812
FXHW60 PHFO 162002
AFDHFO
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
1002 AM HST MON MAR 16 2026
SYNOPSIS
AS THE KONA LOW EXITS TO THE NORTH OF THE HAWAIIAN ISLANDS,
REMNANT BANDS OF MODERATE SHOWERS CONTINUE OVER LEEWARD BIG ISLAND
AND MAUI WHILE CONDITIONS IMPROVE ELSEWHERE. TOWARD THE LATTER
END OF THE WEEK, ANOTHER THREAT OF HEAVY RAIN IS ANTICIPATED AS
LOW PRESSURE DEVELOPS WEST OF THE ISLANDS.
SHORT TERM UPDATE
ISSUED AT 959 AM HST MON MAR 16 2026
SOUTHERLY KONA WINDS CONTINUE ACROSS THE REGION THIS MORNING,
THOUGH SPEEDS FOR LOWER ELEVATIONS HAVE DROPPED SIGNIFICANTLY
VERSUS WHAT WERE OBSERVED YESTERDAY. HOWEVER, WITH THAT SAID,
MOISTURE EMBEDDED WITHIN THE SOUTHERLY FLOW CAN BEEN SEEN ON
LATEST RADAR AND SATELLITE IMAGERY MAKING ITS WAY NORTHEAST. MOST
OF THE RAIN IS OCCURRING IN OR NEAR THE ALENUIHAHA CHANNEL AND
THE BIG ISLAND AT THIS TIME. REGIONAL SATELLITE IMAGERY SHOWS
CONVECTION DEVELOPING UPSTREAM, SOUTHWEST OF THE BIG ISLAND, WHERE
CLOUD TOPS ARE REACHING UP TO AROUND 45,000 FEET. POCKETS OF
HEAVY RAIN CAN BE EXPECTED WITHIN THIS ACTIVITY AS IT APPROACHES
THE WESTERN DISTRICTS OF THE BIG ISLAND LATE THIS MORNING INTO
EARLY AFTERNOON. THIS SCENARIO IS ALSO SUPPORTED IN THE LATEST HI-
RES GUIDANCE AND CAMS, THE MAJORITY OF WHICH SHOW SOME VARIATION
OF AN INCREASE IN SHOWERS AND LOCALLY HEAVY RAIN OVER OR NEAR THE
BIG ISLAND AND EAST MAUI THROUGH THE DAY TODAY BEFORE TAPERING
OFF THIS EVENING. ELSEWHERE, MUCH LIGHTER AND MORE ISOLATED TO
SCATTERED SHOWERS ARE EXPECTED FOR THE REST OF THE DAY.
ADDITIONALLY, OBSERVATIONS FROM THE BIG ISLAND SUMMITS CONTINUE TO
SHOW SUSTAINED WINDS IN EXCESS OF 56 MPH WITH GUSTS EXCEEDING 66
MPH. THEREFORE, THE HIGH WIND WARNING WILL REMAIN IN EFFECT FOR
THE SUMMITS OF THE BIG ISLAND AND FOR HALEAKALA THROUGH THE
REMAINDER OF THE DAY.
PREV DISCUSSION
REMNANT BANDS OF MODERATE SHOWERS CONTINUE TO AFFECT LEEWARD BIG
ISLAND AND AND PORTIONS OF MAUI COUNTY, AND ARE EXPECTED TO
PERSIST THROUGH AT LEAST TONIGHT AND POSSIBLY THROUGH TUESDAY.
HOWEVER, RECENT OBSERVATIONS INDICATE HOURLY RAINFALL RATES REMAIN
BELOW A TENTH OF AN INCH ACROSS BOTH ISLANDS. IN RESPONSE TO THE
REDUCED RAINFALL INTENSITY AND IMPROVED FLOODING THREAD, THE FLASH
FLOOD WATCH FOR MAUI COUNTY AND THE BIG ISLAND HAS BEEN CANCELLED
WITH THE ISSUANCE OF THIS MORNING'S FORECAST PACKAGE.
OBSERVATIONS FROM THE MAUNAKEA WEATHER CENTER, ALONG WITH MODEL
GUIDANCE INDICATING STRONG WINDS NEAR THE 600 MB LEVEL, SUGGEST
THAT HIGH WINDS ACROSS THE BIG ISLAND SUMMITS AND HALEAKALA WILL
PERSIST BEYOND THE PREVIOUSLY SCHEDULED 6 AM HST EXPIRATION TIME.
AS A RESULT, THE HIGH WIND WARNING HAS BEEN EXTENDED THROUGH 6 PM
HST THIS EVENING. CONDITIONS WILL CONTINUE TO BE MONITORED AND
REEVALUATED WITH THE NEXT FORECAST CYCLE.
CONFIDENCE IN THE EXTENDED FORECAST BEYOND MONDAY REMAINS
SOMEWHAT LIMITED AS MODEL GUIDANCE CONTINUES TO EVOLVE. CURRENT
SOLUTIONS MAINTAIN AN UPPER-LEVEL TROUGH ACROSS THE REGION,
SUPPORTING A PATTERN OF LIGHT AND VARIABLE WINDS WITH PERIODS OF
SHOWERS AND THE POTENTIAL FOR ISOLATED THUNDERSTORMS THROUGH MUCH
OF THE WEEK. TOWARD THE LATTER PART OF THE WEEK, MODEL GUIDANCE
DIVERGES SOMEWHAT, WITH THE GFS DEPICTING A FLATTER AND MORE
PROGRESSIVE SURFACE LOW WHILE THE ECMWF SUGGESTS A DEEPER AND
SLOWER-MOVING SYSTEM. THE LATEST GFS RUN HAS TRENDED CLOSER TO THE
ECMWF SOLUTION, INCREASING CONFIDENCE THAT ORGANIZED LOW PRESSURE
COULD DEVELOP OVER OR NEAR THE ISLAND BY LATE WEEK. GIVEN THE
UNCERTAINTY AT THIS RANGE, THE FORECAST WILL CONTINUE TO BE
REFINED IN SUBSEQUENT UPDATES.
AVIATION
ISSUED AT 959 AM HST MON MAR 16 2026
SHOWERS CONTINUE TO BRING INTERMITTENT MVFR AND ISOLATED IFR TO
THE AREA. MOST AREAS WILL BE VFR THROUGH TODAY, EVEN AS SHOWERS
INCREASE IN COVERAGE AND INTENSITY OVER MAUI AND THE BIG ISLAND
THIS AFTERNOON. SHOWERS COVERAGE WILL INCREASE TONIGHT OVER
WESTERN ISLANDS, AND REMAIN OVER THE EASTERN ISLANDS. WINDS HAVE
DECREASED AND TURBULENCE DOES NOT APPEAR TO BE A SIGNIFICANT ISSUE
ANY LONGER.
AIRMET SIERRA IS IN EFFECT FOR MTN OBSC FOR MAUI, LANAI, AND THE
BIG ISLAND. CONDS IN GENERAL WILL IMPROVE WEST TO EAST AND THIS
AIRMET WILL BE ADJUSTED AS NECESSARY.
MARINE
ISSUED AT 328 AM HST MON MAR 16 2026
CONDITIONS OVER THE MARINE AREA WILL CONTINUE TO IMPROVE DURING
THE NEXT COUPLE OF DAYS, AS THE RECENT KONA STORM MOVES NORTHEAST
AND AWAY FROM THE AREA. WINDS AND SEAS HAVE DROPPED BELOW ADVISORY
LEVELS EARLY THIS MORNING, THEREFORE THE SMALL CRAFT ADVISORY
(SCA) HAS BEEN CANCELLED. THE GRADIENT IN THE WAKE OF THE STORM
WILL REMAIN RATHER WEAK TUESDAY AND WEDNESDAY, WITH LIGHT AND
VARIABLE WINDS PREVAILING OVER THE WATERS. THE PATTERN BECOMES
MORE UNCERTAIN LATE IN THE WEEK. A BRIEF PERIOD OF LIGHT TO
MODERATE TRADES WILL BE POSSIBLE THURSDAY AS A WEAK RIDGE BUILDS
NORTH OF THE STATE, FOLLOWED BY LIGHT TO MODERATE SOUTHERLY WINDS
ON FRIDAY AS A NEW STORM SYSTEM APPROACHES FROM THE WEST.
SURF ALONG SOUTH FACING SHORES WILL TREND DOWN LOWER TODAY AS
SOUTH TO SOUTHWESTERLY WINDS EASE. A NEW LONG PERIOD SOUTH SWELL
WILL THEN ARRIVE LATE TONIGHT AND TUESDAY, GIVING A NICE AND
EXTENDED BOOST TO SOUTH SHORE SURF THROUGH LATE THIS WEEK.
A MODERATE SIZED SHORT-PERIOD WEST SWELL ASSOCIATED WITH THE
RECENT KONA STORM WILL AFFECT NORTH AND WEST FACING SHORES TODAY,
BUT SURF WILL REMAIN BELOW ADVISORY LEVELS. AS A RESULT, THE HIGH
SURF ADVISORY FOR WEST FACING SHORES OF THE BIG ISLAND HAS BEEN
CANCELLED. THE SHORT-PERIOD WEST SWELL WILL LOWER TONIGHT AND
TUESDAY, WHILE A NEW MEDIUM-PERIOD NORTH-NORTHWEST SWELL FILLS
IN. THIS NORTH-NORTHWEST SWELL COULD BRING SURF UP CLOSE TO
ADVISORY LEVELS TUESDAY NIGHT AND WEDNESDAY, WITH THE SWELL THEN
SHIFTING MORE NORTHERLY AND LOWERING BELOW ADVISORY LEVELS
THURSDAY INTO NEXT WEEKEND.
SURF ALONG EAST FACING SHORES WILL REMAIN WELL BELOW NORMAL LEVELS
THROUGH LATE IN THE WEEK AS TRADE WINDS OVER AND UPSTREAM OF THE
ISLANDS APPEAR TO REMAIN MOSTLY DISRUPTED.
MARINE
CONDITIONS OVER THE MARINE AREA WILL CONTINUE TO IMPROVE DURING
THE NEXT COUPLE OF DAYS, AS THE RECENT KONA STORM MOVES NORTHEAST
AND AWAY FROM THE AREA. WINDS AND SEAS HAVE DROPPED BELOW ADVISORY
LEVELS EARLY THIS MORNING, THEREFORE THE SMALL CRAFT ADVISORY
(SCA) HAS BEEN CANCELLED. THE GRADIENT IN THE WAKE OF THE STORM
WILL REMAIN RATHER WEAK TUESDAY AND WEDNESDAY, WITH LIGHT AND
VARIABLE WINDS PREVAILING OVER THE WATERS. THE PATTERN BECOMES
MORE UNCERTAIN LATE IN THE WEEK. A BRIEF PERIOD OF LIGHT TO
MODERATE TRADES WILL BE POSSIBLE THURSDAY AS A WEAK RIDGE BUILDS
NORTH OF THE STATE, FOLLOWED BY LIGHT TO MODERATE SOUTHERLY WINDS
ON FRIDAY AS A NEW STORM SYSTEM APPROACHES FROM THE WEST.
SURF ALONG SOUTH FACING SHORES WILL TREND DOWN LOWER TODAY AS
SOUTH TO SOUTHWESTERLY WINDS EASE. A NEW LONG PERIOD SOUTH SWELL
WILL THEN ARRIVE LATE TONIGHT AND TUESDAY, GIVING A NICE AND
EXTENDED BOOST TO SOUTH SHORE SURF THROUGH LATE THIS WEEK.
A MODERATE SIZED SHORT-PERIOD WEST SWELL ASSOCIATED WITH THE
RECENT KONA STORM WILL AFFECT NORTH AND WEST FACING SHORES TODAY,
BUT SURF WILL REMAIN BELOW ADVISORY LEVELS. AS A RESULT, THE HIGH
SURF ADVISORY FOR WEST FACING SHORES OF THE BIG ISLAND HAS BEEN
CANCELLED. THE SHORT-PERIOD WEST SWELL WILL LOWER TONIGHT AND
TUESDAY, WHILE A NEW MEDIUM-PERIOD NORTH-NORTHWEST SWELL FILLS
IN. THIS NORTH-NORTHWEST SWELL COULD BRING SURF UP CLOSE TO
ADVISORY LEVELS TUESDAY NIGHT AND WEDNESDAY, WITH THE SWELL THEN
SHIFTING MORE NORTHERLY AND LOWERING BELOW ADVISORY LEVELS
THURSDAY INTO NEXT WEEKEND.
SURF ALONG EAST FACING SHORES WILL REMAIN WELL BELOW NORMAL LEVELS
THROUGH LATE IN THE WEEK AS TRADE WINDS OVER AND UPSTREAM OF THE
ISLANDS APPEAR TO REMAIN MOSTLY DISRUPTED.
HFO WATCHES/WARNINGS/ADVISORIES
HIGH WIND WARNING UNTIL 6 PM HST THIS EVENING FOR BIG ISLAND
SUMMITS-HALEAKALA SUMMIT.
UPDATE...VAUGHAN
DISCUSSION...PIERCE
AVIATION...PARKER
MARINE...JELSEMA
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