586
FXHW60 PHFO 111359
AFDHFO
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
359 AM HST SAT OCT 11 2025
SYNOPSIS
A NEARBY TROUGH WILL MAINTAIN LIGHT WINDS OVER THE REGION TODAY.
WITH A BRIEF UPTICK IN WINDS EXPECTED. AN UPPER LEVEL LOW MOVING
SOUTH TOWARDS THE ISLANDS SUNDAY NIGHT WILL BRING THE TROUGH
CLOSER TO THE ISLANDS, AND BRING ANOTHER ROUND OF LIGHT WINDS AND
SHOWERS TO THE REGION, WITH A MORE UNSTABLE AIRMASS OVER THE
ISLANDS MIDWEEK.
DISCUSSION
THERE HAVE BEEN CHANGES TO THE FORECAST, SPECIFICALLY TO REMOVE
THE MENTION OF THUNDERSTORMS LATER IN THE FORECAST. WHILE AN
UNSTABLE AIRMASS IS EXPECTED MIDWEEK, IT IS LIKELY TOO EARLY TO
IDENTIFY SPECIFIC AREAS OF THUNDERSTORMS.
WINDS MAY BE WEAK ENOUGH TODAY TO ALLOW FOR SOME LOCALIZED
AFTERNOON SEA BREEZES, HOWEVER WE ARE NOT EXPECTING A REPEAT OF
THE AFTERNOON CONVECTION PRIMARILY BECAUSE THE MAIN MOISTURE AXIS
HAS SHIFTED SOUTH OF THE REGION.
AN UPPER LEVEL LOW TO THE NORTH OF THE ISLANDS IS EXPECTED TO
SINK SOUTHWARD OVER THE NEXT COUPLE OF DAYS AND WILL BRING ANOTHER
UNSTABLE AIRMASS TO THE REGION. MOISTURE UPSTREAM OF THE ISLANDS
WILL BE CARRIED IN BY THE EAST TO SOUTHEAST LOW LEVEL FLOW. THE
NATIONAL BLEND OF MODELS (NBM) ALONG WITH THE GFE AND ECMWF ALL
SHOW THE CHANCE FOR THUNDERSTORMS AS EARLY AS TUESDAY NIGHT, AND
CONTINUING THROUGH THE REST OF THE WEEK. THE MAIN QUESTION WILL BE
HOW WIDESPREAD THE THREAT WILL BE. WILL BE MONITORING FUTURE MODEL
RUNS TO DETERMINE THE EXTENT OF THE THREAT.
AVIATION
LIGHT EAST TO SOUTHEAST WINDS ACROSS THE ISLANDS ARE EXPECTED OVER
THE NEXT COUPLE OF DAYS. VFR CONDITIONS ARE EXPECTED ACROSS MOST
LOCATIONS, HOWEVER PARTICULARLY FOR TODAY AND TOMORROW, LOCALIZED
AFTERNOON SEA BREEZES MAY BRING AN INCREASE IN INTERIOR CLOUDS AND
SHOWERS OVER THE SMALLER ISLANDS. WHILE NO AIRMETS ARE IN EFFECT
IN THE PRE-DAWN HOURS, THERE IS A CHANCE THAT SUCH DEVELOPMENT OF
CLOUDS AND SHOWERS COULD PROMPT THE NEED FOR AN AIRMET FOR
MOUNTAIN OBSCURATION.
MARINE
A TROUGHING PATTERN WILL CONTINUE TO WEAKEN TRADE WINDS NEAR
HAWAIIAN WATERS INTO EARLY NEXT WEEK, ALLOWING FOR DAYTIME ONSHORE
SEA BREEZES TO CONTINUE ALONG NEARSHORE LEEWARD COASTAL WATERS.
AN UPPER LEVEL DISTURBANCE LINGERING NORTH OF THE ISLAND CHAIN
WILL BRING PERIODS OF ENHANCED SHOWERS THROUGH THE WEEKEND. LONG
RANGE GUIDANCE SHOWS INCREASING SOUTHEASTERLY WINDS BY THE MIDDLE
OF NEXT WEEK IN AN UNSTABLE WEATHER PATTERN WITH THE POTENTIAL FOR
INCREASING SHOWER COVERAGE AND THUNDERSTORMS.
A MIX OF A SMALL MEDIUM-PERIOD NORTHWEST (330 DEG) SWELL AND A
SMALL SHORT TO MEDIUM PERIOD NORTH NORTHEAST (020 DEG) SWELL WILL
MAINTAIN SMALL SURF ALONG NORTH FACING SHORES TODAY, FADING INTO
SUNDAY MORNING. THE SMALLER FORERUNNERS OF A MODERATE TO LARGE
LONG PERIOD NORTHWEST (320 DEG) SWELL WILL BUILD INTO HAWAIIAN
WATERS STARTING SUNDAY AFTERNOON. THIS SWELL ENERGY WILL BUILD TO
HIGH SURF ADVISORY (HSA) LEVELS BY MONDAY, THEN LIKELY HOLD
THROUGH TUESDAY BEFORE SLOWLY FALLING BELOW HSA THRESHOLDS FROM
WEDNESDAY ONWARD. PREDICTING SLIGHTLY HIGHER SWELL HEIGHTS THAN
THE LATEST SWELL MODEL GUIDANCE INDICATES, AS RECENT SWELL MODEL
FORECASTS WERE TOO LOW AS COMPARED TO NEARSHORE GROUND TRUTH BUOY
OBSERVATIONS.
SURF ALONG SOUTH FACING SHORES WILL REMAIN SMALL THROUGH THE
WEEKEND WITH A SERIES OF BACKGROUND SOUTH AND SOUTHWEST SWELLS
THROUGH EARLY NEXT WEEK. EAST FACING SHORES WILL REMAIN SMALL AS A
SMALL, MEDIUM PERIOD EASTERLY SWELL, ORIGINATING FROM TROPICAL
CYCLONE PRISCILLA IN THE EAST PACIFIC, WILL BUILD INTO THE
ISLANDS STARTING LATER THIS AFTERNOON AND LASTING INTO SUNDAY.
PEAK HIGH TIDES ASSOCIATED WITH THE LUNAR CYCLE WILL LEAD TO
MINOR COASTAL FLOODING ALONG SHORELINES AND LOW LYING COASTAL
AREAS DURING THE PEAK HIGH TIDE THROUGH THIS MORNING. A COASTAL
FLOOD STATEMENT IS IN EFFECT FOR ALL COASTAL AREAS, AND WILL
LIKELY BE CANCELLED LATER TODAY FOLLOWING THE PEAK MORNING HIGH
TIDE CYCLE.
FIRE WEATHER
LIGHT WINDS AND ISOLATED TO SCATTERED SHOWERS WILL HELP MAINTAIN
FIRE WEATHER BELOW CRITICAL THRESHOLDS FOR THE NEXT SEVERAL DAYS.
INVERSION HEIGHTS WILL RANGE FROM 7,000 TO 9,000 FEET.
HFO WATCHES/WARNINGS/ADVISORIES
NONE.
DISCUSSION...M BALLARD
AVIATION...M BALLARD
MARINE...BOHLIN
FIRE WEATHER...M BALLARD
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