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 6:00AM||Sunset 6:46PM||Friday August 18, 2017 8:17 AM HST (18:17 UTC)||Moonrise 3:00AM||Moonset 4:28PM||Illumination 13%|
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|PHZ123 Big Island Leeward Waters- 330 Am Hst Fri Aug 18 2017 |
.small craft advisory in effect through late this afternoon...
Today..Winds variable less than 10 knots west of the big island...east 25 knots near south point. Wind waves 6 feet. Isolated showers in the morning. Haze in the afternoon.
Tonight..Winds variable less than 10 knots west of the big island...east 20 knots near south point. Wind waves 6 feet. Haze through the night. Isolated showers through the night.
Saturday..Winds variable less than 10 knots west of the big island...east 20 knots near south point. Wind waves 5 feet. Isolated showers in the morning. Haze in the afternoon.
Saturday night..Winds variable less than 10 knots west of the big island...northeast 15 knots near south point. Wind waves 6 feet. Haze through the night. Isolated showers through the night.
Sunday..Winds variable less than 10 knots west of the big island...northeast 10 knots near kawaihae. Wind waves 5 feet. Haze through the day. Isolated showers through the day.
Sunday night..Winds variable less than 10 knots west of the big island...east 15 knots near south point. Wind waves 6 feet. Haze. Isolated showers.
Monday..West of the big island, winds variable less than 10 knots becoming west 10 knots in the afternoon, then becoming variable less than 10 knots. NEar south point, east winds 15 knots. Wind waves 5 to 6 feet. Haze. Isolated showers.
Tuesday..West of the big island, winds variable less than 10 knots. NEar south point, east winds 15 knots rising to to 25 knots after midnight. Wind waves 5 feet. Haze. Scattered showers.
|PHZ100 330 Am Hst Fri Aug 18 2017 |
Synopsis for hawaiian coastal waters.. A surface high far northeast of the islands will continue to move slowly east. Weak low pressure will pass south of the waters early next week.
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 181520 aaa|
area forecast discussion
national weather service honolulu hi
515 am hst Fri aug 18 2017
Reduced the clouds and the pops for windward big island for today.
Moderate to locally breezy trade winds will diminish to light to
moderate speeds late in the weekend. The trade winds will never
the less deliver clouds and showers to windward areas well into
next week. The remnants of a former tropical cyclone will move
through the islands through the first half of next week, resulting
in some warm and muggy conditions. Further more, this moisture
will be aided by an upper level low resulting in some spotty
afternoon and evening showers over the interior and lee areas of
the smaller islands. A drier and more stable air mass will return
Wednesday night and Thursday along with a boost in the trades.
A relatively stable trade wind weather regime will continue into the
early part of the weekend with passing clouds and showers favoring
the windward areas, especially during nights and mornings. The
latest infrared satellite imagery and weather radar shows widely
dispersed rain clouds coming in with the trades, with a tad more
clouds immediately upwind of maui. Water vapor imagery shows a
dry NW flow aloft over the region associated with a ridge aloft
centered SW of the islands.
An upper level low is noted 540 miles nne of oahu at 28n154w. It
will be moving SW toward kauai, coming to a rest a couple of
hundred miles west of kauai by Monday night. In doing so, it
weaken and raise the low level inversion from the current 5-6k
feet to 12k feet by Sunday afternoon.
The latest GFS solution shows the strength of the trades holding
at pretty much marginal mainly moderate speed through Saturday
night. A satellite pass over the islands early in the evening,
revealed wind speed of less than 25 kt in the alenuihaha channel
and waters south of the big island. Still, there is the likelihood
of diurnal pulses reaching 25 kt within these waters later today
due to mixing and differential heating between land and water. The
trades will trend slightly softer over the western half of the
island chain on Sunday to light to moderate speeds. This will be
enough to favor some afternoon clouds and showers over the
interior and lee areas of the smaller islands Sunday afternoon.
The GFS is showing the trades to rebound slightly late Sunday
night and holding through Tuesday although remaining sluggish over
smaller islands. A moderate trade wind flow will stay with the
big island into next week.
Next, we will be dealing with the remnants of once t.C. Jova,
which will be pushing through the islands during the first half
of next week. We will likely see a rise in the dew points into
the lower 70's as early as Saturday night. Once again, our comfort
level will be tested. In terms of precipitable water (pw), the pw
will be increasing from the current 1 to 1.3 inches to 1.4 to 1.7
inches by Sunday afternoon, and to 1.7 to 2 inches at its peak
As we put all these ingredients together, it looks like Sunday
through Tuesday will be an uncomfortable period with high
humidity given the lighter trades and the injection of tropical
moisture. In this hybrid convective and trade regime, daytime
heating and light enough winds will favor spotty afternoon
convective showers across the interior and lee areas of the
smaller islands, while showers riding in with the trades will
likely be enhanced by the upper low. The GFS is suggesting pockets
of dry air within the tropical moisture, which leaves us with some
uncertainty of how widespread these trade showers will be. The
current forecast calls for scattered to likely. Believe this is a
good call, and will stay with it for now. We will be introducing
a slight chance of thunderstorms for the offshore waters north
through west through south of kauai and niihau beginning Sunday.
The GFS is hinting of a slight chance of thunderstorms for the 2|
big island summits both Monday and Tuesday afternoons. It is not
in the forecast now. We will be taking a harder look at this
possibility in the coming days.
Stronger trades will return Tuesday night while the remnants of
jova gradually exit the region. The last of the tropical moisture
should clear kauai Wednesday evening. Moderate to locally breezy
trades will persist through the rest of the week with a slight
down turn late in the week.
The area of disturbed weather SE of the big island is being
monitored closely. In brief, the feature will be severely tested
in the coming days in an unfriendly environment. Please refer to
our tropical weather outlook for more details. At least the gfs
solution has the bulk of the moisture passing south of the
islands Sunday night and Monday.
The high pressure ridge north of the islands will weaken slightly
today as the high center drifts eastward. An upper low north of
the islands will also deepen, resulting in a weakening of our
trade winds. Periods of scattered showers are expected becoming
numerous along northeastern slopes of all islands.
Airmet tango remains in effect for moderate low level turbulence.
Weakening wind speeds will reduce the threat for turbulence and
allow us to drop this airmet later this morning.
Small craft advisory conditions due to strong winds across the
windier channel waters will continue through this afternoon. Winds
are forecast to dip below advisory criteria tonight through early
next week as the gradient slightly relaxes over the region. A
slight uptick in shower coverage due to an upper low moving over
the region will become a possibility Sunday into next week.
Surf along south facing shores will steadily build through the
morning hours and peak later today as a south-southeast swell
associated with a gale south-southeast of tahiti late last week
fills in. The latest observations at 51003 51004 across the
offshore waters to the south have begun to reflect this new energy
within the past several hours within the 15-17 second bands. This
energy should translate to an uptick in surf heights through the
day before slowly easing over the weekend. Heights along south
facing shores are expected to remain below the high surf advisory
criteria through the peak of this event.
Surf along east facing shores will trend down through the weekend
as the trades weaken. This trend will likely continue into next
week. Although confidence remains low this far out, there is an
outside chance of a small long-period east (090 deg) swell from a
developing tropical cyclone over the eastern pacific filling in
through the middle to latter half of next week for eastern
Water levels are running around .8 ft above the predicted levels due
to a sea surface height anomaly associated with an oceanic eddy
moving through the islands from east to west. This combined with
the normal king tide will result in coastal flooding in the
vulnerable low-lying coastal locations each day through the
weekend. Flooding will be expected through the afternoon hours
each day through the weekend around the daily high tide cycles.
The peak of this event is expected Saturday afternoon, when total
waters levels will likely top what was observed in honolulu at the
end of april earlier this year. See the special weather
statement, spshfo, for more details.
Hfo watches warnings advisories
Small craft advisory until 6 pm hst late this afternoon for
maalaea bay, the pailolo and alenuihaha channels, and waters south
of the big island.
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||47 min||NW 5.1 G 6||79°F||81°F||1013.4 hPa|
|ILOH1 - 1617760 - Hilo, HI||50 mi||47 min||SSW 1.9 G 5.1||75°F||81°F||1014.7 hPa|
|KLIH1 - 1615680 - Kahului Bay, Maui, HI||90 mi||47 min||NE 9.9 G 14||77°F||80°F||1015.1 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||24 min||SE 6||10.00 mi||Fair||81°F||64°F||57%||1013.3 hPa|
Wind History from HKO (wind in knots)
|1 day ago||W||SW||S||SW||W||SW||S||S||S||S||S||SE||E||E||SE||SE||Calm||Calm||Calm||SE||SE||SE||NE||Calm|
|2 days ago||S||S||S||S||SW||SW||S||S||S||S||SE||S||NE||NE||NE||NE||Calm||Calm||E||E||E||NE||Calm|
EDIT RT Ports Option Weekend mode (on/off) (on/off)  Help One Week of Data
|Kailua Kona |
Click for Map
Fri -- 12:46 AM HST 1.01 feet High Tide
Fri -- 03:00 AM HST Moonrise
Fri -- 06:05 AM HST Sunrise
Fri -- 06:28 AM HST 0.03 feet Low Tide
Fri -- 01:43 PM HST 2.47 feet High Tide
Fri -- 04:28 PM HST Moonset
Fri -- 06:49 PM HST Sunset
Fri -- 08:45 PM HST 0.29 feet Low Tide
Tide / Current data from XTide NOT FOR NAVIGATION
EDIT (on/off)  Help One Week of Data
Click for Map
Fri -- 01:10 AM HST 0.95 feet High Tide
Fri -- 02:59 AM HST Moonrise
Fri -- 06:04 AM HST Sunrise
Fri -- 06:48 AM HST -0.11 feet Low Tide
Fri -- 02:06 PM HST 2.49 feet High Tide
Fri -- 04:28 PM HST Moonset
Fri -- 06:49 PM HST Sunset
Fri -- 09:06 PM HST 0.16 feet Low Tide
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 (14,3,4,5)(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.