535
FXHW60 PHFO 130649
AFDHFO
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
849 PM HST TUE MAY 12 2026
SYNOPSIS
BREEZY EAST NORTHEASTERLY TRADE WINDS WILL REMAIN THROUGH THE
WEEK AND COULD EASE SLIGHTLY THIS WEEKEND AND BECOME MORE
EASTERLY. SHOWERS WILL FAVOR WINDWARD AND MOUNTAIN AREAS, AS WELL
AS THE NIGHT TIME AND EARLY MORNING HOURS. LATE THIS WEEK INTO THE
WEEKEND, AN UPPER-LEVEL LOW COULD BRING AN UPTICK IN TRADE WIND
SHOWER COVERAGE.
DISCUSSION
AT THE SURFACE, A DOMINATE HIGH PRESSURE SYSTEM RESIDES FAR TO THE
NORTH OF THE HAWAIIAN ISLANDS, AND WILL KEEP EAST TO EASTNORTHEAST
TRADE WINDS BLOWING THROUGH THE WEEKEND AND INTO NEXT WEEK. MOST
OF THE RAIN THIS EVENING HAS FALLEN OVER KAUAI, WITH SOME SHOWERS
UPSTREAM APPROACHING THE OTHER ISLANDS. SHOWERS WILL BE PUSHED
OVER THE TYPICAL WINDWARD AND MOUNTAIN AREAS, FAVORING THE NIGHT
TIME AND EARLY MORNING HOURS.
BY FRIDAY THROUGH THE WEEKEND, MODELS CONTINUE TO SHOW A MID TO UPPER-
LEVEL CUTOFF LOW MOVING OVER THE REGION, BRINGING COOLER TEMPERATURES
ALOFT AND INCREASING INSTABILITY. PRECIPITABLE WATER VALUES AT
THAT TIME ARE EXPECTED TO CLIMB TO 1.5 TO ALMOST 2 INCHES OVER
THE EASTERN END OF THE STATE AS MOISTURE IS DRAWN UP FROM THE
SOUTH. ITS HARD TO KNOW AT THIS MOMENT HOW MUCH RAIN COULD FALL,
AS SOME DRY AIR AND RIDGING COULD LINGER, INHIBITING SHOWERS. BUT
LOCALIZED HEAVY SHOWERS ESPECIALLY OVER THE MOUNTAIN RANGES LOOK
LIKE A POSSIBILITY AT THIS TIME. THIS UPPER LOW IS ALSO EXPECTED
TO USHER IN MUGGIER CONDITIONS AS DEW POINTS CLIMB INTO THE LOWER
70S AND THE EXTRA MOISTURE COULD LINGER INTO EARLY NEXT WEEK.
AVIATION
HIGH PRESSURE FAR NORTH OF THE ISLANDS WILL MAINTAIN A BREEZY
TRADE WIND PATTERN THROUGH AT LEAST WEDNESDAY. MID-LEVEL RIDGING
WILL HELP TO LIMIT SHOWER ACTIVITY WITH A STABLE AIRMASS IN PLACE.
LIMITED SHOWERS WILL CONTINUE TO BE CARRIED IN ON THE TRADE WIND
FLOW. AT TIMES THESE SHOWERS COULD BRING SOME MOUNTAIN OBSCURATION
TO VARIOUS ISLANDS, MOSTLY AT NIGHT AND DURING THE MORNING HOURS.
OTHERWISE, VFR CONDITIONS ARE EXPECTED TO PREVAIL.
AIRMET TANGO REMAINS IN EFFECT FOR MECHANICAL TURBULENCE TO THE
LEE OF THE MOUNTAINS DUE TO THE BREEZY TRADE WINDS. EXPECT THIS TO
REMAIN IN PLACE THROUGH AT LEAST WEDNESDAY
MARINE
A SLOW EASTERN-MOVING AREA OF HIGH PRESSURE NORTH OF THE ISLANDS
WILL MAINTAIN GENERALLY MODERATE TO LOCALLY STRONG SMALL CRAFT
ADVISORY LEVEL TRADE WIND WINDS THROUGH THURSDAY. AN UPPER LEVEL
LOW DROPPING SOUTH IN THE WAKE OF THE EAST EXITING HIGH WILL
INCREASE NORTH AND WEST WATER SHOWER CHANCES FROM FRIDAY INTO THE
WEEKEND.
A SMALL SHORT TO MEDIUM PERIOD NORTHWEST (330 DEGREE) SWELL WILL
SLOWLY DECLINE THROUGH TONIGHT. A LARGER LONG PERIOD NORTHWEST
SWELL WILL ARRIVE LATE WEDNESDAY AND WILL PEAK ON THURSDAY. THIS
WILL PUSH NORTH-FACING SURF TO NEAR OR SLIGHT OVER HEAD HIGH
LEVELS.
VERY SMALL, MEDIUM PERIOD SOUTH SWELL WILL OCCUR THROUGH THE
REMAINDER OF WEEK. A LONG PERIOD SOUTH BUMP ARRIVES SATURDAY AND
THIS WILL PRODUCE SLIGHTLY ELEVATED SOUTH-FACING SHORE SURF.
ENHANCED TRADES WILL MAINTAIN ABOVE SEASONABLE EAST-FACING SHORE
WIND WAVE CHOP THE NEXT SEVERAL DAYS.
HFO WATCHES/WARNINGS/ADVISORIES
SMALL CRAFT ADVISORY UNTIL 6 PM HST WEDNESDAY FOR MAALAEA BAY-
PAILOLO CHANNEL-ALENUIHAHA CHANNEL-BIG ISLAND LEEWARD WATERS-BIG
ISLAND SOUTHEAST WATERS.
DISCUSSION...TSAMOUS
AVIATION...KINO
MARINE...BLOOD
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