High Surf in Hawaii, February 1 to 3, 2016

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
400 AM HST MON FEB 1 2016

.SYNOPSIS...
A SERIES OF WEAK FRONTS PASSING NORTH OF THE ISLANDS THROUGHOUT THE
WEEK WILL RESULT IN THE DISRUPTION OF TRADE WINDS ACROSS THE AREA
AT TIMES...WITH BRIEF PERIODS OF LAND AND SEA BREEZES. A STRONG
COLD FRONT WILL BRING UNSETTLED WEATHER TO THE AREA BY THE
WEEKEND...AND THE COOLEST AIRMASS OF THE YEAR WILL OVERSPREAD THE
ISLANDS IN ITS WAKE.

&&

.DISCUSSION...
WINDS ARE ON THE DECLINE ACROSS THE STATE EARLY THIS MORNING...AS
ANOTHER COLD FRONT IS IN THE PROCESS OF PASSING NORTH OF THE
STATE...RESULTING IN THE WEAKENING THE RIDGE OF HIGH PRESSURE NORTH
OF THE ISLANDS. LATEST SATELLITE IMAGERY REVEALED QUITE A BIT OF LOW
CLOUDS IN THE ISLAND VICINITY...WITH RADAR DATA SHOWING A LINE OF
SHOWERS JUST SOUTH AND SOUTHWEST OF OAHU AND ALONG THE KOOLAU. LOOKS
LIKE THE LINE OF SHOWERS OVER THE COASTAL WATERS MAY STAY
OFFSHORE...THOUGH SHOWERS ALONG THE KOOLAU MAY PERSIST AS THE WIND
FLOW HAS TURNED MORE SOUTHEASTERLY AT THE LOWER LEVELS.

A MID LEVEL SHORT-WAVE WILL PASS BY THE STATE LATER TODAY...WITH AIR
MASS IN THE ISLAND VICINITY BECOMING A LITTLE MORE UNSTABLE. WINDS
AT THE SURFACE WILL BECOME LIGHT ENOUGH FOR THE LOCAL SEA BREEZES TO
DEVELOP. THE LIGHTER BACKGROUND EASTERLY WIND FLOW WILL PROBABLY
STILL BRING SOME LOW CLOUDS AND SHOWERS TO THE ISLANDS AT
TIMES...AFFECTING MAINLY WINDWARD AREAS...WHILE CLOUDS DEVELOPING
OVER THE ISLANDS UNDER CONVERGING SEA BREEZES MAY ALSO PROVIDE SOME
SHOWERS OVER THE INTERIOR SECTION LATER TODAY.

TRADE WINDS WILL BRIEFLY COME BACK TUESDAY AS A SURFACE HIGH
PRESSURE PASSES NORTH OF THE STATE. MORE STABLE ATMOSPHERIC
CONDITIONS WILL RETURN TO THE AREA AS WELL AS THE MID LEVEL
SHORT-WAVE EXITS EAST. ANOTHER FAST MOVING FRONT WILL FOLLOW ON
WEDNESDAY...WITH WINDS WEAKENING AGAIN. HENCE THE ISLANDS WILL
EXPERIENCE ALTERNATING BRIEF PERIODS OF TRADE WIND WEATHER AS WELL
AS LAND AND SEA BREEZES WEATHER THROUGH FRIDAY. RAINFALL AMOUNTS
WILL BE ATTENUATED ACROSS THE AREA UNDER THE MORE STABLE CONDITIONS.

LATEST FORECAST MODELS CONTINUE TO BE QUITE CONSISTENT WITH THE NEXT
SIGNIFICANT WEATHER FRONT MOVING THROUGH THE ISLANDS OVER THE
WEEKEND. THE LATEST ECMWF AND GFS ARE STILL RATHER CLOSE IN THE
TIMING OF THE ARRIVAL OF THIS FEATURE TO THE STATE. THE MAIN LOW
ASSOCIATED WITH THIS SYSTEM IS FORECAST TO REMAIN FAR NORTH OF THE
AREA. THUS MUCH OF THE STRONGEST DYNAMICS WILL STAY NORTH OF THE
ISLANDS. BUT THEN...THIS FRONTAL SYSTEM WILL PROBABLY BE STRONG
ENOUGH TO BRING MEASURABLE RAINFALL TO THE STATE. LOOK FOR
INCREASING CLOUDS AND SHOWERS TO AFFECT THE STATE ON SATURDAY. THE
MUCH COOLER AIRMASS BEHIND THIS FRONT WILL SPREAD TO ALL ISLANDS BY
SUNDAY...WITH RATHER BRISK NORTHERLY WINDS AFFECTING THE STATE
BEHIND THE FRONT.

&&

.AVIATION...
EASTERLY TRADE FLOW IS PUSHING SCANT CLOUD COVER ACROSS
THE ISLANDS THIS MORNING...BUT WINDS ARE EXPECTED TO WEAKEN THROUGH
THE DAY TODAY. VFR CONDITIONS WILL DOMINATE AT THE TERMINALS TODAY
AND TONIGHT. NO AIRMETS ARE IN EFFECT AND NONE ARE EXPECTED.

&&

.MARINE...
READINGS FROM THE BUOY FAR NORTHWEST OF THE ISLANDS INDICATED THE
INCOMING LARGE NORTHWEST SWELL MAY HAVE PEAKED EARLIER. THE NUMBERS
REPORTED CERTAINLY SUPPORT ADVISORY LEVEL SURF ALONG NORTH AND WEST
FACING SHORES OF MOST OF THE SMALLER ISLANDS TODAY. A HIGH SURF
ADVISORY REMAINS POSTED FOR THOSE SHORES THROUGH THIS EVENING. THIS
SWELL WILL PEAK LATER TODAY...THEN SLOWLY SUBSIDING THROUGH
WEDNESDAY. THE ADVISORY MAY NEED TO BE EXTENDED IF THE SWELL
SUBSIDES SLOWER THAN EXPECTED. A REINFORCEMENT NORTHWEST SWELL
ARRIVING TUESDAY MAY BRING SURF ABOVE ADVISORY LEVELS FOR NORTH AND
WEST FACING SHORES OF THE SMALLER ISLANDS INTO WEDNESDAY. THIS SWELL
WILL DECLINE THROUGH THE END OF THE WEEK. A SMALLER NORTHWEST SWELL
IS EXPECTED FRIDAY INTO SATURDAY...WITH A LARGER NORTHWEST SWELL
POSSIBLE LATE SATURDAY INTO SUNDAY.

WINDS ACROSS THE ISLANDS HAVE DECREASED AS EXPECTED
OVERNIGHT...THEREFORE SMALL CRAFT ADVISORY FOR THE WINDIER COASTAL
WATERS AROUND MAUI AND BIG ISLAND IS CANCELLED. BUT THEN BUILDING
SEAS DUE TO THE INCOMING LARGE NORTHWEST SWELL WILL BRING SMALL
CRAFT SEAS CONDITIONS TO COASTAL WATERS EXPOSED TO THE
SWELL...MAINLY THE WINDWARD COASTAL WATERS. CONDITIONS SHOULD
IMPROVE BY LATE MONDAY TO TUESDAY. A STRONG COLD FRONT IS EXPECTED
TO MOVE THROUGH THE ISLAND CHAIN NEXT WEEKEND...WITH ADVISORY LEVEL
WINDS AND/OR SEAS POSSIBLE FOR ALL COASTAL WATERS.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
HIGH SURF ADVISORY UNTIL 6 PM HST THIS EVENING FOR NIIHAU-KAUAI
WINDWARD-KAUAI LEEWARD-WAIANAE COAST-OAHU NORTH SHORE-OAHU
KOOLAU-MOLOKAI-MAUI WINDWARD WEST-MAUI CENTRAL VALLEY-
WINDWARD HALEAKALA.

SMALL CRAFT ADVISORY UNTIL 6 PM HST THIS EVENING FOR KAUAI NORTHWEST
WATERS-KAUAI WINDWARD WATERS-KAUAI LEEWARD WATERS-KAUAI CHANNEL-OAHU
WINDWARD WATERS-KAIWI CHANNEL-MAUI COUNTY WINDWARD WATERS-
ALENUIHAHA CHANNEL-BIG ISLAND WINDWARD WATERS.

&&

DISCUSSION/MARINE...HUI
AVIATION...POWELL