We’ve had a couple of north shore surf episodes already in the last few weeks and it looks like the north shore surf season is about to heat up even more.
According to the official Hawaii surf forecast by Pat Caldwell, “north shores turning up as fall arrives Saturday 9/22.”
He goes on further:
A low pressure tracked east along about 45°N across the north central Pacific as its associated front pushed SE 9/17-19. Winds were strongest on 9/17 in an area over 2000 nm away. The low, medium-period intervals of 12-14 seconds arrived at buoy 51101 WNW of Kauai early Friday and are starting to arrive locally mid Friday from 320-330 degrees. These medium period swell should give way to shorter period surf on Saturday.
The front pushed to within 1200 nm of Hawaii by 9/19 followed by strong to near gale winds over a long, wide fetch within the 325-345 degree band. Jason estimated seas to 13 feet in an area about 1100 nm away early Wednesday 9/19. The Wave Watch III model suggest only 3 feet swell from this source near Waimea, Oahu, though the jason estimate suggests higher heights, which is the basis for the collaborative forecast number for Saturday in the table above. Probability is set to medium due to the conflicting guidance. Shorter-period surf of 10-12 seconds should build locally overnight Friday, with surf within small to moderate levels on Saturday, when the event should peak mid day out of 325-345 degrees. A larger episode is due late Saturday.
A low pressure steadily deepened on Wednesday 9/19 as it tracked from the Aleutians near the dateline to the SE. Severe gales and smaller pockets of storm-force winds filled in over the 320-340 degree fetch, reaching to about 1200 nm away by early Friday 9/21. The jason altimeter measured seas higher than estimated by the Wave Watch III product for 18Z Thursday 9/20. With seas over 20 feet in an area 1000 nm NNW of Hawaii on 9/21 with direction towards Hawaii, this suggests slightly higher swell than guided by the wave models for Sunday locally.
Long-period forerunners are due mid to late Saturday afternoon from 320-330 degrees, with heights approaching moderate on the less frequent, higher sets near sundown. Surf should build to high levels overnight Saturday, with the episode peaking Sunday morning from 320-340 degrees. Surf should drop to within moderate to near high levels on Monday.
The low pressure has dipped to 977 mb by Friday morning 9/21. Models show the system tracking towards the ENE as it exits the Hawaii swell window late Friday into Saturday. Small to moderate surf from 330-360 degrees is expected for Tuesday, dropping to small levels on Wednesday from the same direction.
…models track a gale east along the central Aleutians north of Hawaii by Tuesday, giving way to small to moderate surf for Friday 9/28 from 340-360 degrees, holding into Saturday 9/29.
All that doesn’t do me any good though since I’m still on the disabled list (long story, but the upshot is that I’m rehabing from torn gluteus medius/minimus – yea, a real pain in the ass. Hoping to get back on the water within another couple of weeks). The injury also partially explains the dearth of blog posts here lately, since I’ve been pretty much trying to ignore the wind and waves for the past 6 weeks or so. Sorry about that.