PAT CALDWELL

Hazards

HIGH SURF ADVISORY FOR EAST FACING SHORES

Forecast

Surf along north facing shores will be 10 to 14 feet through Saturday. Surf along west facing shores will be 2 to 4 feet through Saturday. Surf along east facing shores will be 10 to 14 feet through Saturday. Surf along south facing shores will be 2 feet or less through Saturday.

Outlook

Outlook through Friday February 22: High surf along north and east facing shores may remain elevated through today before gradually diminishing over the weekend. A small to moderate west-northwest swell this weekend will produce below advisory-level surf along north and west facing shores. A small north swell is possible 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, 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.

About Collaborative Surf

This collaborative forecast will be updated Monday through Friday at 300 PM when Pat Caldwell is available.

Collaborative Surf Table

FORECAST DATE	SWL HGT	DMNT DIR	DMNT PD	H 1/3	H 1/10	HGT TEND	PROB	WIND SPD	WIND DIR	SPD TEND
1PM 02/13	11	NE	13	14	20	DOWN		17-21	NNE	UP
THU 02/14	2	NW	16	3	5	UP	LOW	19-23	NE	UP
	10	NE	12	10	16	SAME	MED
FRI 02/15	2	NW	13	2	4	DOWN	LOW	19-23	NNE	DOWN
	11	NE	10	8	12	DOWN	LOW
SAT 02/16	3	WNW	20	6	8	UP	LOW	4-6	VRB	SAME
	9	NE	11	10	14	UP	LOW
SUN 02/17	5	NW	16	8	12	SAME	LOW	4-6	VRB	SAME
	4	NNE	14	6	8	UP	LOW
	8	NE	11	8	12	SAME	LOW
MON 02/18	3	NW	14	4	6	DOWN	LOW	9-13	ESE	UP
	7	ENE	10	6	8	SAME	LOW

Collaborative Surf Table Legend

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 in 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)

Disclaimer

Surf heights will vary between different beaches and at the same beach at different break areas.

Collaborative Surf Discussion

DISCUSSION: SUMMARY:. Below average from WNW to NW and above average from NE. DETAILED:. Mid Wednesday on has breakers from 10-40 degrees at levels well below the winter average. Heights should remain below average on Thursday. Exposures to NE swell are topping the heights and should remain active through the period. A blocking jet stream pattern near the Date Line over the Aleutians is keeping surface low pressure systems in the far NW Pacific. A series of events below average are expected. There is a pinch of low NW swell on the PacIOOS/CDIP Waimea buoy 2/13. This was from the first system in the Kamchatka corner 2/8. A second low pressure system was broader and stronger 2/10 though it aimed highest seas at the Aleutians. Wave Watch III (WW3) brings in low swell from this source out of 320 degrees to make small breakers locally Thursday into Friday. The next system was even broader with a better aim towards Hawaii 2/12-13. It is near 50N, 165E mid 2/13 to hurricane force. Models show it moving into the western Bering Sea 2/14. Low, long-period swell from 305-315 degrees is due locally Saturday PM 2/16. The event should be filled in by Sunday 2/17. It should peak at levels below the winter average from 305-320 degrees then drop to small levels on Monday 2/18 from the same direction. A low pressure system in the NE Pacific is modelled to track SE from Kodiak, Alaska 2/14 aiming highest seas at the west coast of the USA. Angular spreading could bring in surf out of 10-30 degrees locally on Sunday 2/17. It should be short-lived. Mid Wednesday on has rough breakers from 20-50 degrees at levels above the trade windswell average. Heights are expected to remain elevated and rough on Thursday. A strong surface high pressure system well north of Hawaii centered near 45N is expected to hold a similar position through the period. A nearby low pressure to the ENE of Hawaii, in combination with the high, set up gales within 30-35N, 145-150W late Monday into Tuesday 2/11-12. This source arrived locally early Wednesday 2/13 as seen in the 12-18s wave period bands at the PacIOOS/Mokapu buoy. The event peaked in the morning 2/13 from 30-50 degrees. The low pressure area to the immediate ENE of Hawaii 2/11-12 moved NE and merged with another low pressure area off the west coast of the USA 2/12-13. A long, wide fetch of strong to near gale breezes between the strong high pressure system and the low formed over the 30-60 degree band 2/13. It is expected to hold for a few days. See the latest NWS State Forecast Discussion regarding the evolving upper level disturbance in the Hawaiian vicinity 2/14-17 and its influence on local winds. In the local surf for Thursday into Friday 2/14-15, the combined seas and swell from 30-60 degrees should keep rough, above average surf. Models suggest the local wind to drop over the weekend. However, strong breezes on the E to N side of the nearby low 2/15-17 is expected to keep breakers from 40-90 degrees above average Saturday into Monday 2/16-18. Stay tuned for updates as the specifics on the weather pattern gain more confidence in the forecasts. Mid Wednesday on has tiny to small breakers. Similar surf is possible for Thursday. WW3 suggests a smidgen of 15s swell out of 190 degrees for 2/13. WW3 continues to show similar slithers of swell from within 180-240 degrees with 13-15s intervals through the period. The more 240 degree energy can be traced to the tropical cyclone activity near Vanuatu that flared up last week and continues this week. It is rare to get surf from such sources in Hawaii. Best odds, though still of high uncertainty, are for 2/17-18 locally. , no surf beyond tiny is expected from the southern hemisphere. Surf from the WNW to NW is expected to remain low. Short- to moderate-period NNE to E surf is expected to top the heights within 2/19-21. Long range forecasts are subject to low confidence. This collaborative forecast will resume on February 15. This forecast was produced through the collaborative efforts of NWS and NCEI. Please send suggestions to w-hfo.webmaster@noaa.gov or call the Warning Coordination Meteorologist at 808-973-5275. ADDITIONAL RESOURCES: See http://www.prh.noaa.gov/hnl/pages/marine.php

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NWS Forecaster and NCEI Pat Caldwell