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)

Jun 19, 2013 3:30 AM HST

Marine
A small craft advisory, SCA, is in effect through this afternoon for locally strong trade winds and rough seas in the windier areas around Maui and the Big Island. Winds will subside slightly tonight through Thursday night, probably enough to allow us to drop the SCA for a day or two. A SCA is likely to go back up again Friday.

Surf will be generally small except for moderate surf along east shores due to the trade winds. A small southeast swell may affect the Big Island starting Sunday, but the Big Island will likely block most of the swell from reaching the rest of the islands.

Watches/Warnings/Advisories
Small craft advisory until 600 pm HST today for Maalaea Bay, the waters south of the Big Island, and the Pailolo and Alenuihaha channels.

Synopsis
Expect trade wind weather to continue through the forecast period, thanks to persistent high pressure to our north. Clouds and showers will favor windward and mauka areas, mainly at night and during the morning hours. Leeward areas of the Big Island will see increased clouds and showers each afternoon and evening.

Discussion
A 1026 mb high near 33°N 142°W, far northeast of the main Hawaiian islands, has an associated ridge which extends west through 30°N 170°W. This ridge is about 600 miles north of the main Hawaiian islands and easterly trade winds dominate across local waters. Satellite loop shows cloud cover across local waters has increased since last evening, with broken to overcast low clouds embedded within trade flow across windward waters and large broken low cloud patches noted across leeward waters. These clouds also cover windward and mauka sections of the islands. Return flow keeps thick cloud cover across leeward and Kau sections of the Big Island this morning even without the assistance of daytime heating. Sky grids have been changed changed to account for this increased cloud cover. Radar shows isolated to scattered light showers, with almost all of this activity taking place over water. Latest soundings show a strong inversion at around 7800 feet, capping the depth of convection and keeping total rainfall light. Water vapor loop shows broad upper troughing west of the islands, with an area of scattered to broken high clouds just southeast through east of the islands marking its eastern flank.

Models show the atmosphere becoming drier, with low-level moisture getting shallower over the next 24 hours. Rainfall will likely become quite sparse later today through Friday. With trade winds continuing, this sparse rainfall will be concentrated over windward areas. Models also continue to show a big low developing near the Aleutians over the next couple of days, with the subtropical ridge to its south weakening and shifting southward. That should weaken the pressure gradient over the islands and cause trade wind speeds to drop off a bit tonight through Thursday night. The ridge will rebuild by the weekend and trades will likely become locally breezy again.

BIG SURF PICTURE Saturday 6/15/13

NPAC     BIG High pressure to the NE is in place for the summer with fresh to strong and even gale trades into yet another weekend.

Currently: It's tiny 2' sets from the NE wrap at Laniakea with most spots missing it at 0-1'...

Next: we actually see a bit of chance for some fun 'out of season' 12 second NW swell as a broad marginal Gale Low streams east this coming Friday-Sunday. ETA for this event is a rise to 2-3' on Monday afternoon 6/24 peaking 2-4' Saturday fading Sunday onward but still rideable into Monday. Not bad.

(See HERE)

SPAC 

Currently: SSW is 2'...  Buoys popped 1' 20 seconds Wednesday afternoon on a new South to SSW which has reached isolated chest high into Saturday. The source was a fetch far off NZL last Thursday-Saturday on a eastbound Low ending under Tahiti.

The freight train of storms keep their march left to right far south of NZL along the roaring 50-60's so no real swell for HI till maybe 2 weeks out Wednesday 26th if WW3 fantasy plays out.

Next: A large powerful Low moves sideways to our swell window Monday-Wednesday which will ruin our chances of getting anything over 3' around Tuesday 6/18-20th.

Next: long range model output hints a slight chance of 2-4' SSW surf with 15 seconds Thursday 6/27-Saturday 6/29...but this is still fantasy but its has a bit more confidence.

Next: The low prior spawned in the Taz and over NZL Sunday 6/23 and gets its fetch off to the East coast but hugging the coast limiting sea development. But, WW3 suggests the potential 3-5' SSW Saturday or Sunday the last day of June. Again, not likely...yet. 

East Shores: It's on the upside of a summery pattern. The steady Strong High to up NE has whipped up fresh-strong trades nearby and upstream allowing enough fetch to push surf up to 3-4+' along all windward shores and even 2-4' adjacent SE and NE reefs; this uptick Wed into the weekend. We'll see it fade alittle Father's Day and get back to below advsry levels Tuesday.

Tropics: Nothing.

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.