SNN BIG PICTURE: Updated Sunday, 6/26 8:30am
Monday, June 27th – Tuesday, July 6th
Local Weather Outlook –
Trade winds ramping up this week with windward showers…
Light to moderate E-ENE trade winds should hold through the weekend and then gradually increase into midweek out of the ENE. Upper level troughing weakened high pressure over the state, which led to diminished trades. On Monday and Tuesday, a large dome of high pressure will build over the eastern and central North Pacific. The trade flow should ramp up to fresh paces with occasionally strong gusts from midweek to next weekend. There are signs that the high will retrograde westward towards the beginning of next week. This would mean a notch weaker trades.
A pattern of windward and mauka showers, especially for the morning hours, will persist through the period.
Surf Outlook –
North and West Shores: Lingering, tiny NE followed by rising trade wrap…
Recent/Now: For early Sunday morning, small surf of 0-1.5’ Hawaiian scale out of the NE prevailed for select spots. Pipeline and Sunset Beach remained flat. The source was an 10-12 second period NE swell originating from off the coast of northern California last Monday-Wednesday. A fetch of 30-40mph winds was aimed at Hawaii. Fresh to strong trades blew along its track to Hawaii, which kept the swell intact as it approached Hawaii. Surf should drop to 0-1’ occ 1.5’ on Monday and return to near flat by Tuesday. Gradually building trade swell over the rest of the week and into early next week could trend surf back up to 0-1.5’ for select spots. Surf of 2’ for favored locations look likely for the peak days of Sunday and Monday.
South and West Shores: BIG South swell through Wednesday, then declining steadily…
Recent/Now (SOLID+): Surf at dawn Sunday was 2-3’ occ + and on the heels of a ramp up from the South. Large surf is imminent. This event comes in two phases. The source was a storm from last weekend. A broad fetch of 45-55mph winds with pockets to 65-75mph was captured northward last Monday. The broader portion of the fetch was well captured by the American Samoa buoy last Thursday, which peaked at 8’ at 15-17 seconds. It likely missed the much stronger, narrower fetch, which was aimed from more to the east and generated satellite-confirmed seas to over 40’. This is likely why the buoy did not measure significant longer period energy. Extra-long period forerunners of 20-23 seconds from the South arrived pre-dawn Saturday. Both offshore buoys SW of Hawaii measured a sharp upward trend in swell height in the 16-19 second band early Sunday. Surf locally should rise to 3-4’ occ 5’ by Sunday afternoon and peak Monday at 3-5’ occ 6’ or borderline-large. There could be occasionally bigger rogue sets. It should trend lower by Tuesday morning to 3-5’.
Finally (LARGE): Last Tuesday, a follow-up, exceptionally broad fetch of 45-55mph winds developed as the low occluded and stalled in its forward track. The fetch had direct aim at Hawaii. Satellite altimeter passes last Wednesday revealed seas of 28-32’ well east of New Zealand. These seas were 3-5’ higher than modelled. Phase two had weaker peak winds and was further away, but the breadth and aim of the fetch should more than compensate and therefore be the larger of the two. Though this fetch was aimed even further east of Samoa, the buoy still felt the energy up to 7’+ of deepwater swell Saturday into Sunday. This raises the odds for a large event for Hawaii. This will manifest as a rise in surf to 4-6’ (large category), perhaps bigger, Tuesday afternoon into early Wednesday with good consistency. Surf should lower to 3-5’ occ + by late Wednesday, 2-3’ occ 4’ for Thursday, 1-2’ occ 3’ for Friday, and 1-2’ for Saturday. Tiny to small surf of 2’ of less should hold for the holiday weekend.
Outlook: High pressure will limit storm activity from eastern Australia to well east of New Zealand June 22-28. This will translate to background surf of 2’ or less through the middle of next week. There are signs that high pressure will fall apart towards July, which could bring surf back up to the summertime average towards the end of next week…
East Shores: Rising trade swell midweek peaking over the holiday weekend…
Recent/Now: Generally small surf of 1-2’ occ + prevailed early Sunday from a mix of 10-12 second period distant NE swell and 7-8 second period ENE trade wind swell. Light to moderate nearshore trade winds this weekend should keep similar surf through Monday.
Finally: Surf should increase a half notch to 1-2’+ on Tuesday as the local trades increase. As the trade flow over and upstream of Hawaii increases further, a sharper increase should occur overnight, and surf should be 2-3’ occ + Wednesday-Friday. Surf could peak at 2-4’ on Sunday and Monday thanks to even stronger trade flow.
Outlook: Models agree that trades should weaken a notch or two early next week, so surf should trend downwards and towards 1-2’+ by next midweek. Models also hint at potentially small, moderate period East swells from tropical cyclones in the eastern Pacific.
Surf Climatology HERE