118
FXHW60 PHFO 240115
AFDHFO
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
315 PM HST SAT AUG 23 2025
SYNOPSIS
THE LOCALLY BREEZY TRADE WIND FLOW WILL EASE SLIGHTLY ON SUNDAY
AND MONDAY AS SURFACE HIGH PRESSURE TO THE NORTH WEAKENS. STABLE
CONDITIONS WILL CONTINUE TO PRODUCE MINIMAL WINDWARD RAINFALL, AND
WITH THE EXCEPTION OF SCATTERED AFTERNOON AND EVENING SHOWERS
OVER THE KONA SLOPES OF THE BIG ISLAND, LEEWARD AREAS WILL BE
MOSTLY DRY. MODERATE TRADE WINDS AND THE TYPICALLY DRY SUMMERTIME
WEATHER PATTERN WILL PREVAIL FOR THE REMAINDER OF NEXT WEEK.
DISCUSSION
THE RATHER DRY SUMMERTIME TRADE WIND WEATHER PATTERN CONTINUES.
BROAD SURFACE HIGH PRESSURE FAR NORTH OF THE ISLANDS IS BEGINNING
TO BE SPLIT BY A NORTH PACIFIC TROUGH, BUT SO FAR, LOCALLY BREEZY
TRADE WINDS ARE ONLY DOWN A FEW MILES PER HOUR COMPARED TO
YESTERDAY. PRECIPITABLE WATER IN THE TRADE FLOW IS RUNNING AROUND
1.1 INCHES, WHICH IS ABOUT 20 TO 25 PERCENT BELOW AUGUST NORMAL,
AND A ROBUST MID-LEVEL RIDGE IS MAINTAINING A STRONG INVERSION
BASED BETWEEN 5,000 AND 7,000 FT. UNDER THESE STABLE AND RATHER
DRY CONDITIONS, RAINFALL HAS BEEN SCANT ACROSS WINDWARD AREAS, AND
ASIDE FROM A FEW SHOWERS DEVELOPING ALONG THE KONA SLOPES OF THE
BIG ISLAND, LEEWARD AREAS CONTINUE TO BE DRY.
ONLY MINOR CHANGES ARE EXPECTED DURING THE NEXT FEW DAYS. TRADES
WILL EASE SLIGHTLY AND SHIFT FROM A MORE EASTERLY DIRECTION
SUNDAY AND MONDAY. AS A RESULT, AFTERNOON SEA BREEZES WILL BE MORE
PREVALENT, BUT MOST AREAS WILL NOT EXPERIENCE ANY INCREASE IN
SHOWER CHANCES, EVEN AS THE INVERSION RISES A BIT. HOWEVER, THE
GFS AND ECMWF MODELS ARE SHOWING A MINOR INCREASE IN MOISTURE NEAR
THE BIG ISLAND MONDAY AND TUESDAY THAT MAY PROVIDE SOME INCREASE
IN AFTERNOON SHOWERS ON THE KONA SLOPES.
MODERATE TRADE WINDS AND STABLE CONDITIONS WITH MODEST RAINFALL
WILL PREVAIL FROM WEDNESDAY INTO NEXT NEXT WEEKEND.
AVIATION
STABLE, MODERATE TO BREEZY TRADES DELIVER CLOUDS AND SHOWERS
WINDWARD AND MAUKA THROUGH THE PERIOD PARTICULARLY OVERNIGHT AND
DURING THE EARLY MORNING HOURS. ISOLATED MVFR WITHIN SHOWERS
OTHERWISE VFR PREVAILS.
NO AIRMETS IN EFFECT.
MARINE
A RIDGE OF HIGH PRESSURE NORTH OF THE HAWAIIAN ISLANDS WILL
CONTINUE TO PRODUCE FRESH TO LOCALLY STRONG TRADES THROUGH EARLY
NEXT WEEK. A SMALL CRAFT ADVISORY (SCA) REMAINS IN EFFECT FOR THE
WINDIER WATERS OF MAUI COUNTY AND THE BIG ISLAND. THIS SCA MAY
CONTINUE INTO THE FIRST HALF OF NEXT WEEK.
SMALL OVERLAPPING MEDIUM AND LONG PERIOD SOUTH SWELLS WILL CONTINUE
THIS AFTERNOON AND SLOWLY FADE INTO BACKGROUND LEVELS BY SUNDAY.
SURF HEIGHTS WILL CONTINUE TO DECLINE INTO MONDAY. ANOTHER SERIES
OF SMALL LONG PERIOD SOUTH SWELLS WILL ARRIVE BY TUESDAY,
BOOSTING SOUTH SHORE SURF HEIGHTS THROUGH FRIDAY.
SURF ALONG NORTH AND WEST FACING SHORES WILL REMAIN NEARLY FLAT
FOR THE NEXT FEW DAYS, WHILE SMALL TRADE WIND DRIVEN WAVE CHOP
WILL LINGER FOR EAST SHORES.
HFO WATCHES/WARNINGS/ADVISORIES
SMALL CRAFT ADVISORY UNTIL 6 PM HST SUNDAY FOR MAALAEA BAY-
PAILOLO CHANNEL-ALENUIHAHA CHANNEL-BIG ISLAND LEEWARD WATERS-BIG
ISLAND SOUTHEAST WATERS.
DISCUSSION...WROE
AVIATION...JVC
MARINE...TSAMOUS
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