HIGH SURF WARNING IN EFFECT FOR NORTH AND WEST FACING SHORES
Surf along north facing shores will be 10 to 14 feet tonight, rising to 25 to 35 feet late tonight, then becoming 40 to 50 feet Wednesday.
Surf along west facing shores will be 6 to 9 feet tonight, rising to 15 to 25 feet late tonight, then becoming 25 to 35 feet Wednesday.
Surf along east facing shores will be 2 to 4 feet through Wednesday, with higher sets in areas exposed to north-northwest swell.
Surf along south facing shores will be 2 feet or less through Wednesday.
Outlook through Tuesday February 16: a large northwest swell will reach the islands late tonight, peak through the day Wednesday, then gradually subside Thursday through Friday. Well above warning-level surf will persist Wednesday through Thursday, and should drop below advisory level by Friday night into Saturday. A smaller northwest swell is expected to produce surf well above advisory levels on Sunday and 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, in the zone of maximum refraction. 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.
About Collaborative Surf
THIS COLLABORATIVE FORECAST WILL BE UPDATED MONDAY THROUGH FRIDAY AT
300 PM WHEN PAT CALDWELL IS AVAILABLE/
Collaborative Surf Table
Collaborative Surf Table Legend
|SWL HGT||OPEN OCEAN SWELL HEIGHT MEASURED FROM TROUGH TO CRESTIN FEET LOCATED 20 NAUTICAL MILES OFFSHORE|
|DMNT DIR||DOMINANT DIRECTION TYPICALLY +/-10 DEGREES IN 16 COMPASSPOINTS|
|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 SURFZONE|
|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 LOCATED20 NAUTICAL MILES OFFSHORE|
|WIND DIR||WIND DIRECTION IN 16 COMPASS POINTS|
|SPD TEND||WIND SPEED TENDENCY (VALID VALUES: UP/DOWN/SAME)|
SURF HEIGHTS WILL VARY BETWEEN DIFFERENT BEACHES AND AT THE SAME
BEACH AT DIFFERENT BREAK AREAS.
Collaborative Surf Discussion
Discussion: summary: Another round of winter caliber surf mid week.
Detailed: Mid Monday on northern shores has breakers above the October to April seasonal average with shorter wave periods of 6-14 seconds from within 330-010 degrees. Heights are trending up Monday and should slowly trend down Tuesday from a similar direction.
A broad Aleutian low pressure north of 40°N had a child low pressure fill in to the parent low 2/4-6. It set up an area of gales starting 2/4 near the Aleutians on the dateline over the 325-345 degree band, that nosed to near 800 nm away 2/6.
The NW Hawaii NOAA buoys 51001 and 51101 and the pacioos/cdip Hanalei, Kauai and Waimea, Oahu buoys all show an upward trend in the morning 2/8 for the 12-16 second period wave bands centered near 340 degrees. Breakers should remain above average locally into Tuesday from 325-360 degrees.
In addition, the strong breezes behind the front that pushed through Hawaii overnight 2/6 generated local seas within 330-030 degrees. This rough windswell peaked locally on Sunday 2/7. The Waimea buoy shows a steady decline in the 6-10 second wave periods on Monday morning 2/8. This windswell should continue to decline with some wobble remaining on northerly exposures for Tuesday morning.
The persistent pattern of deep low pressures in the central to eastern Pacific in January and February has made for above average surf locally. Closer sources make for bigger waves.
A new low pressure deepened sharply late Saturday into Sunday just west of the dateline. It has crossed the dateline Monday morning and is slowly moving east along 45°N.
The pattern has similarities to the source that made the giant surf locally on 1/27. The 1/27 event grew surf locally just after sunrise with a steep increase near 11 am HST 1/27. The event peaked in the late afternoon.
The new pattern unfolding 2/7 is also set for a Wednesday giant surf episode locally. Giant is defined when the less frequent, larger sets in zones of high refraction on outer reefs surpass 40 feet. Near shore wave heights are lower.
The new pattern is about 6-12 hours earlier in its timing crossing the dateline at 45°N relative to the 1/27 source. This should bring the sharp uptick of surf heights locally near dawn on 2/10 from within 310-330 degrees.
Both the 1/27 source and the new pattern had a similar signature of seas in terms of wave heights, width of higher seas, and aim towards Hawaii while each was centered on the dateline. The final judgment for size on 2/10 depends on how close the strongest winds reach to Hawaii late Monday into Tuesday 2/8-9. Wind models bring severe gales to near 900 nm away Tuesday morning, which should be similar to the 1/27 source.
The net result is the local surf height maximum should be about the same in size 2/10 as 1/27 from a similar direction during the peak within 315-335 degrees. This estimate will need fine tuning once validation of ocean surface winds and seas from Monday night to Tuesday morning 2/8-9 become available.
The new pattern occluded near the dateline early 2/8, with deepest pressure to 948 mb at 00Z 2/8, or 2 pm HST 2/7. The 06-18Z synoptic charts 2/8 show pressure near 954 mb.
Models show the low pressure center filling, meaning increasing pressures, 2/8-9 as the winds slowly weaken and the center slowly shifts eastward. However the decrease is expected to be slow with a long, wide fetch of severe gales to storm-force winds aiming near to NE of Hawaii into early Wednesday north of 35°N.
The 1/27 source tracked rapidly past the Hawaii swell window and occluded NE of Hawaii. That made for a rapid fall and rise of the maximum surf locally.
The new pattern with its slower track in the Hawaii swell window should make for a longer-lived event. Heights should remain in the giant category on Thursday morning, with a slow downward trend to extra-large levels, meaning breakers still on outer reefs, Friday morning, and dropping near the average early Saturday. Heights should fall below average on Saturday from 315-340 degrees.
As with the 1/27 event, coast wave run-up should be significant with greatest reach near the higher tides from pre-dawn Wednesday into Thursday morning. Scouring of beaches by the recent heavy surf pattern allows a greater reach for given swell and tides relative to early season with more beach sand.
See the latest NWS state forecast discussion regarding the local weather and winds. Windswell should remain below average through the period.
No surf beyond tiny to small is expected from the southern hemisphere this week into the long range.
Into the long range for the north Pacific, models show a winter caliber low pressure occluding near 42°N, 170°E on 2/10. It is then modelled to slowly track east reaching the dateline 2/12, and a remnant low well north of Hawaii 2/14. While west of the dateline, long period swell is predicted to be generated over the 290-310 degree band. It should arrive locally 2/14. Surf should build above average, potentially to marginally extra-large at its peak early 2/15.
Models show a front pushing near or through Hawaii 2/15, that could make for rough windswell from within 330-030 degrees 2/15-16.
Long range forecasts are subject to major revisions.
This collaborative forecast will resume on Wednesday, February 10.
This forecast was produced through the collaborative efforts of NWS and ncei. 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.
NWS FORECASTER AND NCEI PAT CALDWELL