945
FXHW60 PHFO 011938
AFDHFO
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
938 AM HST SUN DEC 1 2024
SYNOPSIS
LIGHTER LARGE-SCALE WINDS WILL ALLOW LAND AND SEA BREEZES TO OCCUR
OVER ALL ISLANDS. EXPECT FAIRLY DRY AND STABLE CONDITIONS THROUGH
WEDNESDAY, WITH LOW CLOUDS AND A FEW LIGHT SHOWERS EACH AFTERNOON
FAVORING ISLAND INTERIOR AND MOUNTAIN AREAS. RAINFALL TRENDS WILL
INCREASE THURSDAY INTO FRIDAY AS A WEAK COLD FRONT MOVES INTO AND
STALLS OUT OVER THE ISLANDS. PERIODS OF PASSING SHOWERS AND MODERATE
TO LOCALLY BREEZY TRADES WILL LINGER INTO NEXT WEEKEND.
DISCUSSION
WINDS HAVE DECREASED AND TURNED SOUTHEASTERLY THIS MORNING. THIS
IS EVIDENT ON THE FIRST-LIGHT VISIBLE SATELLITE IMAGERY WITH MOSTLY
CLEAR ISLAND INTERIORS, AND BANDS OF STABLE CLOUDS OVER THE WATER
AND MOVING INTO SOUTHEAST FACING AREAS OF THE BIG ISLAND. THE
OVERNIGHT BALLOON SOUNDINGS FROM LIHUE AND HILO SHOW PRECIPITABLE
WATER VALUES OF 0.9 INCHES, WHICH IS WELL BELOW THE AVERAGE OF
AROUND 1.25 INCHES FOR THIS TIME OF YEAR. WITH THE CLEAR AND DRY
CONDITIONS IN PLACE, MANY LOCATIONS EXPERIENCED A QUITE COOL NIGHT
WITH MORNING LOWS NEARING THE DAILY RECORD IN A COUPLE OF SPOTS.
A LIGHT AND VARIABLE WIND PATTERN WILL BEGIN TODAY, WITH EXPANDING
LAND AND SEA BREEZES OVER ALL ISLANDS THROUGH WEDNESDAY.
THE UPPER-LEVEL SUBTROPICAL RIDGE AXIS WILL LINGER JUST SOUTH OF
THE STATE THROUGH WEDNESDAY KEEPING FAIRLY STABLE WEATHER IN THE
FORECAST TO GO WITH THE LIGHT WINDS. EXPECT CLOUDS AND A FEW
LIGHT SHOWERS TO DEVELOP BY LATE MORNING/AFTERNOON OVER ISLAND
MOUNTAIN AND INTERIOR SECTIONS AS THE SEA BREEZES KICK IN EACH
DAY, FOLLOWED BY CLEARING IN THE OVERNIGHT HOURS WITH THE LAND
BREEZES. RAINFALL AMOUNTS WILL REMAIN ON THE LIGHTER SIDE DUE TO
THE LARGE-SCALE ATMOSPHERIC STABILITY.
BY THURSDAY, LONG-RANGE MODEL GUIDANCE CONTINUES TO SHOW A SHALLOW
COLD FRONT CREEPING INTO THE WESTERN ISLANDS FROM THE NORTHWEST.
WIDESPREAD SHOWERS AND BREEZY TRADE WINDS WILL DEVELOP ALONG THE
WEAKENING FRONTAL BOUNDARY AS IT PASSES THROUGH EACH ISLAND. THE
LATEST GUIDANCE CONTINUES TO SHOW THIS FRONTAL CLOUD AND SHOWER
BAND STALLING OUT NEAR MAUI BY FRIDAY MORNING. ALL ISLANDS WILL
BENEFIT FROM A PERIOD OF ENHANCED SHOWERS WITH THIS FEATURE,
ESPECIALLY ALONG THE WINDWARD AND MOUNTAIN SLOPES. THE FRONT WILL
THEN BREAK APART BY FRIDAY AFTERNOON, WITH REMNANT UNSTABLE
CLOUD/SHOWER BANDS DRIFTING INTO THE ISLANDS ON THE STRENGTHENING
EASTERLY TRADE WINDS THROUGH MUCH OF NEXT WEEKEND.
AVIATION
LIGHT SOUTHEAST BACKGROUND FLOW WILL ALLOW THE DEVELOPMENT OF
AFTERNOON SEA BREEZES AND INTERIOR CLOUDS FOLLOWED BY LAND BREEZES
AND CLEARING FOR MOST OF THE ISLANDS TONIGHT. VFR CONDITIONS WILL
PREVAIL. LOW CLOUDS AND BRIEF MOUNTAIN OBSCURATIONS MAY OCCUR
ALONG THE WINDWARD AND SOUTHEAST BIG ISLAND LATER TODAY, BUT NO
AIRMETS ARE IN EFFECT OR ANTICIPATED TODAY.
MARINE
LIGHT BACKGROUND FLOW WILL SHIFT TO SOUTHEASTERLIES TODAY. A
FRONT WILL APPROACH FROM THE NORTHWEST OVER THE NEXT COUPLE OF
DAYS AND KEEP GENTLE SOUTH TO SOUTHEAST WINDS IN PLACE.
THE CURRENT NORTHWEST (310-320) SWELL CONTINUES TO SLOWLY DECLINE
TODAY, BUT A HIGH SURF ADVISORY (HSA) REMAINS IN EFFECT FOR
AFFECTED NORTH AND WEST FACING SHORES OF THE SMALLER ISLANDS
(ONLY NORTH FACING SHORES OF MAUI) THROUGH NOON AS SURF GRADUALLY
EASES IN RESPONSE. SURF SHOULD DROP BELOW ADVISORY LEVELS
EVERYWHERE BY THIS AFTERNOON, BUT WILL SEE ADDITIONAL BOOSTS
LATER THIS WEEK AS THE FIRST OF SEVERAL OVERLAPPING NORTHWEST
SWELLS, RANGING FROM LARGE TO POTENTIALLY EXTRA-LARGE, ARRIVES
TUESDAY. A LARGER ONE IS EXPECTED TO PEAK WEDNESDAY INTO THURSDAY.
SURF ALONG SOUTH FACING SHORES WILL SEE A SLIGHT BOOST OVER THE
NEXT COUPLE OF DAYS FROM A SERIES OF CONSECUTIVE SOUTHWEST PULSES.
SMALL TO MODERATE SOUTH SHORE SURF CAN BE EXPECTED, PEAKING
MONDAY AND TUESDAY. AFTER DECLINING ON WEDNESDAY AND THURSDAY, AN
ADDITIONAL SOUTH PULSE IS EXPECTED NEAR THE END OF THE WEEK.
SURF ALONG EAST FACING SHORES WILL REMAIN SLIGHTLY ELEVATED
THROUGH TODAY DUE TO A LINGERING SHORT-PERIOD NORTH-NORTHEAST
SWELL, BUT WILL DECLINE AND REMAIN SMALL FOR THE REST OF THE WEEK.
FIRE WEATHER
CRITICAL FIRE WEATHER CONDITIONS ARE NOT EXPECTED THROUGH NEXT
WEEK, AS WINDS WILL REMAIN WELL BELOW THE RED FLAG WARNING
THRESHOLD THROUGH THURSDAY. DAYTIME RELATIVE HUMIDITY MAY BRIEFLY
TOUCH CRITICAL LEVELS OVER THE DRIER LEEWARD AREAS INTO EARLY
NEXT WEEK. HOWEVER, INCREASING MOISTURE AND RAINFALL TRENDS WILL
DEVELOP THURSDAY INTO NEXT WEEKEND AS A WEAKENING COLD FRONT MOVES
DOWN THE ISLAND CHAIN, THEN STALLS AND BREAKS UP NEAR MAUI.
HFO WATCHES/WARNINGS/ADVISORIES
HIGH SURF ADVISORY UNTIL NOON HST TODAY FOR NIIHAU-KAUAI LEEWARD-
WAIANAE COAST-OAHU NORTH SHORE-MAUI WINDWARD WEST-KAUAI NORTH-
KOOLAU WINDWARD-MOLOKAI WINDWARD-MOLOKAI NORTH-MOLOKAI WEST-
WINDWARD HALEAKALA.
DISCUSSION...TS
AVIATION...FOSTER
MARINE...VAUGHAN
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