Outlook through Thursday May 28: a series of short period northwest swells are expected through the period, which may generate moderate surf over the weekend for north facing shores. The current moderate southwest swell will see a reinforcement this weekend, and again Monday, from slightly larger and longer-period south-southwest swells. Surf should remain below advisory levels this weekend, but may approach advisory levels on Monday. Surf heights are forecast heights of the face or front of waves. The surf forecast is based on the significant wave height, the average height of the one third largest waves, at the locations of the largest breakers. Some waves may be more than twice as high as the significant wave height. Expect to encounter rip currents in or near any surf zone.
No high surf advisory or warnings.
Surf along north facing shores will be 3 to 5 feet today, rising to 4 to 6 feet Saturday. Surf along west facing shores will be 2 to 4 feet through Saturday. Surf along east facing shores will be 2 feet or less through tonight, rising to 2 to 4 feet Saturday. Surf along south facing shores will be 3 to 5 feet Friday, rising to 4 to 6 feet Saturday.
About Collaborative Surf
This collaborative forecast will be updated Monday through Friday at 300 pm when Pat Caldwell is available.
Collaborative Surf Discussion
SURF HEIGHTS WILL VARY BETWEEN DIFFERENT BEACHES AND AT THE SAME BEACH AT DIFFERENT BREAK AREAS. DISCUSSION: Summary: active pattern from all but trade windswell direction. Detailed: mid Wednesday on northern shores has breakers below the may average from 315-330 degrees. It should fall to tiny levels by Thursday. The north Pacific jet is remaining stronger and more southward for the season. This pattern is modelled to hold into the long range. It is making for a series of short-lived episodes near the may average. The next in the series was a near gale approaching the dateline Monday just south of the Aleutians. The low center moved east along 50°N 5/19-20 as a front pushed SE, associated with an amplifying jet stream trough NNW of Hawaii. Fresh to strong winds nosed to near 1200 nm away by early 5/20. Short- to moderate-period swell of 11-14 seconds should fill in Friday afternoon from 310-320 degrees. It should peak early Saturday from 310-330 degrees. The tail of the strong to near gale breezes was beyond 1800 nm away 5/20, which should keep small surf through Sunday from 315-340 degrees. It should fall to tiny levels on Monday. Models show a surface low pressure forming NNE of Hawaii late Thursday near 30 N. It is modelled to move slowly ENE into Saturday, with fresh to strong winds over the 355-020 degree band about 500 nm away. This should bring in a short-period swell building Friday night, peaking Saturday, and dropping Sunday. Typhoon dolphin weakened as it changed track to the N 5/17-18 way west near 140°E. The compact size and long travel distance limit surf potential. It is also within the kauai-niihau shadow on Oahu. Low, long-period swell from 270-300 degrees should slowly build Sunday into Monday with small breakers. Mid Wednesday on eastern shores has declining breakers below the trade windswell average. Heights are expected to fade toward nil from 60-90 degrees on Thursday. Exposures to northerly swell should have breakers near the trade windswell average Friday night into Sunday as described above from 350-020 degrees. It should fall below average on Monday. Mid Wednesday on southern shores has seasonally minimal conditions. A rise is expected late Wednesday into Thursday. Longitudes from Tasmania to south of French Polynesia entered an active austral fall season extratropical cyclonic mode starting last weekend. It is modelled to hold this week, keeping a steady pace of surf from overlapping episodes within 170-220 degrees off and on into early June. A low over New Zealand had an associated front push northward over the Tasman sea 5/12-15 with gales to severe gales building seas to near 30 feet. The winds weakened though strong breezes from 180-240 degrees pushed well into the subtropics 5/15-17 north of New Zealand. The wide fetch on northward reach of high seas gives better odds locally for a Tasman event, which are limited due to shadowing by New Zealand and islands of the SW Pacific. The pacioos/cdip buoy registered a rise from this source 5/17. Noaa buoy 51002 south of Oahu 5/20 shows building low energy in the 17-19 second band. The first 24 hours of a long-period episode tends to be extra inconsistent. The event should be filled in by late Thursday from 208-220 degrees, peaking early Friday, then dropping on Saturday. A compact sub-tropical gale in eastern French Polynesia could give a small event from 170-180 degrees Friday into Saturday. The Tasman low pressure pattern pushed east of New Zealand 5/16-19 with marginal gales over a long, wide fetch reaching to the subtropics over the 180-200 degree band. Moderate period swell of 13-15 seconds from this source is due to pick up Saturday and hold into Monday at heights near the summer average. Longer-period swell events from a similar direction could surpass it in size locally. A pair of storm-force low pressure systems tracked from SW to SE of New Zealand spaced about 1.5 days apart 5/15-18. The first one had seas to 35 feet SE of New Zealand 5/16. It weakened as it raced eastward 5/17. The american samoa buoy showed a rise in long-period swell 5/20. This event should be in the inconsistent onset phase on Saturday centered on 190 degrees. It should peak on Sunday at levels above average then slowly drop Monday as the second one fills in. The second low SW to SE of New Zealand was stronger with seas above 40 feet validated by the jason satellite SE of New Zealand 06Z 5/18, or Sunday evening locally. The system weakened sharply as it turned to the NE 5/18-19 to the ESE of New Zealand. At the same time, the weaker area of low pressure E of New Zealand deepened with a compact area reaching near gales. The two low pressures merged on 5/19. Wave models are suggesting local surf potential similar to what has already arrived this spring. What should be different is the overlapping events locally 5/24-25, making for more consistent arrival of sets, and in turn, stronger nearshore currents. The onset phase of the second system should start late Sunday from 190-200 degrees. It should be filled in by Monday afternoon, peak early Tuesday 5/26, and remain elevated above average into Wednesday 5/27 from 180-200 degrees. Into the long range, the merged low pressure deepened as it shifted SSE south of French Polynesia. A fetch of gales to severe gales started over the 170-185 degree band 5/19. It is modelled to hold into 5/21 as it weakens. It could keep above average surf locally mid next week with the event filling in late Wednesday 5/27, peaking late Thursday 5/28, then slowly dropping into the weekend of 5/20. In the northern hemisphere, the extratropical remnant of dolphin has strongest winds aimed at the Aleutians. Models show the low near the western Aleutians Friday as the track changes to the east. A compact area of severe gales is modelled to hug the western to central Aleutians 5/22-23, giving an NW to NNW event locally 5/27 near the may average. Long range forecasts are subject to low confidence. This collaborative forecast will resume on Friday, May 22. This forecast was produced through the collaborative efforts of NWS and NCDDC. Please send suggestions to firstname.lastname@example.org or call the Warning Coordination Meteorologist at 808-973-5275. Additional resources: see /in lowercase/ http://www.prh.noaa.gov/hnl/pages/marine.php.
Collaborative Surf Table
Collaborative Surf Table Legend
|SWL HGT||OPEN OCEAN SWELL HEIGHT MEASURED FROM TROUGH TO CREST IN FEET LOCATED 20 NAUTICAL MILES OFFSHORE|
|DMNT DIR||DOMINANT DIRECTION TYPICALLY +/-10 DEGREES IN 16 COMPASS POINTS|
|DMNT PD||DOMINANT PERIOD IN SECONDS|
|H1/3||SIGNIFICANT WAVE HEIGHT IN THE SURF ZONE|
|H1/10||AVERAGE HEIGHT OF THE HIGHEST ONE-TENTH WAVES IN THE SURF ZONE|
|HGT TEND||HEIGHT TENDENCY OF SWELL (VALID VALUES: UP/DOWN/SAME)|
|PROB||PROBABILITY OF OCCURRENCE (VALID VALUES: HIGH/MED/LOW)|
|WIND SPD||OPEN WATER WIND SPEED MEASURED IN KNOTS LOCATED 20 NAUTICAL MILES OFFSHORE|
|WIND DIR||WIND DIRECTION IN 16 COMPASS POINTS|
|SPD TEND||WIND SPEED TENDENCY (VALID VALUES: UP/DOWN/SAME)|
NWS FORECASTER AND NCDDC PAT CALDWELL