Saturday, April29, 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 5:50AMSunset 6:44PM Saturday April 29, 2017 1:30 AM HST (11:30 UTC) Moonrise 9:07AMMoonset 10:34PM Illumination 12% Phase: Waxing Crescent; Moon at 3 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- 933 Pm Hst Fri Apr 28 2017
Rest of tonight..South winds 10 kt. Wind waves 4 ft. Mixed swell northwest 3 ft and south 3 ft. Haze. Scattered showers and Thunderstorms.
Saturday..South winds 15 kt west of the big island... Southeast 10 kt near south point. Wind waves 4 ft. Mixed swell northwest 3 ft and south 3 ft. Haze in the morning. Scattered heavy showers and Thunderstorms through the day.
Saturday night..South winds 15 kt west of the big island... South 10 kt near south point. Wind waves 3 ft. Northwest swell 4 ft. Scattered showers and Thunderstorms.
Sunday..South winds 15 kt. Wind waves 3 ft. Northwest swell 4 ft. Haze. Numerous heavy showers and slight chance of Thunderstorms.
Sunday night..South winds 10 kt in the evening becoming variable less than 10 kt. Wind waves 3 ft. Northwest swell 3 ft. SWell south 3 ft. Haze. Numerous heavy showers and slight chance of Thunderstorms.
Monday..Winds variable less than 10 kt becoming southeast 10 kt in the afternoon. Wind waves 3 ft. Mixed swell northwest 3 ft and south 3 ft. Haze. Heavy showers likely and slight chance of Thunderstorms.
Monday night..Winds variable less than 10 kt. Wind waves 3 ft. Mixed swell northwest 3 ft and south 3 ft. Haze. Numerous heavy showers and slight chance of Thunderstorms.
Tuesday..Winds variable less than 10 kt. Wind waves 3 ft. Mixed swell northwest 3 ft and south 3 ft. Haze. Scattered showers.
Wednesday..Winds variable less than 10 kt becoming northeast 10 kt. Wind waves 2 ft or less. Haze. Scattered showers.
PHZ100 933 Pm Hst Fri Apr 28 2017
Synopsis for hawaiian coastal waters.. A front near kauai will move east slowly before stalling over the central islands Saturday. An upper level low developing north of the state and an associated surface low will then shift over the islands late Saturday...and continue unsettled conditions through the period.

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 290707
afdhfo
area forecast discussion
national weather service honolulu hi
907 pm hst Fri apr 28 2017

Synopsis
An unsettled weather pattern will prevail through the weekend and
into early next week, with thunderstorms and heavy showers in the
forecast. This will occur as a front stalls over the islands and
a potent low aloft significantly destabilizes the atmosphere.

While cool north winds will limit shower coverage and intensity
over kauai county and the front will likely focus the heaviest
rainfall over maui county, thunderstorms will be possible
statewide through early next week. A return to a more typical
trade wind weather pattern is then expected by the middle of
next week.

Discussion
Currently at the surface, a weak 1011 mb low is located around 500
miles north of kahului, with a trough extending southward through
maui county. Meanwhile, a front is located between oahu and
kauai, to the west of the surface trough. Aloft, broad upper level
troughing dominates the synoptic pattern over the central pacific,
with a deep upper level low located around 550 miles north of
honolulu, with the trough axis extending southward and over the
island chain. Additionally, a shortwave trough embedded within the
broad upper level trough is moving through maui and approaching
the big island this evening. Infrared satellite imagery shows
mostly cloudy skies in place across most of the state, with some
pockets or reduced cloud cover over oahu, molokai and lanai.

Meanwhile, radar imagery shows showers scattered about across the
island chain, with the main focus around oahu and maui county at
the moment. Main short term concern revolves around the potential
for heavy rainfall and flooding across the central and eastern
islands through the weekend.

Rest of tonight,
the surface trough running through maui county will remain nearly
stationary through the overnight hours, while the front which
extends through the kauai channel will shift slowly eastward
through oahu later this evening and approach molokai right around
daybreak Saturday. Meanwhile aloft, the shortwave trough currently
moving through maui county will track quickly eastward through the
evening hours, moving east of the big island by midnight. The loss
of daytime heating as well as the best forcing for ascent provided
by the upper level shortwave trough exiting to the east of the
state later this evening, should act to have a stabilizing effect
on the weather across the islands overnight. Showers will likely
remain most prevalent over oahu and maui county through the
overnight hours, with reduced coverage expected across kauai and
the big island. Across kauai and oahu, northerly winds behind the
front will keep most of the shower activity focused over areas
favored in a northerly flow regime, while the surface trough over
maui county will result in a light wind regime with scattered
showers possible almost anywhere through the overnight hours.

Saturday through Monday night,
model solutions are in good agreement showing the front and
surface trough consolidating over maui county on Saturday, then
remaining nearly stationary through Sunday before slowly
dissipating heading into early next week. Meanwhile aloft, a deep
upper level low will shift southward toward kauai on Saturday and
move over kauai by late Saturday night or early Sunday morning.

The upper low will then pivot off to the south of kauai during
the day on Sunday before stalling out around 200 miles south of
kauai Sunday night through Monday night. The deepest moisture is
progged to remain over maui county through the period, but it will
remain very close to both oahu and even closer to the big island.

Shower activity appears to be more limited across kauai where dry
surface dewpoint air will move in from the north, with dewpoints
dropping into the mid 50s through the weekend. That said, with the
core of the upper level low moving over kauai, the instability
aloft will likely be enough to produce some scattered showers, the
coverage should just be reduced in comparison to the other
islands.

The potential remains for a significant hydrology event over the
weekend, particularly across maui county, with the heaviest
rainfall appearing to focus over the area Saturday night and
Sunday when the best forcing for ascent will be in place. In
addition, the instability provided by the upper level low will
keep thunderstorms a possibility across the entire state, with
the best chances for thunder expected across maui county and big
island. A flash flood watch remains in effect from oahu eastward
to the big island through Sunday, with the highest probabilities
for flooding rains expected over maui county at this time.

Additionally, the proximity of the deep moisture to the big island
and the instability aloft may result in wintry conditions over the
big island summits, and the winter storm watch remains in effect
Saturday through Sunday. Windy conditions are also expected to
develop over the big island summits Saturday afternoon, reaching
wind advisory levels possibly right through the day on Monday,
with warning level winds not out of the question Saturday night
and Sunday.

Unsettled conditions are expected to continue Sunday night through
Monday night as the upper level low remains just to the south of
the islands and the lingering moisture from the dissipating
surface trough remains over the island chain. Due to the
continued instability, thunderstorms will need to remain in the
forecast, and the flash flood watch may eventually need to be
extended into early next week.

Tuesday through next Friday,
the upper level low to the south of kauai will begin to weaken
and open up on Tuesday in response to ridging aloft building in
from the west. This should have a stabilizing effect on the
weather over the islands, with a return to more of a typical trade
wind pattern expected Tuesday night through late next week.

Aviation
A diffuse front is in the kauai channel as of 05z, moving E at 10
kt. The front is expect to cross oahu between 08z and 12z and
continue eastward into maui county where it will stall. A shallow
layer of moisture lies immediately west of the front, followed by
a dry and cool air mass. With this said, kauai is expected to
improve early this evening, by 12z, with the lowering of airmet
sierra, followed by oahu by 16z. Airmet sierra is not likely to be
imposed on the remaining islands overnight.

Spotty heavy showers remain along and east of the front to near
upolu point on the big island. Tops of these showers are as high
as 25k feet. During the overnight hours, scattered showers are not
out of the question for the kona coast and the northern part of
the big island. Also, there is a slight chance of an isolated
thunderstorm, favoring the coastal waters.

An upper level trough, above 15kt feet is currently over maui
moving east at 20 kt. So, it should clear the big island by 10z.

Therefore, expect airmet tango, for the high level turbulence to
be lowered with the 10z package.

Airmet tango was updated to include kauai and oahu for low level
turbulence below 8k feet caused by a brisk northerly wind flow.

Expect this flow to ease overnight, but it will be reevaluated
if it will be extended beyond 16z.

Marine
With a front and upper trough in the area, the chance for
thunderstorms over the coastal waters will persist through
Saturday and beyond. Winds in the wake of the surface boundary
are strong enough to warrant a small craft advisory (sca) for
waters around kauai and oahu windward waters, and seas will ramp
up to 10 feet in select zones as well. The SCA is currently in
effect through early Saturday.

Surf along north facing shores will increase some tonight into
Saturday from a short-period, choppy swell associated with the
stronger winds behind the front, but will stay below advisory
conditions. A series of small, longer-period northwest swells are
expected next week, also expected to remain below advisory levels.

A series of long-period south swells will affect the south facing
shores into next week. The first of these swells will continue to
bring advisory level surf (8 ft) to exposed south facing shores
through early Saturday. A high surf advisory has been posted for
these areas. Please refer to the coastal hazard message, cfwhfo,
for more information. A reinforcing south swell will fill in Monday
and Tuesday, and keep surf borderline for advisory conditions.

Hfo watches/warnings/advisories
Flash flood watch through Sunday afternoon for oahu-molokai-
lanai-kahoolawe-maui-big island.

High surf advisory until 6 am hst Saturday for niihau-kauai
windward-kauai leeward-oahu south shore-molokai-lanai makai-
kahoolawe-maui leeward west-maui central valley-leeward
haleakala-kona-south big island.

Winter storm watch from 6 am hst Saturday through Sunday
afternoon for big island summits.

Small craft advisory until 6 am hst Saturday for kauai northwest
waters-kauai windward waters-kauai leeward waters-kauai channel-
oahu windward waters.

Discussion... Jelsema
aviation... Lau
marine... Kinel


Weather Reporting Stations
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Stations Dist Age Wind Air TempWater Temp WavesPressureDewPt
KWHH1 37 mi43 min W 8.9 G 11 76°F 80°F1011.8 hPa
ILOH1 - 1617760 - Hilo, HI 40 mi49 min SSW 5.1 G 7 69°F 77°F1011.8 hPa
51206 45 mi49 min 78°F5 ft

Wind History for Kawaihae, HI
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Airport Reports
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AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Kailua / Kona, Keahole Airport, HI17 mi38 minSE 510.00 miOvercast74°F66°F76%1011.9 hPa
Bradshaw Army Air Field / Hawaii, HI22 mi35 minSE 310.00 miFair46°F40°F81%1010.9 hPa

Wind History from HKO (wind in knots)
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Last 24hrSE9SE7SE6E7E6SE7S8SW9S7SW9S11S13S14S12S13S12S13S13S11S9S6SE7SE7SE4
1 day agoSW8SW7SW5W3SE3SE4S4SW6S9S10S8SW10S10S12S11S9S11S8S9S9S9SE10SE8SE10
2 days agoCalmSE4E7SE8E7E4CalmW6S7SW11SW12SW12SW11SW12SW14SW10SW11W9SW10W11W11SW13SW11SW7

Tide / Current Tables for Kailua Kona, Big Island, Hawaii
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Kailua Kona
Click for Map
Sat -- 12:56 AM HST     0.12 feet Low Tide
Sat -- 05:50 AM HST     0.83 feet High Tide
Sat -- 05:56 AM HST     Sunrise
Sat -- 09:07 AM HST     Moonrise
Sat -- 11:23 AM HST     -0.08 feet Low Tide
Sat -- 06:43 PM HST     2.18 feet High Tide
Sat -- 06:46 PM HST     Sunset
Sat -- 10:35 PM HST     Moonset
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
0.20.10.20.40.60.80.80.70.50.30.1-0.1-0.10.10.511.51.92.12.221.71.30.8

Tide / Current Tables for Kailua Kona, Hawaii Island, Hawaii
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Kailua Kona
Click for Map
Sat -- 12:28 AM HST     0.25 feet Low Tide
Sat -- 05:25 AM HST     1.08 feet High Tide
Sat -- 05:55 AM HST     Sunrise
Sat -- 09:07 AM HST     Moonrise
Sat -- 11:32 AM HST     -0.29 feet Low Tide
Sat -- 06:46 PM HST     Sunset
Sat -- 06:50 PM HST     2.08 feet High Tide
Sat -- 10:35 PM HST     Moonset
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
0.30.30.40.70.91.11.10.90.60.2-0.1-0.3-0.3-0.10.30.81.31.722.11.91.61.20.8

Weather Map and Satellite Images
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Weather Map
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IR Satellite Image from GEOS
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GOES Local Image of Hawaii    EDIT
Geos

Wind Forecast for (7,2,3,4)
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Ground Weather Radar Station South Shore, HI
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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.