Saturday, December16, 2017 L-36.com


Marine Weather and Tides
Kapalua, HI

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 6:55AMSunset 5:49PM Saturday December 16, 2017 2:13 PM HST (00:13 UTC) Moonrise 5:37AMMoonset 5:02PM Illumination 2% Phase: Waning Crescent; Moon at 28 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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PHZ120 Pailolo Channel- 958 Am Hst Sat Dec 16 2017
Rest of today..South winds 15 knots. Wind waves 4 feet. North swell 6 feet. Scattered heavy showers through the day. Slight chance of Thunderstorms in the afternoon.
Tonight..South winds 15 knots. Wind waves 5 feet. North swell 5 feet. Scattered showers and slight chance of Thunderstorms.
Sunday..South winds 10 knots. Wind waves 5 feet. Northwest swell 4 feet. Scattered showers in the morning, then isolated showers in the afternoon.
Sunday night..Winds variable less than 10 knots. Wind waves 4 feet. Northwest swell 4 feet. Isolated showers in the evening, then scattered showers after midnight.
Monday..Winds variable less than 10 knots. Wind waves 4 feet. Northwest swell 4 feet. Isolated showers.
Monday night..Winds variable less than 10 knots. Wind waves 4 feet. Northwest swell 4 feet. Scattered showers.
Tuesday..Winds variable less than 10 knots. Wind waves 3 to 4 feet. Northwest swell 5 to 7 feet. Isolated showers.
Wednesday..Northeast winds 10 knots. Wind waves 4 feet. North swell 7 to 8 feet. Scattered showers.
PHZ100 958 Am Hst Sat Dec 16 2017
Synopsis for hawaiian coastal waters.. A surface low just northeast of oahu will continue to move west today. Light winds will remain over the area into early next week, before increasing out of the northeast as a cold front passes the islands Tuesday and Wednesday.

7 Day Forecast for Marine Location Near Kapalua CDP, HI
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location: 21.02, -156.64     debug


Area Discussion for -
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Fxhw60 phfo 162029
afdhfo
area forecast discussion
national weather service honolulu hi
1029 am hst Sat dec 16 2017

Synopsis
A low pressure area northeast of the islands will begin to weaken
and move westward. This low will keep the airmass unstable, and
with light winds, locally heavy afternoon showers or
thundershowers will be possible today. Quieter weather is expected
for most areas Sunday into Monday. A strong upper level
disturbance and increasing moisture over the southern end of the
chain may lead to episodes of heavy showers or thundershowers for
maui county and the big island Monday night through about
Wednesday.

Discussion
A nearly vertically stacked low is located just NE of oahu this
morning. This low has destablized our airmass, but has only
limited moisture to work with. The uw-cimss mimic total
precipitable water shows anywhere from an inch and a third to an
inch and a half of pw over the smaller islands, with a wedge of
drier air spiralling into the eastern semicircle of the low,
extending across the big island. The surface reflection of the low
is rather broad and weak, so the slack pressure gradient over the
islands is keeping winds light, and many areas are starting the
day with lots of sunshine. Most of the significant weather with
the low for now is remaining over the NE offshore waters, with a
weak zone of moisture convergence extending south across maui
county and the adjacent waters, for a few more showers there.

The available high resolution guidance shows that things should
get fairly active again this afternoon with convection blowing up
over the smaller islands, particularly over parts of maui county
in the vicinity of the low level convergence. Updated the grids
earlier to quiet pops and weather down for the morning but leaving
them alone for now for the afternoon for all but the big island,
which should remain less active in the drier wedge.

By tonight, the surface and upper air reflections of the low will
become increasingly decoupled, with the upper level feature
beginning to pull toward the ne, and the surface- and mid-level
low edging slowly w. Overall the mid and upper level support will
be diminishing, but the lingering low level convergence may still
keep some showers around, especially in the evening, for oahu and
maui county. Relatively light winds may allow some land areas to
clear out again after midnight (especially away from the
convergence band). At this point it looks like pops overall may be
overdone for the overnight period and will likely be making some
adjustments.

As the mid-level low pushes toward the w, a belt of strong
southerlies on the eastern periphery is expected to affect the big
island summits this afternoon into tonight, then diminish on
Sunday. A high wind warning has thus been issued for the summits
of mauna loa and mauna kea until noon Sunday.

On Sunday, the surface low should have weakened to a broad, weak
trough that will be located over kauai. The pressure gradient over
the islands will remain quite slack, with the background flow
temporarily becoming gentle kona winds. The dry slot currently
over and SE of the islands is expected to pull NW over maui, with
the lingering moisture band now over maui county pushing NW to
kauai and oahu, bringing a few showers. Deeper moisture lurking a
few hundred SE of the big island is expected to reach the big
island during the day, which could lead to an increase in
afternoon showers there if it arrives soon enough.

The surface trough will be just NW of the islands Sunday night and
should weaken, leaving the state in a very slack pressure gradient
once again. With weak mid-level ridging temporarily taking over
and limited moisture, expecting most areas to clear out once
again from land breezes. Some parts of the big island might have a
tougher time clearing due to the increased moisture there.

On Monday, the remnants of the surface trough will push back
toward the SE over the islands, with light winds continuing. By
then, the models show plenty of pw and lingering mid-level cool
air for quite a bit of afternoon convection over the big island.

Maui county will be on the edge of this moisture, and drier air is
expected over kauai and oahu to limit afternoon clouds and showers
there.

A diffuse cold front approaching the islands from the NW Monday
night into Tue will begin to turn our flow back to northerlies.

The front may increase clouds and showers on kauai later in the
day, though timing right now is rather uncertain. More
importantly, the front will be accompanied by a sharp mid level
trough which is expected to activate the band of deeper moisture
near maui and the big island, which could lead to some heavy
showers or thunderstorms developing especially for the southern
half of the chain. Another, even stronger mid-level trough drops
in over the islands on Wednesday, maintaining the threat for heavy
showers and thunderstorms near maui or the big island through
midweek. Will likely need to make adjustments to pop and weather
for this time period as well after taking a closer look at the
latest guidance.

Aviation
With an upper low north of the islands and the presence of low
level moisture, a chance for heavy showers and isolated
thunderstorms remains a possibility over the state, especially
west of the big island. Thus MVFR conditions in lower ceilings
and visibilities will likely occur from time to time, and also a
chance of isolated ifr weather.

Airmets are currently posted for mountain obscuration for all the
main isles except the big island.

Marine
A weak surface low just northeast of oahu will continue to drift
west today. Winds will remain light across most of the coastal
waters into early next week. Then a fronts is forecast to pass
northwest to southeast across the state Tuesday and Wednesday.

All marine advisories have been cancelled this morning. Pacioos
nearshore buoys are reporting seas just under 10 ft and should
continue to lower today as the current small north-northeast
swell subsides. The current small north-northwest swell will
gradually decline today with a small, moderate period (4-5 ft, 14
sec) reinforcing west-northwest swell filling in late tonight and
peaking Sunday night. Surf will remain below advisory levels.

Another slightly larger north-northwest swell is then forecast to
build Monday night and peak Tuesday night near 8 ft, 11-12 sec.

Surf may near advisory levels along north facing shores.

Small, moderate to long period south-southwest swells are
forecast for Monday night through Thursday night, providing a
small bump to surf along south facing shores.

Heavy showers and isolated thunderstorms will be possible across
parts of the coastal and offshore waters today and tonight
due to a nearby upper level trough.

Hfo watches warnings advisories
High wind warning for big island summits until noon Sunday.

R ballard kinel eaton


Weather Reporting Stations
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Stations Dist Age Wind Air TempWater Temp WavesPressureDewPt
51205 11 mi43 min 77°F10 ft
KLIH1 - 1615680 - Kahului Bay, Maui, HI 13 mi43 min S 12 G 19 73°F 74°F1009.3 hPa
51202 - Mokapu Point, HI (098) 61 mi69 min 77°F7 ft

Wind History for Kahului, Kahului Harbor, HI
(wind in knots)    EDIT      (on/off)   Help
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N18
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N21
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NE16
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NE22
N12
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E4
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N13
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Airport Reports
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AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Lahaina - West Maui, HI1 mi28 minSSE 1410.00 miMostly Cloudy75°F62°F65%1009.8 hPa
Kahului, Kahului Airport, HI14 mi19 minSW 1310.00 miPartly Cloudy76°F64°F69%1009.7 hPa
Lanai City, Lanai Airport, HI23 mi17 minSSW 910.00 miOvercast70°F64°F82%1009.8 hPa

Wind History from HJH (wind in knots)
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Last 24hrNE10N15N17N14------------------------SE8CalmS11S11S10S14SW6S14
1 day agoNE19
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------------------------NE8NE15
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2 days agoNE15
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G30
NE16
G28

Tide / Current Tables for Lahaina, Maui Island, Hawaii
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Lahaina
Click for Map
Sat -- 02:43 AM HST     2.34 feet High Tide
Sat -- 05:36 AM HST     Moonrise
Sat -- 06:56 AM HST     Sunrise
Sat -- 09:39 AM HST     0.51 feet Low Tide
Sat -- 02:13 PM HST     1.06 feet High Tide
Sat -- 05:02 PM HST     Moonset
Sat -- 05:48 PM HST     Sunset
Sat -- 07:46 PM HST     0.08 feet Low Tide
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
1.622.32.32.21.91.410.70.50.50.60.811.110.90.60.30.10.10.20.51

Tide / Current Tables for Kahului, Kahului Harbor, Hawaii
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Kahului
Click for Map
Sat -- 02:02 AM HST     2.50 feet High Tide
Sat -- 05:35 AM HST     Moonrise
Sat -- 06:55 AM HST     Sunrise
Sat -- 08:20 AM HST     0.90 feet Low Tide
Sat -- 12:46 PM HST     1.48 feet High Tide
Sat -- 05:01 PM HST     Moonset
Sat -- 05:47 PM HST     Sunset
Sat -- 07:13 PM HST     -0.27 feet Low Tide
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
22.42.52.42.11.71.310.90.91.11.31.41.51.41.10.70.2-0.1-0.3-0.20.10.61.2

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 (19,4,5,8)
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Ground Weather Radar Station Molokai, 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.