123
FXHW60 PHFO 091315
AFDHFO
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
315 AM HST FRI JAN 9 2026
SYNOPSIS
WE'LL SEE ANOTHER DAY OF LIGHT WINDS WITH A FEW SHOWERS, MAINLY
DRIVEN BY SEA-BREEZES. A COLD FRONT IS EXPECTED TO MOVE THROUGH
THE STATE SUNDAY NIGHT INTO MONDAY, BRINGING A LINE OF SHOWERS.
RELATIVELY DRY NORTHERLY WINDS WILL FOLLOW THIS FRONT, PROVIDING
FOR A COOL TUESDAY MORNING. A SECOND FRONT IS FORECAST TO MOVE
THROUGH WEDNESDAY NIGHT INTO THURSDAY. NEITHER OF THESE SYSTEMS
APPEAR TO BE FLOODING THREATS AT THIS TIME.
DISCUSSION
SHOWERS CONTINUE THIS MORNING ON THE BIG ISLAND FROM CAPE KUMUKAHI
SOUTHWEST TO SOUTH CAPE, BUT THE STRONGEST SHOWERS ARE NOW
OFFSHORE AS DOWNSLOPING WINDS HAVE PUSHED MOST OF THE ACTIVITY OFF
THE COAST. ELSEWHERE, SKIES WERE MOSTLY CLEAR OVER THE OTHER
ISLANDS.
THE LATEST GUIDANCE IS VERY SIMILAR TO PREVIOUS RUNS, SHOWING A
BOUNDARY STALLING JUST WEST AND NORTH OF THE STATE TODAY. THIS
WILL BRING ENHANCED MOISTURE MAINLY TO THE WESTERN END OF THE
STATE, BUT RIDGING ALOFT WILL BRING TOO MUCH STABILITY, SO
SHOWERS ARE NOT EXPECTED TO BE NUMEROUS OR STRONG. ADDITIONAL
SHOWERS ARE FORECAST FOR MUCH OF THE BIG ISLAND, WHERE WEAK
SOUTHEAST WINDS WILL ALLOW FOR A HEALTHY DOSE OF SEA-BREEZE
CONVERGENCE-DRIVEN CONVECTION. SATURDAY, THE BOUNDARY WILL WASH
OUT AND WHAT LITTLE IS LEFT WILL PULL BACK TO THE NORTH AND WEST,
LEAVING ANOTHER DAY OF SPOTTY SEA-BREEZE DRIVEN SHOWERS.
SUNDAY, AN UPPER LEVEL TROUGH WILL MOVE ACROSS THE CENTRAL PACIFIC
NOT TOO FAR NORTH OF THE STATE, PUSHING A FRONT TOWARD THE AREA.
THIS FRONT WILL PICK UP THE LEFTOVER MOISTURE FROM THE PREVIOUS
SYSTEM AND PUSH ACROSS THE STATE FROM WEST TO EAST. IT IS
FORECAST TO REACH KAUAI COUNTY SUNDAY NIGHT, OAHU AND MAUI MONDAY
MORNING, AND THE BIG ISLAND MONDAY AFTERNOON. THE FRONT SHOULD BE
ACCOMPANIED BY A BAND OF MODERATE TO STRONG SHOWERS FOLLOWED
QUICKLY BY RELATIVELY COOL AND DRY NORTHERLY SURFACE WINDS.
SHOWERS SHOULD BE MOVING FAST ENOUGH TO LIMIT ANY FLOODING
THREAT. IN THE AIRMASS BEHIND THE FRONT, LOWS TUESDAY MORNING
SHOULD BE AROUND 5 DEGREES BELOW NORMAL, AND LIKELY EVEN LOWER IN
SHELTERED VALLEY LOCATIONS OF THE WESTERN ISLANDS WHERE CLOUD
COVER SHOULD BE MINIMAL. TRADES WILL RESUME BEHIND THE FRONT AS
SURFACE HIGH PRESSURE BUILDS BACK INTO THE REGION.
WEDNESDAY, THE OLD FRONTAL BAND WILL MOVE BACK WESTWARD OVER THE
STATE AS A NEW FRONT APPROACHES FROM THE NORTHWEST. THIS NEXT
FRONT WILL BE HELPED ALONG BY YET ANOTHER UPPER LEVEL TROUGH JUST
TO THE NORTH, AND SHOULD MOVE ACROSS THE AREA WEDNESDAY NIGHT
INTO THURSDAY. AT THIS TIME, THE MOISTURE ASSOCIATED WITH THIS
TROUGH APPEARS TO BE LESS IMPRESSIVE THAN THE PREVIOUS ONE.
HOWEVER, MUCH CAN CHANGE IN THE MODEL SOLUTIONS BETWEEN NOW AND
NEXT THURSDAY, SO IT BEARS CLOSE WATCHING. FINALLY, MODELS SHOW A
SURFACE HIGH BUILDING IN BEHIND THIS FRONT, BRINGING ANOTHER
ROUND OF TRADE WINDS AND MORE TYPICAL WEATHER FOR FRIDAY.
AVIATION
A WEAKENING FRONTAL BOUNDARY WILL STALL OUT NEAR KAUAI LATER
TODAY. EXPECT INCREASING SHOWER TRENDS FOR AIRFIELDS ON THE GARDEN
ISLE LATER THIS MORNING WITH BRIEF PERIODS OF MVFR CONDITIONS IN
SHOWERS LASTING INTO SATURDAY.
AIRMET SIERRA REMAINS IN EFFECT FOR MOUNTAIN OBSCURATION ABOVE
2000 FEET, THIS AIRMET WILL DIMINISH LATER THIS MORNING. AIRMET
SIERRA MAY NEED TO RETURN FOR KAUAI LATER THIS AFTERNOON.
MARINE
A HIGH PRESSURE RIDGE OVER THE CENTRAL WATERS WILL REMAIN
STATIONARY AS A FRONT APPROACHES FROM THE NORTHWEST. LIGHT TO
GENTLE SOUTHEAST TO SOUTHERLY WINDS WILL RULE OVER THE MARINE
WATERS TODAY. AS THE FRONT DISSIPATES AND ITS REMNANTS LIFT
NORTHWARD, GENTLE EAST TO SOUTHEAST WINDS WILL PREVAIL SATURDAY
AND EARLY SUNDAY, GIVING WAY TO SOUTHERLY WINDS AGAIN LATE SUNDAY.
DUE TO THESE LIGHTER WINDS, LAND AND SEA BREEZES ARE POSSIBLE
THROUGH THE WEEKEND. A STRONGER FRONT WILL MOVE DOWN THE ISLAND
CHAIN MONDAY AND TUESDAY, LIKELY USHERING IN FRESH NORTHERLY WINDS
IN IT WAKE.
SURF ALONG NORTH FACING SHORES WILL REMAIN SMALL AS THE WEST-
NORTHWEST SWELL CONTINUES TO GRADUALLY DECLINE. SURF IS EXPECTED
TO BUILD IN RAPIDLY SATURDAY WITH LONG PERIOD FORERUNNERS
POTENTIALLY REACHING THE OFFSHORE BUYS THIS AFTERNOON. THIS LARGE
LONG PERIOD NORTHWEST NORTHWEST (330 DEGREES) SWELL THAT LIKELY
PEAK SATURDAY EVENING PRODUCING SURF NEAR HIGH SURF WARNING (HSW)
LEVELS ALONG NORTH AND SOME WEST FACING SHORES. SURF WILL REMAIN
ELEVATED ON SUNDAY BEFORE A POTENTIALLY EVEN LARGER LONG PERIOD
NORTHWEST (320-330 DEG) SWELL WILL BUILD THROUGH THE DAY ON MONDAY
AND HOLD THROUGH TUESDAY LIKELY ABOVE THE HSW THRESHOLDS. STAY
TUNED AS THE LOW DEVELOPS. SURF WILL LIKELY REMAIN ELEVATED
THROUGH THE MIDDLE OF NEXT WEEK.
SURF ALONG EAST FACING SHORES WILL CONTINUE TO DECLINE THROUGH THE
WEEKEND AS WINDS OVER AND UPWIND OF HAWAII REMAIN WEAK. SOME
INCREASE IN EAST SHORE SURF IS POSSIBLE EARLY NEXT WEEK. ALONG
SOUTH SHORES, SURF WILL REMAIN VERY SMALL THROUGH THE FORECAST
PERIOD.
HFO WATCHES/WARNINGS/ADVISORIES
NONE.
DISCUSSION...PARKER
AVIATION...BOHLIN
MARINE...SHIGESATO
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