Waves, Winds, Weather compliments of Used Surfboards Hawaii Labor Day Sale.
Your exclusive SNN Obs for this Monday Sept 1st 640am update...Happy Labor Day!
Another Gorgeous dawn and Super Light trades early this morning with a chance of sea breeze mix late morning-afternoon. Another hot one so pack the Bullfrog. High tide 930am 1.7 drops out all day to a .7 at 430pm. Lingering south keeps us going.
Kaisers, Kewalos (check our Bowls-Courts CAM); light trade wind texture may compete with seabreezes pending land heating. Diamond Head: Holding on the S-SSW at 2-3' maybe a plus' with good light sideoffshore ENE trades (see SNN Cam). Sandy's: Holding on the South and ENE wrap at a nice clean 2-3' and plenty barrels and breaking all over with dumping shorebreak. East: Makapu'u: Holding the ENE swell the relatively clean 1-3'. Some waves on the outside but most on the left to Ala Moana,
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THE WHERE, WHEN & WHY OF HAWAII’S WAVES & WEATHER: A VIDEO PRESENTATION BY SNN
Winds Statewide in a glance ...go HERE (this link is also the 4th drop down under weather)
Sep 01, 2014 4:00 AM HST
A light east-southeast flow is expected to continue today with high pressure remains far northeast , and a surface trough near the islands. Heading towards midweek, light to moderate trades are expected to build in. The light winds will allow afternoon sea breezes to bring localized cloud buildups and a few showers over leeward and interior areas. As the week progresses and the trades strengthen, expect the limited clouds and showers to be focused over the windward slopes. Trade wind showers may increase by Friday as low level moisture rides in on the trades.
The overnight sounding at Hilo showed a low level inversion within 400 ft of the surface. This is similar to an inversion observed yesterday morning, but this morning's is not quite as strong as yesterday's. The strong low level inversion yesterday morning allowed smoke and odors associated with the relatively new lava flow in the Puna district to become trapped near the surface until mid morning when the heat of the day helped to dissipate the inversion. With the morning sounding showing the inversion again, even though not quite as strong, it's very likely similar events will be observed this morning, thus the mention of smoke in the grids. The weaker inversion today may mean it will break up a little sooner than yesterday.
No major changes to the forecast for this morning. The clouds over the Big Island last evening began to break up over the northwest half of the island shortly after midnight, leaving clouds and some showers over the slopes from Hilo to Cape Kumukahi to South Point. This batch of clouds is associated with a weak surface trough draped across the islands of Maui county and the Big Island. These clouds are moving to the west northwest, with the bulk of the clouds expected to pass south of the smaller islands today. The presence of this trough is disrupting the trade wind flow generated by the high pressure system far northeast of the islands.
The models are in good agreement with the high lingering to the far northeast of the islands through much of the week. The surface trough near the islands should start to dissipate and move away from the islands heading into mid week, which will allow the trades to make a return appearance. However, a low northeast of the islands, and a front passing northwest of the islands will help prevent more than light to moderate trades to build back in. As the winds increase, look for clouds and showers to become focused more over the windward slopes. The GFS and ECMWF both show limited low level moisture during the middle of the week, so expect shower activity to be on the light side.
Both models do show additional low level moisture being carried in on the trades at the end of the week. This increased moisture appears to be loosely associated with the remnant of Marie that is passing far northeast of the islands. As such, look for more showers at the end of the week than at midweek.
The near shore buoys continued to show steady readings overnight. The reinforcement to the current south swell started to make an appearance on the 51003 buoy overnight with periodic 15 second energy being picked up. Surf along the south facing shores is expected to remain elevated, but below advisory levels into Tuesday.
A very long period south swell, 20-25 seconds, is due to arrive Tuesday, and build through Wednesday. This swell will likely produce advisory level surf into Thursday.
The long period swell from the east should continue to trend down today. Winds and seas will remain below small craft advisory thresholds for at least the next several days.
BIG SURF PICTURE 8/26/14
The Jet down under has been dominant with equatorial bound (ENE) flows leading to plenty surf, but the last few days its been zonal (west to east) with 2 branches staying the same most this week. By Thursday/Friday there’s another ENE tilt which will enhance a big storm but it'll be sending much of the energy off to our east since the equatorbound flow is far off NZL to under French Polynesia.
Recent: We’ve had nonstop surf for about 2 weeks; 2 Lows tracked SE of NZL Thursday 8/7 and these sources created surf the 1st weekend for the Dukes Oceanfest! Then a powerful Low a few days after with 55kts saw into our window SE of NZL hugging the East coast with a captured fetch. We got 18 sec forerunners Wed the 20th reaching 3’ 15 sec swells or 2-4+ SSW surf Thursday midday and the final Dukes weekend…one of the best weeks for the OceanFest in over 5 years.
Currently, we saw some 4’ sets from the SSW this past F-M from 2 sources: a gale 40kt storm east of NZL mid August. Her fetch head got to 3500 miles away which allowed for head high sets. Then a stronger system further SE of NZL with 47kts added more size over the weekend and into Monday. Some spots peaked 5’ over the weekend but these were special cases/spots. Things level off to head high Tuesday.
Next: Another compact Low SE of NZL tracked east again last Monday-Tuesday and will keep us at 3’ solid before a SSW swell arrives Wednesday.
Next: The Jet set up a long wave trough from Wednesday the 20th. We also saw a big High in the Taz which created solid winds in between the High spinning counter clockwise next to the Low spinning clockwise (opposite spins from the NPAC). This allowed a huge fetch area east of NZL last Thursday-Saturday. The head of the fetch got to within 3000 miles which is about 1000 miles closer than the usual. This means less ocean swell decay over distance and another round of advsry surf filling late Wednesday peaking Thursday into Saturday and even Sunday…High Surf threshold for South swell is 8’ crest to trough which is what typical surfers look for. The NS needs 15’ or twice the size which most surfers don’t look for. Why the large difference is likely extra safety precautions where populations are greatest.
Next: : Models backed down big time on their output a week ago for a new event early Sept. A broad gale Low far east of NZL reached near Tahiti last weekend. Now, it’s going to be 1-3’ South Sunday-Tuesday.
Last couple: Low confidence of models showing a big broad storm up off the Ross Ice Shelf Wed the 27th which fades fast and followed up fast by a much bigger Low Thursday. The issue is the ENE track but side band swell should hit 3 maybe 4’ with long periods Thursday sept 4-6th. Let’s take a better look this weekend.
The weak Jet up North is continuing it’s summer position with poor potential for swell enhancement, and tho’ she’s elongated the winds are too light for anything. Most the deeper troughing occurs under the gulf toward the end of the 7 day forecast.
Recent: It’s been quite and average after the long run of Typhoon West swells and Hurricane N swells making Aug the best in memory. Reliable sources like Pat Kelly with over 40 years up there plus, a former NS Capt and SNN eye’s on the country claimed it.
Next: East wrap from hurricane Maria will send long 2-3’ 14-16 second periods producing surf up 4’ around Kahuku and less to select spots toward Haleiwa starting Thursday and into the weekend.
Next: nothing is on the models out over 10 days.
Recently, small 2’ East swell have been dominant but that’s increasing today from 2 Tropical systems: Lowell and Karina off Baja and weakening. Then it goes up big time with a rare push of 14- 17 second East surf from Cat 5 Hurricane Maria tracking ENE off of Baja (see below). Surf on the windward spots will reach as high as 7’ local scale. We also have two 1030mb High up beyond 40 north or 1200-1500 miles away keeping us in the typical trade wind pattern. So after this upcoming run its back to normal by next Wednesday.
Tropics: Cat 5 Hurricane Maria built this past weekend SSW of Baja and is expected to move NW and weaken to a Tropical Storm before Friday staying over 1200 miles to our NE. She built 40’ seas and will send off some of that High surf advsry East swell Thursday-Saturday. The main feature will be the long periods which refract and shoal off the ocean floor much more than the typical 8-10 sec windswell we usually ride. Watch for spots to break with more power and current.
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.
|North-Facing Shores||15 Feet (8')||25 Feet|
|West-Facing Shores - Big Island||8 Feet (4'+)||12 Feet|
|West-Facing Shores - Remaining Islands||12 Feet (7')||20 Feet|
|South-Facing Shores||8 Feet (4'+)||15 Feet|
|East-Facing Shores||8 Feet (4'+)||15 Feet|