485
FXHW60 PHFO 151913
AFDHFO
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
913 AM HST WED JUL 15 2026
SYNOPSIS
MODERATE TRADES DELIVER SHOWERS WINDWARD AND MAUKA THROUGH THE
WEEKEND. A FEW AFTERNOON SHOWERS ARE POSSIBLE AS WELL, FOR SOUTH
SHORES AND LEEWARD SECTIONS TODAY AND THURSDAY.
SHORT TERM UPDATE
EARLY MORNING SOUNDINGS HAD A BIT OF A SOUTHERLY COMPONENT TO THE
WINDS OFF THE SURFACE, WHICH HAS VEERED LOW CLOUD MOTIONS TOWARD THE
WNW. THE VARIOUS HREF/REFS CAMS AND UNIVERSITY OF HAWAII HIGH
RESOLUTION GUIDANCE ALL HAVE THEIR VARIOUS OPINIONS ON WHAT WILL
HAPPEN, BUT THE GENERAL IDEA IS HIGHER THAN CLIMO POPS OVER THE
SOUTH SHORE AND LEEWARD OAHU THIS AFTERNOON INTO THE EARLY EVENING,
THANKS TO LOW LEVEL CONVERGENCE FROM MAUI COUNTY. DOWNWIND
CONVERGENCE COULD CARRY AFTERNOON SHOWERS TO OTHER ISLANDS TOO.
PLENTY OF SUBSIDENCE ALOFT WILL LIMIT SHOWER INTENSITY, AS THE UPPER
LOW ABOUT 550 MILES NW OF KAUAI IS NOT HAVING ANY SIGNIFICANT EFFECT
ON OUR LOCAL STABILITY. CURRENT FORECAST GRIDS SEEM TO HAVE THIS
WELL IN HAND AND NO UPDATES ANTICIPATED AT THIS TIME.
THE START OF KILAUEA VOLCANO EPISODE 51 OCCURRED AT ABOUT 830 AM,
AND WE ARE WATCHING RADAR AND IN CLOSE COORDINATION WITH USGS TO
DETERMINE WHAT ADVISORIES OR WARNINGS MAY BE NEEDED. IN THE
MEANTIME, A SPECIAL WEATHER STATEMENT WAS ISSUED YESTERDAY AND
REMAINS OUT. MODEL GUIDANCE SHOWS LOW LEVEL WINDS 10000 FEET AND
BELOW WOULD LIKELY PUSH ANY ASH CLOUD TOWARD THE WSW, WHILE WINDS
AT 20000 FEET AND HIGHER WOULD CARRY ANY ASH ABLE TO REACH THAT
HEIGHT TOWARD THE NNE.
PREV DISCUSSION
ISSUED AT 347 AM HST WED JUL 15 2026
LITTLE CHANGE FOR THE NEXT SEVERAL DAYS AS MODERATE TRADES
DELIVER SHOWERS WINDWARD AND MAUKA INTO NEXT WEEK. UPPER AIR
PATTERN REMAINS BLOCKY WITH A CLOSED UPPER LOW POSITIONED
NORTHWEST OF KAUAI AND DOWNSTREAM RIDGING ESTABLISHED OVER AND
EAST OF THE REMAINDER OF THE STATE. AS THE UPPER LOW IS DRAWN
NORTHWARD AND ABSORBED INTO THE WESTERLIES, HEIGHTS GRADUALLY
REBOUND OVER THE ISLANDS TOPPING OUT AROUND 591DM AT 500MB BY THIS
WEEKEND. ATTENDANT SUBSIDENCE WILL REINFORCE HIGH STABILITY
DURING THIS TIME. BRIEF VEERING OF FLOW THROUGH THE LOWEST 10KFT
OF THE ATMOSPHERE AS THIS ADJUSTMENT OCCURS POTENTIALLY SETS THE
STAGE FOR SHOWERS TO DEVELOP WITHIN THE CONVERGENT LEEWARD MOLOKAI
PLUME AND EXTEND OVER PORTIONS OF LEEWARD OAHU THIS AFTERNOON
INTO THIS EVENING. HIGH STABILITY WILL LIMIT POTENTIAL FOR
VERTICAL SHOWER DEVELOPMENT AND SHOULD KEEP SHOWER INTENSITY IN
CHECK, BUT SOME ENHANCED COVERAGE OF SHOWERS COMPARED TO NORMAL
WILL BE POSSIBLE.
AVIATION
MODERATE TRADES EXPECTED THROUGH THE FORECAST PERIOD. EXPECTING
MAINLY SCATTERED LOW CLOUDS AND SHOWERS. BRIEF MVFR CONDITIONS ARE
POSSIBLE IN PASSING SHOWERS, BUT VFR SHOULD PREVAIL ACROSS THE
STATE.
MARINE
ISSUED AT 347 AM HST WED JUL 15 2026
HIGH PRESSURE FAR NORTH OF THE ISLANDS WILL MAINTAIN A TRADE WIND
PATTERN, HOWEVER AS THE HIGH HAS WEAKENED AND LIFTED AWAY FROM
THE ISLANDS, TRADE WINDS ARE NOT QUITE AS STRONG. WINDS ACROSS THE
COASTAL WATERS REMAIN BELOW SMALL CRAFT ADVISORY LEVELS. WINDS
COULD REBOUND THURSDAY INTO THE WEEKEND AS THE HIGH SINKS
SOUTHWARD, TIGHTENING THE PRESSURE GRADIENT OVER THE ISLANDS AND
BRINGING SMALL CRAFT ADVISORY WINDS BACK TO THE TYPICAL WINDY
WATERS.
A SMALL BUMP IN THE OTHERWISE FADING MEDIUM-PERIOD SOUTHWEST
SWELL (AROUND 2.5 FT WITH A 13 SECOND PERIOD) SHOULD BRING A
SLIGHT INCREASE IN SOUTH SURF TODAY, PARTICULARLY THIS MORNING.
THE SOUTHWEST WILL RETURN TO A GRADUALLY DECLINE BY TONIGHT AND
CONTINUE THROUGH THE REST OF THE WEEK. A SERIES OF OVERLAPPING
SMALL SOUTH AND SOUTHWEST SWELLS WILL MAINTAIN SMALL SOUTH SHORE
SURF, WITH A LARGER SOUTH SWELL EXPECTED EARLY NEXT WEEK.
SURF ALONG EAST-FACING SHORES WILL BE SLIGHTLY BELOW SEASONAL AVERAGES
THROUGH THURSDAY WITH LIGHTER TRADE WINDS. SURF MAY THEN CLIMB BACK
UP SOMEWHAT AS TRADES STRENGTHEN THROUGH THE WEEKEND.
A SERIES OF SMALL, LONG TO MEDIUM PERIOD WEST TO WEST-NORTHWEST
SWELLS GENERATED BY FORMER SUPER TYPHOON BAVI WILL BE POSSIBLE
THROUGHOUT THE REST OF THE WEEK. OTHERWISE, NO SIGNIFICANT NORTH
OR NORTHWEST SWELLS ARE EXPECTED.
HFO WATCHES/WARNINGS/ADVISORIES
NONE.
SHORT TERM...R BALLARD
DISCUSSION...JVC
AVIATION...TS
MARINE...QUESADA
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