High Surf Advisory 2, NWS Honolulu, HI

AREA FORECAST DISCUSSION...CORRECTED
NATIONAL WEATHER SERVICE HONOLULU HI
844 PM HST MON JAN 5 2015

CORRECTED DAY IN PARAGRAPH 3 OF DISCUSSION

.SYNOPSIS...
A WEAK FRONT WILL BRING A BAND OF CLOUDS...A FEW SHOWERS AND
INCREASING NORTH WINDS ACROSS THE STATE TONIGHT AND TUESDAY.
OTHERWISE A MOSTLY DRY WEATHER PATTERN IS EXPECTED OVER THE ISLANDS
INTO NEXT WEEKEND. COOL AND DRY NORTH WINDS ON TUESDAY WILL
SWITCH TO TRADE WINDS BY WEDNESDAY. THE TRADE WINDS WILL WEAKEN
THURSDAY AND LIGHT WINDS ARE EXPECTED TO PREVAIL INTO THE WEEKEND...
WITH WARMER TEMPERATURES GRADUALLY RETURNING...ESPECIALLY WHEN
WINDS TURN SOUTHERLY BY LATE IN THE WEEKEND.

&&

.DISCUSSION...
RELATIVELY WEAK /1021 MB/ HIGH PRESSURE CURRENTLY CENTERED ABOUT
1200 MILES NW OF THE ISLANDS WILL BE THE PRIMARY WEATHER FEATURE
CONTROLLING ISLAND WEATHER THROUGH MOST OF THE FORECAST PERIOD AS IT
TRACKS STEADILY E THIS WEEK. ALTHOUGH A WEAK FRONT WILL BRING A FEW
SHOWERS TONIGHT AND TUESDAY...MOSTLY DRY WEATHER IS EXPECTED FOR
MUCH OF THE UPCOMING WEEK...WITH A GRADUAL WARMING TREND BEGINNING
ON WEDNESDAY.

IN THE SHORT TERM...THE HIGH WILL TRACK SE...AND PUSH A SHALLOW AND
DISSIPATING FRONTAL CLOUD BAND SOUTHEASTWARD DOWN THE ISLAND CHAIN
THROUGH TUESDAY. THE PASSAGE OF THIS FEATURE WILL PALE IN COMPARISON
TO THE MOST RECENT FRONTAL PASSAGE...WITH ONLY A SLIGHT SURGE IN N
WINDS AS THE BOUNDARY PASSES. THE ISLAND ATMOSPHERE IS STABLE AND
DRY...AND THIS BOUNDARY WILL HAVE LITTLE IN THE WAY OF DYNAMICS OR
MOISTURE WITH WHICH TO OPERATE. LATEST SATELLITE IMAGERY DEPICTS THE
FRAGMENTED NATURE OF THE FRONT/S ASSOCIATED CLOUD BAND...WITH THE
BAND CURRENTLY STRADDLING KAUAI AND OAHU...MOVING SE ABOUT 15 TO 20
MPH. ONLY A SLIGHT INCREASE IN SHOWERS IS EXPECTED AS IT PASSES...
MAINLY OVER N AND NE FACING SLOPES AND COASTS...WITH ANY SHOWERS
REMAINING LIGHT. AN INCREASE IN WINDS AND CLOUD COVER OVERNIGHT IS
EXPECTED TO KEEP TONIGHT/S LOWS A FEW DEGREES WARMER THAN THE PAST
COUPLE OF NIGHTS...BUT NOT BY ALL THAT MUCH.

THE DISSIPATING FRONT SHOULD CLEAR THE BIG ISLAND BY TUESDAY
EVENING...WITH POST-FRONTAL NORTHERLIES QUICKLY VEERING TO THE NE
TUESDAY AND TUESDAY NIGHT. THIS WILL OCCUR AS THE HIGH TRACKS
STEADILY EASTWARD ALONG 28N...OR ABOUT 400 MILES N OF KAUAI. THE N
WINDS WILL PUSH ANOTHER BATCH OF COOL DRY AIR OVER THE ISLANDS...
WITH DEW POINTS BOTTOMING OUT IN THE MID 50/S LATE TUESDAY. TRADE
WINDS ON WEDNESDAY ARE EXPECTED TO BE DRIER THAN NORMAL AS WELL WITH
THE ISLAND AIR MASS REMAINING DRY AND STABLE. AS THE HIGH CONTINUES
TO TRACK E AND BECOME ESTABLISHED FAR NE OF THE ISLANDS LATER THIS
WEEK...ITS ASSOCIATED RIDGE WILL MOVE INTO A POSITION JUST N OF
KAUAI. THIS WILL LEAD TO LIGHTER E/SE WINDS FOR MOST AREAS ON
THURSDAY AND FRIDAY...WITH TRADE WINDS PERSISTING NEAR AND S OF THE
BIG ISLAND. A MOSTLY DRY LAND AND SEA BREEZE WIND AND WEATHER
PATTERN IS EXPECTED TO DOMINATE ISLAND WEATHER FROM WEDNESDAY NIGHT
INTO SATURDAY. LEEWARD AND INTERIOR AFTERNOON CLOUD BUILD UPS WILL
BE THE RESULT...BUT LIMITED MOISTURE WILL LIKELY PRECLUDE
SIGNIFICANT SHOWER DEVELOPMENT.

OVER THE WEEKEND AND EARLY NEXT WEEK...THE RIDGE WILL SLIDE
SOUTHWARD OVER THE ISLANDS...AND THEN MOVE TO A POSITION NEAR OR S
OF THE BIG ISLAND. THIS OCCURS AS A LARGE GYRE OF LOW PRESSURE SETS
UP BETWEEN HAWAII AND THE ALEUTIAN ISLANDS. IN THIS REGIME...WHICH
IS FAIRLY TYPICAL FOR JANUARY...LIGHTER S WINDS WOULD PREVAIL NEAR
THE BIG ISLAND...WITH STRONGER SW WINDS NEAR KAUAI AND OAHU. THIS
REGIME ALSO TYPICALLY IS ASSOCIATED WITH VOG FROM THE BIG ISLAND
SPREADING TO THE OTHER ISLANDS...AND OVER WINDWARD PORTIONS OF THE
BIG ISLAND.

A FRONT ASSOCIATED WITH THE LARGE GYRE IS EXPECTED TO BE NEAR KAUAI
IN ABOUT A WEEK...KEEPING THE RIDGE SUPPRESSED SOUTHWARD. WHETHER OR
NOT THIS FRONT AFFECTS ANY OF THE ISLANDS EARLY NEXT WEEK REMAINS
UNDECIDED...BUT LONG RANGE FORECAST MODEL GUIDANCE INDICATES THAT
THE SURFACE RIDGE WILL REMAIN NEAR OR S OF THE ISLANDS THROUGH THE
MIDDLE OF NEXT WEEK. WITH WINDS EVENTUALLY TURNING TO THE S AND SW...
THE ISLAND ATMOSPHERE WILL WARM AND MOISTEN. LONG RANGE MOS OUTPUT
INDICATES THAT ISLAND DEW POINTS WILL INCREASE AFTER A MIN IN THE
MID 50/S ON TUESDAY...GRADUALLY CLIMBING INTO THE MID 60/S BY EARLY
NEXT WEEK.

ALTHOUGH WINDS AT THE SUMMITS ON THE BIG ISLAND ARE CURRENTLY BELOW
ADVISORY/WARNING CRITERIA...A TIGHTENING OF THE GRADIENT ALOFT MAY
LEAD TO ADVISORY LEVEL WINDS ON TUESDAY BEFORE DIMINISHING
WEDNESDAY. THERE ALSO APPEARS TO BE POTENTIAL FOR ADVISORY LEVEL
WINDS AGAIN AROUND FRIDAY.

&&

.AVIATION...
A SHALLOW CLOUD BAND ASSOCIATED WITH A WEAK COLD FRONT WILL TRACK SE
DOWN THE ISLAND CHAIN THROUGH TUESDAY...BUT LIMITED MOISTURE MEANS
THAT ASSOCIATED CIGS ARE LIKELY TO REMAIN AOA 030...WITH VFR
CONDITIONS THEREFORE PREVAILING. SOME BRIEF -SHRA AND MVFR CIGS ARE
POSSIBLE ALONG N FACING SLOPES AND COASTS AS THE FRONT MOVES THROUGH
THE ISLANDS...BUT WITH LIMITED DURATION AND COVERAGE.

NO AIRMETS ARE CURRENTLY IN EFFECT. INCREASING N TO NE WINDS MAY
LEAD TO LOW LEVEL TURB TO THE S AND SW OF ISLAND TERRAIN LATER
TONIGHT AND TUESDAY...POTENTIALLY REQUIRING AN AIRMET.

&&

.MARINE...
A SMALL CRAFT ADVISORY /SCA/ IS SET TO BEGIN FOR WATERS AROUND KAUAI
LATER TONIGHT...AS N WINDS INCREASE BEHIND A WEAK FRONTAL BAND.
CURRENT FORECAST GRIDS INDICATE THAT WINDS WILL INCREASE TO SCA
LEVELS IN OTHER ISLAND WATERS ON TUESDAY...AND WAVE WATCH GUIDANCE
INDICATES COMBINED SEAS WILL INCREASE TO 10 FEET OR GREATER IN MANY
MARINE ZONES LATER TUESDAY AND TUESDAY NIGHT AS A SHORT-PERIOD N
SWELL INCREASES IN HEIGHT. THUS THE EXPECTATION IS THAT THE SCA WILL
BE EXPANDED TO INCLUDE ADDITIONAL ZONES BY TUESDAY MORNING AT THE
LATEST.

MIXED SWELLS FROM BOTH THE N AND NW WILL IMPACT N AND W FACING
SHORES THROUGH THE PERIOD. A SMALL BOOST TO BOTH SWELLS WILL OCCUR
OVERNIGHT...WHILE N WINDS WILL STRENGTHEN BEHIND A WEAK FRONT
CURRENTLY NEAR KAUAI. A LARGER N SWELL BUILDING TUESDAY NIGHT
COMBINED WITH NE TRADE WINDS WILL LIKELY BOOST SURF HEIGHTS TO HIGH
SURF ADVISORY HEIGHTS ALONG N FACING SHORES OF MOST ISLANDS BY
WEDNESDAY. THE N SWELL...ALONG WITH THE TRADE WINDS...WILL
SLOWLY DIMINISH FROM THURSDAY THROUGH THE END OF THE WEEK. A NEW
LONG PERIOD NW SWELL BUILDING ON FRIDAY MAY PRODUCE SURF APPROACHING
THE HIGH SURF ADVISORY CRITERIA ALONG MOST N AND W FACING SHORES OF
THE SMALLER ISLANDS FRIDAY NIGHT AND SATURDAY. THE OAHU SURF
DISCUSSION /SRDHFO/ WAS UPDATED EARLIER TODAY...CONTAINS A HIGH
RESOLUTION DISCUSSION OF EXPECTED SWELLS OVER THE NEXT 5 DAYS...AND
CAN LOOSELY BE APPLIED STATEWIDE.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
SMALL CRAFT ADVISORY FROM MIDNIGHT TONIGHT TO 6 PM HST WEDNESDAY
FOR KAUAI NORTHWEST WATERS-KAUAI WINDWARD WATERS-KAUAI LEEWARD
WATERS.

&&

BIRCHARD