High Surf in Hawaii, April 10 to 12, 2016

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
334 AM HST SUN APR 10 2016

.SYNOPSIS...
TRADE WIND WEATHER TO PREVAIL MUCH OF THE WEEK WITH HIGH PRESSURE
NORTH OF THE ISLANDS. CLOUDS AND SHOWERS WILL FAVOR WINDWARD AND
MAUKA AREAS. LOCALLY BREEZY TRADE WINDS CAN BE EXPECTED AT TIMES
DURING THE WORK WEEK...WHICH COULD BLOW A FEW SHOWERS TO LEEWARD
AREAS.

&&

.DISCUSSION...
NO CHANGE IN FORECAST PHILOSOPHY THIS MORNING. HIGH PRESSURE WILL
BE THE DOMINANT FEATURE FOR THE WEEK...MAINTAINING TRADE WINDS
OVER THE REGION. THE TRADES WILL KEEP CLOUDS AND SHOWER FOCUSED
OVER THE WINDWARD AND MAUKA AREAS OF THE ISLANDS.

HIGH PRESSURE TO THE NORTHEAST OF THE ISLANDS IS MOVING TO THE
EAST...WITH A RIDGE REMAINING TO THE NORTH OF THE ISLANDS. A FRONT
NORTHWEST OF THE ISLANDS IS EXPECTED TO MOVE TO THE EAST TODAY...
STAYING NORTH OF THE ISLANDS. THIS WILL KEEP THE TRADES WEAK
TODAY. BEHIND THE FRONT...ANOTHER HIGH PRESSURE SYSTEM IS EXPECTED
TO BUILD NORTH OF THE ISLANDS TONIGHT AND MONDAY...BRINGING
LOCALLY BREEZY TRADES TO THE ISLANDS...ALONG WITH SHOWERS FOCUSED
OVER THE WINDWARD AND MAUKA AREAS.

THE HIGH WILL LINGER NORTH OF THE ISLANDS...AND GET REINFORCED BY
WEDNESDAY...WHICH WILL CONTINUE THE PATTERN OF LOCALLY BREEZY
TRADES. THURSDAY THE HIGH MOVES TO THE EAST AS A STRONGER FRONT
PUSHES IN BEHIND THE HIGH. THE FRONT IS EXPECTED TO STAY NORTH OF
THE ISLANDS FRIDAY AS IT MOVES TO THE EAST. THIS WILL DISRUPT THE
TRADE WIND FLOW...AND ALLOW SOME ADDITIONAL LOW LEVEL MOISTURE TO
BE CARRIED IN ON THE LIGHTER TRADES AT THE END OF THE WEEK...WITH
ANOTHER HIGH MOVING IN NORTH OF THE ISLANDS BEHIND THE FRONT.

&&

.AVIATION...
A LOW LEVEL TRADE WIND FLOW WITH AN INVERSION AROUND 8 KFT IS
EXPECTED TO MAINTAIN RELATIVELY STABLE ATMOSPHERIC CONDITIONS ACROSS
THE ISLAND CHAIN THROUGH THIS EVENING. VFR CONDITIONS WILL LIKELY
DOMINATE ACROSS LEEWARD AREAS...WHILE BRIEF PERIODS OF MVFR
CONDITIONS MAY OCCUR OVER SOME HIGHER TERRAIN AND ALONG WINDWARD
FACING SLOPES. AN AREA OF LOW CLOUDS AND SCATTERED SHOWERS OVER
PORTIONS OF WINDWARD AND INTERIOR KAUAI IS EXPECTED TO DEPART THAT
ISLAND LATER THIS MORNING.

MODEL GUIDANCE CONTINUES TO SUGGEST THAT TRADE WIND SPEEDS MAY
INCREASE LATER TODAY OR TONIGHT. IF SO...THERE IS A POSSIBILITY THAT
AIRMET TANGO MAY BE REQUIRED FOR TEMPO MODERATE LOW LEVEL TURBULENCE
LEEWARD OF THE MOUNTAINS ON THE ISLANDS.

&&

.MARINE...
A NEW NORTHWEST SWELL IS EXPECTED TO ARRIVE TODAY...WITH SURF
HEIGHTS EXCEEDING ADVISORY LEVELS. A HIGH SURF ADVISORY IS IN
EFFECT FOR THE SHORES AFFECTED FOR THE SMALLER ISLANDS THROUGH 6
AM MONDAY. THE SWELL IS EXPECTED TO GRADUALLY DECLINE MONDAY.
ALTHOUGH WINDS HAVE DROPPED JUST BELOW ADVISORY LEVELS OVER THE
COASTAL WATERS...THE INCOMING SWELL WILL BRING SEAS OVER 10
FT...THUS A SMALL CRAFT ADVISORY REMAINS POSTED...BUT THE LOCATION
HAS CHANGED TO AREAS IMPACTED BY THE SWELL. EXPECT OTHER AREAS TO
POSSIBLY BE ADDED AS THE SWELL ARRIVES.

ANOTHER ADVISORY LEVEL NORTHWEST SWELL IS EXPECTED TO ARRIVE
MONDAY NIGHT...PEAK TUESDAY...AND THEN GRADUALLY LOWER WEDNESDAY
THROUGH THURSDAY.

STRONG TRADES THIS WEEK MAY CAUSE SURF TO REACH ADVISORY LEVELS AT
TIMES ALONG THE EAST FACING SHORES. THERE WILL ALSO BE A SERIES OF
SMALL SOUTH SWELLS THROUGHOUT THE WEEK.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
HIGH SURF ADVISORY UNTIL 6 AM HST MONDAY 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 AM HST MONDAY FOR KAUAI NORTHWEST
WATERS-KAUAI WINDWARD WATERS-KAUAI LEEWARD WATERS-KAUAI CHANNEL-
OAHU WINDWARD WATERS.

&&

DISCUSSION/MARINE...M BALLARD
AVIATION...HOUSTON