233
FXHW60 PHFO 221325
AFDHFO
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
325 AM HST FRI AUG 22 2025
SYNOPSIS
HIGH PRESSURE NORTH OF THE ISLANDS WILL MAINTAIN MODERATE TO
LOCALLY BREEZY TRADE WINDS THROUGH THE WEEKEND, FOLLOWED BY A
SLIGHT DECREASE IN WINDS EARLY NEXT WEEK. STABLE SUMMERTIME
CONDITIONS WILL BRING PERIODS OF MAINLY WINDWARD AND MAUKA
SHOWERS, WHILE MOST LEEWARD AREAS REMAIN RATHER DRY.
DISCUSSION
NO SIGNIFICANT CHANGES TO THE FORECAST THIS MORNING. THE FORECAST
HAS BEEN NUDGED TOWARDS THE LATEST NATIONAL BLEND OF MODELS, WHICH
DOES BOOST POPS OVER THE WINDWARD SLOPES OF THE BIG ISLAND LATER
TODAY IN RESPONSE TO AN AREA OF LOW CLOUDS UPSTREAM OF THE ISLANDS
BEING CARRIED IN ON THE TRADES. THIS SOLUTION ALSO LOWERS POPS A
BIT OVER THE BIG ISLAND WINDWARD SLOPES ON MONDAY AND TUESDAY,
AND THE WINDWARD SIDES OF ALL THE ISLANDS THURSDAY.
BROAD HIGH PRESSURE REMAINS TO NORTH AND NORTHEAST OF THE ISLANDS,
WITH MID LEVEL RIDGING OVER THE ISLANDS. ALTHOUGH THE HIGH IS NOT
PARTICULARLY STRONG, THE ITCZ IS NEAR 10N, MAKING IT A LITTLE
FURTHER NORTH THAN NORMAL. THIS COMBINATION WILL CONTINUE TO BRING
A STABLE AND RELATIVELY DRY WEATHER PATTERN OVER THE ISLANDS WITH
MODERATE TO LOCALLY BREEZY TRADES. THE OVERNIGHT SOUNDINGS
CONTINUE TO SHOW AN INVERSION BASED BETWEEN 5,000 AND 7,000 FT,
AND LITTLE TO NO ORGANIZED MOISTURE IS NOTED IN THE TRADE WIND
FLOW. ANTICIPATE WINDWARD RAINFALL TOTALS TO REMAIN LOW.
LITTLE CHANGE IS EXPECTED TO THE RELATIVELY DRY AND STABLE TRADE
WIND WEATHER PATTERN THROUGH SUNDAY. TRADES MAY EASE A NOTCH AND
SHIFT OUT OF A MORE EASTERLY DIRECTION FOR MONDAY AND TUESDAY AS
THE SURFACE RIDGE TO THE NORTH IS BRIEFLY WEAKENED. THE MID-LEVEL
RIDGE SHOULD REMAIN STRONG ENOUGH TO MAINTAIN STABLE CONDITIONS,
AND AN AREA OF TROPICAL MOISTURE MAY CLIP THE BIG ISLAND ON MONDAY
OR TUESDAY, THOUGH ODDS FAVOR THE MOISTURE PASSING TO THE SOUTH.
LONGER TERM GUIDANCE SUGGESTS MODERATE TRADES AND CONTINUED
MODEST SHOWER ACTIVITY FOR THE SECOND PART OF NEXT WEEK.
AVIATION
HIGH PRESSURE REMAINS TO THE NORTH AND NORTHEAST OF THE ISLANDS
AND WILL MAINTAIN MODERATE TO BREEZY TRADES. MID LEVEL RIDGING
WILL HELP TO PROVIDE A STABLE AIRMASS OVERHEAD THAT WILL LIMITED
RAINFALL TOTALS. CLOUDS AND SHOWERS WILL REMAIN FOCUSED PRIMARILY
OVER THE WINDWARD AND MOUNTAIN AREAS, PARTICULARLY OVERNIGHT AND
INTO THE MORNING HOURS. MVFR CONDITIONS WILL BE POSSIBLE IN
SHOWERS, OTHERWISE VFR WILL LIKELY PREVAIL.
NO AIRMETS ARE CURRENTLY IN EFFECT, AND NONE ARE EXPECTED TO BE
ISSUED TODAY.
MARINE
A HIGH PRESSURE RIDGE NORTH OF THE HAWAIIAN ISLANDS WILL MAINTAIN
FRESH TO LOCALLY STRONG TRADE WINDS THROUGH EARLY NEXT WEEK. THE
SMALL CRAFT ADVISORY (SCA) WAS EXTENDED IN TIME THROUGH SUNDAY
FOR THE WINDIER WATERS AND CHANNELS NEAR MAUI COUNTY AND THE BIG
ISLAND THROUGH SATURDAY. THIS SCA WILL LIKELY CONTINUE FOR THESE
WINDIER WATERS INTO EARLY NEXT WEEK.
A SERIES OF SMALL OVERLAPPING MEDIUM AND LONG PERIOD SOUTH
(170-190 DEGREE) SWELLS WILL CONTINUE THROUGH SATURDAY, WITH SURF
HEIGHTS NEAR THE SUMMERTIME AVERAGE THROUGH FRIDAY ALONG SOUTH
FACING SHORES. SURF HEIGHTS SHOULD DECREASE TO BACKGROUND LEVELS
EARLY NEXT WEEK AS THE SWELL ENERGY FADES. ANOTHER SMALL, LONG
PERIOD SOUTH SWELL WILL ARRIVE BY NEXT WEEK TUESDAY.
CHOPPY CONDITIONS WILL CONTINUE FOR EAST FACING SHORES THROUGH
THE FORECAST PERIOD DUE TO THE PERSISTENT FRESH TRADES. SURF ALONG
NORTH FACING SHORES WILL REMAIN NEARLY FLAT THROUGH NEXT WEEK.
PEAK HIGH TIDES ASSOCIATED WITH THE LUNAR CYCLE WILL LEAD TO
MINOR COASTAL FLOODING ALONG SHORELINES AND LOW LYING COASTAL
AREAS DURING THIS AFTERNOON'S HIGH TIDE. A COASTAL FLOOD
STATEMENT REMAINS IN EFFECT FOR MINOR COASTAL FLOODING. THESE
COASTAL HIGH WATER LEVELS WILL DECREASE ON SATURDAY.
FIRE WEATHER
TRADE WINDS WILL REMAIN IN THE MODERATE TO LOCALLY BREEZY RANGE
INTO SUNDAY, WHILE A RIDGE ALOFT MAINTAINS AN INVERSION BETWEEN
5,000 AND 7,000 FT. UNDER THIS STABLE AND RATHER DRY WEATHER
PATTERN, RELATIVE HUMIDITY WILL DROP INTO THE LOW TO MID 40S
PERCENT RANGE EACH AFTERNOON, BRINGING NEAR CRITICAL FIRE WEATHER
CONDITIONS. WE DO NOT ANTICIPATE FIRE WEATHER HEADLINES THROUGH
THE WEEKEND, BUT FIRE WEATHER CONCERNS WILL BE ELEVATED.
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...M BALLARD
AVIATION...M BALLARD
MARINE...BOHLIN
FIRE WEATHER...M BALLARD
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