Thursday, July18, 2019 L-36.com


Marine Weather and Tides
St. Helens, OR

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6/2/2019. Many thanks to a user for reporting an error on one of the Edit pages. The switch to PHP 7.2 caused many pages that previously worked to quit working. I fixed many but I still depend on users to report ones I missed. Please report errors HERE or send an email to me at L-36.com. Allen

Sunrise 5:37AMSunset 8:56PM Thursday July 18, 2019 2:48 AM PDT (09:48 UTC) Moonrise 9:20PMMoonset 6:15AM Illumination 98% Phase: Waning Gibbous; Moon at 16 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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PZZ210 Columbia River Bar- 920 Pm Pdt Wed Jul 17 2019
In the main channel.. - general seas...5 ft Wednesday night and Thursday. - first ebb...strong ebb around 630 am Thursday. Seas building to 7 ft. - second ebb...around 7 pm Thursday. Seas building to 7 ft. - third ebb...around 7 am Friday. Seas building to 9 ft.
PZZ200 920 Pm Pdt Wed Jul 17 2019
Synopsis for the southern washington and northern oregon coast.. Surface high pressure builds tonight and Thursday morning, then holds through Saturday. A thermally-induced trough along the south oregon coast will strengthen in the afternoon and evenings Thursday through Friday. A developing low in the ne pacific on Sunday will weaken the surface pressure gradient across the oregon and washington coastal waters Sunday and Monday.


7 Day Forecast for Marine Location Near St. Helens, OR
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location: 45.87, -122.8     debug


Area Discussion for - Portland, OR
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Fxus66 kpqr 180457
afdpqr
area forecast discussion
national service portland or
925 pm pdt Wed jul 17 2019

Synopsis A frontal system will result in light rain spreading
southward across the area tonight. Drier and cooler air arrives
behind the front. Then warmer weather is expected for the weekend.

Short term Tonight through Saturday... Water vapor satellite
imagery this afternoon reveals an unusually strong jet stream
stretching across the lower gulf of alaska. It is currently taking
aim at southern british columbia and washington state. Models have
initialized a 160-170 kt jet off the coast, which will weaken as it
pushes inland over the next 12-24 hours. Even then it may end up
outside what has been observed over washington state this time of the
year via a 30 year naefs reanalysis climatology. Closer to the
surface, an extensive area of clouds composed of multiple decks is
apparent over the northeast pacific via visible satellite imagery.

The bulk of these clouds are forming in an area of weak warm
advection, which will slowly sag southward across the area this
evening. Doppler radar and surface observations reveal plenty of
light rain is reaching the surface across clatsop and pacific
counties. This area of rain and drizzle should continue spread
southward through the remainder of this evening. There may be just
enough westerly flow to produce some rain shadowing across portions
of the willamette valley, though. With relatively high precipitable
water values, hourly rainfall rates could peak in the 0.1"-0.2" hour
range across the most favored west facing slopes in the coast range,
particularly in tillamook, clatsop and pacific counties. Elsewhere,
expect just a couple hundredths of an inch per hour or less.

Between drier air pushing in behind a trailing cold front tonight and
a lowering subsidence inversion, expect rain chances to decrease
rather markedly Thursday morning. Continuing onshore flow on Thursday
should result in high temperatures topping out a few degrees below
average for this time of the year.

Another shortwave trough will swing around the parent gulf of alaska
trough and brush the region Thursday night into Friday morning. This
could result in some light showers streaming onto our north coast
during this time. However, the low level flow direction is a little
more northwesterly than preferred and the NAM and gem suggest the low
level moisture and instability may not be quite deep enough to
produce light rain showers. Nonetheless, have at least included some
slight chance to chance pops around the long beach peninsula and
western clatsop & northwestern tillamook counties Thursday night into
Friday morning given the ec GFS scenario. Once again, expect another
day of high temperatures topping out several degrees below average on
Friday.

Finally, it should also be noted that dewpoints should drop closer to
more typical levels for this time of the year, i.E. Around 50f, which
should result in Thursday and Friday feeling much less muggy than the
past week or so. Neuman

Long term Saturday night through Wednesday... A high pressure
ridge over northwest oregon and southwest washington will persist
through much of next week. This ridging pattern will keep
temperatures fairly mild, skies clearer and conditions dry through
much of the forecast area. A shortwave trough is advancing towards
the coast on Monday. This trough, while staying mostly offshore,
will bring a chance of clouds to the coast and foothills Monday
through Tuesday morning. On Wednesday, another shortwave will pass
over southwest washington. This shortwave, combined with
southwesterly flow, will advect marine stratus over the coast,
foothills, and potentially spread into the valley. Clouds will be
more concentrated during the evening and morning hours.

Aviation A weak frontal system will maintain light rain and
MVFR conditions along the coast through this evening evening, with
ifr conditions likely late tonight into Thursday morning. Showers
will end along the coast late tonight, but drizzle will maintain
MVFR-ifr conditions through Thursday morning. Showers and MVFR cigs
will remain over the cascades through Thursday morning, but end in
the interior valleys late tonight. Otherwise, lowVFR trending to
MVFR across the interior after 08z.

Kpdx and approaches...VFR expected this afternoon and evening with
ceilings around 3500-4500 feet. The ceilings may lower to 2500 feet
after midnight tonight in the wake of a dissipating front. SW winds
this afternoon should become W tonight around 06z, then NW early
Thursday morning around 11z.

Marine Buoy observations show that the wind gusts are
diminishing quickly behind a weak warm front. With wind gusts
below 20 kt at buoys 46089 and 46029, and diminishing gusts at
46050, have decided to end the small craft advisory early this
afternoon. Northwest winds will develop behind the front this
evening as surface high pressure builds into the waters. The
surface pressure gradient strengthens south of cascade head
Thursday afternoon and evening as a thermally induced trough
builds across the south oregon coast. This will likely allow
north winds to gust just above 20 kt briefly south of cascade
head Thursday night. This surface pressure pattern will persist
into the weekend and expect north winds south of cascade head to
strengthen greater than 20 kt each evening.

A long period (16+ second) 2-4 ft SW swell dominates the seas
this afternoon and evening. Persistent northwest winds over the ne
pacific will build a 9-10 second NW swell with heights around 6 feet
into the waters tonight that will persist through at least Saturday.

Steep wind-driven waves can be expected south of cascade head in the
afternoons and evenings Thursday through Saturday. ~tj

Pqr watches warnings advisories
Or... None.

Wa... None.

Pz... Small craft advisory until 2 pm pdt this afternoon for coastal
waters from CAPE shoalwater wa to florence or out 60 nm.

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Weather Reporting Stations
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Stations Dist Age Wind Air TempWater Temp WavesPressureDewPt
LOPW1 - 9440422 - Longview, WA 18 mi55 min 69°F1015.6 hPa
ASTO3 - 9439040 - Astoria, OR 56 mi49 min NW 13 G 17 62°F 69°F1015.7 hPa (+0.9)
TLBO3 - 9437540 - Garibaldi, Tillamook Bay, OR 63 mi55 min 63°F1016.5 hPa

Wind History for Longview, WA
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Airport Reports
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AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Scappoose Industrial Airpark, OR8 mi56 minNW 610.00 miOvercast63°F57°F81%1014.9 hPa
Southwest Washington Regional Airport, WA18 mi53 minWNW 410.00 miOvercast61°F57°F90%1016.1 hPa
Pearson Airfield, WA19 mi56 minNW 67.00 miLight Rain62°F57°F86%1015.1 hPa
Portland, Portland International Airport, OR21 mi56 minNNW 610.00 miOvercast63°F57°F84%1015.1 hPa
Portland-Hillsboro Airport, OR24 mi56 minNW 810.00 miOvercast61°F55°F84%1015 hPa

Wind History from SPB (wind in knots)
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Last 24hrW3CalmCalmCalmS3SE7SE6S6S8S75
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SW9SW9SW106SW8NE5CalmCalmCalmCalmNW5NW6
1 day agoNW3NW3CalmCalmCalmCalmNE4CalmW33E7E43NW3N7N9NW8NW8
G14
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2 days agoN6N7--N7N3CalmCalmCalmCalmS3CalmS5CalmSE73NW5N5N6NW3N4N4N4N4NW3

Tide / Current Tables for Saint Helens, Oregon - IGNORE HEIGHTS
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Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.


Tide / Current Tables for Kalama, Washington - IGNORE HEIGHTS
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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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wmap_P
GOES Local Image of PacificNorthwest    EDIT
NOTE: East coast views moved to GEOS-16. They are experimental and not well supported by NOAA so they may not be correct so be warned. This change required redoing a large amount of the GOES code. If the image you are expecting is not showing, please let me know. You may need to use the EDIT function to update your location.
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Other links: Northern Pacific     Contential US     Full GOES-East
Wind Forecast for Portland, OR (5,6,7,8)
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Ground Weather Radar Station Portland, OR
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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.