936
FXHW60 PHFO 301931
AFDHFO
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
931 AM HST SAT NOV 30 2024
SYNOPSIS
MODERATE TRADE WINDS WILL CONTINUE TODAY, THEN WEAKEN TONIGHT
THROUGH THE FIRST HALF OF NEXT WEEK. CONDITIONS SHOULD REMAIN
FAIRLY STABLE, WITH LOW CLOUDS AND LIGHT SHOWERS FAVORING INTERIOR
AND MOUNTAIN LOCATIONS. RAIN CHANCES INCREASE MID TO LATE NEXT
WEEK AS A FRONT MOVES SLOWLY ACROSS THE ISLANDS.
DISCUSSION
A BAND OF HIGH CIRRUS CLOUDS IS STREAMING IN FROM WEST TO EAST
ACROSS THE ISLAND CHAIN DUE TO THE PRESENCE OF A SUBTROPICAL JET
STREAM OVER THE AREA. THE LOW-LEVEL CLOUDS LOOK FAIRLY STABLE IN
THE MORNING SATELLITE IMAGERY. UPPER AIR BALLOON SOUNDINGS FROM
LIHUE AND HILO EARLY THIS MORNING SHOW SUBSIDENCE INVERSION HEIGHTS
AROUND 6,000 FEET. THESE STABLE CONDITIONS ALOFT WILL TEND TO LIMIT
CLOUD HEIGHTS AND KEEP THE WINDWARD-FOCUSED SHOWER ACTIVITY IN THE
ISOLATED TO SCATTERED RANGE, WITH MEAGER RAINFALL TOTALS FOR MOST
AREAS THROUGH TONIGHT.
A FRONT APPROACHING FROM THE NORTHWEST WILL STALL AND WEAKEN
NORTHWEST OF THE COASTAL WATERS THIS WEEKEND. OTHERWISE, A WEAK
SUBTROPICAL RIDGE AXIS WILL REMAIN OVER OR NEAR THE ISLANDS WITH
WEAK RIDGING ALOFT THROUGH THE MIDDLE OF NEXT WEEK. WINDS WILL
WEAKEN TONIGHT AND BECOME LIGHT AND VARIABLE OVER MUCH OF THE
STATE SUNDAY INTO MONDAY, THEN REMAIN ON THE LIGHTER SIDE THROUGH
WEDNESDAY. DURING THIS TIME, EXPECT CLOUDS AND SHOWERS TO FOCUS
OVER THE MOUNTAIN AND INTERIOR AREAS OF EACH ISLAND DUE TO SEA
BREEZE DEVELOPMENT DURING THE LATE MORNING/EARLY AFTERNOON EACH
DAY. RAINFALL AMOUNTS WILL BE LIGHT 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.
WHILE THE GFS AND ECMWF STILL DIFFER ON THE SPEED OF THE FRONT,
INCREASED SHOWERS AND BREEZY TRADE WINDS WILL DEVELOP ALONG THE
WEAKENING BOUNDARY AS IT PROGRESSES EASTWARD. ALL ISLANDS WILL
LIKELY BENEFIT FROM A PERIOD OF ENHANCED SHOWERS ALONG THE FRONTAL
BAND, ESPECIALLY ALONG THE WINDWARD MOUNTAIN SLOPES. BOTH MODELS
HAVE THE FRONT STALLING OUT NEAR MAUI BY FRIDAY MORNING AND BREAKING
UP/DISSIPATING BY THE AFTERNOON, WITH REMNANT UNSTABLE CLOUD BANDS
DRIFTING INTO EACH ISLAND ON THE STRENGTHENING EASTERLY TRADE WINDS.
THE GLOBAL MODELS BOTH INDICATE ANOTHER FRONT APPROACHING THE STATE
FROM THE NORTHWEST SATURDAY NIGHT INTO SUNDAY, UNCERTAINTY REMAINS
WHETHER THE BOUNDARY MAKES IT TO THE ISLANDS BEFORE DISSIPATING.
AVIATION
LIGHT TO LOCALLY MODERATE TRADES WILL CONTINUE TO WEAKEN THROUGH
THE WEEKEND, ALLOWING FOR LOCALIZED LAND/SEA BREEZE DEVELOPMENT
TODAY THAT WILL BECOME MORE WIDESPREAD TOMORROW. ISOLATED TO
SCATTERED LIGHT SHOWERS WILL FAVOR WINDWARD AND MOUNTAIN AREAS
OVERNIGHT, THEN SEA BREEZES WILL BRING CLOUDS AND ISOLATED SHOWERS
TO SOME ISLAND INTERIORS IN THE AFTERNOON. MVFR CONDITIONS WILL
BE POSSIBLE IN SHOWERS, OTHERWISE, VFR CONDITIONS WILL PREVAIL.
AIRMET TANGO IS IN EFFECT FOR MODERATE TURBULENCE BETWEEN FL250
AND FL450 ACROSS THE STATE.
SIGMET PAPA FOR SEVERE UPPER LEVEL TURBULENCE IS ALSO IN EFFECT
ACROSS THE STATE.
MARINE
A FRONT APPROACHING FROM THE NORTHWEST WILL STALL AND WEAKEN
NORTHWEST OF THE COASTAL WATERS THIS WEEKEND. LIGHT BACKGROUND
FLOW WILL SHIFT TO SOUTHEASTERLIES BY SUNDAY. ANOTHER FRONT WILL
APPROACH FROM THE NORTHWEST EARLY NEXT WEEK WILL KEEP GENTLE SOUTH
TO SOUTHEAST WINDS IN PLACE.
AN EXTRA-LARGE NORTHWEST (310-320) SWELL THAT PEAKED WELL ABOVE
GUIDANCE OVERNIGHT IS BEGINNING TO DECLINE TODAY. HOWEVER, THIS
SWELL WILL CONTINUE TO GENERATE SURF HEIGHTS IN EXCESS OF WARNING
THRESHOLDS ALONG AFFECTED NORTH AND WEST FACING SHORES THROUGH
TODAY. A HIGH SURF WARNING (HSW) REMAINS IN EFFECT THROUGH 6PM HST
THIS EVENING FOR MOST NORTH AND WEST-FACING SHORES OF THE SMALLER
ISLANDS, AND FOR WEST FACING SHORES OF THE BIG ISLAND. EXPECT
PERIODIC OVERTOPPING OF VULNERABLE COASTAL ROADWAYS AND WAVE RUNUP
TO COASTAL PROPERTIES. A GRADUAL DOWNWARD TREND WILL CONTINUE
THROUGH THIS WEEKEND AND SURF SHOULD DECREASE BELOW ADVISORY
THRESHOLDS DURING THE DAY ON SUNDAY. IN ADDITION, A SMALL CRAFT
ADVISORY (SCA) REMAINS IN EFFECT FOR MOST COASTAL WATERS FOR SEAS
GREATER THAN 10 FT. THIS SCA IS EXPECTED TO HOLD THROUGH THE REST
OF TODAY.
LOOKING AHEAD TO NEXT WEEK, A STRETCH OF ELEVATED NORTH AND WEST
SHORE SURF IS EXPECTED, PRODUCED BY OVERLAPPING NORTHWEST PULSES
RANGING FROM LARGE TO POTENTIALLY EXTRA-LARGE WITH THE FIRST
ARRIVING TUESDAY AND A LARGER ONE PEAKING WEDNESDAY INTO THURSDAY.
SURF ALONG EAST FACING SHORES WILL REMAIN SLIGHTLY ELEVATED THROUGH
THE WEEKEND DUE TO THE LINGERING SHORT-PERIOD NORTH-NORTHEAST SWELL.
EARLY NEXT WEEK, SURF ALONG EAST FACING SHORES WILL REMAIN SMALL.
SURF ALONG SOUTH FACING SHORES WILL SEE AN UPTICK HEADING INTO
NEXT WEEK FROM A SERIES OF CONSECUTIVE SOUTHWEST PULSES. THIS WILL
RESULT IN SMALL TO MODERATE SURF, PEAKING MONDAY AND TUESDAY.
FIRE WEATHER
CRITICAL FIRE WEATHER CONDITIONS ARE NOT EXPECTED THROUGH NEXT
WEEK AS WINDS REMAIN BELOW WARNING THRESHOLDS. DAYTIME RELATIVE
HUMIDITY MAY BRIEFLY TOUCH CRITICAL LEVELS OVER THE DRIER LEEWARD
AREAS INTO EARLY NEXT WEEK, BEFORE INCREASING WITH THE ARRIVAL OF
A FRONT MOVING THROUGH THE STATE DURING THE SECOND HALF OF THE
WEEK.
HFO WATCHES/WARNINGS/ADVISORIES
HIGH SURF WARNING UNTIL 6 PM HST THIS EVENING FOR NIIHAU-KAUAI
LEEWARD-WAIANAE COAST-OAHU NORTH SHORE-MAUI WINDWARD WEST-KONA-
KOHALA-KAUAI NORTH-KOOLAU WINDWARD-MOLOKAI WINDWARD-MOLOKAI
NORTH-MOLOKAI WEST-WINDWARD HALEAKALA.
SMALL CRAFT ADVISORY UNTIL 6 PM HST THIS EVENING FOR ALL
HAWAIIAN WATERS EXCEPT MAALAEA BAY-
DISCUSSION...TS
AVIATION...FARRIS
MARINE...VAUGHAN
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page