Big Picture
BIG Picture updated 7/6 at 11am
Monday, July 7th – Tuesday, July 15th
Robust E-ENE trades into next week…
Thanks to a large area of high pressure centered 1,300 nautical miles NNE of Hawaii on Sunday, E-ENE trades over Hawaii increased to fresh to locally strong paces over the weekend (15-30mph). This will hold into Tuesday before the ridge of high pressure weakens slightly. The wind should switch more ENE and drop to fresh paces (15-25mph) midweek, and then switch back to E-ENE for the remainder of the period at similar speeds. Isolated to scattered windward and mauka showers should be the norm into next week.
Surf Outlook –
North Shore: Seasonably tiny conditions continue…
Recent/Now/Next: Surf on Sunday was flat along most reefs but up to 1.5’ at reefs that best refract trade wind swell wrap. It should be similar through early next week as the trade wind swell holds.
Next: A weak trough will pass near the central Aleutian Islands Jul 7-8 with a very short area of 20-30mph winds aimed to the SE. Low, 12-13 second period energy from the NNW should arrive early Friday. Surf should peak at 1-1.5’ late Friday into early Sunday.
Finally: A slightly stronger system will approach and travel past the dateline Jul 10-11 with 25-30mph winds. 12-13 second period energy from the NW could arrive early next Monday. Surf could peak on Tuesday at 1-1.5’.
Outlook: As is typical for this time of the year, not much is in store for the North Shore. Storm activity will be suppressed by high pressure spanning the entire length of the North Pacific through Jul 18 and likely beyond. Global models have backed off on typhoon activity over the western North Pacific for the next 2 weeks, limiting surf potential from the West.
South Shore and West Shore: Fun surf towards midweek, then slowing down in the foreseeable future…
Recent/Now: Surf on Sunday was 1-occ. 2’ on a mix of a 12-13 second period S-SSE swell and a 16-17 second period SSW swell. The S-SSE swell is the continuation of the even that peaked last Tuesday. The source was a large cyclone over the east-central South Pacific that directed a wide fetch of 40-50mph winds to the NNE Jun 27-28. Surf from this source will slowly decline over the next 2 days. The source of the SSW swell was a series of shortwave troughs that passed south of New Zealand Jun 28-29. Surf from this source should hold at 1-1.5’ into Monday.
Next (NEAR AVERAGE): A wide trough passed south of New Zealand Jun 30-Jul 1 and directed a long, very wide fetch of 35-45mph winds to the ENE. The aim was quite zonal and did not improve until the system reached the central South Pacific, so most of the energy will arrive at the Americas. Multiple troughs followed in the same path into Jul 3, though these were weaker and a tad further south. Long period forerunners of 19 seconds from the SSW should arrive overnight on Monday. Surf should rise to 1-occ. 2’ on Tuesday and peak on Wednesday and Thursday at 1-2’ occ. 3’ as the swell angle shifts from SSW to South. Surf should drop to 1-2’ occ. + on Friday, 1-occ. 2’ on Saturday, and 1-1.5’ on Sunday as the angle shifts to the SSE.
Next (AVERAGE): A large, very powerful storm entered the Tasman Sea Jul 1-2. While it brought severe weather and surf impacts to the western coast of Australia, the storm-force winds were confined to a very small area. The larger fetch of 40-50mph winds was aimed highest west of Hawaii. The best aim occurred when winds began to weak on Jul 3-4. 16-18 second period energy from the SW could arrive early Wednesday. Surf should peak at 1-1.5 on Thursday and Friday.
Finally (BACKGROUND): Confined well south of New Zealand and an area of high pressure, a potent storm was tracking eastward with a wide fetch of 40-50mph winds aimed to the NE-ENE on Jul 6. It will gain storm force winds of 45-55mph Jul 7 and nudge northward as it crosses the central South Pacific. Very long period forerunners of 20-22 seconds from the SSW should arrive Sunday. The swell angle should quickly turn South on Monday, Jul 13 with surf rising to 1-2’ occ. + on Monday and Tuesday.
Outlook: High pressure will meander between the western and central South Pacific into Jul 20 and likely beyond. It is unlikely for surf to reach or exceed the summer average (3’) through Jul 25 and possibly for the rest of the month.
East Shores: Average ENE trade wind swell through most of the period…
Recent/Now/Next: Surf on Sunday was 1-3’ on an average, 8-second period ENE trade wind swell. Surf could bump up to 2-3’ on Monday and Monday as the trade wind fetch peaks. Surf should return to 1-3’ and hold into early next week. It could start inching slightly smaller towards early next week as the upstream trades weaken a notch.
Finally: Hurricane Flossie reached category 3 status on Jul 3-4 as it tracked NW and parallel to the coast of Mexico. It rapidly weakened as it got into the zone more favorable for swell for Hawaii. 11-13 second period energy from the East could arrive on Monday and bring surf up to 1.5’ into Tuesday. This will be overshadowed by the trade wind swell.
Outlook: Models are now less amped up for significant tropical cyclones in the eastern North Pacific for the middle of July. Remnant tropical disturbances could approach the islands after mid-month and weaken the upstream trades, leading smaller trade wind swell.
The next SNN Big Picture will be issued on Sunday, July 13.
Forecaster Jonathan Huynh
Surf Climatology HERE
