FZHW50 PHFO 211845
SRFHFO

SURF ZONE FORECAST
NATIONAL WEATHER SERVICE HONOLULU HI
900 AM HST SAT NOV 21 2009
 
HIZ005>011-220100-
OAHU-
900 AM HST SAT NOV 20 2009

SURF ALONG EAST FACING SHORES WILL BE 4 TO 6 FEET THROUGH SUNDAY 

SURF ALONG NORTH FACING SHORES WILL BE 4 TO 7 FEET TODAY RISING
12 TO 16 FEET SUNDAY.

SURF ALONG WEST FACING SHORES WILL BE 1 TO 3 FEET TODAY RISING
TO 4 TO 8 FEET SUNDAY.

SURF ALONG SOUTH FACING SHORES WILL BE 2 TO 4 FEET THROUGH SUNDAY.

OUTLOOK THROUGH THURSDAY NOV 26:
A LARGE NORTHWEST SWELL WILL LIKELY REACHING ADVISORY LEVELS SUNDAY 
AND MONDAY THEN SLOWLY LOWERING INTO TUESDAY.  A LARGER NORTHWEST 
SWELL IS EXPECTED TO FILL IN TUESDAY NIGHT...AND PEAK LATE WEDNESDAY 
OR WEDNESDAY NIGHT.

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.

&&

COLLABORATIVE NEARSHORE SWELL AND WIND FORECAST FOR OAHU
NWS/NCDDC HONOLULU HI
300 PM HST THU NOV 19 2009

THIS COLLABORATIVE FORECAST WILL BE UPDATED MONDAY THROUGH FRIDAY AT
300 PM WHEN PAT CALDWELL IS AVAILABLE. WHEN PAT CALDWELL IS NOT
AVAILABLE...THE LATEST COLLABORATIVE FORECAST WILL REMAIN POSTED FOR 
4 DAYS. 

FORECAST  SWL  DMNT DMNT  H    H     HGT          WIND   WIND   SPD
DATE      HGT  DIR  PD    1/3  1/10  TEND   PROB  SPD    DIR    TEND

1 PM        5  N     11     6    10  SAME         17-21   ENE   SAME
11/19       8  ENE    8     4     6  DOWN
            2  SSW   14     2     4  SAME

FRI         4  NNE   10     6     8  DOWN   LOW   17-21   ENE   SAME
11/20       8  ENE    8     4     6  SAME   MED 
            2  SSW   13     2     4  SAME   LOW 

SAT         4  N     13     6     8  UP     LOW   17-21   E     SAME
11/21       8  E      8     4     6  SAME   MED 
            2  SSW   13     2     4  SAME   LOW 

SUN         7  NW    18    14    18  UP     HIGH  17-21   E     DOWN
11/22       8  E      8     4     6  DOWN   LOW 
            2  SW    16     2     4  UP     LOW 

MON         8  NNW   16    16    20  DOWN   HIGH  11-16   ENE   SAME
11/23       6  E      8     2     4  DOWN   LOW 
            2  SW    15     2     4  SAME   LOW 

TUE         6  NNW   14    10    12  DOWN   LOW   11-16   ENE   SAME
11/24       6  E      8     2     4  SAME   LOW 
            2  SSW   14     2     4  SAME   LOW 

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)

SURF HEIGHTS WILL VARY BETWEEN DIFFERENT BEACHES AND AT THE SAME 
BEACH AT DIFFERENT BREAK AREAS.

DISCUSSION:
SUMMARY...
RETURN TO SEASONAL HIGH SURF ON NORTH SHORES ON SUNDAY.

DETAILED...
MID THURSDAY ON NORTHERN SHORES HAS SUB-MODERATE BREAKERS FROM 
345-020 DEGREES WITH 8-14 SECOND PERIODS. IT WAS GENERATED BY NEAR 
GALES TO GALES FROM A SYSTEM CENTERED ON ABOUT 145W TO THE NNE OF 
HAWAII ON MONDAY INTO TUESDAY. THIS EPISODE SHOULD FAVOR SMALL 
LEVELS ON FRIDAY FROM 350-020 DEGREES.

A REINFORCEMENT LOW PRESSURE SYSTEM FORMED ON THE WEST SIDE OF THE 
EXISTING LOW PRESSURE AREA TO THE NNE OF HAWAII ALSO CENTERED ON 
ABOUT 145W BRINGING MORE NEAR GALES TO MARGINAL GALES AIMED AT 
TARGETS EAST OF HAWAII OVER THE PAST 24 HOURS. ANGULAR SPREADING 
COULD BRING IN SUB-MODERATE BREAKERS ON SATURDAY FROM 000-030 
DEGREES...DROPPING ON SUNDAY.

THE BLOCKING RIDGE OVER THE NORTHWEST PACIFIC SHIFTED EAST ENOUGH TO 
ALLOW A STORM- TO HURRICANE-FORCE SYSTEM INTO THE OPEN WATERS OFF 
THE NORTHERN KURIL ISLANDS AND KAMCHATKA OVER THE PAST 48 HOURS. THE 
CENTERED TRACKED TO THE NNE DURING THE FIRST 24 HOURS STARTING LATE 
TUESDAY...ACROSS THE GREAT CIRCLE RAYS RELATIVE TO HAWAII...WHICH 
REDUCES SURF POTENTIAL BY SHORTENING THE DURATION. BY LATE 
WEDNESDAY...THE TRACKED TURNED MORE NE AS IT BROADENED...ALLOWING A 
LONGER APPARENT FETCH. THIS TRACK IS SIMILAR TO THE SYSTEM THAT 
PRODUCED THE HALLOWEEN WEEKEND SURF THAT WENT WELL INTO THE 
EXTRA-LARGE BRACKET. IN COMPARING QUIKSCAT DATA FOR THAT ONE VERSUS 
THIS ONE...THE PREVIOUS ONE HAD A LONGER FETCH WITH SLIGHTLY 
STRONGER WINDS. NONE-THE-LESS...MARGINAL EXTRA-LARGE SURF IS 
EXPECTED TO SLOWLY BUILD LOCALLY ON SUNDAY...WITH FORERUNNERS 
FILLING IN SATURDAY NIGHT FROM 310-325 DEGREES. THE EPISODE SHOULD 
PEAK SUNDAY NIGHT INTO MONDAY MORNING FROM 315-325 DEGREES. IT 
SHOULD SLOWLY FADE BELOW HIGH SURF LEVELS SOMETIME ON TUESDAY FROM 
320-340 DEGREES.

MID THURSDAY ON EASTERN SHORES HAS MODERATE TO MARGINALLY HIGH 
BREAKERS...ESPECIALLY FOR ZONES EXPOSED TO THE THE NORTHERLY 
COMPONENT SWELL AS DESCRIBED ABOVE. MORE OF THE SAME IS EXPECTED 
INTO SATURDAY AS LOCAL TRADES REMAIN FRESH. A DOWNWARD TREND IN SURF 
AND WIND FOR WINDWARD SHORES IS EXPECTED ON SUNDAY...EXCEPT FOR 
LOCATIONS EXPOSED TO REFRACTING LONG-PERIOD SWELL FROM THE NW. 
MODERATE TRADES ARE EXPECTED MONDAY INTO TUESDAY WITH SMALL BREAKERS 
FROM 45-90 DEGREES.

MID THURSDAY ON SOUTHERN SHORES HAS TINY TO SMALL BREAKERS...DOWN 
FROM RECENT DAYS. MORE OF THE SAME IS EXPECTED THROUGH THE PERIOD.

A STORM-FORCE LOW PRESSURE SYSTEM IN THE SOUTHERN TASMAN SEA LAST 
WEEKEND COULD BRING IN A SMALL EPISODE FROM 208-220 DEGREES THIS 
SUNDAY INTO MONDAY.

INTO THE LONG RANGE...TINY TO SMALL SURF FOR SOUTHERN SHORES NEXT 
WEEK. MODELS SUGGEST A SMALL TO MODERATE EPISODE FROM A NEW ZEALAND 
SYSTEM ARRIVING AROUND NOVEMBER 29...AND ANOTHER ABOUT 5 DAYS LATER.

IN THE NORTHERN HEMISPHERE...MODELS DEPICT A REGIME CHANGE WITH THE 
DATELINE RIDGE GIVING WAY TO A TROUGH...AND AN OVERALL SOUTHWARD 
SHIFT TO THE TRACK OVER MOST OF THE NORTH PACIFIC...BRINGING SYSTEMS 
CLOSER TO HAWAII AND INCREASING THE SURF SIZE. A SEVERE GALE IS 
MODELLED TO NOSE WITHIN 1000 NM OF HAWAII BY MONDAY...BRINGING 
EXTRA-LARGE SURF LOCALLY ON WEDNESDAY FROM 320-340 DEGREES. WINDS 
ARE EXPECTED TO VARY DAY TO DAY AS THE WEATHER SYSTEMS PASS NORTH OF 
THE ISLANDS...WITH SOME DAYS OF MODERATE TRADES AND OTHERS MOSTLY 
LIGHT AND VARIABLE.

LONG RANGE FORECASTS ARE SUBJECT TO LOW CONFIDENCE.

THIS COLLABORATIVE FORECAST WILL RESUME ON MONDAY...NOVEMBER 23.

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

$$