About Collaborative Surf

14 Feb 2012 01:00:00 GMT

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

Collaborative Surf Table

14 Feb 2012 01:00:00 GMT

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	8	NW	17	16	20	UP		13-19	E	SAME
1PM 02/13	7	E	8	4	6	SAME		13-19	E	SAME
TUE 02/14	8	NW	14	14	18	SAME	HIGH	7-10	ESE	DOWN
TUE 02/14	5	E	8	2	4	DOWN	LOW	7-10	ESE	DOWN
WED 02/15	7	NNW	13	12	14	DOWN	MED	11-16	ESE	UP
	7	WNW	18	14	18	UP	MED
	5	E	8	2	4	SAME	LOW
THU 02/16	11	WNW	16	22	30	DOWN	LOW	13-19	E	UP
THU 02/16	6	E	7	2	4	SAME	LOW	13-19	E	UP
FRI 02/17	8	NW	14	14	18	SAME	LOW	17-21	E	SAME
FRI 02/17	7	E	8	3	5	UP	LOW	17-21	E	SAME
SAT 02/18	7	NW	13	12	14	DOWN	LOW	17-21	E	SAME
SAT 02/18	8	E	8	4	6	SAME	LOW	17-21	E	SAME

Collaborative Surf Table Legend

14 Feb 2012 01:00:00 GMT

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)

Disclaimer

14 Feb 2012 01:00:00 GMT

Collaborative Surf Discussion

14 Feb 2012 01:00:00 GMT

SURF HEIGHTS WILL VARY BETWEEN DIFFERENT BEACHES AND AT THE SAME BEACH AT DIFFERENT BREAK AREAS. DISCUSSION: Summary: winter-caliber surf holding through the week. Detailed: mid Monday on northern shores has high surf from 305-325 degrees with 14-19 second intervals. Buoy 51101 WNW of Kauai on Monday morning suggests the peak of this episode for Monday 2/13 in the afternoon. High surf is expected on Tuesday from a wider directional spread of 305-350 degrees. A long-wave trough in the jet stream has dominated the northwest Pacific from Japan to near the dateline. At the surface, a massive cyclonic, or counter-clockwise, gyre has filled the area with embedded smaller scale cyclonic gyres associated with transient low pressure cells. This complex pattern has resulted in long fetches of varying speeds within gale to storm-force levels reaching to within about 1500 nm of Hawaii that should make for average to above average WNW to NNW surf this week. One of the enhanced fetches associated with an eastward tracking low pressure cell formed 2/8 over the 295-320 degree band. The fetch stretched from the western edge of the NW Pacific basin to the dateline by 2/10. This is the dominant source for the surf on Monday 2/13. The winds over the fetch gradually weakened to low-end gales on 2/11 and sub-gale by 2/12. This should keep high surf on Tuesday 2/14 from this direction on Tuesday, dropping to moderate to marginally high levels by Wednesday morning. A new high episode is expected Wednesday afternoon. Late on Friday 2/10, a hurricane-force low pressure formed on the dateline and tracked NNE to the eastern Aleutians. The fetch over the 320-345 degree band was limited in length and duration. The highest seas were aimed at targets NE of Hawaii. The fetch aimed at Hawaii plus the angular spreading should add moderate long-period energy on Tuesday into Wednesday 2/14-15 from 320-350 degrees. A new low pressure cell formed east of Japan on 2/12. Severe gale to storm-force winds have set up over the 290-310 degree band. The head of the fetch is about 2000 nm away on 2/13. Models show the fetch over 290-310 degrees to weaken on 2/14. Long-period forerunners are due locally mid Wednesday from this source, building to high levels before sundown, and into extra-large levels, meaning breakers on outer reefs, by Wednesday night. Such westerly leaning swell component receives shadowing on Oahu by Kauai, making for larger error bars on the surf estimate. Additional swell energy from 310-340 degrees is expected on Thursday. This is based on models of the newly forming hurricane-force low pressure near the dateline on 2/13 tracking towards the eastern Aleutians on 2/14, similar to the pattern of 2/10-11. Models show a long fetch of gales over the 310-325 degree band nosing to within 1000 nm of Hawaii by early Wednesday. The strongest winds associated with the deep low pressure cell is expected to have swell development restrictions from the shorter fetch length and duration over the 320-345 degree band. The combined effects should be a wider directional spread by mid Thursday into Friday from 290-345 degrees as high surf continues. Heights are expected to moderate on Saturday from 290-350 degrees. Mid Monday on eastern shores has small to moderate breakers under moderate to low-end fresh trades, both from 70-90 degrees. Surf is expected to drop on Tuesday. See the latest NWS state weather forecast discussion regarding the driving forces for the changing wind pattern this week. Upstream within the trades, or to the east of Hawaii, moderate to fresh speeds are expected to continue. Thus surf from windswell should hold at least at small levels during the local wind minimum on Tuesday into Wednesday. Freshening trades Thursday into Friday should slowly rebuild the short-period breakers, back to moderate levels by the weekend from within 60-90 degrees. Mid Monday on eastern shores has small breakers from refracting easterly windswell. Similar conditions are expected through the period. No long-period swell is expected from the southern hemisphere this period. Into the long range, models suggest the trough over the NW Pacific holding though a little further north for 2/16-19. The next surface low pressure is predicted to form 2/16 and reach the dateline south of the Aleutians 2/17. This scenario would make for a moderate episode building 2/20 from 305-325 degrees. The prognosis shows fresh trades holding 2/19-21 with moderate breakers from windswell out of 60-90 degrees. In the southern hemisphere, a low-end gale low pressure ESE of New Zealand on 2/12-13 could make for a tiny to small episode from 180-190 degrees 2/20-22. Long range forecasts are subject to major revisions. This collaborative forecast will resume on Wednesday, February 15. This forecast was produced through the collaborative efforts of NWS and NCDDC. Please send suggestions to w-hfo.webmaster@noaa.gov or call the Warning Coordination Meteorologist at 808-973-5275. Additional resources: see /in lowercase/ http://www.prh.noaa.gov/hnl/pages/marine.php.

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14 Feb 2012 01:00:00 GMT

NWS AND NCDDC PAT CALDWELL