447
FXHW60 PHFO 130144
AFDHFO
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
344 PM HST THU MAR 12 2026
SYNOPSIS
A POWERFUL KONA STORM WILL NEAR THE STATE PRODUCING PERIODS OF
HAZARDOUS WEATHER IMPACTS ACROSS THE HAWAIIAN ISLANDS THROUGH THE
WEEKEND. EXPECT A COMBINATION OF THREATS RANGING FROM SIGNIFICANT
FLASH FLOODING, DAMAGING WINDS, STRONG TO SEVERE THUNDERSTORMS,
AND SNOW AND ICE OVER THE HIGHEST BIG ISLAND SUMMITS. SOUTHWESTERLY
WINDS WILL BE STRONGEST FROM FRIDAY TO SATURDAY AND WILL PRODUCE
DAMAGING WIND GUSTS ALONG NORTH AND EAST OF THE ISLAND MOUNTAINS.
UNSETTLED WET WEATHER CONDITIONS WITH SOUTHWESTERLY WINDS WILL
CONTINUE INTO EARLY NEXT WEEK. THE KONA STORM BEGINS TO LIFT
NORTHWARD ON MONDAY, AND UNSETTLED WEATHER WILL START TO EASE
ACROSS THE HAWAII REGION. HIGH PRESSURE WILL BUILD BACK IN NORTH
OF THE STATE ALLOWING TRADE WINDS TO RETURN FROM NEXT WEDNESDAY
ONWARD.
DISCUSSION
LATEST SATELLITE IMAGERY SHOWS A COMPLEX SURFACE LOW 1500 SM
NORTHWEST OF KAUAI WITH BANDS OF WIDELY SCATTERED TO NUMEROUS
MODERATE THUNDERSTORMS ALONG THE EASTERN FLANK OF THE COMPLEX. ONE
OF THESE BANDS WITH ISOLATED MODERATE THUNDERSTORMS IS CURRENTLY
MOVING THROUGH THE STATE PRODUCING WIDESPREAD LIGHT TO MODERATE
SHOWERS ALONG THE THE WEST BIG ISLAND COAST MOVING NORTH OVER THE
ISLAND OF MAUI. A BRIEF BREAK IN THE RAIN WILL OCCUR AFTER THIS
BAND MOVES THROUGH REST OF THIS AFTERNOON WITH ANOTHER BAND
SETTING UP RIGHT BEHIND THIS ONE WITH A NORTH NORTHEAST TRACK.
LATEST HIGH RESOLUTION MODEL GUIDANCE SHOWS MODERATE TO HEAVY
SHOWERS REORGANIZING AND TRAINING FROM SOUTH TO NORTH OVER KAUAI
EARLY THIS EVENING WITH THE PASSAGE OF THIS SECOND BAND OF
SHOWERS. INCREASING PROBABILITY OF MODERATE TO HEAVY SHOWERS AND
THUNDERSTORMS WILL CONTINUE INTO THE OVERNIGHT HOURS AS THE KONA
LOW SAGS SOUTHEAST AND UPPER LEVEL DYNAMICS INTENSIFIES, LEADING
TO SHOWERS INTENSIFYING AND SLOWLY SPREADING FROM KAUAI TO OAHU
OVERNIGHT AND EARLY MORNING FRIDAY.
EXPECT A WELL ORGANIZED BAND OF MODERATE TO HEAVY SHOWERS TO
SPREAD STATE WIDE FRIDAY ASSOCIATED WITH THE KONA LOW. IN
ADDITION, SOUTHWESTERLY WINDS WILL RAMP UP WITH WINDS SPEED UP
INTO THE 50 TO 70 MPH RANGE AROUND THE 5,000 FOOT LEVEL AS THE
KONA LOW INCHES CLOSER TO THE STATE. A HIGH WIND WARNING HAS BEEN
ISSUED FOR THE SMALLER ISLANDS AND FOR THE SUMMITS OF HALEAKALA
AND THE BIG ISLAND AS STRONG SOUTHWESTERLY WINDS DEVELOP AROUND
KAUAI AND THEN SPREAD THROUGH MAUI COUNTY THROUGH THE DAY FRIDAY.
A HIGH WIND WATCH FOR THE LOWER ELEVATIONS OF THE BIG ISLAND
REMAINS IN EFFECT AS STRONGER WINDS MAY NOT ARRIVE TILL FRIDAY
AFTERNOON OR EVENING THUS WILL CONTINUE TO MONITOR. ALREADY
SATURATED GROUND CONDITIONS AND TREES UNACCUSTOMED TO SOUTHWEST
WINDS WILL FALL AND LIKELY CAUSE BLOCKED ROADWAYS AND LEAD TO
POWER OUTAGES. A WINTER STORM WARNING HAS BEEN ISSUED FOR THE
SUMMITS OF THE BIG ISLAND AS INCREASING CHANCES OF PRECIPITATION
AND FREEZING TEMPERATURE ALOFT WILL GENERATE PERIODS OF HEAVY SNOW INTO
THE WEEKEND.
HIGH LEVELS OF INSTABILITY, WIND SHEAR AND ATMOSPHERIC FORCING
INGREDIENTS ARE ALL COMING INTO FOCUS OVER THE ISLANDS FROM FRIDAY
THROUGH SATURDAY FOR A POTENTIAL SEVERE WEATHER EVENT. A SEVERE
THUNDERSTORM WATCH MAY BE NEEDED FOR FRIDAY THROUGH SATURDAY TIME
PERIOD. HOWEVER, WE WILL LIKELY WAIT UNTIL WE SEE THESE SEVERE
THUNDERSTORM DEVELOPING OVER THE LOCAL AREA BEFORE PULLING THE
TRIGGER ON THIS SEVERE THUNDERSTORM WATCH WITH A SHORT LEAD TIME
MEASURED IN HOURS. OUTSIDE OF TERRAIN ENHANCING WIND GUSTS ANY
STRONG THUNDERSTORMS ARE CAPABLE OF PRODUCING SEVERE HURRICANE
FORCE WIND GUSTS OVER ISLANDS OR COASTAL WATERS THROUGH SATURDAY.
FROM SATURDAY NIGHT TO SUNDAY ANOTHER UPPER LEVEL SHORT WAVE
TROUGH PASSES OVER THE ISLANDS LEADING TO ANOTHER UPWARD PULSE IN
MODERATE TO HEAVY SHOWER ACTIVITY. THUNDERSTORMS WILL ALSO
THREATEN THE ISLANDS AND BECOME MORE OF A FLOODING THREAT AS
DECREASING UPPER LEVEL AND SURFACE WIND SPEEDS DIMINISH THE
DAMAGING WIND GUST THREATS. THE THREAT FOR FLASH FLOODING WILL
CONTINUE INTO THE WEEKEND DUE TO BOTH SATURATED SOIL CONDITIONS
THAT MORE EASILY LEAD TO GROUND RUNOFF AND FLOODING FROM EVEN MORE
MODERATE CONTINUOUS RAINFALL RATES. THE HIGHEST FLOOD THREATS
ACROSS THE STATE WILL FAVOR SOUTHERN AND WESTERN SLOPES OF ALL
ISLANDS. THESE ARE TYPICALLY THE DRIER SIDES OF THE ISLANDS, LESS
ACCUSTOMED TO HEAVY RAIN AND FLOODING. DRIVING UNDER THESE HEAVY
SHOWER BANDS WILL BECOME CHALLENGING WITH PONDING OF WATER ON AREA
ROADWAYS. A FLOOD WATCH CONTINUES FOR ALL HAWAIIAN ISLANDS INTO
SATURDAY, THIS FLOOD WATCH MAY NEED TO BE EXTENDED IN TIME AS THE
HEAVY RAINFALL THREAT MAY LINGER INTO SUNDAY.
MONDAY AND TUESDAY, THE LARGE KONA STORM BEGINS TO LIFT NORTHWARD
DRIFTING SLOWLY AWAY FROM THE HAWAIIAN ISLANDS. THIS MEANS WET
WEATHER CONTINUES, HOWEVER MODERATE TO HEAVY RAINFALL RATES WILL
DECREASE AND SOUTHWEST WINDS WILL GRADUALLY WEAKEN THROUGH THE
FIRST HALF OF NEXT WEEK.
BY WEDNESDAY, THE LATEST LONG RANGE GUIDANCE SHOWS A HIGH PRESSURE
SYSTEM BUILDING BACK INTO POSITION JUST NORTH OF THE ISLAND CHAIN,
ALLOWING A RETURN TO A TYPICAL TRADE WIND WEATHER PATTERN WITH
MORE TYPICAL BRIEF PASSING SHOWERS OVER WINDWARD MOUNTAIN AREAS.
AVIATION
SHOWER ACTIVITY CONTINUES ACROSS THE ISLANDS THIS AFTERNOON,
BEFORE A BRIEF DRY SPELL WILL TAKE HOLD THIS EVENING. EXPECT MVFR
TO IFR CONDITIONS UNDER SHOWERS, TO LOCALLY AS LOW AS LIFR. WINDS
WILL REMAIN PRIMARILY OUT OF THE SOUTH AND SOUTHEAST. SHOWERS ARE
THEN EXPECTED TO BECOME MORE WIDESPREAD OVERNIGHT, STARTING AT
KAUAI AND MOVING EASTWARD. WINDS WILL ALSO BECOME GUSTY TO STRONG
TOMORROW OUT OF THE SOUTH, WITH WIDESPREAD GUSTS UP TO AND OVER
35 KTS EXPECTED.
AIRMET SIERRA REMAINS IN EFFECT FOR KAUAI, OAHU, MOLOKAI, LANAI,
AND MAUI DUE TO MOUNTAIN OBSCURATION FROM SHOWERS. SOME RELIEF IS
EXPECTED THIS EVENING AS SHOWERS DECREASE IN COVERAGE, BUT
CURRENT THINKING IS THAT THIS AIRMET WILL REMAIN IN EFFECT SO LONG
AS SHOWER ACTIVITY PERSISTS ACROSS THE ISLANDS.
AIRMET TANGO REMAINS IN EFFECT FOR MODERATE UPPER-LEVEL TURBULENCE
BETWEEN FL240 AND 360. THIS ONGOING KONA LOW SHOULD KEEP
TURBULENCE PREVAILING OVER THE NEXT FEW DAYS.
AIRMET ZULU IS ALSO IN EFFECT, AS HIGH CLOUDS FROM THESE SHOWERS
PRESENT ICING CONCERNS BETWEEN FL120 AND 260. ONCE AGAIN, SOME
RELIEF IS EXPECTED THIS AFTERNOON, BEFORE HIGH CLOUDS ENVELOP THE
ISLANDS ONCE AGAIN LATER THIS EVENING.
MARINE
A POWERFUL KONA STORM WILL CONTINUE TO BRING HEAVY RAIN,
THUNDERSTORMS, AND ROUGH SEAS TO THE HAWAIIAN COASTAL AND
OFFSHORE WATERS INTO THE WEEKEND. SOUTHERLY WINDS WILL
STRENGTHEN TONIGHT INTO THE WEEKEND, WITH GALE-FORCE WINDS
POSSIBLE. A GALE WARNING HAS BEEN ISSUED FOR THE WATERS NEAR KAUAI
AND OAHU WITH GALE-FORCE WINDS FORECAST FRIDAY AND FRIDAY NIGHT.
WINDS ARE EXPECTED TO NEAR MAUI COUNTY SATURDAY AND SATURDAY
NIGHT TO NEAR GALE-FORCE, SO A GALE WATCH HAS BEEN POSTED FOR
THOSE AREAS DURING THAT TIME. THESE STRONG TO GALE-FORCE WINDS
WILL LAST INTO THE WEEKEND IN ASSOCIATION WITH A BAND OF HEAVY
SHOWERS AND THUNDERSTORMS PUSHING EASTWARD ACROSS THE FORECAST
AREA ASSOCIATED WITH THE KONA STORM.
A SERIES OF SMALL, SHORT TO MEDIUM PERIOD WEST-NORTHWEST SWELLS
WILL BRING SMALL SURF TO NORTH AND WEST FACING SHORES THROUGH THE
REMAINDER OF THE WEEK. KAUAI WILL BLOCK SOME OF THIS SWELL ENERGY
FROM REACHING OAHU AND MAUI, BUT IT WILL MAKE IT INTO THE WEST
FACING SHORES OF THE BIG ISLAND. THE NEXT WEST-NORTHWEST SWELL IS
EXPECTED TO BUILD FRIDAY INTO THE WEEKEND. ADDITIONALLY, A SMALL,
MEDIUM PERIOD NORTH SWELL ORIGINATING FROM ALASKA PENINSULA GAP
WINDS IS EXPECTED TO ARRIVE TONIGHT AND CONTINUE INTO THE WEEKEND.
ROUGH AND CHOPPY SURF WILL CONTINUE ALONG SOUTH-FACING SHORES DUE
TO THE SOUTHERLY WIND DIRECTION. THESE SOUTH WINDS WILL INTENSIFY
TONIGHT INTO FRIDAY, CAUSING SOUTH SHORE SURF TO BUILD FRIDAY
INTO THE WEEKEND, LIKELY REACHING ADVISORY LEVELS. ONCE SOUTHERLY
WINDS DIMINISH EARLY NEXT WEEK, A SMALL TO MODERATE, LONG-PERIOD
SOUTH SWELL GENERATED BY A GALE FORCE LOW EAST-SOUTHEAST OF NEW
ZEALAND WILL ARRIVE ALONG SOUTH-FACING SHORES AND BUILD INTO
MIDWEEK.
CHOPPY SURF ALONG EAST-FACING SHORES WILL CONTINUE TO TREND
DOWNWARD AND REMAIN BELOW SEASONAL LEVELS AS SOUTH TO SOUTHEAST
WINDS PREVAIL.
HFO WATCHES/WARNINGS/ADVISORIES
FLOOD WATCH THROUGH SATURDAY AFTERNOON FOR NIIHAU-KAUAI LEEWARD-
KAUAI MOUNTAINS-WAIANAE COAST-OAHU NORTH SHORE-OLOMANA-CENTRAL
OAHU-WAIANAE MOUNTAINS-LANAI MAUKA-KAHOOLAWE-MAUI WINDWARD WEST-
MAUI LEEWARD WEST-HALEAKALA SUMMIT-KONA-KOHALA-BIG ISLAND
INTERIOR-KAUAI NORTH-KAUAI EAST-KAUAI SOUTH-EAST HONOLULU-
HONOLULU METRO-EWA PLAIN-KOOLAU WINDWARD-KOOLAU LEEWARD-MOLOKAI-
LANAI WINDWARD-LANAI LEEWARD-LANAI SOUTH-MAUI CENTRAL VALLEY
NORTH-MAUI CENTRAL VALLEY SOUTH-WINDWARD HALEAKALA-KIPAHULU-
SOUTH MAUI/UPCOUNTRY-SOUTH HALEAKALA-BIG ISLAND SOUTH-BIG ISLAND
SOUTHEAST-BIG ISLAND EAST-BIG ISLAND NORTH.
HIGH WIND WARNING UNTIL 6 AM HST SUNDAY FOR NIIHAU-KAUAI LEEWARD-
KAUAI MOUNTAINS-WAIANAE COAST-OAHU NORTH SHORE-OLOMANA-CENTRAL
OAHU-WAIANAE MOUNTAINS-LANAI MAUKA-KAHOOLAWE-MAUI WINDWARD WEST-
MAUI LEEWARD WEST-KAUAI NORTH-KAUAI EAST-KAUAI SOUTH-EAST
HONOLULU-HONOLULU METRO-EWA PLAIN-KOOLAU WINDWARD-KOOLAU LEEWARD-
MOLOKAI-LANAI WINDWARD-LANAI LEEWARD-LANAI SOUTH-MAUI CENTRAL
VALLEY NORTH-MAUI CENTRAL VALLEY SOUTH-WINDWARD HALEAKALA-
KIPAHULU-SOUTH MAUI/UPCOUNTRY-SOUTH HALEAKALA.
HIGH WIND WARNING UNTIL 6 PM HST SUNDAY FOR HALEAKALA SUMMIT-BIG
ISLAND SUMMITS.
HIGH WIND WATCH FROM FRIDAY MORNING THROUGH LATE SATURDAY NIGHT
FOR KONA-KOHALA-BIG ISLAND INTERIOR-BIG ISLAND SOUTH-BIG ISLAND
SOUTHEAST-BIG ISLAND EAST-BIG ISLAND NORTH.
WINTER WEATHER ADVISORY UNTIL 4 PM HST THIS AFTERNOON FOR BIG
ISLAND SUMMITS.
WINTER STORM WARNING UNTIL 6 PM HST SATURDAY FOR BIG ISLAND
SUMMITS.
GALE WARNING UNTIL 6 AM HST SATURDAY FOR KAUAI NORTHWEST WATERS-
KAUAI WINDWARD WATERS-KAUAI LEEWARD WATERS-KAUAI CHANNEL-OAHU
WINDWARD WATERS-OAHU LEEWARD WATERS.
GALE WATCH FROM SATURDAY MORNING THROUGH SATURDAY EVENING FOR
OAHU WINDWARD WATERS-KAIWI CHANNEL-MAUI COUNTY WINDWARD WATERS-
MAUI COUNTY LEEWARD WATERS-ALENUIHAHA CHANNEL.
DISCUSSION...ALMANZA
AVIATION...EVANS
MARINE...M BALLARD
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