814
FXHW60 PHFO 060659
AFDHFO
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
859 PM HST THU MAR 5 2026
SYNOPSIS
THE HIGH PRESSURE SYSTEM NORTH OF THE ISLANDS WILL REMAIN IN PLACE
THROUGH SUNDAY WITH BRIEF PASSING SHOWERS POSSIBLE, FAVORING THE
WINDWARD AND MOUNTAIN AREAS. THIS WEATHER PATTERN CHANGES
SIGNIFICANTLY FROM MONDAY TO TUESDAY AS A CUT OFF LOW MOVES INTO
POSITION SEVERAL HUNDRED MILES NORTHWEST OF KAUAI. SOUTHERLY
WINDS ON THE EAST SIDE OF THIS LOW WILL DRAW UP UNSTABLE MOISTURE
FROM THE DEEP TROPICS, INCREASING THE THREATS OF HEAVY RAIN,
THUNDERSTORMS AND FLOODING ACROSS THE STATE.
SHORT TERM UPDATE
TYPICAL TRADE WIND WEATHER WILL CONTINUE THROUGH SUNDAY. BY MONDAY
A CUT OFF LOW APPROACHES THE HAWAII REGION FROM THE NORTHWEST,
CAUSING THE WIND DIRECTIONS TO VEER MORE FROM THE SOUTH. SOUTHERLY
WINDS ON THE EAST SIDE OF THIS LOW WILL DRAW UP UNSTABLE MOISTURE
FROM THE DEEP TROPICS, INCREASING THE THREATS OF HEAVY RAIN,
THUNDERSTORMS AND FLOODING ACROSS THE STATE. THESE HEAVIER SHOWERS
AND THUNDERSTORMS WILL INITIALLY IMPACT THE WESTERN ISLANDS OF
NIIHAU, KAUAI AND OAHU. FROM TUESDAY NIGHT ONWARD, THESE IMPACTS
MAY SPREAD ACROSS THE REST OF THE STATE.
ISLAND BY ISLAND IMPACTS WILL BE PRIMARILY BASED ON THE PRECISE
LOCATION OF THE SURFACE LOW RELATIVE TO THE HAWAIIAN ISLANDS.
SMALLER (MESOSCALE) UNSTABLE CONVECTIVE BANDS WILL DRIVE THE HOUR
BY HOUR TRENDS, POTENTIALLY LEADING TO FLASH FLOODING IMPACTS. A
FUTURE FLOOD WATCH MAY BE ISSUED AT SOME POINT EARLY NEXT WEEK FOR
THIS EVENT. THESE IMPACTS ARE CURRENTLY TOO FAR AWAY FOR DIALED
IN ISLAND BY ISLAND THREAT FORECASTING.
PREVIOUS DISCUSSION
ISSUED AT 319 PM HST THU MAR 5 2026.
DRY AND STABLE BREEZY ESE WINDS CONTINUE INTO EARLY NEXT WEEK.
BLOCKING OF THE FLOW BY THE LARGER ISLANDS WILL FACILITATE
AFTERNOON SEA BREEZE DEVELOPMENT OVER THE WESTERN END OF THE STATE
THAT WILL FAVOR INTERIOR CLOUDS CLOUDS AND ISOLATED SHOWERS EACH
AFTERNOON FOR THE SMALLER ISLANDS. DEVELOPING LAND BREEZES BRING
CLEARING OVERNIGHT.
ATTENTION THEN TURNS TO MONDAY NIGHT THROUGH THE REMAINDER OF NEXT
WEEK WHICH MAY BE PARTICULARLY ACTIVE. BY LATE THIS WEEK, THE TAIL
END OF A COLD FRONT LIFTING INTO THE GULF OF ALASKA IS MODELED TO
SETTLE IMMEDIATELY WEST OF THE ISLANDS AS BROAD ESE LOW-LEVEL FLOW
PERSISTS. LOW PRESSURE NESTLED WITHIN THE LEFT EXIT OF DIGGING
PACIFIC JET WILL ABSORB THIS REMNANT FRONTAL BAND AND USHER IT EAST
INTO THE FORECAST AREA AS EARLY AS MONDAY NIGHT, MOST LIKELY IN THE
VICINITY OF KAUAI. IMPRESSIVE DYNAMICS ALOFT WILL DEVELOP THE FRONT
VERTICALLY ALLOWING HEAVY SHOWERS TO ORGANIZE AS THEY INCREASE IN
COVERAGE AND INTENSITY. AT THE SAME TIME, DEEP SOUTHERLY FLOW
TRANSPORTS PWATS OF AT LEAST 1.75" INTO THE FORECAST AREA
DEEPENING THE WARM CLOUD LAYER, PROVIDING ADDITIONAL MOISTURE FOR
HEAVY RAIN, AND ENVELOPING THE FORECAST AREA IN A BROAD CORRIDOR
OF WEAK ISENTROPIC ASCENT THAT WILL LIKELY PRODUCE AT LEAST A FEW
POCKETS OF HEAVY RAIN WELL IN ADVANCE OF THE FRONT. AGGREGATE LOW
PRESSURE REMAINS ESTABLISHED NW OF THE STATE FOR THE ENTIRETY OF
NEXT WEEK WITH MULTIPLE EMBEDDED SHORTWAVES PROVIDING PERIODS OF
STRONGER FORCING AS THE FRONTAL BAND SLOWLY ADVANCES EAST. ON
THIS MUCH, CONSENSUS IS VERY STRONG AMONG THE GLOBAL GUIDANCE.
CLARITY ON TIMING FOR EACH ISLAND AND MAGNITUDE OF RAINFALL WILL
COME DURING THE NEXT FEW DAYS AS THE EVENT DRAWS NEARER AND
ESPECIALLY ONCE IT ENTERS THE HI-RES WINDOW. REGARDLESS, A LONG-
LIVED FLASH FLOOD THREAT IS POISED TO MANIFEST OVER PART OR ALL OF
THE ISLANDS FOR ESSENTIALLY ALL OF NEXT WEEK.
AVIATION
ISSUED AT 319 PM HST THU MAR 5 2026.
EAST-SOUTHEAST MODERATE SURFACE WINDS WILL CONTINUE TONIGHT AND
FRIDAY. THERE WILL BE AREAS OF MVFR IN LOW CLOUDS AND SHOWERS,
MAINLY ON EAST AND SOUTH SECTIONS OF KAUAI AND OAHU. VFR IN MOST
LOCATIONS.
AIRMET SIERRA CURRENTLY IN EFFECT FOR E THROUGH S KAUAI AND OAHU,
AND THIS IS EXPECTED TO CONTINUE INTO TONIGHT.
MARINE
ISSUED AT 319 PM HST THU MAR 5 2026.
FRESH TO LOCALLY STRONG EAST-SOUTHEAST TRADE WINDS WILL CONTINUE
TONIGHT INTO FRIDAY AS HIGH PRESSURE REMAINS CENTERED FAR
NORTHEAST OF THE MAIN HAWAIIAN ISLANDS. THEREFORE, A SMALL CRAFT
ADVISORY (SCA) REMAINS IN EFFECT THROUGH FRIDAY EVENING FOR THE
TYPICALLY WINDY CHANNELS AND WATERS OF MAUI COUNTY AND THE BIG
ISLAND. THIS GENERAL WIND PATTERN IS LIKELY TO HOLD THROUGH THE
WEEKEND. A LARGE LOW PRESSURE SYSTEM APPROACHING FROM THE WEST
THIS WEEKEND WILL STALL NORTHWEST OF THE ISLANDS BEGINNING EARLY
NEXT WEEK. WINDS WILL VEER MORE SOUTHERLY IN RESPONSE TO THE LOW'S
COLD FRONT MAKING A CLOSE APPROACH, OR EVEN ENTERING THE
NORTHWEST OFFSHORE WATERS, BY MID-WEEK. LOCALLY STRONG SOUTHERLY
WINDS WILL BE POSSIBLE DEPENDING ON HOW CLOSE THE COLD FRONT GETS
TO THE ISLANDS.
SURF ALONG NORTH AND WEST-FACING SHORES WILL REMAIN SMALL AS A
SERIES OF SMALL, LONG- TO MEDIUM-PERIOD NORTHWEST SWELLS REACH
THE HAWAIIAN ISLANDS OVER THE NEXT WEEK OR SO. FORERUNNERS OF THE
NEXT SMALL NORTHWEST SWELL HAVE BEEN OBSERVED AT NORTHWEST HAWAII
BUOY 51001 TODAY, AND SHOULD ARRIVE IN THE ISLANDS THIS EVENING.
THIS SMALL NORTHWEST SWELL IS EXPECTED TO PROVIDE A SMALL BUMP IN
SURF ALONG NORTH AND WEST-FACING SHORES. IT WILL BE FOLLOWED BY
ANOTHER SMALL NORTHWEST SWELL THAT WILL MAINTAIN THE SMALL SURF
THROUGH THE WEEKEND. A COMPACT STORM-FORCE LOW CURRENTLY JUST OFF
THE COAST OF JAPAN WILL LIKELY PRODUCE ANOTHER SMALL WEST-
NORTHWEST SWELL EARLY NEXT WEEK.
CHOPPY EAST SHORE SURF WILL REMAIN NEAR SEASONAL AVERAGES AS
EAST-SOUTHEASTERLY TRADE WINDS VARY MINIMALLY OVER THE NEXT FEW
DAYS, WITH A CHANCE FOR A SLIGHT INCREASE OVER THE WEEKEND. SURF
ALONG EAST-FACING SHORES WILL THEN DECLINE EARLY NEXT WEEK AS
WINDS VEER MORE SOUTHERLY.
SURF ALONG SOUTH-FACING SHORES WILL REMAIN SMALL THROUGH THE
WEEKEND, BUT IS THEN EXPECTED TO INCREASE AND BECOME CHOPPIER
WITH THE SHIFT TO A MORE SOUTHERLY WIND DIRECTION EARLY NEXT WEEK.
A SMALL, LONG-PERIOD SOUTH SWELL IS ALSO POSSIBLE AROUND TUESDAY
OF NEXT WEEK.
HFO WATCHES/WARNINGS/ADVISORIES
SMALL CRAFT ADVISORY UNTIL 6 PM HST FRIDAY FOR ALENUIHAHA
CHANNEL-BIG ISLAND LEEWARD WATERS-BIG ISLAND SOUTHEAST WATERS-
BIG ISLAND WINDWARD WATERS-MAUI COUNTY WINDWARD WATERS-PAILOLO
CHANNEL.
PREVIOUS DISCUSSION...BOHLIN
DISCUSSION...JVC
AVIATION...PARKER
MARINE...VAUGHAN
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