Friday, August18, 2017 L-36.com


Marine Weather and Tides
Mercer Island, WA

Version 3.4
What's New / NOTES
6/25/2017 - NOAA is having a major issue that impact the 7 day forecast load times. Many users are reporting problems. The issue has been reported.
5/23/2017 - Worked with NOAA again to speed up the 7 day forecast load times. Thanks to them for being responsive.
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.

Sunrise 6:09AMSunset 8:15PM Friday August 18, 2017 9:12 AM PDT (16:12 UTC) Moonrise 1:36AMMoonset 5:11PM Illumination 14% 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
    EDIT      (on/off)   Help
PZZ135 Puget Sound And Hood Canal- 839 Am Pdt Fri Aug 18 2017
.small craft advisory in effect from this evening through late tonight...
Today..S wind 5 to 15 kt. Wind waves 2 ft or less.
Tonight..SW wind 15 to 25 kt easing to 5 to 15 kt after midnight. Wind waves 2 to 4 ft subsiding to 2 ft or less after midnight.
Sat..SW wind to 10 kt. Wind waves 1 ft or less.
Sat night..SW wind 5 to 15 kt becoming S to 10 kt after midnight. Wind waves 2 ft or less.
Sun..Light wind becoming sw to 10 kt in the afternoon. Wind waves 1 ft or less.
Sun night..SW wind 5 to 15 kt easing to 10 kt after midnight. Wind waves 2 ft or less.
Mon..NW wind to 10 kt. Wind waves 1 ft or less.
Tue..SW wind to 10 kt rising to 10 to 20 kt. Wind waves 1 ft or less building to 1 to 3 ft.
PZZ100 839 Am Pdt Fri Aug 18 2017
Synopsis for the northern and central washington coastal and inland waters..A typical august pattern will prevail through the middle of next week. Expect onshore flow of varying strength to persist due to high pres offshore and lower pres east of the cascades.

7 Day Forecast for Marine Location Near Mercer Island, WA
   Hourly   EDIT   Help
location: 47.54, -122.26     debug


Area Discussion for - Seattle, WA
      (on/off)   Help   NOTE: mouseover dotted underlined text for definition
Fxus66 ksew 181531
afdsew
area forecast discussion
national weather service seattle wa
831 am pdt Fri aug 18 2017

Synopsis A weak system moving by to the north of the area today
will give clouds to the northern half of western washington and a
chance of showers to the northern olympic peninsula and the north
cascades. Onshore flow will increase this evening, resulting in
slightly cooler conditions on Saturday. High pressure will begin
to rebuild over the region Sunday afternoon. High pressure aloft
and light northwesterly flow will give dry and warmer conditions
to the area Monday and Tuesday.

Short term The only change to the morning forecast package is
an increase in cloud cover for the northern 2 3 of the area this
morning through early this afternoon.

Details: satellite imagery shows the remnants of an old frontal
system extending from central alberta southwestward through
northern portions of western washington and out into the pacific
along about 46n latitude. This weak disturbance has increased
lower to mid level clouds across the northern two thirds of the
area this morning, and may result in a few light showers today for
the northern olympic peninsula and the north cascades. Behind
this system, low level onshore flow is expected to increase early
this evening bringing gale force westerly winds through the
eastern two-thirds of the strait of juan de fuca and increasing
low level moisture across western washington. Temperatures will
be in the 60s to mid 70s across the area today, near normal for
mid august, and will likely be 1 to 3 degrees cooler on Saturday
after our increase in onshore flow.

Flat ridging offshore is expected to shunt another weakening
frontal system to the north of the area late Saturday night into
Sunday morning, though some mid level left- over cloud cover will
drag across the area. Sunday high temperatures will likely be
about 1 to 3 degrees higher than Saturday with the passing clouds
during the first half of the day breaking up about noon.

Ridging building offshore will move east across the area later
Monday. The ridging will result in clearing and a warming trend.

There may be some morning clouds around that may impair viewing of
the first half of the solar eclipse on Monday, but it is too
early to tell at this time. Highs on Monday may reach 80 in the
interior from seattle southward (but temperatures will possibly be
held down a couple of degrees due to the eclipse in the mid to
late morning hours). Albrecht

Long term From the previous long term discussion... On the back
side of the ridge... Temps will not be too much different Tuesday
than what is expected Monday. An upper level low off the canadian
coast will spell some troughiness for the area starting Wednesday.

Cooling temperatures are a sure bet... But models really are not
coming up with an agreed solution for the path of this low and
thus the degree to which wa will see precip. Both solutions (ecmwf
and gfs) show precip for Wed and thu... But with the ECMWF showing
a more northerly track... That would likely result in lower pops
whereas the GFS has the low actually dipping south enough to pass
over the northern third of the CWA producing higher and more
widespread pops. With no discernible agreement... Simply went
middle of the road and ran with slight chance to chance pops for
that period. Beyond that... Looks like another pacific ridge will
influence next weekend with models in disagreement as to the
amplitude of that ridge. Smr

Aviation Westerly flow aloft continues over western washington
this morning, with a weak upper trough moving through british
columbia. Surface high pressure remains offshore with lower
pressure east of the cascades for onshore low level flow. The air
mass is moist, mainly below 6000 ft.

Marine stratus with ceilings ovc005-012 covers the coast and much
of the northwest interior and southwest interior of western
washington. The puget sound region, which is mostly free of the
low stratus, has a sct-bkn040 cloud deck. The stratus should burn
off by midday, especially away from the coast. However, cloud
layers associated with the weak upper trough should develop this
afternoon, mainly between 4000 and 10,000 ft. Stronger onshore
flow this evening and tonight could push low stratus into most of
the western washington interior lowlands late tonight.

Ksea... Light southwest flow becoming west to northwest 6-12 kt
this afternoon, then north to northeast after sunset, and then
light and variable overnight. The clouds at 040 should increase to
bkn-sct during the next couple hours. Low stratus with ceilings
010-014 is possible late tonight. Mcdonnal

Marine A weak system moving by to the north will result in
increasing onshore flow over western washington later this
afternoon and this evening. Gale warnings are in effect for the
central and eastern strait of juan de fuca, along with small
craft advisories for admiralty inlet and the northern inland
waters.

Otherwise, a typical august pattern will prevail through
the middle of next week; onshore flow of varying strength will
persist due to high pressure offshore and lower pressure east of
the cascades. Small craft advisory westerlies are possible in
the central and eastern strait of juan de fuca in the evening and
early morning hours beginning Saturday evening and continuing into
the middle of next week. Mcdonnal

Sew watches warnings advisories
Wa... None.

Pz... Gale warning from 6 pm this evening to 3 am pdt Saturday for
central u.S. Waters strait of juan de fuca-east entrance
u.S. Waters strait of juan de fuca.

Small craft advisory from 6 pm this evening to 3 am pdt Saturday
for admiralty inlet-northern inland waters including the
san juan islands.

Small craft advisory until 6 pm pdt this evening for central
u.S. Waters strait of juan de fuca.



Weather Reporting Stations
   EDIT       (on/off)   Help   NOTE: Click on distance to see the station location on a map
Stations Dist Age Wind Air TempWater Temp WavesPressureDewPt
EBSW1 - 9447130 - Seattle, WA 6 mi42 min NW 4.1 G 6 57°F 57°F1022 hPa
WPOW1 - West Point, WA 13 mi72 min NW 1.9 G 1.9 57°F 1022.1 hPa (+0.5)53°F
46120 17 mi36 min Calm 56°F 1021.5 hPa53°F
TCMW1 - 9446482 - Tacoma Met, WA 20 mi42 min N 2.9 G 2.9
TCNW1 - 9446484 - Tacoma, WA 21 mi42 min 59°F 58°F1022.3 hPa
46121 31 mi40 min 3.9 56°F 1021.8 hPa52°F
PTWW1 - 9444900 - Port Townsend, WA 48 mi42 min SSE 5.1 G 6 56°F 53°F1022.2 hPa

Wind History for Seattle, Puget Sound, WA, WA
(wind in knots)    EDIT      (on/off)   Help
9
AM
10
AM
11
AM
12
PM
1
PM
-12
PM
3
PM
4
PM
5
PM
6
PM
7
PM
8
PM
9
PM
10
PM
11
PM
12
AM
1
AM
2
AM
3
AM
4
AM
5
AM
6
AM
7
AM
8
AM
Last
24hr
NW4
NW3
NW3
NW5
--
NW3
NW3
NW3
NW8
NW8
NW6
W1
NE4
N3
G9
W3
SW1
--
--
--
NW1
NE1
SW3
W4
1 day
ago
NW5
NW4
N1
G5
NW1
NW1
G4
NW4
NW2
G7
NW5
W2
NW8
N1
G4
SE1
W6
G9
SW4
SW1
NW2
NW2
E4
--
E4
G7
SE2
SE1
NW4
2 days
ago
W5
NW4
G7
W8
G11
W6
W6
G10
W10
NW10
NW5
G10
NW6
NW3
G6
N3
G8
NW3
G6
W2
SW2
--
W3
N1
NE3
NW4
S2
SE2
W3

Airport Reports
    EDIT      (on/off)   Help   Click EDIT to display multiple airports
AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Boeing Field - King County International Airport, WA2 mi79 minN 010.00 miPartly Cloudy61°F55°F81%1021.6 hPa
Renton Municipal Airport, WA3 mi79 minS 47.00 miMostly Cloudy60°F55°F86%1022.2 hPa
Seattle, Seattle-Tacoma International Airport, WA7 mi79 minWSW 310.00 miMostly Cloudy57°F54°F90%1022.5 hPa

Wind History from BFI (wind in knots)
10
AM
11
AM
12
PM
1
PM
2
PM
3
PM
4
PM
5
PM
6
PM
7
PM
8
PM
9
PM
10
PM
11
PM
12
AM
1
AM
2
AM
3
AM
4
AM
5
AM
6
AM
7
AM
8
AM
9
AM
Last 24hrCalmSE3N4W4W4SW1033SE7NW6NW6NW8NW853NW3N4CalmN3CalmCalmCalmCalm3
1 day ago3S4Calm43N444N5NW6N4N43NE4CalmE4E4E3NE4E4S4CalmSW3Calm
2 days ago35NW5N6NW6NW76NW7NW7NW5NW5NW5NW4N7N6N4CalmCalmCalmCalmCalmCalmSE6S4

Tide / Current Tables for Duwamish Waterway, Washington
   EDIT   RT Ports Option   Weekend mode (on/off)   (on/off)   Help   One Week of Data
Duwamish Waterway
Click for Map
Fri -- 01:20 AM PDT     10.39 feet High Tide
Fri -- 02:36 AM PDT     Moonrise
Fri -- 06:09 AM PDT     Sunrise
Fri -- 08:52 AM PDT     -1.13 feet Low Tide
Fri -- 04:07 PM PDT     10.49 feet High Tide
Fri -- 06:10 PM PDT     Moonset
Fri -- 08:15 PM PDT     Sunset
Fri -- 09:25 PM PDT     6.09 feet Low Tide
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
9.610.310.29.27.65.430.8-0.7-1.1-0.41.43.86.48.61010.510.29.386.86.26.27

Tide / Current Tables for Restoration Point, 0.6 miles ESE of, Washington Current
   EDIT      (on/off)   Help   One Week of Data
Restoration Point
Click for Map
Fri -- 01:20 AM PDT     -0.00 knots Slack
Fri -- 02:37 AM PDT     Moonrise
Fri -- 05:42 AM PDT     -1.04 knots Max Ebb
Fri -- 06:10 AM PDT     Sunrise
Fri -- 09:39 AM PDT     0.00 knots Slack
Fri -- 12:08 PM PDT     0.76 knots Max Flood
Fri -- 04:08 PM PDT     -0.00 knots Slack
Fri -- 06:11 PM PDT     Moonset
Fri -- 07:01 PM PDT     -0.59 knots Max Ebb
Fri -- 08:15 PM PDT     Sunset
Fri -- 10:28 PM PDT     0.00 knots Slack
Fri -- 11:54 PM PDT     0.28 knots Max Flood
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
0.20.1-0.2-0.5-0.8-1-1-0.9-0.6-0.30.20.60.80.70.60.30-0.3-0.5-0.6-0.5-0.3-0.10.2

Weather Map and Satellite Images
       (on/off)   Help
Weather Map
wmap_P
IR Satellite Image from GEOS
west_satellite

GOES Local Image of PacificNorthwest    EDIT
Geos

Wind Forecast for Seattle, WA (12,3,4,5)
      (on/off)   Help

Ground Weather Radar Station Seattle/Tacoma, WA
   (on/off)   Help
weather_mapweather_map weather_map

Ad by Google

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.