiston 40 58 39 63 47 63 / 30 30 0 10 30 60
colville 37 57 37 58 41 60 / 30 20 20 10 40 40
sandpoint 35 52 35 55 38 54 / 70 50 40 10 60 70
kellogg 34 48 36 53 38 51 / 70 50 20 10 50 80
moses lake 38 64 36 63 47 68 / 10 10 0 0 10 10
wenatchee 40 61 39 62 45 63 / 10 10 0 10 20 10
omak 39 63 37 63 44 66 / 10 10 10 10 20 10

Otx watches/warnings/advisories
Id... None.

Wa... None.



Weather Reporting Stations
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Airport Reports
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AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Omak, Omak Airport, WA35 mi28 minNW 410.00 miPartly Cloudy57°F32°F39%1012.4 hPa

Wind History from OMK (wind in knots)
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Last 24hrW18
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NW6W6NW9NW8NW6W5CalmCalmCalmW5W5CalmCalmCalmS3CalmSE83--NW4N16
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1 day agoS14SE12
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2 days agoN7NW7NW7NW8W4NW3W3NW3N6NW5N6N6NE5NE33Calm3E3SE7SE14SE6NE3S3S10

Tide / Current Tables for
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Weather Map and Satellite Images
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Weather Map
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IR Satellite Image from GEOS
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GOES Local Image of PacificNorthwest    EDIT
Geos

Wind Forecast for Spokane, WA (22,6,7,8)
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Ground Weather Radar Station Spokane, WA
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Disclaimer:
The information on this web site has not been checked for accuracy. It is for entertainment purposes only and should be independently verified before using for any other reason. There are five sources. 1) Documents and manuals from a variety of sources. These have not been checked for accuracy and in many cases have not even been read by anyone associated with L-36.com. I have no idea of they are useful or accurate, I leave that to the reader. 2) Articles others have written and submitted. If you have questions on these, please contact the author. 3) Articles that represent my personal opinions. These are intended to promote thought and for entertainment. These are not intended to be fact, they are my opinions. 4) Small programs that generate result presented on a web page. Like any computer program, these may and in some cases do have errors. Almost all of these also make simplifying assumptions so they are not totally accurate even if there are no errors. Please verify all results. 5) Weather information is from numerious of sources and is presented automatically. It is not checked for accuracy either by anyone at L-36.com or by the source which is typically the US Government. See the NOAA web site for their disclaimer. Finally, tide and current data on this site is from 2007 and 2008 data bases, which may contain even older data. Changes in harbors due to building or dredging change tides and currents and for that reason many of the locations presented are no longer supported by newer data bases. For example, there is very little tidal current data in newer data bases so current data is likely wrong to some extent. This data is NOT FOR NAVIGATION. See the XTide disclaimer for details. In addition, tide and current are influenced by storms, river flow, and other factors beyond the ability of any predictive program.