385
FXHW60 PHFO 011300
AFDHFO
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
300 AM HST SUN JUN 1 2025
SYNOPSIS
MODERATE TO LOCALLY BREEZY EAST-SOUTHEAST TRADES WILL HOLD IN
PLACE THROUGH MONDAY, AS A BROAD SURFACE TROUGH DEVELOPS TO THE
WEST OF THE STATE. A DISTURBANCE ALOFT MAY ENHANCE THE TRADE
SHOWERS A BIT DURING THIS TIME, WITH SHOWERS FAVORING EAST AND
SOUTHEAST FACING SLOPES AND COASTS AT NIGHT, AND LEEWARD AREAS
EACH AFTERNOON. THE TROUGH WILL DAMPEN OUT AND SHIFT WESTWARD
MONDAY NIGHT AND TUESDAY, BRINGING A RETURN OF MODERATE TO
LOCALLY BREEZY EAST-NORTHEAST TRADES, AND A WINDWARD AND MAUKA
FOCUSED SHOWER PATTERN. THIS PATTERN WILL HOLD IN PLACE THROUGH
THE REMAINDER OF THE WORK WEEK, WITH THE TRADES POTENTIALLY
EASING NEXT WEEKEND.
DISCUSSION
CURRENTLY AT THE SURFACE, A STRONG 1037 MB HIGH IS CENTERED
AROUND 2000 MILES NORTH-NORTHEAST OF HONOLULU, WITH A WEAKENING
COLD FRONT AROUND 1000 MILES WEST-NORTHWEST OF KAUAI. CLOSER TO
THE ISLANDS, A TROUGH OF LOW PRESSURE IS DEVELOPING AROUND 200
MILES WEST OF THE GARDEN ISLE. THE LOW-LEVEL TRADE FLOW IS
RESPONDING TO THE DEVELOPING TROUGH, SHIFTING EAST-SOUTHEAST AT
MODERATE SPEEDS IN AREAS NOT SHELTERED BY TERRAIN. INFRARED
SATELLITE IMAGERY SHOWS INCREASING HIGH CLOUDS MOVING OVERHEAD,
ALONG WITH LOWER CLOUDS MOVING ALONG WITH THE TRADES. OVERALL,
PARTLY TO MOSTLY CLOUDY CONDITIONS PREVAIL ACROSS THE STATE EARLY
THIS MORNING. RADAR IMAGERY SHOWS SCATTERED TO NUMEROUS SHOWERS
MOVING INTO EAST AND SOUTHEAST FACING SLOPES AND COASTS, WITH A
FEW SHOWERS ALSO AFFECTING PORTIONS OF LEEWARD OAHU AND LEEWARD
BIG ISLAND. MAIN SHORT TERM FOCUS REVOLVES AROUND TRADE WIND
TRENDS AND THERE IMPACT ON RAIN CHANCES DURING THE NEXT COUPLE
DAYS.
STRONG HIGH PRESSURE WILL REMAIN FAR TO THE NORTH-NORTHEAST OF THE
STATE THROUGH MONDAY, WHILE THE FRONT AND TROUGH MERGE INTO A
BROAD TROUGH A FEW HUNDRED MILES WEST OF THE ISLAND CHAIN. THIS
WILL KEEP MODERATE TO LOCALLY BREEZY EAST-SOUTHEASTERLY TRADES
BLOWING, WITH SOME TERRAIN SHELTERED LEEWARD AREAS EXPERIENCING
SEA AND LAND BREEZES. SHOWERS WILL FAVOR EAST AND SOUTHEAST FACING
SLOPES AND COASTS, PARTICULARLY AT NIGHT AND DURING THE MORNIGN
HOURS, WHILE LEEWARD AREAS SEE SOME SHOWER DEVELOPMENT WITH THE
ASSISTANCE OF SEA BREEZES EACH AFTERNOON. MEANWHILE, TROUGHING
ALOFT TO THE WEST OF THE STATE MAY ALLOW FOR A SLIGHT ENHANCEMENT
TO THE SHOWER ACTIVITY, WHILE ALSO BRINGING CONSIDERABLE HIGH
CLOUDINESS TO THE REGION.
THE BROAD TROUGH WEST OF THE STATE WILL DAMPEN OUT AND SHIFT
WESTWARD MONDAY NIGHT AND TUESDAY. THIS WILL BRING A RESURGENCE OF
MODERATE TO LOCALLY BREEZY EAST-NORTHEASTERLY TRADE WINDS, AND
A MORE TYPICAL WINDWARD AND MAUKA FOCUSED SHOWER PATTERN. THIS
PATTERN WILL THEN CHANGE LITTLE THROUGH THE REMAINDER OF THE WORK
WEEK, AS STRONG HIGH PRESSURE PERSISTS TO THE NORTHEAST OF THE
STATE. THE TRADES MAY EASE UP AND SHIFT EAST-SOUTHEASTERLY AGAIN
NEXT WEEKEND AS ANOTHER TROUGH DEVELOPS WEST OF THE AREA. DETAILS
ON THIS REMAIN UNCLEAR HOWEVER, WITH THE MODELS SPLIT ON HOW CLOSE
THIS NEXT TROUGH MANAGES TO GET TO THE ISLANDS CHAIN.
AVIATION
BREEZY EAST-SOUTHEASTERLY TRADES EXPECTED TODAY. LOW CIGS AND
SHRA SHOULD STILL HAVE WINDWARD AND MAUKA IMPACTS WITH LEEWARD
AREAS GETTING IN ON A FEW SHRA AS WELL. MVFR CONDS CAN BE EXPECTED
IN HEAVIER SHRA, OTHERWISE VFR PREVAILS. LLWS IS EXP THIS
AFTERNOON AT HOG.
AIRMET SIERRA IS IN EFFECT FOR MTN OBSC FOR N THRU SE SECTIONS OF
ALL ISLANDS. CONDS SHOULD IMPROVE IN THE MORNING HOURS.
AIRMET TANGO IS IN EFFECT FOR MOD TURB OF ALL ISLANDS DOWNWIND OF
ISLAND TERRAIN. WITH WINDS VEERING SE EXP TURB TO MOVE TO THE
NORTHWEST OF THE ISLANDS.
MARINE
MODERATE TO LOCALLY STRONG EAST-SOUTHEAST TRADE WINDS WILL PREVAIL
THROUGH MONDAY. AS A RESULT, THE SMALL CRAFT ADVISORY (SCA) HAS
BEEN EXTENDED FOR MANY ZONES AROUND MAUI AND THE BIG ISLAND
THROUGH 6 PM MONDAY. THE TRADES ARE EXPECTED TO SHIFT MORE EAST-
NORTHEAST MONDAY NIGHT AND TUESDAY, AND THIS WILL LIKELY REQUIRE A
RECONFIGURATION OF THE ZONES IN THE SCA ALONG WITH AN EXTENSION
THROUGH LATE IN THE WORK WEEK.
THE CURRENT NORTHWEST SWELL WILL DECLINE TODAY, WITH NORTH SHORE
SURF DROPPING TO NEAR JUNE AVERAGE FOR THE FIRST HALF OF THE WORK
WEEK. TINY SURF IS EXPECTED THURSDAY THROUGH NEXT WEEKEND.
A MIX OF SMALL BACKGROUND SOUTH SWELLS WILL KEEP SOME SMALL SURF
MOVING INTO SOUTH FACING SHORES OVER THE NEXT COUPLE DAYS. A SMALL
SOUTHWEST SWELL MAY BRING A BOOST TO SOUTH SHORE SURF LATE TUESDAY
AND WEDNESDAY. A MORE SIGNIFICANT LONG-PERIOD SOUTH-SOUTHWEST
SWELL WILL BUILD LATE THIS WEEK, THEN PEAK WELL ABOVE THE JUNE
AVERAGE NEXT WEEKEND.
SURF ALONG EAST-FACING SHORES WILL REMAIN SMALL AND CHOPPY THROUGH
SUNDAY, THEN GRADUALLY BUILD TO NEAR OR ABOVE SEASONAL AVERAGE
MONDAY THROUGH WEDNESDAY DUE TO A RETURN OF FRESH TO STRONG
TRADES OVER AND UPSTREAM OF THE ISLANDS.
HFO WATCHES/WARNINGS/ADVISORIES
SMALL CRAFT ADVISORY UNTIL 6 PM HST MONDAY FOR MAUI COUNTY
WINDWARD WATERS-PAILOLO CHANNEL-ALENUIHAHA CHANNEL-BIG ISLAND
WINDWARD WATERS-BIG ISLAND LEEWARD WATERS.
DISCUSSION...JELSEMA
AVIATION...WALSH
MARINE...JELSEMA
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