HIGH SURF ADVISORY FOR NORTH AND WEST FACING SHORES
Surf along north facing shores will be 10 to 15 ft through tonight, rising to 22 to 28 feet Tuesday.
Surf along west facing shores will be 8 to 12 ft through tonight, rising to 15 to 20 ft Tuesday.
Surf along east facing shores will be 1 to 3 feet through Tuesday.
Surf along south facing shores will be 4 to 7 feet through tonight, lowering to 1 to 3 feet Tuesday.
Outlook through Monday February 13: warning-level surf associated with a large west-northwest swell is expected to continue along the exposed north and west facing shores Tuesday night through Wednesday. This swell will gradually ease Thursday and Thursday night. Another west-northwest swell will lead to advisory-level surf from late Friday through the weekend along north and west facing shores.
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: Dominant swell veering more northerly.
Detailed: Mid Friday on has declining breakers from 280-330 degrees. Heights should reach a winter minimum Saturday morning with an increase in the afternoon.
A fast-moving low pressure tracked NE for near 30°N, 180°W to 40°N, 160°W 2/15-16. The system intensified as it left the Hawaii swell window to the NE. The portion aimed at Hawaii within 300-330 degrees was duration limited for the marginal gales. It should make shorter-period swell building Saturday afternoon, peaking Saturday night below average, and dropping Sunday as a new event fills in.
Another weak low pressure has formed near the dateline 2/17. It is expected to take a similar track with a similar pattern of deepening as it reaches the longitude of Hawaii. The strongest winds late 2/18 while north of Hawaii are expected to aim at targets NE of Hawaii. However it is modelled to be followed by a strong surface high pressure system. The tight pressure gradient between the high and the low and its associated front is expected to set up a large fetch of marginal gales over the 325-360 degree band beyond 500 nm and strong to near gale winds closer 2/18-19.
See the latest NWS state forecast discussion regarding the timing of the frontal passage for Oahu. Post-frontal, gusty northerlies are expected Sunday morning making for rough conditions as the new short-period swell of 10-14 seconds builds from 315-360 degrees. Breakers should rapidly build above the active season, September to may, average Sunday morning. It is expected to peak Sunday night, remain above average Monday from 330-360 degrees, then drop below average Tuesday from 340-020 degrees.
Further west, models show a winter-caliber low pressure forming 2/19 near 40°N, 170°E with a NE track. It is predicted to drop to 960 mb by Monday morning near the Aleutians on the dateline.
Long-period swell from 310-325 degrees is predicted to fill in Wednesday morning, peaking Wednesday night into Thursday morning above average.
Mid Friday on has near nil energy from the trade wind belt of 45-90 degrees. Similar low conditions from this direction are expected for Saturday.
More northerly exposures of the east side should trend up Sunday into Monday from the NNW aforementioned. Northerly component surf should decline Tuesday into Wednesday.
See the latest NWS marine forecast products for specifics on the upcoming trade wind event. The table above has nominal same speeds Monday to Wednesday, though there are some subtle features that could make some ups and downs.
The upstream fetch is expected to increase Monday to Wednesday, with surf from trade windswell building above average from 50-80 degrees during this period.
Mid Friday on has small breakers for more westerly exposures. Heights should drop on Saturday.
The long-lived spell of short-period, w-component swell is coming to an end. No surf is expected this period from the southern hemisphere.
Into the long range, models show a low pressure forming NE of Hawaii 2/22 with a slow SW drift. Models are increasing surf from 000-030 degrees 2/24-25.
A second winter-caliber low pressure is modelled west of the dateline 2/21-22, that could bring another near to above average WNW to NW event for the weekend of 2/25.
Windswell from 60-90 degrees is predicted to decrease 2/23-25.
Long range forecasts are subject to low confidence.
This collaborative forecast will resume on Tuesday, February 21.
This forecast was produced through the collaborative efforts of NWS and ncei. Please send suggestions to email@example.com 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