Marine Weather and Tides
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 6:19AM||Sunset 6:33PM||Friday March 23, 2018 8:27 PM HST (06:27 UTC)||Moonrise 11:22AM||Moonset 12:00AM||Illumination 49%|
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|PHZ123 Big Island Leeward Waters- 334 Pm Hst Fri Mar 23 2018 |
Tonight..West of the big island, west winds 10 knots, becoming northeast after midnight. NEar south point, east winds 20 knots. Wind waves around 7 feet. Northeast swell 5 feet and northwest 3 feet. Isolated showers this evening, then scattered showers after midnight.
Saturday..Southeast winds 15 knots. Wind waves around 4 feet. Northeast swell 4 feet. Occasional heavy showers and a chance of Thunderstorms. Some Thunderstorms may be severe in the afternoon.
Saturday night..South winds 10 knots. Wind waves around 4 feet. Northeast swell 4 feet. Heavy showers likely and a chance of Thunderstorms in the evening, then scattered showers after midnight. Some Thunderstorms may be severe.
Sunday..Southwest winds 10 knots. Wind waves around 3 feet. Northeast swell 4 feet and northwest 3 feet. Scattered showers.
Sunday night..Southwest winds 10 knots. Wind waves around 3 feet. Northeast swell 3 feet and northwest 3 feet. Scattered showers.
Monday..South winds 10 knots. Wind waves around 3 feet. Northeast swell 3 feet and northwest 3 feet. Scattered showers.
Monday night..Southwest winds 15 knots in the evening, becoming variable less than 10 knots. Wind waves around 3 feet. Northeast swell 3 feet and northwest 3 feet. Scattered showers, mainly in the evening.
Tuesday..West of the big island, winds variable less than 10 knots, becoming north 10 knots in the evening, then becoming variable less than 10 knots after midnight. NEar south point, winds variable less than 10 knots, becoming northeast 10 knots after midnight. Wind waves around 3 feet. Northeast swell 3 feet and northwest 3 feet. Hazy. Isolated showers.
Wednesday..West of the big island, winds variable less than 10 knots, becoming southeast 10 knots after midnight. NEar south point, east winds 15 knots. Wind waves 4 to 5 feet. Northeast swell 3 feet. Hazy. Isolated showers.
|PHZ100 334 Pm Hst Fri Mar 23 2018 |
Synopsis for hawaiian coastal waters.. A series of low pressure troughs will move through the state through Saturday night, bringing unsettled weather to the region. Heavy rainfall and Thunderstorms will be possible through Saturday night, with improving conditions on Sunday.
7 Day Forecast for Marine Location Near Holualoa, HIHourly EDIT Help
Area Discussion for -  (on/off)  Help NOTE: mouseover dotted underlined text for definition
|Fxhw60 phfo 240153|
area forecast discussion
national weather service honolulu hi
353 pm hst Fri mar 23 2018
Unsettled weather conditions are expected through the Saturday
night as a series of low pressure troughs move through the state.
Heavy rainfall and thunderstorms will be possible at times as
these disturbances move through. Conditions are expected to
improve across the area on Sunday. A light wind regime will allow
for daytime sea breezes and overnight land breezes Sunday through
the middle of next week. This will allow for daytime shower
development over interior and leeward sections of the islands,
with showers hugging the coast at night. Light trade winds may
return late next week.
Currently at the surface, a trough of low pressure is evident in
satellite imagery around 125 miles southwest of honolulu, and was
captured well by an ascat pass earlier today. Another trough of
low pressure which has lingered for several days now to the west
of the state, is located around 400 miles west of kauai this
afternoon. Meanwhile aloft, a strong shortwave trough can be seen
in water vapor imagery around 750 miles west-northwest of kauai,
and this feature is tracking southeastward at around 35 mph.
Satellite imagery shows mostly cloudy to overcast conditions
across most of the state, with a few breaks evident in the cloud
cover over the big island. Radar imagery shows mainly light
showers over the islands of kauai and oahu, with a few heavier
showers now beginning to develop over the waters to the south and
east of kauai. Meanwhile across maui county and the big island, a
few light windward and daytime heating driven showers are
occurring. Main short term concerns revolve around the potential
for heavy rainfall and severe weather through Saturday night.
Tonight through Saturday night,
the GFS and ECMWF are in good agreement showing a pair of low
pressure troughs shifting across the state. The first trough south
of the state is expected to sharpen up this evening with a weak surface
low developing just south of oahu and maui county by daybreak
Saturday. The models then show this weak low tracking eastward
near or over the big island Saturday afternoon into Saturday
evening, before exiting east of the state after midnight Saturday.
The other trough currently west of the state is expected to
approach from the west tonight, then shift eastward across the
smaller islands Saturday into Saturday evening.
Overall, we expect a fairly wet night on kauai and oahu, with
showers increasing across maui county, particularly after
midnight. The most persistent shower activity is then expected to
shift from west to east across the island chain Saturday and
Saturday night, exiting to the east of the state after midnight
Saturday. Although the deepest moisture will shift east of kauai
and oahu by Saturday afternoon, there will likely remain some
lingering shower activity through Saturday night here in
association with the secondary trough of low pressure.
Across the big island, scattered showers are expected across
windward areas tonight, with isolated showers possible in leeward
locales. Rain is then expected to increase in coverage and
intensity on Saturday with showers continuing into the evening
before decreasing after midnight.
As far as flooding potential goes, the combination of deep
tropical moisture surging northward in advance of the pair of low
pressure troughs along with strong forcing for ascent, could
result in some heavy rainfall and thunderstorms across the
islands. The most probable time frame for flash flooding across
the smaller islands is expected tonight through Saturday, so will
adjust the timing of the flash flood watch to run through 6 pm
Saturday. Heavy rainfall is expected to hold off tonight across
the big island before increasing on Saturday. As a result, have
adjusted the flash flood watch timing to run from 6 am Saturday
through 6 am Sunday for the big island.
In addition to the potential for heavy rainfall, there is a threat
for severe weather mainly across the big island as the lead
trough of low pressure moves through. Model solutions show plenty
of deep layer shear, with 45-55 knots in the 0-6 km layer to
support organized convection. The limiting factor will be surface
based instability, with most unstable (mu) CAPE values in the 500
to 1000 j kg range. The other factor that lowers confidence about
severe weather occurring is that the model solutions have shifted
quite a bit from the previous run regarding location where the
severe weather potential would be highest. That said, based on the
latest guidance, the highest probability of severe weather|
appears to be across the big island, with damaging straight line
winds of 60+ mph and isolated tornadoes not out of the question.
As a result, have included a mention of possible severe
thunderstorms across the big island Saturday afternoon and
Finally, the summit weather on the big island will likely go down
hill tonight. H6 winds are expected to increase significantly,
and a high wind warning has been issued through 6 am Sunday.
Additionally, with the deep moisture moving through, there is the
potential for heavy snow at the summits. This remains a little
uncertain given summit level temperatures around or a little above
freezing. Nevertheless the potential appears to be there for a
heavy snow event, so a winter storm watch has been issued running
from 6 am Saturday through 6 am Sunday.
Sunday through next Friday,
conditions should improve across the islands on Sunday as a
surface low intensifies north of the state. A weak wind regime
will remain in place Sunday through the first half of the week,
with light trades returning by late next week. As a result, we
should see a more convective weather pattern featuring daytime
shower development over the interior and leeward sections of the
islands, with shower activity remaining offshore or near the coast
A surface trough moving in from the west is already impacting
western portions of the state with widespread cloud cover
stretching over the smaller islands. The trough is expected to
continue moving eastward similarly impacting lanai maui and the
big island. Airmet sierra is in effect for mountain obscurations
for the big island kauai oahu and molokai due to the clouds. Will
probably be updating airmet sierra to include maui as the surface
trough is expected to be over maui county overnight tonight into
the morning Saturday. Isolated periods of ifr conditions may
Temporary light in-cloud icing expected for oahu kauai molokai and
surrounding waters through tonight.
Surf reports and the nearshore buoys indicate the northeast swell
continues to decline, with surf along east facing shores below
high surf advisory levels. Thus the advisory is being cancelled
with the afternoon package. The current northeast swell will
continue to subside this weekend, and no other significant swells
are expected through early next week. A modest north-northeast
swell is expected from Saturday night into Monday. A small
northwest swell is also expected from Sunday night through
Tuesday, followed by another small northwest swell during the
middle of next week. Small south-southwest and southwest swells
are also expected from today into early next week.
Winds have been on the decline, and have fallen below small craft
advisory (sca) criteria, so the SCA has been cancelled with the
afternoon package. Even though winds and seas are expected to be
below SCA levels starting tonight, mariners should be aware of the
threat of inclement weather this weekend.
An area of low pressure is expected to move across the state this
weekend, producing an extended period of rain, with a chance of
thunderstorms and locally heavy rainfall. The current forecast
continues to show a belt of localized south to southwest winds
approaching 25 knots developing along the eastern flank of this
low. Should this pan out, we may need to re-post an SCA Saturday
for portions of the waters adjacent to the western islands. Once
this low begins to depart the state, expect westerly winds to
spread across the islands from Saturday night through Sunday,
followed by light and variable winds early next week.
Hfo watches warnings advisories
Flash flood watch through Saturday afternoon for niihau-kauai-
Flash flood watch from Saturday morning through late Saturday
night for the big island.
High wind warning until 6 am hst Sunday for big island summits.
Winter storm watch from Saturday morning through late Saturday
night for big island summits.
marine... M ballard
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|
|KWHH1||28 mi||40 min||W 6 G 8||1015.5 hPa|
|ILOH1 - 1617760 - Hilo, HI||50 mi||46 min||SSW 2.9 G 6||69°F||74°F||1017.4 hPa|
|KLIH1 - 1615680 - Kahului Bay, Maui, HI||90 mi||46 min||ENE 11 G 15||74°F||76°F||1015.5 hPa|
Wind History for Kawaihae, HI(wind in knots) EDIT (on/off)  Help
Airport ReportsEDIT (on/off)  Help Click EDIT to display multiple airports
|Kailua / Kona, Keahole Airport, HI||0 mi||35 min||W 4||10.00 mi||Mostly Cloudy||77°F||64°F||66%||1015.3 hPa|
Wind History from HKO (wind in knots)
|1 day ago||SE||SE||SE||SE||Calm||NE||NE||E||E||Calm||SE||SE||SE||SW||SW||SW||SW||W||W||W||W||W||W||SW|
|2 days ago||SE||SE||E||SE||NE||Calm||E||SE||NE||Calm||SE||SE||S||SE||S||W||SW||W||W||W||NW||NW||SE||SE |
EDIT RT Ports Option Weekend mode (on/off) (on/off)  Help One Week of Data
|Kailua Kona |
Click for Map
Sat -- 12:50 AM HST Moonset
Sat -- 05:16 AM HST 0.35 feet Low Tide
Sat -- 05:35 AM HST First Quarter
Sat -- 06:24 AM HST Sunrise
Sat -- 09:46 AM HST 0.68 feet High Tide
Sat -- 12:18 PM HST Moonrise
Sat -- 03:15 PM HST 0.16 feet Low Tide
Sat -- 06:36 PM HST Sunset
Sat -- 10:52 PM HST 1.93 feet High Tide
Tide / Current data from XTide NOT FOR NAVIGATION
EDIT (on/off)  Help One Week of Data
Click for Map
Sat -- 12:50 AM HST Moonset
Sat -- 05:24 AM HST 0.47 feet Low Tide
Sat -- 05:35 AM HST First Quarter
Sat -- 06:23 AM HST Sunrise
Sat -- 09:56 AM HST 0.79 feet High Tide
Sat -- 12:17 PM HST Moonrise
Sat -- 03:22 PM HST 0.25 feet Low Tide
Sat -- 06:35 PM HST Sunset
Sat -- 11:07 PM HST 2.09 feet High Tide
Tide / Current data from XTide NOT FOR NAVIGATION
Weather Map and Satellite Images(on/off)  HelpWeather Map
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.
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Wind Forecast for (2,6,7,8)(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.