Thursday, March23, 2017 L-36.com


Marine Weather and Tides
Honaunau-Napoopoo, 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 6:19AMSunset 6:33PM Thursday March 23, 2017 12:29 AM HST (10:29 UTC) Moonrise 3:12AMMoonset 2:48PM Illumination 18% Phase: Waning Crescent; Moon at 25 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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PHZ123 Big Island Leeward Waters- 922 Pm Hst Wed Mar 22 2017
Rest of tonight..Winds variable less than 10 kt west of the big island...northeast 20 kt near south point. Wind waves 6 ft. Northwest swell 4 ft. Haze through the night. Isolated showers after midnight.
Thursday..West of the big island...winds variable less than 10 kt becoming northwest 10 kt in the afternoon. NEar south point...east winds 20 kt. Wind waves 6 ft. Northwest swell 4 ft. Haze. Isolated showers.
Thursday night..Winds variable less than 10 kt west of the big island...east 20 kt near south point. Wind waves 6 ft. Northwest swell 4 ft. Haze. Isolated showers.
Friday..West of the big island...winds variable less than 10 kt becoming west 10 kt in the afternoon. NEar south point...east winds 20 kt. Wind waves 8 ft. Northwest swell 4 ft. Haze. Isolated showers.
Friday night..Winds variable less than 10 kt west of the big island...east 20 kt near south point. Wind waves 8 ft. Northwest swell 3 ft. Haze. Isolated showers.
Saturday..West winds 10 kt west of the big island...east to 25 kt near south point. Wind waves 9 ft. Northwest swell 4 ft. Haze.
Saturday night..Winds variable less than 10 kt west of the big island...east to 25 kt near south point. Wind waves 10 ft. Northwest swell 7 ft. Haze through the night. Isolated showers after midnight.
Sunday..West of the big island...west winds 10 kt becoming variable less than 10 kt. NEar south point...east winds to 25 kt. Wind waves 9 to 10 ft. Northwest swell 8 ft. Haze. Isolated showers.
Monday..West of the big island...northwest winds 10 kt veering northeast. NEar south point...east winds to 25 kt. Wind waves 9 ft. Northwest swell 6 to 8 ft. Haze. Isolated showers.
PHZ100 922 Pm Hst Wed Mar 22 2017
Synopsis for hawaiian coastal waters.. A ridge to the north will weaken through Friday. A new high will build north of the area over the weekend. A very large west northwest swell will affect the area starting Saturday and continuing through early next week.

7 Day Forecast for Marine Location Near Honaunau-Napoopoo, HI
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location: 19.5, -155.74     debug


Area Discussion for -
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Fxhw60 phfo 230713
afdhfo
area forecast discussion
national weather service honolulu hi
913 pm hst Wed mar 22 2017

Synopsis
Expect mainly dry trade wind weather through early Friday, with
brief trade showers mainly along windward facing slopes,
especially over the eastern end of the island chain. Trade wind
speeds are forecast to strengthen again starting late Friday, with
a slight increase in trade showers expected mainly over some
windward areas this weekend.

Discussion
A 1026 mb high located about 1470 miles east-northeast of hilo is
moving slowly toward the east-northeast. A weakening surface
ridge extends west-southwest from this high through a point about
230 miles north of lihue. However, a surface front is also located
about 540 miles north-northwest of lihue. The close proximity of
the front has weakened the surface ridge, and therefore the
pressure gradient across the islands early this evening. As a
result, trade wind speeds have decreased, especially over the
western end of the state, where surface winds have been shifting
from an east-southeast direction. These weaker trades are
allowing local land breezes to develop over interior sections of
some of the islands.

Aloft, water vapor imagery continues to show a middle tropospheric
ridge near the big island, which is maintaining relatively stable
atmospheric conditions across the islands. Dry conditions also
remain across the area early this evening. Elsewhere, the axis of
an upper tropospheric short-wave trough is evident about 730 miles
west of lihue. This feature is moving rapidly toward the east-
northeast.

The cold front north of the region is forecast to continue
pushing eastward. This will nudge the weakening surface ridge
closer to the islands, which will continue to cause surface winds
to veer to the east-southeast, especially over the western end of
the island chain. Note that the weaker background flow may allow
local afternoon sea breezes and nighttime land breezes to develop
over interior sections of the individual islands, especially on
kauai and oahu, through Thursday night.

The forecast guidance continues to indicate there may be a slight
increase in low-level moisture over the eastern islands starting
later tonight and Thursday. Satellite derived precipitable water
(pw) values show estimates of 1.2-1.3 inches just southeast of the
big island. However, the pw appears to be below normal with
values of 1 inch or less over most of the state. The low-level
flow already appears to be bringing increased low cloud cover and
showers from the east-southeast toward the big island, based on
loops of satellite imagery and radar reflectivity data. Therefore,
we anticipate there will be a gradual increase in low clouds and
showers, especially along the windward facing sections of the big
island, and possibly maui, from later tonight into Friday.

The middle tropospheric ridge may begin to erode near the eastern
end of the state during the next couple of days. This is due in
part to the short-wave trough moving by just to the north of the
islands during the next 24 to 36 hours. Once this feature is
northeast of the big island, the models suggest an upper
tropospheric trough will deepen east and northeast of the big
island starting late Thursday night and continuing into this
weekend. This may allow some increase in inversion heights,
especially near the windward big island this weekend.

High pressure will gradually build north of the area after the
front dissipates, resulting in an increase in trade wind speeds.

The trades will also likely be from a more typical east-northeast
direction starting late Friday, and continuing through this
weekend. In addition, as the inversion heights increase this
weekend, expect an increase in trade wind showers, particularly
along windward facing slopes of the eastern islands. The models
also show a new high moving to a position far north of the islands
late Saturday. The pressure gradient south of this feature will
maintain trade wind weather into Monday as it continues moving
toward the east-northeast.

Aviation
A cold front passing well north of the state will weaken the high
pressure ridge, thereby decreasing the strength of the trade winds
and keeping the wind direction more east to southeasterly.

Cloud remnants from an old frontal boundary to our east will drift
into the big island and possibly eastern maui tonight producing
isolated to scattered MVFR ceilings and a few showers.

Elsewhere mostlyVFR conditions are forecast.

No airmets are in effect at this time.

Marine
A surface high is currently located far northeast of the area
with a surface ridge trailing west to about 200nm north of kauai.

The high will move east and the ridge will weaken over the next
couple of days as two fronts pass north of the area. Winds are
expected to remain below small craft advisory (sca) speeds for the
next two days.

The surface ridge will strengthen again north of the area starting
Friday. Winds are expected to reach SCA strength by Saturday and may
reach near-gale strength around the big island and maui over the
weekend as a new high builds north of the area. Surf along east
facing shores will increase a bit again as the trade winds
strengthen.

A storm east of japan will produce a very large west-northwest
swell reaching the islands Saturday. Surf from this swell will be
well above the advisory threshold through early next week and may
reach warning levels. Surf will be highest on kauai and niihau.

Those islands will block some of the swell, so surf will have
somewhat lower heights on the rest of the smaller islands. As this
swell subsides next Tuesday, a new moderate northwest swell is
expected to arrive.

Hfo watches/warnings/advisories
None.

Discussion... Houston
aviation... Bohlin
marine... Ts


Weather Reporting Stations
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Stations Dist Age Wind Air TempWater Temp WavesPressureDewPt
KWHH1 37 mi42 min NE 4.1 G 6 75°F 79°F1020.2 hPa
ILOH1 - 1617760 - Hilo, HI 40 mi42 min SW 5.1 G 6 74°F 78°F1020.8 hPa
51206 45 mi48 min 78°F6 ft

Wind History for Kawaihae, HI
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Airport Reports
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AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Kailua / Kona, Keahole Airport, HI17 mi37 minESE 610.00 miMostly Cloudy76°F63°F64%1019.7 hPa
Bradshaw Army Air Field / Hawaii, HI22 mi34 minS 810.00 miFair60°F11°F14%1016.8 hPa

Wind History from HKO (wind in knots)
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Last 24hrN5NE6NE4CalmCalmE3SE4SE7S8S10SW9SW9SW10W9W8SW9SW8S7S8S8SE7SE8E6E6
1 day agoE18NE17
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NE5E5CalmE3SW7SW8S10SW11S10SW13SW8S9S8S8S8N10NE7N5NW4W6
2 days agoNE5NE9NE3E4CalmNE6CalmNE53S8SW9S8S7SW7S8S9S11S10S8S8S6NE7SE6E12

Tide / Current Tables for Kailua Kona, Big Island, Hawaii
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Kailua Kona
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Thu -- 12:43 AM HST     1.84 feet High Tide
Thu -- 03:13 AM HST     Moonrise
Thu -- 06:25 AM HST     Sunrise
Thu -- 07:43 AM HST     0.16 feet Low Tide
Thu -- 01:06 PM HST     0.98 feet High Tide
Thu -- 02:49 PM HST     Moonset
Thu -- 06:35 PM HST     Sunset
Thu -- 06:38 PM HST     0.14 feet Low Tide
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
1.81.81.71.41.10.70.40.20.20.30.50.70.910.90.80.50.30.20.20.30.611.4

Tide / Current Tables for Kailua Kona, Hawaii Island, Hawaii
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Kailua Kona
Click for Map
Thu -- 01:09 AM HST     1.68 feet High Tide
Thu -- 03:13 AM HST     Moonrise
Thu -- 06:25 AM HST     Sunrise
Thu -- 07:50 AM HST     0.29 feet Low Tide
Thu -- 01:05 PM HST     1.02 feet High Tide
Thu -- 02:48 PM HST     Moonset
Thu -- 06:35 PM HST     Sunset
Thu -- 06:53 PM HST     0.05 feet Low Tide
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
1.61.71.61.41.10.80.50.30.30.40.60.80.9110.80.60.30.10.10.20.40.81.2

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 (6,6,7,8)
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Ground Weather Radar Station South Shore, 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.