Sunday, April23, 2017 L-36.com


Marine Weather and Tides
Laupahoehoe, HI

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 5:54AMSunset 6:42PM Sunday April 23, 2017 9:51 AM HST (19:51 UTC) Moonrise 3:58AMMoonset 4:12PM Illumination 6% Phase: Waning Crescent; Moon at 27 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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PHZ122 Big Island Windward Waters- 949 Am Hst Sun Apr 23 2017
.small craft advisory in effect through early Tuesday morning...
Rest of today..East winds to 25 kt. Wind waves 6 ft. North swell 5 ft and north 3 ft. Scattered showers...then isolated showers in the afternoon.
Tonight..East winds 20 kt. Wind waves 6 ft. North swell 4 ft. Isolated showers.
Monday..East winds 20 kt. Wind waves 6 ft. North swell 4 ft. Isolated showers.
Monday night..East winds 20 kt. Wind waves 6 ft. Northwest swell 4 ft. Isolated showers.
Tuesday..East winds 20 kt. Wind waves 7 ft. Northwest swell 4 ft. Isolated showers.
Tuesday night..East winds to 25 kt. Wind waves 6 ft. Northwest swell 4 ft. Scattered showers.
Wednesday..East winds to 25 kt easing to 15 kt. Wind waves 5 ft. Northwest swell 4 ft. Scattered showers.
Thursday..East winds 15 kt. Wind waves 4 to 5 ft. Northwest swell 4 ft. Scattered showers.
PHZ100 949 Am Hst Sun Apr 23 2017
Synopsis for hawaiian coastal waters.. High pressure will remain nearly stationary about 1200 nm northeast of hawaii. Strong east southeast winds for exposed areas around the big island and maui county with lighter winds elsewhere into early next week. Mainly small swells will affect this islands this week.

7 Day Forecast for Marine Location Near Laupahoehoe, HI
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location: 20.8, -154.34     debug


Area Discussion for -
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Fxhw60 phfo 231340
afdhfo
area forecast discussion
national weather service honolulu hi
340 am hst Sun apr 23 2017

Synopsis
Moderate to locally breezy trade winds will continue the next couple
of days, supported by high pressure northeast of the islands. A wet
trade wind weather pattern is expected to continue today, with
windward showers occasionally spreading leeward, and some briefly
heavy downpours on kauai. Fewer showers are expected to ride in on
the trade winds from tonight through Tuesday. Increasing showers are
possible from Wednesday into next weekend, with the potential for
unsettled weather toward the end of the week.

Discussion
The current weather pattern features a nearly stationary ne-sw
oriented trough axis aloft located about 350 miles NW of kauai, with
the associated SW flow aloft sending broken to overcast high clouds
over all islands. Instability associated with the low is allowing
moisture approaching kauai to become enhanced, with cloud tops near
kauai reaching as high as 15-20 kft, based on radar and the early
morning sounding from phli. Towering cumulus and isolated
thunderstorms are noted over hawaiian offshore waters near the
trough axis W of kauai. A more stable air mass lies over the big
island, with a subsidence inversion based near 8 kft.

A 1027 mb surface high centered about 1000 miles NE of the area has
an associated surface ridge located about 600 miles N of oahu, and
is supplying the islands with a moderate to locally breezy trade
wind flow. In the low-levels, low-level moisture associated with a
dissipated front is becoming difficult to identify, partly due to
the thick high cloud coverage, and also due to the boundary becoming
increasingly diffuse. Nonetheless, latest radar imagery depicts
fairly widespread shower coverage over windward areas from kauai to
maui.

This relatively wet trade wind flow is expected to continue from
kauai to maui this morning, with especially heavy showers expected
to occasionally move across kauai. A gradual drying trend is
expected from E to W across the area later today. Diminished
moisture is expected to fuel fewer trade wind showers from tonight
through Tuesday, despite the continued presence of the low aloft to
the W of the area. Associated high clouds are expected to shift E of
the area by tonight.

The trade wind supplying high to the NE will drift slowly E through
the upcoming week, but a front impacting the W end of the ridge is
expected to lead to some veering (to the E or ese) and weakening of
the trade wind flow tonight and Monday. Latest guidance indicates
that moderate E to ese low-level flow will deliver passing windward
showers Tuesday and Wednesday, which are expected to be most active
nights and mornings. Increasing trade showers are possible Wednesday
night and Thursday, with a trend toward an unsettled weather pattern
toward week's end.

A significant surface trough/front is forecast to be near/over the
islands toward the end of the week, supported by an amplifying
trough aloft and associated cold air which could significantly
destabilize the island atmosphere. Models are currently honing in on
the Thursday night through Saturday time frame for the greatest
instability, with the ECMWF now more aggressive in destabilizing the
atmosphere. Forecast confidence is low due to poor run-to-run and
model-to-model consistency.

Aviation
An old frontal boundary remains stalled over the state. Light to
locally moderate trade wind flow has focused the associated moisture
over windward and mountain areas. Leeward sections of maui molokai
and the big island will remain mostly dry, otherwise tempo MVFR
ceilings in scattered showers will persist across all islands
through midday.

Airmet sierra for mountain obscuration continues for kauai.

Conditions are expected to persist through midday.

Marine
The latest scatterometer pass missed the windiest areas, but showed
20 kt just downstream of those areas. The station at makapulapai, on
the north shore of molokai, has been gusting 25 to 30 kt for the
last several hours, indicating likely small craft advisory (sca)
winds over the windward waters of molokai and maui. This is due to
the flow shifting a little more out of the southeast, which
subsequently puts maalaea bay in the wind shadow of haleakala. We
have extended the SCA through the day today, with the exception of
wind-sheltered maalaea bay.

Otherwise, relatively quiet for the next few days with a number of
mainly small swells affecting nw, s, and E shores. A small NW swell
will arrive tonight into mon, and gradually diminish by tue. Another
will arrive later Tue and spread down the chain Tue night, then
diminish wed. A couple of small s-ssw swells will bring minor bumps
to S facing beaches for much of this week as well. A surface high
will stall roughly halfway between hi and ca for a few days, which
will keep a long fetch of moderate trades aimed at us. This will
maintain choppy and elevated E shore surf, though remaining below
advisory criteria.

Lingering moisture associated with the old frontal band interacting
with an upper level low about 300 nm west of kauai could result in a
few thunderstorms over the far W and NW offshore waters today.

Hfo watches/warnings/advisories
Small craft advisory until 6 pm hst this evening for maui county
windward waters-pailolo channel-alenuihaha channel-big island
windward waters-big island leeward waters-big island southeast
waters.

Discussion... Birchard
aviation... Bedal
marine... Ts


Weather Reporting Stations
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Stations Dist Age Wind Air TempWater Temp WavesPressureDewPt
ILOH1 - 1617760 - Hilo, HI 83 mi51 min S 7 G 9.9 83°F 76°F1019.4 hPa (+1.4)

Wind History for Hilo, Hilo Bay, Kuhio Bay, HI
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Airport Reports
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AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Hilo, Hilo International Airport, HI84 mi58 minSSE 510.00 miMostly Cloudy79°F66°F65%1019.5 hPa

Wind History from HTO (wind in knots)
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Last 24hrE5SE8E10E9E5E11E105NE5CalmSW4S5SW5SW4SW4SW6CalmSW5SW3SW4SW4SW5SW4S5
1 day agoCalmNE3E8E11E9E7E9NE7NE6NE3NE3SW4SW3SW5SW6SW6SW6SW6SW5SW6SW7SW5Calm4
2 days agoN5N7N8E6E5N8N6NE5CalmNE3CalmCalmSW3SW3SW5SW6SW6SW6SW6SW7SW6SW6SW4E4

Tide / Current Tables for Hilo, Hilo Bay, Kunio Bay, Hawaii Island, Hawaii
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Hilo
Click for Map
Sun -- 12:54 AM HST     2.15 feet High Tide
Sun -- 03:59 AM HST     Moonrise
Sun -- 05:56 AM HST     Sunrise
Sun -- 07:20 AM HST     -0.14 feet Low Tide
Sun -- 01:33 PM HST     1.99 feet High Tide
Sun -- 04:15 PM HST     Moonset
Sun -- 06:40 PM HST     Sunset
Sun -- 07:29 PM HST     0.10 feet Low Tide
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
2.12.221.61.10.50.1-0.1-0.10.20.71.21.71.921.71.30.80.40.10.10.40.81.4

Tide / Current Tables for Hana, Maui Island, Hawaii
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Hana
Click for Map
Sun -- 12:27 AM HST     1.98 feet High Tide
Sun -- 04:04 AM HST     Moonrise
Sun -- 05:58 AM HST     Sunrise
Sun -- 06:45 AM HST     -0.21 feet Low Tide
Sun -- 01:16 PM HST     1.93 feet High Tide
Sun -- 04:19 PM HST     Moonset
Sun -- 06:45 PM HST     Sunset
Sun -- 07:05 PM HST     0.06 feet Low Tide
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
21.91.71.20.70.2-0.1-0.2-00.40.91.41.71.91.91.51.10.60.20.10.20.50.91.4

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

GOES Local Image of Hawaii    EDIT
Geos

Wind Forecast for (15,3,4,5)
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Ground Weather Radar Station Kohala, HI
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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.