999
FXHW60 PHFO 271349
AFDHFO
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
349 AM HST WED NOV 27 2024
SYNOPSIS
STABLE AND RATHER DRY NORTHERLY WINDS WILL SHIFT OUT OF THE
NORTHEAST ON WEDNESDAY, PRODUCING LIMITED SHOWERS OVER MAINLY
NORTH AND WINDWARD SLOPES. WINDS WILL STRENGTHEN A BIT AND SHIFT
FROM A MORE EASTERLY TRADE WIND DIRECTION FROM THURSDAY INTO
SATURDAY. EXPECT A FEW MORE CLOUDS AND BRIEF PASSING OVERNIGHT TO
EARLY MORNING SHOWERS, MAINLY OVER WINDWARD AND MOUNTAIN AREAS AS
THE TRADE WINDS RETURN. TRADE WINDS WILL DECLINE SUNDAY AND WILL
BE DISRUPTED EARLY NEXT WEEK.
DISCUSSION
THE LEADING EDGE OF A RETURN TO MODERATE TRADE WINDS SHOWS UP ON
THIS MORNINGS SATELLITE IMAGERY AND LOCAL RADAR AS A SURFACE
TROUGH WITH A NARROW CLOUD BAND MOVING IN FROM THE NORTH INTO THE
ISLANDS OF MOLOKAI AND MAUI AT 3:30 AM HST. BASED ON THE MOTION OF
THIS CLOUD BAND AND ASCAT SCATTEROMETRY SATELLITE DATA,
NORTHEASTERLY WINDS AROUND 15 TO 20 MPH WILL DEVELOP AS THIS
CONVERGENCE BOUNDARY WASHES THROUGH EACH ISLAND THROUGH THE
MORNING HOURS. A BRIEF BOOST IN CLOUDS AND A FEW SHOWERS WILL
DEVELOP AS THIS WIND SPEED CONVERGENCE BOUNDARY SWIFTLY PASSES
THROUGH EACH ISLAND.
OUTSIDE OF THE SLIGHT BOOST IN CLOUDS AND FEW SHOWERS ALONG THE
APPROACHING SURFACE TROUGH, WE EXPECT THE STRONG SUBSIDENCE ALOFT
WILL KEEP TEMPERATURE INVERSION HEIGHTS IN THE ROUGHLY 4,000 TO
5,000 FOOT RANGE THROUGH TONIGHT, AND THEN AROUND THE 5,000 TO
7,000 FOOT RANGE THEREAFTER. RESULTING IN LIMITED LOW CLOUDS IN
THIS STABLE PATTERN WITH MOSTLY ISOLATED TO SCATTERED RAINFALL
COVERAGE OVER THE WINDWARD MOUNTAIN PEAKS OF EACH ISLAND, NEAR
ZERO CHANCES FOR RAINFALL ELSEWHERE. RELATIVELY DRY MOISTURE
LEVELS ACROSS THE STATE WILL ALLOW FOR INCREASED RADIATIONAL
COOLING (RELEASING HEAT INTO SPACE),RESULTING IN BELOW NORMAL
OVERNIGHT TO EARLY MORNING TEMPERATURES STATEWIDE THROUGH
THURSDAY MORNING.
TRADE WINDS WILL INCREASE SLIGHTLY AND VEER FROM A MORE EASTERLY
DIRECTION FROM THURSDAY INTO THE WEEKEND ALLOWING FOR A SMALL
INCREASE TO HUMIDITY LEVELS. OVERALL ATMOSPHERIC CONDITIONS WILL
REMAIN FAIRLY STABLE AND DRY WEATHER TRENDS WILL CONTINUE INTO THE
UPCOMING WEEKEND.
TRADE WINDS WILL TRANSITION TO LIGHT WINDS WITH LAND AND SEA
BREEZES NEXT WEEK FROM SUNDAY THROUGH NEXT WEDNESDAY WITH LIMITED
CLOUDS AND SHOWERS AS THE HIGH PRESSURE RIDGE WEAKENS DUE TO AN
APPROACHING COLD FRONT. THE NEXT BEST CHANCE FOR MORE WIDESPREAD
RAINFALL WILL DEVELOP BY NEXT WEEK THURSDAY AS A WEAKENING COLD
FRONT MOVES INTO THE HAWAIIAN ISLANDS FROM THE NORTHWEST WITH THE
LATEST MODEL PROJECTIONS SHOWING THE FRONTAL BAND STALLING OUT
SOMEWHERE BETWEEN THE WESTERN ISLANDS OF KAUAI AND OAHU. RAINFALL
WITH THIS WEAKENING FRONT WILL MAINLY FALL ALONG THE FRONTAL ZONE.
HOW FAR EASTWARD DOWN THE ISLAND CHAIN IS LESS CERTAIN AT THIS
POINT IN TIME.
AVIATION
LIGHT NORTH- NORTHEAST WINDS WILL PREVAIL THROUGH THE FORECAST
PERIOD AND GIVE WAY TO LOCALIZED SEA BREEZES AND LAND BREEZES IN
THE MOST SHELTERED AREAS. SHOWER ACTIVITY ESSENTIALLY NIL THROUGH
THE AFTERNOON.
NO AIRMETS IN EFFECT.
MARINE
LIGHT TO MODERATE NORTH TO NORTHEAST WINDS WILL VEER OUT OF THE
NORTHEAST AND INCREASE INTO THE MODERATE TO FRESH CATEGORY TODAY,
THEN OUT OF THE EAST-NORTHEAST THROUGH THE SECOND HALF OF THE
WEEK AS HIGH PRESSURE BUILDS NORTH OF THE AREA. WINDS MAY EASE
NEXT WEEKEND AND INTO EARLY NEXT WEEK WITH A POTENTIAL FRONT
PASSING TO THE NORTH. SEAS WILL POTENTIALLY EXCEED THE 10 FT SMALL
CRAFT ADVISORY LEVEL FRIDAY THROUGH SATURDAY FOR WATERS EXPOSED
TO LARGE WEST-NORTHWEST SWELLS.
SURF ALONG EXPOSED NORTH AND WEST FACING SHORES WILL REMAIN SMALL
THROUGH THURSDAY, DUE TO A MIX OF A MEDIUM-PERIOD NORTH-NORTHWEST
SWELL AND A LINGERING, SHORTER PERIOD NORTH-NORTHEAST SWELL. A
DEVELOPING HURRICANE FORCE LOW AROUND 1500 NM NORTHWEST OF THE
ISLANDS WILL SEND A LARGE, LONG-PERIOD WEST-NORTHWEST SWELL
THROUGH THE AREA FRIDAY INTO THE WEEKEND, POTENTIALLY DRIVING SURF
HEIGHTS TO WARNING LEVELS LATE FRIDAY INTO EARLY SATURDAY AS IT
PEAKS. A GRADUAL DOWNWARD TREND WILL FOLLOW OVER THE WEEKEND, WITH
SURF POTENTIALLY DIPPING BELOW THE ADVISORY LEVELS BY THE END OF
THE WEEKEND.
SURF ALONG EAST FACING SHORES WILL REMAIN UP THROUGH THE WEEKEND
DUE TO THE LINGERING SHORT-PERIOD NORTH-NORTHEAST SWELL AND A
SHORT-PERIOD NORTHEAST SWELL EXPECTED LATE THURSDAY THROUGH THE
WEEKEND. HEIGHTS WILL PEAK FRIDAY INTO THE WEEKEND BELOW THE
ADVISORY LEVEL AS THIS NORTHEAST SWELL ARRIVES AND PEAKS.
SURF ALONG SOUTH FACING SHORES WILL REMAIN NEAR SEASONAL AVERAGES
THIS WEEK, DRIVEN BY A MIX OF SHORT-PERIOD SOUTHEAST AND
BACKGROUND LONG PERIOD SOUTH-SOUTHWEST SWELLS. AN UPWARD TREND IS
EXPECTED THIS WEEKEND THROUGH THE FIRST WEEK OF DECEMBER, DUE TO
AN ACTIVE PATTERN EVOLVING WITHIN OUR SWELL WINDOW NEAR NEW
ZEALAND.
FIRE WEATHER
WE DO NOT FORESEE ANY CRITICAL FIRE WEATHER CONDITIONS DEVELOPING
THROUGH THE FIRST HALF OF NEXT WEEK AS WIND SPEEDS WILL REMAIN
BELOW CRITICAL THRESHOLDS. DRY RELATIVE HUMIDITY LEVELS MAY
BRIEFLY TOUCH FIRE WEATHER CRITERIA OVER DRIER LEEWARD ZONES THIS
WEEK.
HFO WATCHES/WARNINGS/ADVISORIES
NONE.
DISCUSSION/FIRE WEATHER...BOHLIN
AVIATION...SHIGESATO
MARINE...GIBBS
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