THE LATEST IN DEPTH VIDEO PRESENTATION OF HAWAII'S WAVES,WINDS & WEATHER FROM SURF NEWS NETWORK & SPONSORED BY HAWAIIAN SOUTH SHORE

Winds Statewide in a glance ...just go HERE (this link is also the 4th drop down under weather)

May 22, 2013 4:00 AM HST

Synopsis
A weakening surface low pressure north of the islands will keep winds light across the state today, with onshore sea breezes during the day. Clouds and showers may return over the islands this afternoon under day time heating. This low will move west and dissipate overnight into Thursday, allowing the trade winds to return to the islands. Trades will strengthen through the weekend as a strong high pressure moves to the far northeast of the state.

Discussion
A surface low pressure system continues north of the state early this morning, keeping light winds over the islands. Night-time land breezes have developed but brought only partial clearing to the island skies as moisture associated with the low pressure system lingering in the island vicinity has spread across the area. Radar data indicate fewer showers over the coastal waters early this morning compared to yesterday. Low clouds.on the other hand, are a little more widespread across the islands early this morning. Both early morning Lihue and Hilo soundings indicate a marginally stable air mass, though Hilo sounding is still a bit more moist than Lihue's. Should be a fair weather morning across the state with a slight chance of showers. Strong winds continue to affect the Big Island summits overnight into early this morning. Therefore the wind advisory for the summits has been extended to this evening. As the surface low lingers north of the islands today, convective weather pattern is expected to repeat once again. Clouds and showers may increase over the islands in the afternoon and evening under day time heating as well as converging sea breezes.

The low north of the state will finally move west and dissipate tonight into Thursday. Meanwhile, a high pressure will settle to the far northeast of the state. A ridge associated with the high pressure system will develop north of the islands. In turn, trade winds as well as trade wind weather will return slowly to the islands overnight into Thursday. This ridge will persist north of the islands through the weekend, and will maintain trade winds to the area. Moreover, trade winds will strengthen over the state over the weekend, as the surface pressure gradient across the area tightens. Forecast models indicate an upper level trough will pass over the islands through the weekend, then an upper level low will develop east-northeast of the state early next week. The passage of this upper level trough may help to destabilize the air mass somewhat over the weekend, allowing more trade wind showers to develop. Trade winds will prevail early next week, as the high pressure ridge persists north of the area. Trade wind weather, possible wetter than usual, will continue over the islands as well.

Marine
The current south swell continues its downward trend, though it will remain high enough to bring advisory level surf to south facing shores of all islands today. The west-northwest swell has reached Oahu overnight, bringing quite elevated surf for north and west facing shores for this time of the year. This swell will peak later today, then subside in the following days.

Trade winds are expected to be strong enough by the weekend for small craft wind conditions to develop over the windier coastal waters around Maui county and the Big Island.

Watches/Warnings/Advisories
High surf advisory until 6 pm HST this evening for south facing shores of all islands.

Wind advisory until 6 pm HST this evening for the Big Island summits.

BIG SURF PICTURE Wednesday 5/13/13 

NPAC  Looking above average from Saturday through next Saturday.

Currently: lingering N swell at up to 0-2' for Laniakea and 1.5' for other spots.

Next: A marginal gale floats east off the Kurils all week crossing the dateline Wednesday up above 40 degrees north or about 1000 miles away. We can expect a fun spring time 11 second, 2-3+ NW filling Saturday and holding 3' Sunday before fading next week.

Last: Models keep supporting a unseasonal Low off Japan tonight which will stall then track ENE about 2000 miles away; she fades near the dateline Sunday but not before pushing out some 14 second NW swell with easy 4-6' surf Wednesday. We may give it an upgrade as buoy forecast currently show 6' 15 seconds which is enough for "almost" 8' at focal reefs like Sunset.

Long range fantasys need focus.

(See HERE)

SPAC  It has been a really good spring with half a dozen swells aready but now it's really 'up there' in the ratings.

Currently: its cranking 4-6 from the S to SSW with higher sets and buoys 5' 17 seconds. So some reefs hit 8' today.

Buoys popped Wednesday nite at  20 sec forerunners from a rare run of SSW to S swell. Ascat wind measurements confirm a big storm with a good ''following fetch' on its NE track up and then out from the east coast of NZL this past Thursday-Saturday. Seas are about 35-40' and winds were solid 45kts over a wide area. We'll see our 1st of 4 advisory SSW swells filling late Thursday to solid 4' and even 6' at 'select reefs; a peak of 5' open ocean 16-18 second event (country hits 8' with this kind of reading). Our guesstimate peak on Friday afternoon is 4-7' surf (2.5 times overhead) into Saturday and even Sunday since the system stalled.

Next: This giant storm stalls or occludes over the weekend of the 18th more to our South allowing for another shot of lasting South swell in the 3-6' range but with 15 seconds.

Next: Another Low has its fetch off to the SE of NZL Monday-Tuesday 5/14 pushing up some solid 3-5+' South by Monday-Tuesday 5/20-21. She'll be a notch smaller than the 1st pulses.

Next: The final shot from this 4 swell series is filling late Tuesday peaking Wednesday at 3-5' then down 2-4' Thursday....

Last: we go into a relatively quite period till further notice. But models have a more background 1-3' South surf  with 15 seconds (2' open ocean) from Friday afternoon into Monday; this is from more distant zonal storms.

East Shores: Strong 1028 mb High to out NE fixes out weather and waves. Up to 3' is the trend from the fresh NE winds and N swell.

Tropics: This past Thursday model have a storm moving west under Baja . She dies off this Sunday as soon as she hits cooler water.

FETCH: Often called the fetch length, is a term for the length of water or distance over which a given wind direction has blown. Fetch length along with the wind speed (or strength) determines the size of waves produced. The longer the fetch length and the faster the wind speed, the larger and stronger the wave will be and vice versa.
CAPTURED or FOLLOWING FETCH: Not only does the fetch length determine the power and energy of the wave. Additionally, if the winds/fetch are blowing in the same direction as during the wave's or storm's lifetime, the wave will in turn be even stronger. The fetch is related to the orbit of the wave and track of the storm.The longer the wind drags along the sea the more energy the wave will have. This can be seen not just in vertical height measurement but in wave period (the measurement of waves through time).
WAVES PERIOD:Time, in seconds, between the passage of consecutive wave crests past a fixed point. In general the longer the period the bigger the wave. Windswell or 'close interval' swells are under 10 seconds. Big 'ground swells' are 17-20+ seconds (note: a 20+ second swell needs storm force 50+kt winds blowing over a 1500 mile fetch to be fully developed' into 20-25' beasts; these 20 second waves can be felt 1000 feet down!). This is why they jack so much more, pulling large amounts of H2O off the outer reefs.

More generic marine definitions click this link  http://www.prh.noaa.gov/hnl/pages/marinedef.php

....All surf height observations and forecasts are for the full face surf height, from the trough to the crest of the wave.