Saturday, July22, 2017 L-36.com


Marine Weather and Tides
Westhaven-Moonstone, CA

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 6:02AMSunset 8:42PM Saturday July 22, 2017 1:52 PM PDT (20:52 UTC) Moonrise 4:19AMMoonset 7:12PM Illumination 1% Phase: Waning Crescent; Moon at 29 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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PZZ450 Pt St George To Cape Mendocino Out 10 Nm- 901 Am Pdt Sat Jul 22 2017
.small craft advisory in effect from 3 pm this afternoon through Monday afternoon...
Today..N winds 10 to 20 kt. Gusts to 30 kt this afternoon. Waves N 5 ft at 7 seconds.
Tonight..N winds 10 to 20 kt with gusts to 30 kt. Waves nw 7 ft at 9 seconds. Patchy fog.
Sun..NW winds 5 to 15 kt. Waves nw 9 ft at 10 seconds. Patchy fog.
Sun night..NW winds 5 to 15 kt. Waves nw 9 ft at 11 seconds.
Mon..NW winds 5 to 10 kt. Waves nw 8 ft at 12 seconds. Slight chance of Thunderstorms.
Tue..NW winds 5 to 10 kt. Waves nw 8 ft at 8 seconds. Slight chance of Thunderstorms.
Wed..NW winds 5 to 15 kt. Waves nw 7 ft at 7 seconds.
PZZ400 901 Am Pdt Sat Jul 22 2017
Synopsis for northern california waters..Northerly winds are forecast to strengthen this weekend with gale force gusts occurring over the outer waters. Steep seas will build as a result with the largest waves occurring over the northern outer waters. Winds may slacken toward the middle of next week.

7 Day Forecast for Marine Location Near Westhaven-Moonstone, CA
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location: 41.05, -124.1     debug


Area Discussion for - Eureka, CA
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Fxus66 keka 221136
afdeka
area forecast discussion
national weather service eureka ca
436 am pdt Sat jul 22 2017

Synopsis
Very warm and dry conditions will persist for much of the interior
this weekend, with somewhat more seasonably warm conditions
expected closer to the coast. Coastal low clouds and areas of patchy
fog will develop each night, burning off by late morning. A few
thunderstorms may develop Sunday through late Tuesday for portions
of humboldt and trinity counties, and all of del norte county.

Discussion
Short term
(today through Sunday morning)
a developing offshore flow will help erode the coastal stratus this
morning, with a repeat performance likely Sunday. In fact, stratus
penetration inland should be less tomorrow morning, as increased
mixing further east helps act as a road block for its progression.

Otherwise, as heights and temperatures aloft continue to rise, very
warm conditions will develop for our interior valleys. Here, the
latest numerical guidance continues to support highs at least in the
90s, with some of the more typical hot spots climbing into the 100
to 105 degrees fahrenheit range.

Closer to the coast, a surface trough will set up near the coast.

With northeast to easterly surface winds found just to its east,
downsloping affects will help increase afternoon temperatures,
especially just a few miles inland from the shore.

Long term
(Sunday afternoon through Friday)
the sixty-four thousand dollar question continues to be which
numerical model is correct, and what are our thunderstorm chances
during the first half of the week. In short, all of the guidance is
in good agreement with the development of a mid-level low off the
northwestern california coast. Disturbances are also seen crossing
northern portions of the state as the rotate around the low, but
that's where the model agreement ends. So lets look at some of the
more often-used convective models.

The GFS has been very consistent for several days now, with the
convective signal expanding in coverage and precipitation amounts.

Meanwhile, although the NAM still has no hint of precipitation, it
does tip its hand when taking a closer look at the 700-500mb
relative humidity (rh) values. Here, it develops "increasing rh
bombs" as disturbances rotate around the low, and they indicate
precipitation falling aloft, evaporating in the dry sub-cloud
airmass. This model indicates cloud bases running in the 13,000 to
15,000 feet range, compared to 8000 feet seen int he GFS soundings.

This makes sense why it's showing no precipitation, as it's
literally mixing it our before reaching the surface. Our european
counterpart (the ecmwf) has a smaller grid scale resolution than the
american models, yet it also develops precipitation (albeit not
until Tuesday afternoon evening), just not to the extend of the
gfs. However, both the GFS and NAM do show decent some instability
in the soundings, with the GFS being much higher.

So what's going to happen remains still remains a question. From a
pattern recognition standpoint all models have what would be a
favorable setup for at least isolated thunderstorms to develop
during the first half of the week. Given the consistency seen in the
gfs with some indication from the other models as well, thunder
potential was maintained and expanded in the zones. Although severe
weather is not expected as a whole, any thunderstorm that develops
may produce some gusty winds given the dry sub-cloud airmass seen in
the data, with perhaps some small hail in the strongest storms given
very good lapse rates in the mid-levels seen in the numerical
guidance.

Heading into the second half of the week, a zonal southwest to
westerly flow will advect drier air across the region, with seasonal
temperatures expected. Pd

Aviation
Coastal stratus is observed this morning along the coast
from CAPE mendocino northward to crescent city, while areas inland
are mostly clear. Stratus is forecast to dissipate along the coast
during the afternoon, and then redevelop tonight, with the highest
probability for ifr ceilings occurring in the vicinity of acv.

Farther north at cec, low clouds may be more scattered tonight due
to northeasterly offshore winds developing immediately above a
stable surface inversion.

Marine
Temperatures over inland portions of northern california
are forecast to warm to around 100 f Saturday and Sunday afternoon,
which will aid in lowering surface pressure and subsequently
tightening the gradient along the coast. Northerly winds will
strengthen as a result, with gale force gusts forecast to occur over
the northern outer waters Saturday afternoon through Monday
afternoon. In addition, large waves will build in response to the
increasing winds... Especially for the outer waters. By midweek,
model guidance indicates the tight pressure gradient may shift
slightly westward, which would favor weakening winds across the
coastal waters.

Fire weather
High pressure aloft will build across the region today, resulting in
strong warming and drying. Easterly ridge top winds will also
increase as a surface trough develops near the coast. The upper
elevations will likely have poorer recoveries as a result. Interior
temperatures of 95 to 105 degrees are expected this weekend, with
very low humidities in the afternoon. Gusty easterly winds will
likely develop across the upper elevations of del norte and far
northern humboldt counties tonight into Sunday morning.

As we head into the Sunday through Tuesday evening time frame, an
upper-level low will develop off the coast and interact with
increasing instability. As a result, a few thunderstorms may develop
across all of del norte county, and across portions of humboldt,
trinity, and northeastern mendocino counties. Soundings continue to
indicate cloud bases running near 8000 feet, making gusty winds a
concern in addition to the lightning with any storm that develops.

Drier westerly flow aloft will put an end to our convective threat
for the middle to end of the week. Pd

Eka watches warnings advisories
Ca... None.

Northwest california coastal waters... Small craft advisory from 3 pm this afternoon to 5 pm pdt Monday
for pzz450.

Small craft advisory until 3 pm pdt this afternoon for pzz470.

Gale warning from 3 pm this afternoon to 5 pm pdt Monday for
pzz470.

Small craft advisory until 11 am pdt Sunday for pzz455.

Small craft advisory until 5 pm pdt Monday for pzz475.

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Weather Reporting Stations
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Stations Dist Age Wind Air TempWater Temp WavesPressureDewPt
46244 - Humboldt Bay, North Spit, CA 17 mi62 min 62°F5 ft
HBYC1 - 9418767 - North Spit, CA 21 mi77 min NW 2.9 G 4.1 57°F 53°F1016.4 hPa
46022 - EEL RIVER - 17NM West-Southwest of Eureka, CA 32 mi63 min N 18 G 21 59°F 58°F5 ft1015.4 hPa (-0.7)55°F
CECC1 - 9419750 - Crescent City, CA 48 mi53 min S 6 G 8 54°F 53°F1015.5 hPa (-1.3)

Wind History for North Spit, Humboldt Bay, CA
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Airport Reports
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AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Arcata / Eureka, Arcata Airport, CA4 mi60 minW 510.00 miMostly Cloudy60°F55°F86%1016.1 hPa

Wind History from ACV (wind in knots)
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Last 24hrNW15NW12NW16NW14NW12NW12NW10NW10NW8CalmS3S4S3S4SE3E3E4CalmCalmCalmNW64NW5W5
1 day agoNW14NW16NW16NW15NW15NW12NW10
G22
N8N4N5N3E3E3CalmCalmE3CalmCalmCalmW5NW6NW6NW8NW9
2 days agoNW16
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N3N4CalmCalmCalmCalmCalmCalmCalmN3N6N6N8N11NW12NW13

Tide / Current Tables for Trinidad Harbor, California
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Trinidad Harbor
Click for Map
Sat -- 05:19 AM PDT     Moonrise
Sat -- 05:37 AM PDT     -1.57 feet Low Tide
Sat -- 06:03 AM PDT     Sunrise
Sat -- 12:12 PM PDT     5.79 feet High Tide
Sat -- 05:22 PM PDT     2.27 feet Low Tide
Sat -- 08:11 PM PDT     Moonset
Sat -- 08:42 PM PDT     Sunset
Sat -- 11:23 PM PDT     7.87 feet High Tide
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
6.95.33.31.3-0.4-1.4-1.5-0.70.72.44.15.35.85.64.83.82.82.32.43.14.45.87.17.8

Tide / Current Tables for Mad River Slough, Arcata Bay, Humboldt Bay, California
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Mad River Slough
Click for Map
Sat -- 05:20 AM PDT     Moonrise
Sat -- 06:03 AM PDT     Sunrise
Sat -- 06:15 AM PDT     -1.64 feet Low Tide
Sat -- 01:05 PM PDT     6.53 feet High Tide
Sat -- 06:00 PM PDT     2.46 feet Low Tide
Sat -- 08:11 PM PDT     Moonset
Sat -- 08:41 PM PDT     Sunset
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
8.97.963.61.2-0.7-1.6-1.3-0.21.43.24.96.16.56.25.342.92.52.945.67.28.5

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

GOES Local Image of CentralWestCoast    EDIT
Geos

Wind Forecast for Eureka, CA (16,3,4,5)
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Ground Weather Radar Station Eureka, CA
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weather_mapweather_map weather_map

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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.