Marine Weather and Tides
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 6:17AM||Sunset 5:51PM||Tuesday October 24, 2017 1:08 AM HST (11:08 UTC)||Moonrise 10:28AM||Moonset 9:51PM||Illumination 18%|
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|PHZ122 Big Island Windward Waters- 918 Pm Hst Mon Oct 23 2017 |
.small craft advisory in effect from Tuesday morning through Wednesday afternoon...
Rest of tonight..South winds 20 knots. Wind waves 5 feet. Northwest swell 5 feet. Haze. Numerous heavy showers and isolated Thunderstorms.
Tuesday..South winds 15 knots. Wind waves 6 feet. Northwest swell 5 feet. Haze. Frequent heavy showers and isolated Thunderstorms.
Tuesday night..North winds 15 knots. Wind waves 5 feet. Northwest swell 7 feet and south 3 feet. Haze in the evening. Showers likely through the night.
Wednesday..North winds 15 knots. Wind waves 4 feet. Northwest swell 9 feet and south 4 feet. Showers likely in the morning, then scattered showers in the afternoon.
Wednesday night..North winds 15 knots. Wind waves 5 feet. Northwest swell 9 feet and south 3 to 4 feet. Scattered showers.
Thursday..North winds 15 knots. Wind waves 5 feet. North swell 7 feet and south 3 feet. Scattered showers in the morning, then isolated showers in the afternoon.
Thursday night..North winds 15 knots. Wind waves 4 feet. North swell 7 feet increasing to northwest 9 feet after midnight. Scattered showers.
Friday..Northeast winds 10 knots. Wind waves 3 feet. Northwest swell 10 to 12 feet. Isolated showers.
Saturday..East winds 10 knots. Wind waves 3 feet. Northwest swell 9 to 11 feet. Isolated showers.
|PHZ100 918 Pm Hst Mon Oct 23 2017 |
Synopsis for hawaiian coastal waters.. A strong cold front moving over the northwest waters will continue to advance eastward down the island chain through midweek. The front is forecast to stall and weaken across the big island waters Wednesday through Thursday. High pressure will build northwest of the region Thursday through Friday.
7 Day Forecast for Marine Location Near Wainaku, HIHourly EDIT Help
Area Discussion for -  (on/off)  Help NOTE: mouseover dotted underlined text for definition
|Fxhw60 phfo 240735|
area forecast discussion
national weather service honolulu hi
935 pm hst Mon oct 23 2017
Heavy showers and isolated thunderstorms associated with a strong
cold front and upper trough could lead to flash flooding,
especially from oahu to the big island through Tuesday. The front
will move through oahu late tonight or early Tuesday, then
continue down the island chain and shift east of the big island
Wednesday night into Thursday. Cooler and drier air with northerly
winds will follow the front through the second half of the week.
Currently at the surface, a strong cold front has shifted through
kauai this evening and is approaching oahu from the northwest.
Meanwhile well upstream of the islands a 1026 mb high is centered
around 1250 miles northwest of kauai. Aloft, a deep upper level
trough extends from the aleutian islands southward to just west of
the state, with an upper level low beginning to close off around
500 miles north of kauai. The combination of the approaching
front, a tap into deep tropical moisture, and the approaching
upper level trough is leading to a band of heavy showers and
thunderstorms moving through the island chain this evening. Main
short term concerns revolve around the potential for
thunderstorms, heavy rainfall and flash flooding.
Tonight through Tuesday night,
the cold front will continue to shift southeastward and move
through oahu late tonight, then continue to shift through maui
county during the day on Tuesday before slowing its southeastward
progression between maui and the big island Tuesday night. Strong
forcing for ascent associated with the upper trough just west of
the state, in combination with the cold front and tap into deep
tropical moisture, will keep the threat for heavy rainfall and
thunderstorms in place through Tuesday and possibly into Tuesday
evening. The best forcing for ascent will then shift to the north
and east of the islands Tuesday night. The threat for
thunderstorms and the potential for heavy rainfall and flooding
will be highest over oahu and maui county tonight, then over maui
county and the big island on Tuesday. The flash flood watch will
likely be able to be cancelled for the island of oahu with the 4
am forecast package, while the watch will likely need to be
continued for maui county and the big island through 6 pm Tuesday.
Drier air will work it's way into the islands from northwest to
southeast in the wake of the cold front. The front appears that it
will hang up in the vicinity of the alenuihaha channel by Tuesday
night, keeping the highest chances for rain in place across maui
and the big island.
Additionally, the upper level trough is expected to increase the
winds on the big island summits later tonight, and a high wind
warning remains posted through the day on Tuesday.
Wednesday through next Monday,
the upper level low will begin to open up on Wednesday, with the
trough axis lifting northeastward and across the island chain by
Wednesday night. This should give the front in the vicinity of
maui and the big island a kick off to the east of the island chain
by Wednesday night or early Thursday. High pressure building north
of the islands will then shift the northerly winds around to a
more typical northeasterly trade wind direction by Thursday or
A much drier airmass should keep fairly dry trade wind weather in
place following the frontal passage and continuing right into
next weekend. The one exception may be across the eastern end of
the state where lingering deep moisture may keep a more showery
pattern in place. A cold front approaching from the northwest may
bring another round of deep tropical moisture back northward into
the area by late Sunday into early next week.
A prefrontal convergence boundary over oahu and molokai this
evening continues to sweep eastward across the hawaiian islands
bringing numerous showers and scattered thunderstorms with MVFR
and local ifr conditions expected from tonight through tomorrow
morning. Showers and thunderstorms along this convergence boundary
will spread MVFR ifr conditions, currently over oahu, into
molokai, lanai and maui through 18-20z. Showers will eventually
reach the big island around 12-14z Tuesday morning.|
A cold frontal boundary currently moving eastward through kauai
will bring improving conditions along with a wind shift to
northwest wind directions. Improving weather conditions will
reach oahu by 12-14z.
Airmet sierra in effect for mountain obscuration over oahu,
molokai and lanai this evening, spreading to maui around 08z.
Airmet tango in effect for upper level turbulence from oahu to
maui including adjacent waters in the 080 200 layer.
Airmet zulu in effect for light icing from oahu to maui including
adjacent waters in the 140 230 layer.
We have received multiple reports of moderate turbulence and a
few reports of light icing with this system.
A band of heavy showers and thunderstorms associated with a
strong front moving down the island chain will continue to impact
the waters into midweek. The cold front is currently moving
across the kauai waters this evening and should push east of oahu
by daybreak Tuesday, then over the maui county and the big island
waters through midweek. Northwest winds have already reached
barking sands, marking the frontal passage. Strong thunderstorms
are currently moving over the leeward oahu and kaiwi channel
waters and will continue eastward over the maui county waters
overnight through Tuesday. Some of these storms will be strong
with gusty winds and locally higher seas.
Fresh to strong northerly winds will continue to fill in across
the northwest waters through the overnight hours tonight in the
wake of the front, then continue eastward across the eastern half
of the island chain through midweek following the frontal
boundary. Winds will gradually shift out of the northeast through
the second half of the week and remain in the moderate to fresh
range as high pressure builds over the region.
A combination of fresh to strong northerly winds and a large,
shorter period (12 sec), north-northwest swell filling in across the
waters will translate to rough boating conditions across the exposed
waters into Wednesday before trending down. A small craft advisory
has been issued for these exposed waters, which continues through
Wednesday afternoon. The northwest offshore buoys have already
ramped up to just under 15 ft this evening, which remains in line
with the latest wavewatch iii (ww3) guidance. Ww3 and the ecmwf-wave
depicts a broad peak occurring late tonight through Tuesday, then
temporarily trending down Tuesday night through Thursday.
Surf along north facing shores will remain rough through midweek due
to northerly winds and the new north-northwest swell filling in from
the strong pressure gradient that has setup north of the state
between a developing storm-force low and 1028 mb high pressure
centered north of midway across the central pacific. Dangerous and
rough beach conditions are expected along north facing shores
through this time. See the high surf advisory for more details on
expected impacts, which will remain in place for north facing
shores of the smaller islands through Wednesday.
The active period across the northern pacific is progged to continue
into the second half of the week. The latest analysis showed a large
fetch across the northwest pacific associated with a developing
hurricane-force low (response to former typhoon lan lifting
north). An ascat pass today showed a large area of gale-to storm-
force winds focused toward the islands within the 310-320 deg
band. As this low continues eastward and intensifies (940 mb) near
the aleutian islands, the latest wave model guidance is showing
seas within this fetch peaking within the 50 to 60 ft range. This
will likely translate to well above warning-level surf for the
exposed north and west facing shores beginning Thursday night and
continuing into Saturday before slowly fading. Wave model guidance
is indicating forerunners Thursday night with peak periods as
high as 25 seconds.
Surf along southern shores will hold into the midweek period as a
mix of south-southwest and southeast energy continues to impact
the waters. Surf heights are expected to remain below advisory
levels and gradually trend down through the second half of the
For more detailed information on the surf for oahu, see the latest
collaborative forecast at:
Weather Reporting StationsEDIT (on/off)  Help NOTE: Click on distance to see the station location on a map
|Stations||Dist||Age||Wind||Air Temp||Water Temp||Waves||Pressure||DewPt|
|ILOH1 - 1617760 - Hilo, HI||0 mi||50 min||SW 5.1 G 8||73°F||79°F||1009.5 hPa|
|51206||6 mi||41 min||80°F||7 ft|
|KWHH1||46 mi||50 min||ENE 2.9 G 4.1||78°F||82°F||1009.3 hPa|
Wind History for Hilo, Hilo Bay, Kuhio Bay, HI(wind in knots) EDIT (on/off)  Help
Airport ReportsEDIT (on/off)  Help Click EDIT to display multiple airports
|Hilo, Hilo International Airport, HI||1 mi||15 min||N 0||2.00 mi||Heavy Rain Fog/Mist||73°F||73°F||100%||1008.7 hPa|
Wind History from HTO (wind in knots)
|1 day ago||SW||SW||SW||SW||E||S||SW||SE||SE||SE||E||E||SE||E||SE||SE||Calm||SW||SW||S||S||SW||S||S|
|2 days ago||W||SW||S||SW||SE||SW||Calm||SW||NW||SW||N||NE||NE||E||NE||E||Calm||SW||SW||SW||SW||SW||SW||SW |
EDIT RT Ports Option Weekend mode (on/off) (on/off)  Help One Week of Data
Click for Map
Tue -- 05:59 AM HST 2.40 feet High Tide
Tue -- 06:18 AM HST Sunrise
Tue -- 10:27 AM HST Moonrise
Tue -- 12:44 PM HST 0.99 feet Low Tide
Tue -- 05:01 PM HST 1.35 feet High Tide
Tue -- 05:50 PM HST Sunset
Tue -- 09:50 PM HST Moonset
Tue -- 11:14 PM HST 0.37 feet Low Tide
Tide / Current data from XTide NOT FOR NAVIGATION
EDIT (on/off)  Help One Week of Data
Click for Map
Tue -- 06:21 AM HST Sunrise
Tue -- 06:52 AM HST 2.06 feet High Tide
Tue -- 10:31 AM HST Moonrise
Tue -- 02:08 PM HST 0.44 feet Low Tide
Tue -- 05:53 PM HST Sunset
Tue -- 06:51 PM HST 0.84 feet High Tide
Tue -- 09:53 PM HST Moonset
Tide / Current data from XTide NOT FOR NAVIGATION
Weather Map and Satellite Images(on/off)  Help
|Weather Map ||IR Satellite Image from GEOS|
GOES Local Image of Hawaii EDIT
Wind Forecast for (7,2,3,4)(on/off)  Help
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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.