Thursday, March23, 2017

Marine Weather and Tides
Stevenson, 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 7:02AMSunset 7:28PM Thursday March 23, 2017 9:27 AM PDT (16:27 UTC) Moonrise 3:42AMMoonset 1:42PM Illumination 16% Phase: Waning Crescent; Moon at 26 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 Stevenson, WA
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location: 45.68, -121.9     debug

Area Discussion for - Portland, OR
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Fxus66 kpqr 231017
area forecast discussion
national weather service portland or
316 am pdt Thu mar 23 2017

Synopsis Weak high pressure in between frontal systems is bringing
a break in the precipitation for most this morning, though a few
showers linger over SW washington. The next occluding pacific frontal
system will spread rain across the forecast area later this afternoon
into tonight, with showers and perhaps a couple thunderstorms
lingering into Friday. Higher pressure will cause showers to taper
off later Saturday, but the next frontal system will likely bring
more rain Sunday followed by showers Monday. Occasionally wet weather
is expected to linger through the middle of next week, with temps
fairly typical for late march. Snow levels will occasionally dip
below cascade pass level, but the more significant accumulations will
likely stay up toward the higher ski resort elevations.

Short term Today through Saturday... Infrared satellite imagery
shows plenty of low clouds banking up along the coast range and
cascades, but generally clearer skies over the willamette valley.

Weak high pressure is sliding across the pac NW this morning, though
enough low-level moisture and shallow instability exist to keep a few
showers going... Primarily over SW washington where the air mass is
slightly cooler aloft. Expect these showers to decrease this morning,
but by then high clouds should already be increasing in advance of
our next pacific frontal system. This system is presently crossing
130w, with the leading edge of the high cloud field just 75-100 miles
offshore. As a result, there probably will not be much in the way of
sunshine today... Except perhaps during the first few hours of the

The approaching frontal system has a tap to subtropical moisture just
north of hawaii, but the deepest moisture plume of 1.25-1.50
precipitable water values remains 35n southward. Models continue to
aim the axis of deepest moisture and heaviest QPF south of our
forecast area this evening, focusing instead on the or/ca border
region as a triple point develops along the approaching front. While
the heaviest rain is expected to stay to our south, there will
probably be a decent period of light to moderate rain spreading
onshore around 3-4 pm. The 00z wrf-arw fcst reflectivity then shows
rain spreading across the willamette valley just in time for this
evening's rush hour... Continuing all the way through this evening
before the main front pushes across the forecast area late tonight or
early Fri morning.

The 06z NAM shows a decent ribbon of 60-65 kt s-sw 850 mb winds with
the front this evening, but gradients will likely remain too offshore
for wind gusts much higher than 40-50 mph along the coast. As
mentioned above, a triple-point is expected to develop along the
front this evening near CAPE blanco, which would probably keep the
strongest wind south of lane county. The wave of low pressure
associated with this triple point will ride NE along the front, which
is likely what will keep rain fairly steady throughout tonight.

The upper trough associated with this system will start to push
onshore Friday, with the 00z ECMWF swinging a decent vortmax through
during the midday and afternoon hours fri. This shortwave will likely
be the leading edge of the cold pool aloft... With the 06z GFS showing
500 mb temps down to -27 deg c Fri afternoon. Given some sunbreaks,
this could be enough to support some deep but skinny CAPE and li's in
the 0 to -2 deg c range. 0-3 km shear profiles look fairly decent for
the coast and willamette valley Friday, so any cells that develop in
the 200-500 j/kg of CAPE Fri afternoon could be robust despite only
having tops around 20 kft. Based on all this, we decided to add a
slight chance of thunder for all but the cascades Fri afternoon and

Higher pressure and warming temps aloft should cause convection to
become less robust Saturday, though there will probably still be
plenty of showers around. Expect showers to begin tapering off sat
afternoon, then coming to an end Sat night as subsidence and a
stabilizing air mass take over.

Snow levels - on average - should be just above the cascade passes
tonight and Friday. As the secondary shot of cold air comes in fri
afternoon and evening, expect snow levels to lower to around 3000 ft
with some minor accumulation possible on the passes Fri night/sat.

More significant accumulations are likely above 5000-5500 ft, where
around 3-6 inches of snow are expected. Weagle

Long term Saturday night through Wednesday... Lingering
showers Saturday night will come to an end by early Sunday as
shortwave ridging moves across the region in between systems.

However, the next round of moisture in the form of a pacific front
is not far behind and will likely spread another of round of steady
rain later Sunday... With post-frontal showers continuing into Monday.

00z gfs/ecmwf and most of their ensembles are trending wetter for
midweek, as the overall pattern remains progressive and another
frontal system pushes onshore Tue night or wed. It does appear this
system will dive SE toward the great basin, but the ridging behind it
remains flat on both the 00z ECMWF and gfs. This seems to indicate
that models are becoming less bullish on drying us out late next
week... As the flat ridging would probably lend to a continued
progressive pattern across the NE pac through the end of next week.

Overall, expect generally more of the same for the next 7-10 days,
with occasional rain and temperatures remaining within a few degrees
of typical late march values. Weagle/cullen

Aviation A low endVFR deck near 4-5kft has developed across
the region. It may lower at a few sites to around 2.5-3kft this
morning, but confidence is low in whether or not this will occur.

An area of rain associated with a cold front moving eastward
towards the region later today will likely produce a brief period
of MVFR conditions at some TAF sites between 00-06z Friday.

Increasing low level instability behind the front should allow
conditions to return toVFR rather quickly.

Kpdx and approaches... There is a chance the current 4-5kft deck
in the region may lower to 2.5-3kft and produce a period of MVFR
conditions this morning, but this appears increasingly unlikely.

An area of steady rain associated with a front may bring a very
short period of MVFR conditions between 00-06z Friday. Conditions
should return rather quickly toVFR after 06z Friday as the lower
atmosphere destabilizes behind the front. /neuman

Marine An approaching front will result in southerly winds
increasing into gale force criteria this afternoon and evening.

Seas should respond accordingly and climb into at least the mid
teens. The strongest winds will likely hold off across the inner
waters until this evening so the current start times for the
gale warning appear on track. Expect winds to decrease rather
quickly behind frontal passage, which should happen around
midnight or shortly thereafter. Seas should then subside and
should fall to near 10 ft towards daybreak on Friday. A secondary
weak front will move into the waters Friday and will likely keep
gusty 25 kt winds going across the waters with seas hovering
around 10 ft.

High pressure shifting over the waters Saturday should finally
produce a more substantial decrease in winds and a slight
decrease in seas Saturday and Saturday night. However, yet
another front appears likely to bring winds and high seas
Sunday. At this point, gale force winds appear the most probable
scenario, but it's certainly far from guaranteed given the time
between now and then. The weather pattern looks to remain active
for much of next week with additional rounds of at least small
craft advisory level wind gusts of 25-30 kt. /neuman

Pqr watches/warnings/advisories
Or... None.

Wa... None.

Pz... Gale warning from 11 am this morning to 3 am pdt Friday for
waters from CAPE shoalwater wa to florence or from 10 to
60 nm.

Gale warning from 5 pm this afternoon to 3 am pdt Friday for
coastal waters from CAPE shoalwater wa to florence or out
10 nm.

Small craft advisory for rough columbia river bar until 4 am
pdt early this morning.

Small craft advisory for rough columbia river bar from noon
today to 5 am pdt Friday.

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Weather Reporting Stations
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Stations Dist Age Wind Air TempWater Temp WavesPressureDewPt
LOPW1 - 9440422 - Longview, WA 63 mi39 min 45°F1019.4 hPa

Wind History for Longview, WA
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1 day
2 days

Airport Reports
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AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure

Wind History from CZK (wind in knots)
Last 24hr24------------------------SW12
1 day ago53------------------------322SW632SE2E21S2
2 days ago----------------------------1214334434

Tide / Current Tables for Ellsworth, Washington - IGNORE HEIGHTS
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Click for MapNote: The Columbia River is subject to annual freshets. Short range predictions are available at local river forecast centers. The data for stations above Harrington Point apply only during low river stages. There is a tidal influence along most of the

Thu -- 12:35 AM PDT     1.20 feet Low Tide
Thu -- 04:43 AM PDT     Moonrise
Thu -- 05:14 AM PDT     6.65 feet High Tide
Thu -- 07:06 AM PDT     Sunrise
Thu -- 12:35 PM PDT     3.34 feet Low Tide
Thu -- 02:44 PM PDT     Moonset
Thu -- 04:31 PM PDT     7.49 feet High Tide
Thu -- 07:27 PM PDT     Sunset
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.

Tide / Current Tables for Vancouver, Washington - IGNORE HEIGHTS
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Click for MapNote: The Columbia River is subject to annual freshets. Short range predictions are available at local river forecast centers. The data for stations above Harrington Point apply only during low river stages. There is a tidal influence along most of the

Thu -- 12:10 AM PDT     1.20 feet Low Tide
Thu -- 04:44 AM PDT     Moonrise
Thu -- 04:48 AM PDT     6.65 feet High Tide
Thu -- 07:07 AM PDT     Sunrise
Thu -- 12:10 PM PDT     3.34 feet Low Tide
Thu -- 02:45 PM PDT     Moonset
Thu -- 04:05 PM PDT     7.49 feet High Tide
Thu -- 07:27 PM PDT     Sunset
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.

Weather Map and Satellite Images
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Weather Map
IR Satellite Image from GEOS

GOES Local Image of PacificNorthwest    EDIT

Wind Forecast for Portland, OR (12,3,4,5)
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Ground Weather Radar Station Portland, OR
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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 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 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.