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Marine Weather and Tides
Version 3.4 |
3/3/2018 - There is a new GOES Satellite for the east coast that required rewriting that part of the code. Please report any issues. 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. |
Sunrise 5:53AM | Sunset 6:43PM | Wednesday April 25, 2018 11:18 PM HST (09:18 UTC) | Moonrise 3:06PM | Moonset 3:07AM | Illumination 84% | ![]() |
Marine Forecasts
EDIT (on/off)  HelpPHZ122 Big Island Windward Waters- 934 Pm Hst Wed Apr 25 2018 Tonight..East winds 15 knots. Wind waves 6 feet. North swell 4 feet. Scattered showers. Thursday..East winds 15 knots. Wind waves 6 feet. Northwest swell 3 feet. Scattered showers. Thursday night..East winds 15 knots. Wind waves 5 feet. Northwest swell 4 feet. Scattered showers. Friday..Southeast winds 15 knots. Wind waves 5 feet. Northwest swell 5 feet. Scattered showers. Friday night..South winds 15 knots. Wind waves 4 feet. Northwest swell 5 feet. Scattered showers. Saturday..Southwest winds 10 knots veering north in the afternoon. Wind waves 4 feet. Northwest swell 5 feet. Showers likely. Saturday night..North winds 15 knots. Wind waves 4 feet. Northwest swell 7 feet. Showers likely. Sunday..North winds 10 knots becoming variable less than 10 knots. Wind waves 3 feet. North swell 8 to 10 feet. Showers likely. Monday..Winds variable less than 10 knots becoming north 10 knots. Wind waves 3 feet. North swell 7 to 9 feet. Showers likely. | PHZ100 934 Pm Hst Wed Apr 25 2018 Synopsis for hawaiian coastal waters.. Strong high pressure northeast of the area will weaken through Thursday. A low will develop north of the islands on Friday, and linger through the weekend. A front associated with the low will move down the island chain Friday through Saturday, with the front stalling near the big island Sunday and Monday. |
7 Day Forecast for Marine Location Near Nanawale Estates, HI
Hourly EDIT Helplocation: 19.49, -154.81 debug
Area Discussion for -
  (on/off)  Help NOTE: mouseover dotted underlined text for definitionFxhw60 phfo 260639 afdhfo area forecast discussion national weather service honolulu hi 839 pm hst Wed apr 25 2018 Synopsis Trade winds will begin to decrease late tonight through Thursday night as high pressure to our north weakens. Low level flow will shift to southeasterlies late Thursday and Thursday night as a front approaches from the northwest. This front will bring increased rainfall to the islands, with showers reaching kauai Thursday night and Friday, before moving down the island chain Friday night through Sunday morning. Showers may linger into the new work week over the big island. Discussion A 1031 mb high far north of the main hawaiian islands continues to drive moderate to locally breezy trade winds across the chain this evening. Satellite loop shows a band of broken to overcast low clouds embedded within trade flow approaching the islands from the east, but skies are generally partly cloudy to clear across most areas of the islands at this hour. Trade showers will likely pick up tonight as the cloud band arrives. Rainfall will continue to favor windward and mauka areas. Models show trade winds will begin to decrease late tonight through Thursday night as the high to our north weakens and gets pushed eastward by a front expected to develop to our northwest. Local winds will begin to change from weak northeasterly trades to southeasterlies as this front approaches the islands late Thursday and Thursday night. The front will reach kauai early Friday, spreading increased showers along and ahead of it. Uncertainty remains concerning the strength of the front as it moves across the islands Friday into Sunday. Models show colder temperatures aloft developing by Sunday, likely making this front a more prolific rain producer as it reaches the big island late in the weekend. The probability for heavy rainfall increases from Friday through Sunday, but it remains too early to tell which island, if any, is under threat. The frontal boundary may stall near the big island, possibly providing that islands with lots of rainfall into early next week. We expect drier trade wind flow will return to the smaller islands after frontal passage, setting up a pattern of windward and mauka showers, post-frontally, into next week. Moisture from the frontal boundary near the big island may enhance these showers from time to time. Aviation Moderate strength trade winds will begin to weaken on Thursday as a trough approaches the islands from the northwest. Airmet tango remains in effect overnight for tempo moderate turbulence over and |
downwind of mountain areas. This low level turbulence airmet will likely be removed by Thursday morning as trade wind speeds decrease. A band of unstable clouds just east of the big island will drift slowly across the state producing periods of MVFR ceilings and showers mainly along windward slopes of all islands through Thursday morning. A few of these showers will drift leeward, however mostlyVFR conditions are forecast along southern and western slopes of each island. Marine A surface high far to the nne will move E and gradually weaken over the next two days as a low develops about 1000 miles N of the islands. Fresh to locally strong trade winds will weaken Thursday, then collapse completely Thursday night as a weak trough develops over the area. A small craft advisory (sca) currently posted for the windier marine zones around maui and the big island will likely be allowed to expire Thursday morning as the high weakens and trade winds begin to diminish. A front associated with the developing low is expected to reach kauai sometime Friday, then move down the chain through Saturday before potentially stalling near the big island through the rest of the weekend. Initially, right behind the front, N winds may briefly reach SCA criteria in some of the marine zones. The low will send a mix of swells and seas toward the islands this weekend into next week, with associated seas rising above 10 feet in most zones, necessitating a SCA from late Saturday into Monday. A moderate long-period nnw swell is expected to arrive tomorrow and peak Friday, with peak surf heights below advisory levels. The low that develops N of the islands late in the week will remain in place until early next week. The amount of swell surf that arrives in the islands is somewhat uncertain, and will depend on the evolution of the low and associated fetch. Current indications are that a fairly significant (but poorly organized) swell will produce advisory-level surf along exposed N and W facing shores, with the peak of the swell around Sunday. Elsewhere, several pulses of relatively small SW to S swell are expected over the next week or so, with a peak in swell energy around Sunday. Rough and choppy surf along E facing shores will diminish Thursday and Friday. The oahu surf discussion (srdhfo) contains further details on the sources of the swells. Hfo watches warnings advisories Small craft advisory until 6 am hst Thursday for maalaea bay- pailolo channel-alenuihaha channel-big island leeward waters-big island southeast waters. Discussion... Powell aviation... Bohlin marine... Morrison |
Weather Reporting Stations
EDIT (on/off)  Help NOTE: Click on distance to see the station location on a mapStations | Dist | Age | Wind | Air Temp | Water Temp | Waves | Pressure | DewPt |
ILOH1 - 1617760 - Hilo, HI | 21 mi | 55 min | S 2.9 G 4.1 | 72°F | 76°F | 1019.1 hPa | ||
51206 | 22 mi | 52 min | 77°F | 7 ft |
Wind History for Hilo, Hilo Bay, Kuhio Bay, HI
(wind in knots) EDIT (on/off)  Help11 PM | 12 AM | 1 AM | 2 AM | 3 AM | 4 AM | 5 AM | 6 AM | 7 AM | 8 AM | 9 AM | 10 AM | 11 AM | 12 PM | 1 PM | 2 PM | 3 PM | 4 PM | 5 PM | 6 PM | 7 PM | 8 PM | 9 PM | 10 PM | |
Last 24hr | NE | NW G10 | SW | W | W | SE | W | SW | S | SW | NW | N | N | N | N | NE G12 | N G11 | NE | NE | NE G9 | NE | NW | W | W |
1 day ago | SW | SW | SW | SW | SW | S | W | W | SW | W | W G7 | W | SW | -- | NE G14 | NE G13 | E G9 | E G12 | NE G10 | NE G9 | NE G11 | NE G11 | NE G14 | NE G13 |
2 days ago | SW | SW | S G6 | NE | N G11 | N | N G16 | N G17 | N G8 | E G9 | N G13 | N G11 | NW | W | W | E G7 | NE G13 | NE |
Airport Reports
EDIT (on/off)  Help Click EDIT to display multiple airportsAirport | Dist | Age | Wind kt | Visibility | Sky/Weather | Temp | DewPt | Humidity | Pressure |
Hilo, Hilo International Airport, HI | 21 mi | 26 min | SSE 4 | 6.00 mi | Light Rain Fog/Mist | 71°F | 66°F | 87% | 1019.5 hPa |
Wind History from HTO (wind in knots)
11 PM | -12 PM | 1 AM | 2 AM | 3 AM | 4 AM | 5 AM | 6 AM | 7 AM | 8 AM | 9 AM | 10 AM | 11 AM | 12 PM | 1 PM | 2 PM | 3 PM | 4 PM | 5 PM | 6 PM | 7 PM | 8 PM | 9 PM | 10 PM | |
Last 24hr | NE | SW | W | SW | Calm | W | Calm | S | W | NW | N | N | N | E G15 | NE | NE | NE | NE | NE | NE | Calm | SW | SW | SW |
1 day ago | W | SW | Calm | SW | SW | SW | W | Calm | W | W | W | SW | E | E | E | E | E | E | E | NE | E | NE | NE | |
2 days ago | S | W | SW | Calm | W | SW | SW | SW | W | N | N | NE | NE | NE | NE | NE | E | N | W | W | NW | E | Calm | SW |
Tide / Current Tables for Hilo, Hilo Bay, Kunio Bay, Hawaii Island, Hawaii
EDIT RT Ports Option Weekend mode (on/off) (on/off)  Help One Week of DataHilo Click for Map Thu -- 12:44 AM HST 2.17 feet High Tide Thu -- 03:51 AM HST Moonset Thu -- 05:54 AM HST Sunrise Thu -- 07:15 AM HST -0.13 feet Low Tide Thu -- 01:28 PM HST 1.88 feet High Tide Thu -- 04:03 PM HST Moonrise Thu -- 06:41 PM HST Sunset Thu -- 07:18 PM HST 0.19 feet Low Tide Tide / Current data from XTide NOT FOR NAVIGATION |
12am | 1am | 2am | 3am | 4am | 5am | 6am | 7am | 8am | 9am | 10am | 11am | 12pm | 1pm | 2pm | 3pm | 4pm | 5pm | 6pm | 7pm | 8pm | 9pm | 10pm | 11pm |
2.1 | 2.2 | 2 | 1.6 | 1 | 0.5 | 0.1 | -0.1 | -0.1 | 0.2 | 0.7 | 1.2 | 1.6 | 1.9 | 1.8 | 1.6 | 1.2 | 0.8 | 0.4 | 0.2 | 0.3 | 0.5 | 1 | 1.5 |
Tide / Current Tables for Honuapo, Hawaii Island, Hawaii
EDIT (on/off)  Help One Week of DataHonuapo Click for Map Thu -- 01:22 AM HST 2.20 feet High Tide Thu -- 03:53 AM HST Moonset Thu -- 05:56 AM HST Sunrise Thu -- 07:48 AM HST -0.13 feet Low Tide Thu -- 02:06 PM HST 1.90 feet High Tide Thu -- 04:06 PM HST Moonrise Thu -- 06:43 PM HST Sunset Thu -- 07:51 PM HST 0.19 feet Low Tide Tide / Current data from XTide NOT FOR NAVIGATION |
12am | 1am | 2am | 3am | 4am | 5am | 6am | 7am | 8am | 9am | 10am | 11am | 12pm | 1pm | 2pm | 3pm | 4pm | 5pm | 6pm | 7pm | 8pm | 9pm | 10pm | 11pm |
2 | 2.2 | 2.1 | 1.9 | 1.4 | 0.8 | 0.3 | -0 | -0.1 | 0 | 0.4 | 0.9 | 1.4 | 1.8 | 1.9 | 1.8 | 1.5 | 1 | 0.6 | 0.3 | 0.2 | 0.3 | 0.7 | 1.2 |
Weather Map and Satellite Images
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GOES Local Image of Hawaii EDIT
NOTE: East coast views moved to GEOS-16. They are experimental and not well supported by NOAA so they may not be correct so be warned. This change required redoing a large amount of the GOES code. If the image you are expecting is not showing, please let me know. You may need to use the EDIT function to update your location.
Link to Loop

Other links: Northern Pacific Contential US Full GOES-East
Wind Forecast for (5,6,7,8)
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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. |