951
FXHW60 PHFO 130628
AFDHFO
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
828 PM HST SAT APR 12 2025
SYNOPSIS
BREEZY TRADE WINDS WILL CONTINUE FOR THE NEXT SEVERAL DAYS, WITH
PASSING CLOUDS AND SHOWERS FAVORING WINDWARD AND MAUKA AREAS.
LIGHTER WINDS ARE EXPECTED BY THE MIDDLE OF NEXT WEEK, WITH FEWER
WINDWARD SHOWERS, AND A GREATER CHANCE FOR AFTERNOON INTERIOR
SHOWERS.
DISCUSSION
A BATCH OF MOISTURE RIDING IN ON THE BREEZY TRADES THIS EVENING
IS BRINGING SCATTERED SHOWERS TO WINDWARD AND MAUKA AREAS ACROSS
THE ISLAND CHAIN, WITH A FEW SHOWERS SPILLING OVER TO LEEWARD
AREAS AT TIMES. AS THE NIGHT PROGRESSES, UPSTREAM MOISTURE SEEN ON
SATELLITE IMAGERY IS EXPECTED TO FOCUS OVER THE EASTERN HALF OF
THE STATE, WITH THE SOUTHEAST STEERING FLOW AT 850MB BACKING TO
BECOME MORE EASTERLY AND PREVENTING THE SPREAD OF THAT MOISTURE UP
THE ISLAND CHAIN. DRIER AIR WILL FILTER ACROSS THE WESTERN END OF
THE STATE, BRINGING CLEARER CONDITIONS ACROSS OAHU AND KAUAI BY
TOMORROW MORNING.
MEANWHILE, HIGH PRESSURE FAR NORTHEAST OF THE STATE WILL HELP TO
MAINTAIN BREEZY TRADE WINDS THROUGH THE NEXT COUPLE OF DAYS. MORE
BATCHES OF MOISTURE CAUGHT UP IN THESE TRADES WILL PERIODICALLY
FILTER IN ACROSS THE ISLAND CHAIN, WITH CLOUDS AND SHOWERS
GENERALLY FOCUSING ACROSS WINDWARD AND MAUKA AREAS. AN UPPER-LEVEL
LOW WILL MOVE OVER THE STATE FROM THE WEST STARTING LATE TOMORROW
AND REMAIN THERE THROUGH MID WEEK, BRINGING SOME INSTABILITY
ALOFT, WHICH MAY HELP TO ENHANCE WINDWARD SHOWERS AT TIMES.
A STRONG LOW PRESSURE SYSTEM TO THE FAR NORTH WILL DISPLACE THE
RIDGE TO BRING IT CLOSER TO, OR OVER, THE ISLAND CHAIN BY MID
WEEK. THE PROXIMITY OF THIS RIDGE AND THE APPROACH OF A FRONT/TROUGH
FROM THE NORTHWEST WILL BRING LIGHTER SOUTHEAST WINDS ACROSS THE
AREA, ALLOWING LAND AND SEA BREEZES TO EXPAND IN COVERAGE AND
DOMINATE THE LOCAL WEATHER REGIME. THIS WILL LEAD TO MOSTLY CLEAR
NIGHTS AND MORNINGS GIVING WAY TO AFTERNOON CLOUDS AND SHOWERS
OVER INTERIOR/LEEWARD AREAS. AN UPPER LEVEL TROUGH WILL DIVE
SOUTHEAST ACROSS THE CENTRAL PACIFIC AND MOVE OVERHEAD BY
WEDNESDAY EVENING, BRINGING COOLER TEMPERATURES ALOFT. THE
INSTABILITY ASSOCIATED WITH THIS FEATURE COMBINED WITH POCKETS OF
MOISTURE MOVING ACROSS THE ISLAND CHAIN ON THE SOUTHEAST FLOW MAY
LEAD TO ENHANCED DIURNAL SHOWERS WITH BRIEF HEAVY DOWNPOURS OVER
ISLAND INTERIORS DURING THE DAY, PARTICULARLY ON THURSDAY AND
FRIDAY.
AVIATION
MODERATE TO BREEZY TRADE WINDS WILL CONTINUE FOR THE NEXT FEW
DAYS. A STRONG TRADE WIND INVERSION ALOFT WILL KEEP MOISTURE
TRAPPED IN THE LOWER LEVELS. SHOWER ACTIVITY WILL BE MOSTLY LIGHT
AND INTERMITTENT. CLOUDS AND SHOWERS WILL FAVOR WINDWARD SLOPES
AND COASTS AND BE MOST ACTIVE IN THE LATE NIGHT AND MORNING HOURS.
AIRMET TANGO REMAINS IN EFFECT FOR OCCASIONAL MODERATE TURBULENCE
BELOW 8000 FEET OVER AND TO THE LEE OF HIGHER TERRAIN DUE TO
MODERATE TO STRONG WINDS AT SUMMIT LEVEL.
AIRMET SIERRA IS NOW IN EFFECT FOR MOUNTAIN OBSCURATION ALONG
NORTH AND EAST FACING SLOPES OF OAHU, MOLOKAI, AND MAUI. SIERRA
MAY NEED TO BE EXPANDED LATER TONIGHT TO INCLUDE PORTIONS OF KAUAI
OR WINDWARD BIG ISLAND. CONDITIONS ARE NOT LIKELY IMPROVE UNTIL
AFTER SUNRISE SUNDAY.
MARINE
HIGH PRESSURE NORTHEAST OF THE STATE WILL MAINTAIN MODERATE TO
STRONG TRADES THROUGH MONDAY. AS A RESULT, A SMALL CRAFT ADVISORY
(SCA) REMAINS IN EFFECT FOR THE TYPICALLY WINDY WATERS AROUND
MAUI AND THE BIG ISLAND THROUGH 6 PM MONDAY. THE TRADES WILL BEGIN
TO EASE TUESDAY AND BECOME FURTHER DISRUPTED WEDNESDAY AND
THURSDAY AS AN APPROACHING FRONT INDUCES SURFACE TROUGHING OVER
THE WESTERN END OF THE STATE. WINDS WILL BECOME LIGHT AND VARIABLE
OVER THE WESTERN WATERS AS A RESULT, WHILE WINDS OVER THE EASTERN
ISLANDS SHIFT EAST-SOUTHEASTERLY AT LIGHT TO MODERATE SPEEDS.
EAST SHORE SURF WILL REMAIN AT OR ABOVE NORMAL LEVELS THROUGH
TUESDAY, AND WILL BE RATHER ROUGH DUE TO THE STRONG TRADES,
PARTICULARLY THROUGH MONDAY. AS THE TRADES DIMINISH SURF ALONG
EAST FACING SHORES WILL DROP BELOW NORMAL WEDNESDAY THROUGH NEXT
SATURDAY.
NORTH SHORE SURF WILL REMAIN VERY SMALL THROUGH THE WEEKEND. A
SMALL NORTHWEST SWELL WILL GIVE A BOOST TO SURF ALONG NORTH AND
WEST FACING SHORES MONDAY AND TUESDAY, FOLLOWED BY A DECLINE
WEDNESDAY AND THURSDAY. A NEW MODERATE SIZED NORTH-NORTHWEST
SWELL WILL ARRIVE LATE THURSDAY, POTENTIALLY BRINGING ADVISORY
LEVEL SURF TO NORTH AND WEST FACING SHORES FRIDAY, THEN LOWERING
THROUGH NEXT WEEKEND.
SURF ALONG SOUTH FACING SHORES WILL REMAIN SMALL AND MOSTLY AT
BACKGROUND LEVELS THROUGH LATE NEXT WEEK.
HFO WATCHES/WARNINGS/ADVISORIES
SMALL CRAFT ADVISORY UNTIL 6 PM HST MONDAY FOR MAALAEA BAY-
PAILOLO CHANNEL-ALENUIHAHA CHANNEL-BIG ISLAND LEEWARD WATERS-BIG
ISLAND SOUTHEAST WATERS.
DISCUSSION...FARRIS
AVIATION...BEDAL
MARINE...JELSEMA
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