383
FXHW60 PHFO 090647
AFDHFO
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
847 PM HST SAT MAR 8 2025
SYNOPSIS
HIGH PRESSURE NORTH OF THE ISLANDS WILL MAINTAIN STRONG TRADE
WINDS INTO THE MIDDLE OF THE WEEK. EXPECT PERIODS OF WINDWARD AND
MAUKA SHOWERS, PARTICULARLY OVERNIGHT AND DURING THE EARLY
MORNING HOURS. WINDS WILL EASE SOME DURING THE SECOND HALF OF THE
WEEK.
DISCUSSION
NO CHANGES TO THE FORECAST THIS EVENING, BUT ANTICIPATE MAKING
SOME TWEAKS TO THE FORECAST WITH THE MORNING PACKAGE. NOT
EXPECTING ANY SIGNIFICANT CHANGE, BUT RATHER SOME TWEAKS TO BRING
THE FORECAST INTO BETTER ALIGNMENT WITH THE CURRENT NATIONAL
BLEND OF MODELS.
MOST SHOWERS THIS EVENING ARE OVER MAUI COUNTY, IN A BAND THAT IS
SINKING SOUTHWARD AND WILL IMPACT THE BIG ISLAND IN THE NEXT FEW
HOURS. RAINFALL TOTALS REMAIN LIGHT, BASED ON RAIN GAGE DATA.
A DISSIPATING COLD FRONT NORTH OF THE ISLANDS WILL CONTINUE TO
DECAY OVER THE NEXT COUPLE OF DAYS AS IT SINKS SOUTHWARD.
LEFTOVER MOISTURE FROM THE FRONT WILL SINK OVER THE ISLANDS OVER
THE COMING DAYS. STRONG HIGH PRESSURE FAR NORTH OF THE ISLANDS
WILL MAINTAIN THE STRONG TRADE WINDS INTO THE MIDDLE OF THE WEEK.
THE TRADES WILL FOCUS THE SHOWERS OVER THE WINDWARD AND MAUKA
AREAS OF THE ISLANDS.
SHOWERS ASSOCIATED WITH THE REMNANTS OF THE FRONT BAND ARE
EXPECTED TO REACH KAUAI EARLY SUNDAY MORNING, AND OAHU MIDDAY. THE
BAND WILL CONTINUE TO SINK SOUTHWARD, REACHING MAUI COUNTY AND THE
BIG ISLAND SUNDAY NIGHT AND INTO MONDAY. ALTHOUGH THE SHOWERS WILL
BE CONCENTRATED OVER THE WINDWARD AND MAUKA AREAS, EXPECT SOME
SHOWERS TO REACH LEEWARD AREAS DUE TO THE STRONG TRADES.
SATELLITE DERIVED PRECIPITABLE WATER SHOWS A DRIER AIRMASS
IMMEDIATELY BEHIND THE FRONT. COUPLED WITH A STABLE UPPER AIRMASS.
SHOWER ACTIVITY SHOULD BE LIMITED OVER THE WESTERN END OF THE
STATE ON MONDAY, AND INTO TUESDAY FOR THE EASTERN END. A SHALLOW
INVERSION COMBINED WITH THE DRY AIR COULD LEAD TO SOME
GUSTY WINDS MONDAYS THAT COULD APPROACH ADVISORY LEVELS. WINDS MAY
NOT BE QUITE AS STRONG ON TUESDAY AS ADDITIONAL MOISTURE IS
EXPECTED TO RIDE IN ON THE TRADES.
A DEVELOPING TROUGH TO THE WEST OF THE ISLANDS WILL HELP PUSH THE
HIGH PRESSURE SYSTEM CLOSER TO THE ISLANDS DURING THE SECOND HALF
OF THE WEEK. THIS WILL LEAD TO WEAKENING TRADES, AND THE
POSSIBILITY OF SOUTHEASTERLY WINDS BY NEXT WEEKEND.
AVIATION
BREEZY TO LOCALLY STRONG TRADE WINDS WILL PERSIST OVER THE NEXT
SEVERAL DAYS. REMNANT MOISTURE FROM A FRONTAL BOUNDARY WILL SAG
SOUTHWARD OVER THE ISLANDS LATE TONIGHT INTO SUNDAY. THIS FEATURE
SHOULD HELP GENERATE SCATTERED TO NUMEROUS SHOWERS ALONG MAINLY
WINDWARD LOCATIONS WITH PERIODS OF ASSOCIATED MVFR CEILINGS AND
VISIBILITY. OTHERWISE, VFR CONDITIONS SHOULD GENERALLY PREVAIL FOR
LEEWARD LOCATIONS.
AIRMET SIERRA WILL LIKELY BE NEEDED FOR KAUAI LATER TONIGHT TO
ACCOUNT FOR LOW CEILINGS AND REDUCED VISIBILITY AS THE BAND OF
MOISTURE BEGINS TO PUSH OVER THE ISLANDS.
AIRMET TANGO REMAINS IN EFFECT FOR MODERATE LOW-LEVEL TURBULENCE
OVER AND DOWNWIND OF ISLAND TERRAIN. THIS AIRMET WILL LIKELY
CONTINUE OVER THE NEXT SEVERAL DAYS.
MARINE
HIGH PRESSURE CENTERED APPROXIMATELY 800 NAUTICAL MILES NORTH OF
THE HAWAIIAN ISLANDS IS MAINTAINING A VERY TIGHT PRESSURE GRADIENT
BETWEEN ITSELF AND LOWER EQUATORIAL PRESSURE. THIS HAS RESULTED
IN SEVERAL DAYS OF FRESH TO LOCALLY STRONG TRADE WINDS. AS THIS
HIGH MOVES EAST AND IS REPLACED BY A HIGH JUST TO ITS NORTHWEST,
THE DOWNSTREAM PRESSURE GRADIENT WILL REMAIN TIGHT ENOUGH TO
SUPPORT LOCAL FRESH TO NEAR GALE FORCE TRADES. GALE FORCE WINDS
ARE POSSIBLE OVER THE NOTORIOUSLY WINDIER CHANNELS AND BAYS
SURROUNDING MAUI COUNTY AND BIG ISLAND, AS WELL AS SOUTH OF BIG
ISLAND, FROM MONDAY EVENING THROUGH LATE THURSDAY. AN ALL-WATER
SMALL CRAFT ADVISORY FOR STRONG WINDS AND RESULTANT ELEVATED SEAS
WILL REMAIN IN THE EFFECT FOR THE NEAR FUTURE.
THE PASSAGE AND PEAK OF A MODERATE SIZE, MEDIUM PERIOD NORTHWEST
(310-330 DEGREE) SWELL TODAY HAS PRODUCED NORTH AND WEST-FACING
SHORE DOUBLE HEAD HIGH HIGH SURF ADVISORY (HSA) SURF. THESE HSA
HEIGHTS WILL HANG IN THROUGH THE PRE-DAWN SUNDAY MORNING HOURS
BEFORE THIS VEERING SWELL DECLINES THROUGH THE DAY SUNDAY.
EAST-FACING SHORE ROUGH, SHORT PERIOD WIND-DRIVEN SEAS WILL HOLD
THROUGH MOST OF NEXT WEEK IN RESPONSE TO A PERSISTENT FRESH TO
STRONG TRADE FETCH OVER AND UPSTREAM OF THE ISLANDS. TRADES COULD
POSSIBLY STRENGTHEN EARLY NEXT WEEK. THIS WILL FURTHER AGITATE
SEAS AND CREATE AN EVEN ROUGHER CHOP TO EASTERN SEAS THROUGH THE
MIDDLE OF THE WEEK.
SURF ALONG SOUTH-FACING SHORES WILL REMAIN SMALL. SOME LONGER
PERIOD NORTH SWELL AND EAST WIND WAVE SWELL MAY WRAP INTO MORE
EASTERN-FACING SOUTHERN EXPOSURES.
HFO WATCHES/WARNINGS/ADVISORIES
HIGH SURF ADVISORY UNTIL 6 AM HST SUNDAY FOR NIIHAU-KAUAI
LEEWARD-WAIANAE COAST-OAHU NORTH SHORE-MAUI WINDWARD WEST-KAUAI
NORTH-MOLOKAI WINDWARD-MOLOKAI NORTH-MOLOKAI WEST-MAUI CENTRAL
VALLEY NORTH-WINDWARD HALEAKALA.
SMALL CRAFT ADVISORY UNTIL 6 PM HST MONDAY FOR ALL HAWAIIAN
WATERS-
DISCUSSION...M BALLARD
AVIATION...THOMAS
MARINE...BLOOD
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