Thursday, February22, 2018 L-36.com


Marine Weather and Tides
Hilo, 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 6:42AMSunset 6:24PM Thursday February 22, 2018 12:42 PM HST (22:42 UTC) Moonrise 11:38AMMoonset 12:00AM Illumination 52% Phase: First Quarter Moon; Moon at 8 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
    EDIT      (on/off)   Help
PHZ122 Big Island Windward Waters- 944 Am Hst Thu Feb 22 2018
Rest of today..Southeast winds 20 knots. Wind waves 5 feet. Mixed swell northwest 6 feet and east 4 feet. Heavy showers likely and isolated Thunderstorms.
Tonight..Southeast winds to 25 knots. Wind waves 6 feet. Mixed swell northwest 6 feet and east 4 to 5 feet. Heavy showers likely and slight chance of Thunderstorms.
Friday..Southeast winds to 25 knots. Wind waves 6 feet. Mixed swell northwest 5 feet and east 6 feet. Haze in the morning. Showers likely in the morning, then occasional showers in the afternoon.
Friday night..East winds to 25 knots. Wind waves 6 feet. Mixed swell northwest 4 feet and east 6 feet. Occasional showers.
Saturday..East winds to 25 knots. Wind waves 6 feet. Mixed swell northwest 3 feet and east 6 feet. Showers likely.
Saturday night..East winds to 25 knots. Wind waves 6 feet. Mixed swell northwest 3 feet and east 7 feet. Showers likely.
Sunday..East winds to 25 knots. Wind waves 7 feet. Mixed swell north 3 feet and east 6 to 7 feet. Showers likely.
Monday..East winds to 25 knots. Wind waves 6 feet. SWell east 6 to 8 feet. Scattered showers.
PHZ100 944 Am Hst Thu Feb 22 2018
Synopsis for hawaiian coastal waters.. Strong high pressure far northeast of the area gradually shifting south and a nearly stationary surface trough northwest of kauai will support increasing southeast winds over the coastal waters today through next week. An upper- level disturbance will bring heavy showers and a slight chance of a Thunderstorms from south to north through Friday night.

7 Day Forecast for Marine Location Near Hilo, HI
   Hourly   EDIT   Help
location: 19.72, -155.08     debug


Area Discussion for -
      (on/off)   Help   NOTE: mouseover dotted underlined text for definition
Fxhw60 phfo 221958
afdhfo
area forecast discussion
national weather service honolulu hi
958 am hst Thu feb 22 2018

Synopsis
Low pressure at the surface and aloft to the west of the islands
will continue to draw moist tropical air over the islands the next
few days. This will lead to periods of heavy rain and possible
thunderstorms into the weekend. There may be some improvement
later in the weekend as the low pressure shifts very slowly
westward.

Discussion
A broad surface trough is located about 300 mi W of kauai, and a
large, strong 1041 mb surface high is centered about 1800 mi to
the nne of the islands. Neither of these systems is budging much,
keeping us stuck in an increasingly moist and unstable ese flow at
the surface. An upper low out to our NW is maintaining relatively
cold air aloft over the islands, and the tropical moisture
undercutting the cold air aloft is making the local airmass quite
unstable. This is fueling a large area of showers and a few
embedded thundershowers south of the islands extending across maui
and the big island.

This pattern is only going to evolve very slowly with time. What
makes this a very tricky forecast is that we will be on the edge
of what is likely to be even more active weather out to our west.

Through at least Friday, our concern for heavy rain and flash
flooding is maximized over the E and SE facing slopes and mauka
sections of each island where the low level flow will focus
orographic lift. In addition, these areas are starting off with
saturated antecedent conditions from last weekend's heavy rains.

This is not to say that other areas won't have heavy rain and
flash flooding, however, and the risk is high enough to maintain
the statewide flash flood watch through at least Friday.

The surface trough is expected to sharpen with time as the high to
the NE shoves it's way south. This will eventually pull the axis
of heaviest rain to the W of the islands. When exactly this
happens is still very uncertain, and the models continue to
struggle mightily with this. We may have to extend the flash flood
watch into the weekend, but confidence is not yet high enough to
do so at the moment. One thing that we can say is that the threat
will linger the longest for kauai.

We will remain in relatively moist SE flow into the middle of next
week. Total precipitable water remains above normal in the
guidance but not quite as moist as the next couple of days are
showing. The models are showing the strong NE pacific high
building southward and increasing the pressure gradient over the
islands, with rather strong background winds from a fairly
unusual ese or SE direction by the middle of next week.

Aviation
The atmosphere will be moist and unstable through at least
tonight. A strong mid to upper level trough to the west of state
is gradually drawing up an area of deep moisture toward the
islands from the southwest. Meanwhile, east to east-southeast low
level winds continue to focus rainfall along windward and se
facing slopes.

Multiple airmets are in place and will likely remain posted
through at least tonight. Expect widespread MVFR conditions
across island terrain and E to SE facing slopes, and periods of
ifr conditions in heavy showers and thunderstorms will be
possible anywhere. As a result, airmet sierra is in place for
mountain obscuration for portions of all islands. Light icing will
be possible in the middle and high clouds. This is mentioned in
the airmet bulletin, but conditions are expected to remain below
the airmet threshold. Also, airmet tango remains posted for mid
level turbulence. Guidance shows the likelihood of this turbulence
decreasing, and without any supporting observations, this airmet
will probably be cancelled today.

Marine
Ample moisture and an upper level low just west of the state will
aide in the development of heavy showers and thunderstorms today.

Most activity will move into the area from the south. Coastal
water areas can expect to experience periods of reduce
visibility, gusty winds, and rough seas in any of these shower or
thunderstorm areas. Special marine warnings may need to be issued
on a case by case basis today. The threat for heavy showers and
thunderstorms will gradually shift north and west into Saturday.

The current northwest swell will hold today, with surf heights
below advisory levels. After this swell fades tonight into the
weekend, long term guidance does not favor another west-
northwest northwest swell through at least next week.

Persistent strong high pressure northeast of the state will
continue to produce an area of strong winds directed towards the
area. A lingering surface trough, just west of the offshore
waters will help to force a more southeast wind pattern for the
state. The east-southeast southeast winds are expected to start to
increase around the state today, and remain elevated through most
of next week. Model guidance continues to show the potential of
winds reaching gale force strength by the middle of next week.

The strongest winds will be around the big island and windward
waters of the smaller islands, continuing to favor the more
unusual southeast direction. The swell generated from these winds
will produce elevated surf along east- facing shores. A high surf
advisory will likely be needed for these areas by early Friday
morning and could potentially reach warning levels by the middle
of next week. The combination of the elevated seas and increased
winds will produce small craft advisory conditions starting this
evening, mainly for the channels and exposed windward waters.

See the latest oahu surf discussion (srdhfo) for additional
details on surf and swell.

Hfo watches warnings advisories
Flash flood watch through Friday afternoon for niihau-kauai-oahu-
molokai-lanai-kahoolawe-maui-kona-south big island-big island
north and east-kohala-big island interior.

Winter weather advisory until 6 pm hst Friday for big island
summits.

R ballard wroe eaton


Weather Reporting Stations
   EDIT       (on/off)   Help   NOTE: Click on distance to see the station location on a map
Stations Dist Age Wind Air TempWater Temp WavesPressureDewPt
ILOH1 - 1617760 - Hilo, HI 1 mi42 min WSW 5.1 G 6 72°F 75°F1018.2 hPa (-0.8)
51206 7 mi45 min 75°F8 ft
KWHH1 45 mi42 min SW 1.9 G 2.9 76°F 77°F1015.5 hPa (-0.5)

Wind History for Hilo, Hilo Bay, Kuhio Bay, HI
(wind in knots)    EDIT      (on/off)   Help
1
PM
2
PM
3
PM
4
PM
5
PM
6
PM
7
PM
8
PM
9
PM
10
PM
11
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
Last
24hr
SE5
G9
SW6
W4
S3
G6
SW3
--
SW3
S4
S3
E1
S4
S4
S2
SW6
S2
S3
G7
SW3
W9
W9
G12
SW5
G9
W8
SW4
G7
SW5
SW5
1 day
ago
SE9
G15
E6
G11
NE3
G7
SW4
SW5
S2
G5
S4
G7
S1
SW3
SW2
S4
S4
SW6
S1
S4
G7
SW6
SW6
G9
SW7
G10
S2
G5
S2
SW4
SW6
SW4
S2
G7
2 days
ago
NE12
NE7
G12
W3
SW3
NE1
NW4
SW4
SW4
S4
S4
SW8
S6
S6
SW5
S6
G10
S7
S5
S8
S6
S4
G7
S1
SE4
G9
SE7
G13
SE7
G12

Airport Reports
    EDIT      (on/off)   Help   Click EDIT to display multiple airports
AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Hilo, Hilo International Airport, HI1 mi49 minWSW 610.00 miLight Rain74°F69°F85%1018.7 hPa

Wind History from HTO (wind in knots)
1
PM
2
PM
3
PM
4
PM
5
PM
6
PM
7
PM
8
PM
9
PM
10
PM
11
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
Last 24hrSE5SW6W4CalmW4CalmCalmCalmS3CalmCalmE3S3CalmCalmS3S3W4NW6W7W5SW6SW5W6
1 day agoE10E8E6CalmW4SW5S5CalmSW3SW5SW4SW4SW4SW5S5SW4W5SW3SW4SW5W3SW5W6SE5
2 days agoN10NE6NE8S3CalmCalmW4SW4SW5S4SW6SW6SW5SW6SW6SW8SW4SW6SW6SW6CalmSE4SE12E12

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 Data
Hilo
Click for Map
Thu -- 01:52 AM HST     0.94 feet Low Tide
Thu -- 06:44 AM HST     Sunrise
Thu -- 07:00 AM HST     1.50 feet High Tide
Thu -- 11:38 AM HST     Moonrise
Thu -- 02:00 PM HST     0.09 feet Low Tide
Thu -- 06:22 PM HST     Sunset
Thu -- 09:39 PM HST     1.88 feet High Tide
Thu -- 10:09 PM HST     First Quarter
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
1.110.911.11.31.41.51.41.310.70.40.20.10.20.40.71.11.41.71.91.91.8

Tide / Current Tables for Kawaihae, Big Island, Hawaii
   EDIT      (on/off)   Help   One Week of Data
Kawaihae
Click for Map
Thu -- 03:28 AM HST     0.72 feet Low Tide
Thu -- 06:47 AM HST     Sunrise
Thu -- 08:22 AM HST     1.19 feet High Tide
Thu -- 11:40 AM HST     Moonrise
Thu -- 02:52 PM HST     0.11 feet Low Tide
Thu -- 06:25 PM HST     Sunset
Thu -- 10:09 PM HST     First Quarter
Thu -- 10:23 PM HST     1.88 feet High Tide
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
1.310.80.70.70.811.11.21.210.80.60.30.20.10.20.40.81.11.51.71.91.9

Weather Map and Satellite Images
       (on/off)   Help
Weather Map
wmap_P
IR Satellite Image from GEOS
cpac_satellite

GOES Local Image of Hawaii    EDIT
Geos

Wind Forecast for (17,4,5,8)
      (on/off)   Help

Ground Weather Radar Station Kohala, HI
   (on/off)   Help
weather_mapweather_map weather_map

Ad by Google

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.