Outlook through Thursday February 5: the persistent northwest swell will be reinforced Saturday. This swell will gradually decline through early next week. A new northwest swell expected to arrive later Wednesday into Thursday may again bring surf to near advisory levels 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.
HIGH SURF ADVISORY FOR NORTH FACING SHORES
Surf along north facing shores will be 10 to 15 feet today, rising to 14 to 18 feet Saturday. Surf along west facing shores will be 7 to 10 feet today, rising to 8 to 12 feet Saturday. Surf along east facing shores will be 1 to 3 feet through Saturday. Surf along south facing shores will be 2 feet or less through 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: steady winter-typical surf with veering trend WNW to NNW. Detailed: mid Wednesday on northern shores has surf near to above the October to April, seasonal average from 290-315 degrees. Similar surf is expected for Thursday. Since January 9, swell of more westerly component within 270-320 degrees has been steady. This is expected to last a few more days, then swing to a spell of more NNW dominant direction into the long range. A low pressure occluded just east of Hokkaido, Japan 1/23 and slowly moved east along 45°N 1/24-1/25. This is the source for the long-period surf locally that filled in Tuesday afternoon from 290-310 degrees. Partial shadowing by Kauai on Oahu is seen by looking at swell heights of NOAA buoy 51101 and the pacioos/cdip Waimea buoy on 1/28. The tail of the fetch on 1/25 was about 2200 nm away for the WNW energy, which should keep similar surf on Thursday. A steady decline to below average heights from 290-310 degrees is estimated for Friday. On Monday 1/26, the low cell that originated off Hokkaido crossed the dateline with a weakening trend to the surface winds. Gales were about 1500 nm away mid Monday, which should bring in 13-15 second wave periods from 310-320 degrees on Thursday, making for an overall direction spread from 290-320 1/29. The WNW to NW energy is modelled to decline Thursday night into Friday as shorter-period NW to NNW swell builds. The low pressure east of the dateline moved to near 160°W within 40-45°N Tuesday and has remained nearly stationary Wednesday. The low pressure area is large, with strong to near gale winds on the SW to S side of the system nosing to near 700 nm away by late on 1/27. The proximity of this wide fetch should make for a rising trend mid Friday morning from 320-340 degrees, maintaining heights near to just above the seasonal average. This shorter-period NNW surf is predicted to decline early Saturday as moderate period-nnw swell pick up. The stationary surface low pressure NNW of Hawaii 1/28 is associated with a sharp upper level trough of 1/27 that is pinching off a gyre on 1/28. This occlusion has provided enhancement to the surface winds while the surface low center takes a jog to the south. Gales are setting up on the NW to W side of this low cell. The initial winds have aimed more at targets west of Oahu early on 1/28. Models show a more direct aim later on 1/28 into 1/30, with the head of the fetch reaching 1500 nm away late Wednesday and about 800 nm away early Friday. Surf from this source is calculated to arrive mid morning Saturday from 320-340 degrees, peaking late Saturday, then slowly dropping on Sunday to levels near the seasonal average. Heights are modelled drop below average on Monday 2/2 from the same direction. See the latest NWS state forecast discussion regarding the weak frontal passage on Friday and the gentle winds of varying direction 1/29-2/2. No local windswell is expected this period. No surf from the southern hemisphere beyond tiny is expected this period and into the long range. Into the the long range for the sources in the northern hemisphere, a blocking ridge east of Kamchatka that has formed this week is expected to keep moderate- to long-period, W to NW surf locally near nil 2/3-6. Hints of a WNW swell at levels below to near average for the weekend of 2/7. Weather models place moderate to strong westerly winds within 500 nm to the W to NW of Hawaii next week that could make for short-period surf for westerly exposures 2/3-6. A long-lived, jet-level trough N to NE of Hawaii and its associated surface features 1/29-2/5 should make for steady NNW to N surf 2/3-7. Long range forecasts are subject to low confidence. This collaborative forecast will resume on Friday, January 30. This forecast was produced through the collaborative efforts of NWS and NCDDC. 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.
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