186
FXHW60 PHFO 110646
AFDHFO
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
846 PM HST THU SEP 10 2026
SYNOPSIS
A DRIER AND LESS HUMID TRADE WIND FLOW WILL CONTINUE TO DEVELOP
OVER THE STATE THROUGH FRIDAY. SHOWER ACTIVITY WILL BE FOCUSED
ACROSS WINDWARD AREAS AND WILL BECOME LESS FREQUENT, THOUGH
LEEWARD BIG ISLAND MAY STILL EXPERIENCE SCATTERED BRIEFLY HEAVY
SHOWERS IN THE AFTERNOON. A TROPICAL DISTURBANCE MOVING WITHIN THE
TRADE WINDS MAY BRING INCREASED HUMIDITY AND SHOWERS AGAIN LATE
TUESDAY OR WEDNESDAY.
DISCUSSION
A DIFFUSE BAND OF MOISTURE TRAILING FORMER TROPICAL CYCLONE LOWELL
IS SLOWLY PUSHING WESTWARD AND CLEARING PORTIONS OF THE ISLAND
CHAIN THIS EVENING. MODERATE EAST-SOUTHEAST WINDS ARE SHIFTING
TOWARD A MORE TYPICAL EASTERLY TRADE WIND DIRECTION. THIS HAS
CLEARED THE DEEPER MOISTURE OVER OAHU AND MUCH OF MAUI COUNTY,
WHERE SHOWER ACTIVITY HAS BEEN OVER WINDWARD AREAS DURING THE
PAST SEVERAL HOURS, AND LEEWARD DEW POINTS ON THESE ISLANDS HAVE
FALLEN BELOW 70 DEG F FOR THE FIRST TIME IN SEVERAL DAYS,
PROVIDING RELIEF FROM RECENT HUMIDITY. THE DEEPER MOISTURE REMAINS
HUNG UP ON BIG ISLAND AND KAUAI, WHERE SHOWERS ARE MORE ACTIVE
THIS EVENING AND DEW POINTS REMAINS IN THE 70S. EXPECT RAINFALL TO
DECLINE ON THESE ISLANDS TONIGHT, WITH THE EXCEPTION OF LINGERING
SPOTTY SHOWERS, SOME HEAVY, OVER THE KONA DISTRICT.
EXPECT A DRIER AND LESS HUMID DAY OVER MOST OF THE ISLAND CHAIN
FRIDAY. MODERATE TRADE WINDS WILL PUSH THE BULK OF THE DEEPER
MOISTURE WEST OF THE ISLANDS, ALLOWING LEEWARD DEW POINTS TO FALL
INTO THE MID 60S. TYPICAL SCATTERED SHOWERS ARE EXPECTED OVER
WINDWARD AREAS, BUT RAINFALL ACCUMULATION WILL BE LOW. SPOTTY
AFTERNOON SHOWERS, SOME BRIEFLY HEAVY CANNOT BE RULED OUT ON
LEEWARD BIG ISLAND AND TO A LESSER DEGREE ON LEEWARD KAUAI.
MODERATE TRADE WINDS WILL BRING RATHER TYPICAL TRADE WIND WEATHER
THIS WEEKEND THROUGH EARLY NEXT WEEK. A WEAK UPPER-LEVEL TROUGH
WILL LINGER OVER THE AREA, KEEPING MODEST INSTABILITY AND A WEAK
INVERSION OVER THE STATE. AS A RESULT, THERE WILL BE A CHANCE OF A
FEW HEAVY SHOWERS OVER THE KONA SLOPES OF BIG ISLAND EACH
AFTERNOON AND EVENING.
A TROPICAL DISTURBANCE MOVING WITHIN THE TRADE WINDS MAY BRING
INCREASED HUMIDITY AND SHOWERS AGAIN LATE TUESDAY OR WEDNESDAY.
DIFFERENCES IN TIMING AND PLACEMENT OF THIS MOISTURE PERSIST
BETWEEN THE GFS AND ECMWF, WHICH IS KEEPING THE DETAILS ELUSIVE AT
THIS POINT. THIS MOISTURE COULD PERSIST THROUGH THURSDAY OF NEXT
WEEK.
AVIATION
THE TRADE WINDS ARE GRADUALLY EASING THIS EVENING, WITH A FEW
SHOWERS LINGERING AROUND THE ISLANDS. HEAVIER PRECIPITATION CAN BE
FOUND OFFSHORE, MOVING WESTWARD. SATELLITE IMAGERY THIS EVENING
IS A BIT MESSY, WITH A MIX OF LOW, MID, AND HIGH LEVEL CLOUDS. TAF
SITES, DEPICT THIS AS WELL, WITH CIGS VARYING FROM 2500FT TO
6000FT IN ADDITION TO HIGH CLOUDS STREAMING WAY OVERHEAD. CURRENT
THINKING IS THAT THE CLOUDS WILL LINGER OVERNIGHT, AND IMPROVE
FRIDAY MORNING. THE WINDWARD SIDES OF ISLANDS MAY STRUGGLE A BIT
WITH CLOUD CLEARING, AS SHOWERS REMAIN IN THE FORECAST.
AIRMET SIERRA REMAINS FOR THE BIG ISLAND, MAUI, OAHU AND KAUAI
THROUGH AT LEAST 10Z. ISOLATED SHOWERS REMAIN IN THE FORECAST
TONIGHT, WITH THE WINDWARD SIDES OF THESE ISLAND POTENTIALLY
SEEING ADDITIONAL SHOWERS TOMORROW. WILL NEED TO ASSESS HOW DRY
THE TRADE WINDS WILL GET AND HOW THAT IMPACTS SHOWERS AND CLOUDS
ON FRIDAY.
MARINE
MODERATE TO LOCALLY FRESH TRADE WINDS WILL RETURN TONIGHT AS A
WEAK TROUGH ORIENTATED NORTH TO SOUTH SHIFTS WEST OF KAUAI. A
COUPLE OF TROUGHS FAR NORTHEAST AND SOUTHEAST WILL KEEP A WEAK
PRESSURE GRADIENT ACROSS THE STATE THROUGH THE WEEKEND. THE TROUGH
FROM THE SOUTHEAST WILL NEAR THE STATE SATURDAY ALLOWING WINDS TO
SHIFT OUT OF THE NORTHEAST THROUGH EARLY NEXT WEEK.
A MODERATE MID-PERIOD SOUTH SWELL WILL CONTINUE TO STEADILY
DECLINE OVER THE NEXT FEW DAYS WITH BELOW AVERAGE SURF EXPECTED BY
THE WEEKEND. BACKGROUND SOUTHERLY SWELLS WILL KEEP SURF FROM
GOING FLAT OVER THE WEEKEND INTO EARLY NEXT WEEK. A GALE LOW JUST
EAST AUSTRALIA WILL SHIFT EAST OF NEW ZEALAND OVER THE NEXT
COUPLE OF DAYS IN A MORE FAVORABLE POSITION FOR MORE CONSISTENT
SOUTH SWELLS FOR HAWAII LATE NEXT WEEK. FORERUNNERS FROM THE
CAPTURED FETCH FROM THIS SYSTEM COULD START TRICKLING IN BY MID
WEEK AND GRADUALLY BUILD THROUGH THE REST OF THE WEEK INTO NEXT
WEEKEND, GENERATING ABOVE AVERAGE SURF.
ALONG EAST FACING SHORES, NEAR SEASONAL AVERAGE SURF GENERATED BY
FORMER TROPICAL CYCLONES WILL GRADUALLY FADE TO BELOW AVERAGE BY
SATURDAY AND HOLD INTO EARLY NEXT WEEK AS TRADES LOCALLY AND
UPSTREAM REMAIN DISRUPTED.
TINY SURF ALONG NORTH FACING SHORES AS LOWELL WILL DROP TONIGHT AS
THE SMALL SWELL FROM LOWELL CONTINUES TO FADE.
FIRE WEATHER
FIRE WEATHER RISK WILL REMAIN LOW THE NEXT SEVERAL DAYS DUE LIGHT
TO MODERATE WINDS AND THE EFFECTS OF RECENT RAINFALL. INVERSION
HEIGHTS ARE EXPECTED TO REMAIN ELEVATED OR WEAK THROUGH MONDAY.
HFO WATCHES/WARNINGS/ADVISORIES
NONE.
DISCUSSION...WROE
AVIATION...ROGACHESKI
MARINE...ALMANZA
FIRE WEATHER...WROE
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