385
FXHW60 PHFO 140607
AFDHFO
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
807 PM HST WED MAY 13 2026
SYNOPSIS
BREEZY TRADE WINDS WILL PERSIST INTO THURSDAY, WITH SHOWERS
FAVORING WINDWARD AND MAUKA AREAS. FRIDAY INTO THE WEEKEND, TRADES
WILL EASE SLIGHTLY AND A PASSING UPPER-LEVEL DISTURBANCE, ALONG
WITH INCREASING MOISTURE, SHOULD BRING AN UPTICK IN TRADE WIND
SHOWER ACTIVITY, WITH POCKETS OF HEAVY RAIN POSSIBLE. THEN A MORE
STABLE, BREEZY TRADE WIND PATTERN SHOULD REDEVELOP BY MIDWEEK NEXT
WEEK.
SHORT TERM UPDATE
LATEST SATELLITE IMAGERY IS SHOWING A BAND OF CUMULUS CLOUDS 100
TO 150 MILES EAST OF THE BIG ISLAND. THIS BAND OF MOISTURE SHOULD
ARRIVE LATE TONIGHT INTO THURSDAY MORNING ACROSS WINDWARD AREAS OF
THE EASTERN HALF OF THE STATE. WITH THE INCREASE OF SHOWERS
EXPECTED, I DID INCREASE THE POP'S FOR WINDWARD AREAS DURING THIS
TIME ESPECIALLY OVER THE BIG ISLAND. OTHERWISE, NO MAJOR CHANGES
THIS EVENING.
PREV DISCUSSION
ISSUED AT 339 PM HST WED MAY 13 2026
BROAD HIGH PRESSURE TO THE FAR NORTH OF THE STATE (CENTERED
AROUND 40 N) WILL MAINTAIN BREEZY TRADE WINDS ACROSS THE REGION
INTO THURSDAY, DELIVERING CLOUDS AND ISOLATED TO SCATTERED SHOWERS
TO WINDWARD AND MAUKA AREAS, PARTICULARLY DURING THE OVERNIGHT TO
EARLY MORNING HOURS.
DURING THIS TIME, A WEAKNESS WILL DEVELOP IN THE RIDGE ALOFT AND A
MID- TO UPPER-LEVEL LOW WILL BREAK AWAY FROM THE BASE OF A
LONGWAVE TROUGH AND MOVE DIRECTLY OVER THE MAIN HAWAIIAN ISLANDS
BY FRIDAY EVENING. THIS UPPER LEVEL DISTURBANCE WILL INDUCE A
BROAD SURFACE TROUGH OVER THE REGION, WEAKENING THE LOCAL PRESSURE
GRADIENT AND ALLOWING THE TRADE WINDS TO EASE AND VEER SLIGHTLY.
COOLER TEMPERATURES ALOFT AND THE POTENTIAL WEAKENING OF THE LOW-
LEVEL INVERSION WILL HELP TO CREATE A MORE UNSTABLE ENVIRONMENT
OVER THE STATE, LIKELY ENHANCING TRADE WIND SHOWERS. IN ADDITION,
DEEP TROPICAL MOISTURE WILL MOVE UP FROM THE SOUTH, WITH MODELS
SHOWING PRECIPITABLE WATER VALUES CLIMBING INTO THE 1.5 TO ALMOST
2 INCH RANGE OVER THE EASTERN END OF THE STATE. THIS SETUP WILL
LIKELY BRING ENHANCED SHOWERS TO THE WESTERN END OF THE STATE
BEGINNING ON FRIDAY WHERE THE GREATEST INSTABILITY WILL BE, THEN
TRANSITION OVER THE EASTERN END BY SUNDAY INTO MONDAY, WHERE THE
DEEPEST MOISTURE WILL BE. THE MAIN LIMITING FACTOR TO A MORE
ORGANIZED ENHANCED SHOWER SETUP IS THE LACK OF ANY STRONG LIFTING
MECHANISM AT THE SURFACE. AS SUCH, THE MOST LIKELY LOCATIONS TO
EXPERIENCE HEAVY RAIN ARE THE WINDWARD AND MAUKA AREAS THAT ARE
IMPACTED BY OROGRAPHIC LIFT IN A TRADE WIND PATTERN, THOUGH THE
HI-RES GUIDANCE IS JUST NOW REACHING FRIDAY AFTERNOON WHERE THEY
ALSO HIGHLIGHT INTERIOR AND LEEWARD OAHU AS THE UPPER-LEVEL LOW
MOVES OVERHEAD AND THE BACKGROUND WINDS BECOME LIGHT ENOUGH TO
SUPPORT SEA BREEZE DEVELOPMENT. IN ADDITION TO THE THE POTENTIAL
FOR POCKETS OF HEAVY RAIN THIS WEEKEND, DEW POINTS ARE EXPECTED TO
RISE INTO THE LOWER 70S, LEAVING THIS WEEKEND FEELING MUGGIER
WITH LIGHTER WINDS.
BEYOND MONDAY, DIFFERENCES BETWEEN THE GLOBAL MODELS BECOME MORE
APPARENT, BUT FOR NOW, EXPECTING A MORE STABLE, BREEZY TRADE WIND
PATTERN TO REDEVELOP BY MIDWEEK NEXT WEEK.
AVIATION
BREEZY TRADES EXPECTED FOR NEXT FEW DAYS. LOW CIGS AND SHRA
EXPECTED ALONG WINDWARD AND MAUKA LOCATIONS. MVFR CONDS POSSIBLE
BUT VFR SHOULD PREVAIL.
AIRMET TANGO IS IN EFFECT FOR TURB LEE OF TERRAIN DUE TO THE
BREEZY TRADE WINDS.
MARINE
HIGH PRESSURE ESTABLISHED NORTH OF THE ISLANDS MAINTAINS LOCALLY
STRONG TRADES UNTIL AN UPPER DISTURBANCE CAUSES WINDS TO WEAKEN
BY THIS WEEKEND. OUR CURRENT FRESH TO LOCALLY STRONG TRADES SHOULD
HOLD THROUGH THE DAY THURSDAY THEN GRADUALLY WEAKEN AND VEER
TOWARDS THE EAST-SOUTHEAST THURSDAY NIGHT INTO FRIDAY. MODERATE TO
FRESH EAST TO EAST-SOUTHEAST WINDS ARE EXPECTED FRIDAY INTO THE
WEEKEND. THE SCA REMAINS IN EFFECT FOR THE WINDIER ZONES OF MAUI
COUNTY AND THE BIG ISLAND THROUGH THURSDAY AFTERNOON.
SMALL, SHORT PERIOD NW SWELL FADES TONIGHT AND WILL BE REPLACED
BY A SMALL TO MODERATE, LONG PERIOD NW SWELL THAT WILL PEAK ON
THURSDAY BRINGING SMALL TO MODERATE SURF TO FAVORED EXPOSURES.
LATEST READINGS ON BUOY 51001 IS SHOWING LONG-PERIOD FORERUNNERS
IN THE 15 TO 17 SECOND ENERGY BANDS, WHICH SHOULD STEADILY FILL IN
TONIGHT.
SMALL, MEDIUM TO LONG PERIOD S SWELL MAINTAINS SMALL SURF ALONG S
SHORES. A SERIES OF GALES INITIALLY PASSING SOUTH OF NEW ZEALAND
A FEW DAYS AGO AND NOW SETTING UP E OF NEW ZEALAND SHOULD SEND A
SERIES OF SMALL SOUTH SWELLS ALL OF NEXT WEEK. SURF SHOULD RISE TO
NEAR THE SUMMER AVERAGE AROUND SUNDAY AND HOLD NEAR THE SUMMER
AVERAGE THROUGHOUT NEXT WEEK. MEANWHILE ALONG EAST FACING SHORES,
LOCALLY STRONG TRADES WILL MAINTAIN ROUGH AND CHOPPY SURF ALONG E
FACING SHORES. A SLIGHT DECREASE OF WIND SWELL IS EXPECTED
THURSDAY INTO FRIDAY AS THE TRADES WEAKEN TO MODERATE TO LOCALLY
FRESH SPEEDS.
TIDES PEAK AROUND 2.5 FT MLLW THIS WEEKEND. COMBINED WITH ONGOING
TRADES AND A MODEST BOOST IN S SWELL, WATER LEVELS WILL PEAK
AROUND 3.0 FT LATE THIS WEEKEND INTO EARLY NEXT WEEK. MINOR
OVERWASH OF LOW LYING COASTAL AREAS WILL BE POSSIBLE DURING THE
AFTERNOON HIGH TIDES AT THIS TIME.
HFO WATCHES/WARNINGS/ADVISORIES
SMALL CRAFT ADVISORY UNTIL 6 PM HST THURSDAY FOR ALENUIHAHA
CHANNEL-BIG ISLAND LEEWARD WATERS-BIG ISLAND SOUTHEAST WATERS-
MAALAEA BAY-PAILOLO CHANNEL.
UPDATE...KINO
DISCUSSION...FARRIS
AVIATION...WALSH
MARINE...KINO
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