616
FXHW60 PHFO 301900
AFDHFO
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
900 AM HST SUN AUG 30 2026
SYNOPSIS
MODERATE TO BREEZY TRADES WILL CONTINUE THROUGH AT LEAST THE
MIDDLE OF NEXT WEEK. SHOWERS WILL GENERALLY FAVOR WINDWARD AND
MAUKA AREAS, PARTICULARLY DURING THE OVERNIGHT THROUGH EARLY
MORNING HOURS EACH DAY. TROPICAL STORM LOWELL REMAINS FAR ESE OF
THE MAIN HAWAIIAN ISLANDS, AND UNCERTAINTY REGARDING ITS TRACK AND
INTENSITY FORECAST IS HIGH AT THIS TIME.
SHORT TERM UPDATE
BENIGN TRADE WIND PATTERN THROUGH AT LEAST WEDNESDAY AND PROBABLY
THURSDAY AS STRONG LONGWAVE RIDGING APPROACHING 594DM REMAINS
ANCHORED NEAR 170W LONGITUDE BEFORE MIGRATING EAST DURING THE LATTER
PORTION OF THE WEEK. THIS IN TURN FAVORS EXPANSIVE SURFACE HIGH
PRESSURE IN MAINTENANCE OF BREEZY TRADES THROUGH THIS TIME. AN
UPTICK IN SHOWERS FOR WINDWARD AND MAUKA IS EXPECTED NEXT WEEK AS
MOISTURE ORIGINATING OFF THE CALIFORNIA COAST ENTRAINS IN THE
TRADES, REACHING THE ISLANDS AROUND WEDNESDAY.
THE TROPICS REMAIN ACTIVE WITH ATTENTION TURNING TOWARD THE FRIDAY
SEPT 4TH (DAY 5) TO WEDNESDAY SEP 9TH (DAY 10) PERIOD. DURING THIS
TIME, UNCERTAINTY RUNS CONSIDERABLY HIGHER THAN NORMAL OWING TO WEAK
STEERING FLOW FOLLOWED BY POTENTIAL EMERGENCE OF A CLOSED UPPER
LOW NW OF THE ISLANDS THAT WILL ALTER STEERING FLOW AND INTRODUCE
A COMPONENT OF SHEARING AS WELL. TC LOWELL AND TC KARINA BOTH
CARRY POTENTIAL TO COME PRECARIOUSLY CLOSE TO THE ISLANDS DURING
THIS TIME WINDOW. GUIDANCE REGARDING BOTH SYSTEMS IS PLAGUED WITH
THE SAME UNCERTAINTY FOR THE SAME REASONS, SO POTENTIAL OUTCOMES
UNFORTUNATELY REMAIN WIDE OPEN DESPITE THE DECREASING LEAD TIME.
IT IS WORTH NOTING THAT MACHINE LEARNING GUIDANCE REMAINS
SUPRESSED FAIRLY FAR SOUTH WITH LOWELL AND THE 12Z ECMWF HAS
TRENDED STRONGLY IN THIS DIRECTION. CONSULT NHC FOR THE OFFICIAL
TRACK AND INTENSITY FORECAST.
PREV DISCUSSION
ISSUED AT 415 AM HST SUN AUG 30 2026
A 1034 MB HIGH FAR NORTH OF THE STATE WILL CONTINUE TO PRODUCE
BREEZY CONDITIONS ACROSS THE STATE TODAY. LATEST RADAR AND
SATELLITE IMAGERY IS SHOWING SOME SCATTERED LIGHT SHOWERS RIDING
IN WITH THE BREEZY TRADES EARLY THIS MORNING. SHOWER ACTIVITY
SHOULD GENERALLY TREND DOWN THROUGHOUT THE DAY TODAY WITH MOSTLY
DRY CONDITIONS EXPECTED THIS AFTERNOON.
STARTING TONIGHT, WE SHOULD SEE A SLIGHT INCREASE OF SHOWERS MOVE
IN WITH THE BREEZY TRADES DUE TO A SUBTLE INCREASE OF LOW LEVEL
MOISTURE. SOME PASSING SHOWERS WILL LIKELY LINGER ACROSS WINDWARD
AND MAUKA AREAS THROUGH MONDAY WITH A FEW LIGHT SHOWERS POSSIBLE
OVER LEEWARD AREAS AS WELL. TUESDAY AND WEDNESDAY WILL ALSO BE
FAIRLY SIMILAR TO MONDAY WITH SOME PASSING SHOWERS OVER WINDWARD
AND MAUKA AREAS. TRADES MAY BRIEFLY WEAKEN SLIGHTLY LATE TUESDAY
INTO WEDNESDAY.
FOR THE SECOND HALF OF THIS WEEK, THE WEATHER FORECAST FOR HAWAII
WILL BE DEPENDENT ON THE TRACK OF T.C LOWELL. CURRENTLY LOWELL IS
A TROPICAL STORM LOCATED NEAR 13N139W AND IS EXPECTED TO
STRENGTHEN INTO A HURRICANE OVER THE NEXT FEW DAYS. THE LATEST
FORECAST TRACK FROM THE NATIONAL HURRICANE CENTER (NHC) HAS LOWELL
PASSING AROUND 300 MILES SOUTH OF THE BIG ISLAND THURSDAY
MORNING. WHILE THE 00Z RUN FROM THE ECMWF AND THE 06Z RUN FROM THE
GFS SHOW A SLOWER TRACK BUT A CLOSER TRACK TO THE STATE. THE 06Z
RUN FROM THE BETTER PERFORMING GDM MODEL SHOWS IT FURTHER SOUTH
(ROUGHLY 400 MILES SOUTH OF THE BIG ISLAND) THAN THE OFFICIAL
TRACK. SO AS YOU CAN SEE, THERE IS A LOT OF SPREAD IN THE FORECAST
MODELS, THUS IT IS TOO EARLY TO PREDICT ANY POTENTIAL IMPACTS TO
HAWAII AT THIS TIME. WHILE IT IS TOO EARLY TO PREDICT ANY IMPACTS,
IT IS LOOKING LIKELY THAT WE WILL SEE WINDIER WEATHER TOWARDS THE
END OF THIS WEEK. HOW STRONG THE WINDS WILL BE IS YET TO BE
DETERMINED...
AVIATION
ISSUED AT 415 AM HST SUN AUG 30 2026
CONDITIONS WILL BE MOSTLY VFR. TRADES WILL CONTINUE AT BREEZY
SPEEDS, CREATING OCCASIONAL TURBULENCE DOWNSTREAM OF MOUNTAINS. IN
ADDITION, SHOWERS WILL FOCUS ON WINDWARD SITES, BUT SHOULD REMAIN
ISOLATED. LOW CEILINGS MAY OCCUR BRIEFLY, BUT LIMITED MOISTURE
SHOULD PREVENT SITES FROM GETTING BOGGED DOWN IN LONG- LASTING
MVFR.
AIRMET TANGO IS IN EFFECT FOR MOD LOW-LEVEL TURBULENCE LEE OF
TERRAIN AND MAY BE NEEDED FOR A FEW DAYS.
MARINE
A STRONG SURFACE HIGH WILL REMAIN NEARLY STATIONARY FAR NORTH OF
THE HAWAIIAN ISLANDS THIS WEEK. MODERATE TO LOCALLY STRONG TRADE
WINDS WILL PREVAIL THROUGH THE WEEK. TROPICAL CYCLONE LOWELL MAY
MOVE INTO THE HAWAIIAN OFFSHORE WATERS FROM WEDNESDAY INTO THURSDAY.
WIND AND WEATHER IMPACTS AND TIMING FOR THE COASTAL WATERS WILL BE
DRIVEN BY THE SPEED AND TRACK OF LOWELL AS IT MOVES TOWARDS THE REGION.
THE CURRENT SOUTH SWELL WILL SLOWLY DECREASE OVER THE NEXT SEVERAL
DAYS. OVERLAPPING SMALL, LONG- AND MEDIUM-PERIOD SOUTH SWELL ENERGY
WILL KEEP SMALL SURF ALONG SOUTH FACING SHORES THROUGH THE WEEK.
THE NEXT GOOD BOOST IN SOUTH SWELL ENERGY WILL ARRIVE AND FILL IN
FROM TUESDAY TO WEDNESDAY AT AROUND 2 TO 3 FEET WITH AN 18 SECOND
PERIOD. THIS SWELL WILL PEAK ON WEDNESDAY, JUST BELOW SOUTH SHORE
ADVISORY THRESHOLDS, AND THEN SLOWLY DECLINE THROUGH THE END OF
THE WEEK. TRADE WIND SWELL ENERGY WILL CONTINUE TO KEEP ELEVATED
SURF HEIGHTS ALONG ALL EAST FACING SHORES THIS WEEK.
FIRE WEATHER
ISSUED AT 415 AM HST SUN AUG 30 2026
WE SAW A FAIRLY DRY DAY ACROSS PARTS OF THE STATE YESTERDAY WITH
HUMIDITIES GETTING DOWN INTO THE UPPER 30S FOR SELECT LEEWARD
AREAS. ANOTHER BREEZY AND DRY DAY IS EXPECTED TODAY WITH
HUMIDITIES DOWN INTO THE LOW 40S AND POSSIBLY UPPER 30S AGAIN FOR
A FEW LEEWARD AREAS THIS AFTERNOON. WHILE FUEL CONDITIONS DO NOT
REMAIN CRITICAL AT THIS TIME DUE TO THE ABUNDANT RAINFALL WE
RECEIVED OVER THE PAST SEVERAL WEEKS, MODERATE FIRE DANGER WILL BE
POSSIBLE FOR AREAS THAT HAVE NOT RECEIVED MUCH RAINFALL OVER THE
PAST FEW WEEKS. AN INCREASE OF SHOWERS AND HUMIDITIES IS EXPECTED
TONIGHT INTO MONDAY. WHILE THE PASSING SHOWERS SHOULD BE CONFINED
TO MAINLY WINDWARD AND MAUKA AREAS, SOME HIGHER MINIMUM HUMIDITIES
IS EXPECTED FOR MONDAY. SOUNDINGS SHOW THE TEMPERATURE INVERSION
BETWEEN 5000 TO 6000 FEET TODAY. WE SHOULD SEE THE INVERSION
RISE TO 6000 TO 7000 FEET ON MONDAY.
HFO WATCHES/WARNINGS/ADVISORIES
SMALL CRAFT ADVISORY UNTIL 6 PM HST THIS EVENING FOR ALENUIHAHA
CHANNEL-BIG ISLAND LEEWARD WATERS-BIG ISLAND SOUTHEAST WATERS-
BIG ISLAND WINDWARD WATERS-KAIWI CHANNEL-KAUAI CHANNEL-KAUAI
LEEWARD WATERS-KAUAI NORTHWEST WATERS-KAUAI WINDWARD WATERS-
MAALAEA BAY-MAUI COUNTY LEEWARD WATERS-MAUI COUNTY WINDWARD
WATERS-OAHU LEEWARD WATERS-OAHU WINDWARD WATERS-PAILOLO CHANNEL.
SHORT TERM UPDATE...JVC
DISCUSSION...KINO
AVIATION...PARKER
MARINE...TS
FIRE WEATHER...KINO
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