819
FXHW60 PHFO 020641
AFDHFO
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
841 PM HST SUN DEC 1 2024
SYNOPSIS
DRY AND STABLE CONDITIONS WILL PERSIST THROUGH MID WEEK WITH LIGHT
WINDS THAT WILL ALLOW FOR SEA BREEZES EACH DAY AND LAND BREEZES
OVERNIGHT. A COLD FRONT WILL MOVE THROUGH THE WESTERN END OF THE
STATE ON THURSDAY AND THEN DISSIPATE ACROSS MAUI COUNTY,
INCREASING THE CHAIN OF RAIN AHEAD OF AND ALONG THE FRONTAL
BOUNDARY AND BRINGING MODERATE TO BREEZY NORTHEAST WINDS IN ITS
WAKE. FORECAST DETAILS FOR NEXT WEEKEND BECOME A BIT MURKY DUE TO
SIGNIFICANT MODEL DIFFERENCES.
DISCUSSION
DRY AND STABLE CONDITIONS WILL CONTINUE THROUGH THE FIRST HALF OF
THE WEEK AS RIDGING ALOFT AND AT THE SURFACE DOMINATE AND MOISTURE
REMAINS LIMITED. UPPER AIR SOUNDINGS FROM THIS AFTERNOON AT HILO
AND LIHUE CONFIRM THESE CONDITIONS WITH TEMPERATURE INVERSION
HEIGHTS AROUND 5000 FEET AND PRECIPITABLE WATER VALUES ONLY NEAR
AN INCH. THE ORIENTATION OF A SURFACE RIDGE CENTERED TO THE EAST-
NORTHEAST OF HAWAII ALONG WITH A COLD FRONT APPROACHING FROM THE
NORTHWEST (CURRENTLY NEAR MIDWAY THIS EVENING) HAVE BROUGHT LIGHT
TO LOCALLY MODERATE SOUTHEAST WINDS TO THE STATE TODAY AND THESE
LIGHTER SOUTHERLY WINDS WILL BE MAINTAINED THROUGH WEDNESDAY,
AHEAD OF THE FRONT. THIS LIGHTER FLOW WILL ALLOW FOR THE
DEVELOPMENT OF AFTERNOON SEA BREEZES THAT WILL BRING CLOUDS AND
ISOLATED SHOWERS OVER ISLAND INTERIORS AND FOR OVERNIGHT LAND
BREEZES THAT WILL HELP TO CLEAR OUT THESE INTERIOR CLOUDS AND
SHOWERS.
THE AFOREMENTIONED COLD FRONT IS EXPECTED TO REACH KAUAI'S
DOORSTEP SOMETIME LATE WEDNESDAY NIGHT INTO THURSDAY MORNING, WITH
DECENT AGREEMENT AMONGST THE DETERMINISTIC GFS AND ECMWF IN THIS
TIMING. SOME PREFRONTAL MOISTURE LOOKS TO STREAM ACROSS THE
WESTERN HALF OF THE STATE ON WEDNESDAY, POSSIBLY BRINGING A
LITTLE BOOST TO THE DIURNAL SEA BREEZE SHOWERS. THEN RAIN CHANCES
WILL INCREASE ALONG THE FRONTAL BOUNDARY AS IT MOVES DOWN THE
ISLAND CHAIN ON THURSDAY AND DISSIPATES SOMEWHERE IN THE VICINITY
OF MAUI COUNTY. MODERATE TO BREEZY NORTHEAST WINDS WILL FILL IN
BEHIND THE FRONT ON THURSDAY, THEN MODERATE EASTERLY TRADES WILL
PERSIST FRIDAY INTO SATURDAY MORNING WITH HIGH PRESSURE DOMINATING
TO THE FAR NORTHEAST.
THE FORECAST DETAILS BECOME A BIT MURKIER SATURDAY AND BEYOND AS
THE GLOBAL MODEL SOLUTIONS BEGIN TO DIVERGE MORE SIGNIFICANTLY.
THE GFS HAS A FAIRLY POTENT COLD FRONT BARGE THROUGH THE ISLAND
CHAIN SATURDAY NIGHT INTO SUNDAY AND USHER IN MUCH DRIER AIR
ACROSS THE STATE WITH BREEZY NORTHERLY WINDS, WHEREAS THE ECMWF
MAINTAINS A FAIRLY WET MODERATE TO BREEZY EASTERLY TRADE WIND
PATTERN THROUGH THE WEEKEND. NEEDLESS TO SAY, FORECAST CONFIDENCE
SATURDAY AND BEYOND IS ON LOWER SIDE RIGHT NOW.
AVIATION
A STUBBORN RIDGE OF HIGH PRESSURE TO THE NORTHEAST OF THE STATE
WILL KEEP TRADE WINDS AT BAY THROUGH MOST OF THE WEEK. LOW LEVEL
FLOW WILL REMAIN WEAK BUT SUFFICIENT TO STEER OCCASIONAL BANDS OF
LIGHT SHOWERS TOWARDS SOUTH AND EAST FACING COASTS OF THE BIG
ISLAND AND MAUI. ELSEWHERE, DAYTIME SEA BREEZES AND NIGHTTIME LAND
BREEZES WILL DRIVE LOCAL WEATHER PATTERNS. EXPECT CUMULUS BUILD-
UPS OVER ISLAND INTERIORS DURING THE AFTERNOON AND EARLY EVENING
HOURS. CLEAR SKIES WILL PREVAIL OVERNIGHT, ESPECIALLY ALONG WEST
AND NORTHWEST FACING SLOPES AND COASTS.
NO AIRMETS ARE IN EFFECT OR ANTICIPATED AT THIS TIME.
MARINE
A FRONT APPROACHING FROM THE NORTHWEST HAS SHIFTED A RIDGE OF HIGH
PRESSURE OVER THE STATE WHICH WILL MAINTAIN GENTLE SOUTH TO
SOUTHEAST WINDS THROUGH WEDNESDAY AS THE FRONT PASSES NORTH OF THE
STATE. A SECOND FRONT MAY MOVE INTO THE NORTHWEST OFFSHORE BOUNDARY
WEDNESDAY AND THEN MOVE DOWN THE STATE THROUGH THURSDAY BEFORE
STALLING AND DISSIPATING FRIDAY. NORTHERLY WINDS BEHIND THE FRONT
WILL QUICKLY BECOME NORTHEASTERLY AS THE FRONT DISSIPATES AND A
WEAK HIGH DEVELOPS NORTHWEST OF THE STATE.
THE CURRENT NORTHWEST (310-320 DEGREE) SWELL IS EXPECTED TO
CONTINUE TO SLOWLY DECLINE THROUGH MONDAY. A SERIES OF NORTHWEST
SWELLS GENERATED BY A COMPLEX GALE LOW SYSTEM SOUTH OF THE
ALEUTIAN ISLANDS WILL KEEP SURF ELEVATED ALONG NORTH AND WEST
FACING SHORES THROUGHOUT THE WEEK. A MODERATE, MEDIUM PERIOD
NORTHWEST (320-330 DEGREE) IS EXPECTED TO FILL IN MONDAY AFTERNOON
AND PEAK MONDAY NIGHT. A SECOND, OVERLAPPING MODERATE, AND
SLIGHTLY LONGER PERIOD NORTHWEST SWELL IS EXPECTED TO FILL IN
TUESDAY MORNING. SURF HEIGHTS ARE ANTICIPATED TO PEAK NEAR OR JUST
BELOW ADVISORY LEVELS TUESDAY NIGHT THEN HOLDING JUST BELOW
ADVISORY LEVELS THROUGH WEDNESDAY. A COUPLE OF LARGER NORTHWEST
SWELLS (310-330 DEGREE)MAY FURTHER BOOST SURF WELL ABOVE ADVISORY
LEVELS LATER IN THE WEEK THURSDAY INTO FRIDAY.
ANOTHER OUT OF SEASON LONG PERIOD, SMALL SOUTH SWELL IS STARTING
TO SHOW UP ALONG NEAR SHORE BUOYS AND SHOULD CONTINUE TO FILL
TONIGHT AND PEAK MONDAY, GENERATING NEAR SUMMERTIME AVERAGE SURF
ALONG SOUTH FACING SHORES BEFORE SLOWLY TRENDING DOWN THROUGH
WEDNESDAY. AN ADDITIONAL SOUTH PULSE IS EXPECTED SLOWLY FILL IN
DURING THE SECOND HALF OF THE WEEK INTO THE WEEKEND.
SURF ALONG EAST FACING SHORES WILL DECLINE AS A LINGERING SMALL,
SHORT PERIOD NORTH-NORTHEAST SWELL FADES THROUGH MONDAY AND WIND
SWELLS REMAIN SMALL DUE TO LIGHT WINDS DURING THE FIRST HALF OF
THE WEEK.
FIRE WEATHER
CRITICAL FIRE WEATHER CONDITIONS ARE NOT EXPECTED THROUGH NEXT
WEEK. EVEN THOUGH DAYTIME RELATIVE HUMIDITY VALUES MAY BRIEFLY
TOUCH CRITICAL LEVELS EARLY THIS WEEK, WINDS WILL REMAIN LIGHT
AND PRECLUDE ANY FIRE WEATHER CONCERNS. INCREASING MOISTURE AND
RAINFALL TRENDS WILL DEVELOP THURSDAY INTO NEXT WEEKEND AS A
WEAKENING COLD FRONT MOVES DOWN THE ISLAND CHAIN, THEN DISSIPATES
NEAR MAUI COUNTY.
HFO WATCHES/WARNINGS/ADVISORIES
NONE.
DISCUSSION/FIRE WEATHER...FARRIS
AVIATION...BEDAL
MARINE...ALMANZA
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