028
FXHW60 PHFO 051601 CCA
AFDHFO
AREA FORECAST DISCUSSION...CORRECTED
NATIONAL WEATHER SERVICE HONOLULU HI
601 AM HST MON JAN 5 2026
SYNOPSIS
A SURFACE TROUGH WEST OF KAUAI AND ITS PARENT UPPER LEVEL LOW
WILL SAG SOUTHWARD TODAY. THIS WILL CONTINUE THE THREAT OF FLASH
FLOODING INTO TUESDAY. BREEZY EAST-SOUTHEAST WINDS WILL
STRENGTHEN TO BREEZY TO WINDY LEVELS TODAY WHICH MAY REQUIRE A
WIND ADVISORY FOR LOWER ELEVATIONS ALONG RIDGES AND POINTS.
SIGNIFICANT SNOW AND ICE ACCUMULATIONS WILL CONTINUE FOR THE BIG
ISLAND SUMMITS TODAY. THE UPPER LEVEL LOW IS EXPECTED TO WEAKEN
TODAY INTO TUESDAY AS THE SURFACE TROUGH SHIFTS WEST OF THE STATE,
ALLOWING CHANCES OF THUNDERSTORMS AND HEAVY RAIN TO TAPER OFF.
CLOUDY CONDITIONS WILL STILL CONTINUE THROUGH THE REST OF THE WEEK
AS LIGHT WINDS DEVELOP DURING THE SECOND HALF OF THE WEEK
ALLOWING FOR SEA BREEZES TO DEVELOP BUT SHOWERS WILL ONLY BE
LIGHT TO MODERATE.
DISCUSSION
LATEST SATELLITE IMAGERY SHOWS A THICK BAND OF CLOUDS WITH
EMBEDDED HEAVY SHOWERS AND THUNDERSTORMS MAINLY OVER THE WESTERN
OFFSHORE AND KAUAI COASTAL WATERS. HIGH CLOUDS FROM THE UPPER
LEVEL LOW ARE STREAMING OVER THE STATE FROM THE SUBTROPICAL JET.
NUMEROUS LOW LEVEL CLOUDS AND MODERATE TO LOCALLY HEAVY SHOWERS
ARE FOCUSED ALONG SOUTHEAST AND EASTERN SLOPES OF THE BIG ISLAND,
WITH SCATTERED CLOUDS AND ISOLATED MODERATE TO BRIEF HEAVY SHOWERS
DEVELOPING ELSEWHERE ALONG SOUTHEAST AND EASTERN SLOPES OF THE
ISLAND CHAIN.
THE STATEWIDE FLOOD WATCH REMAINS IN EFFECT THROUGH THIS AFTERNOON,
AND MAY NEED TO BE EXTENDED INTO TUESDAY FOR ALL OR PORTIONS OF
THE STATE. LATEST NEAR-TERM MODEL GUIDANCE SHOWS THE THE GREATEST
POTENTIAL FOR EXCESSIVE RAIN AND FLOODING TO OCCUR OVER KAUAI
COUNTY AND ALONG SOUTHEAST AND EASTERN EXPOSURES OF BIG ISLAND AND
MAUI COUNTY TODAY AND TONIGHT. HOWEVER THE CONVECTIVE NATURE OF
THIS PATTERN WILL STILL KEEP SOME POTENTIAL OF HEAVY RAIN AND
THUNDERSTORMS OVER THE REST OF THE STATE.
HEAVY SNOW AND ICY CONDITIONS WILL CONTINUE FOR THE BIG ISLAND
SUMMITS THROUGH TODAY. IN ADDITION, WINDS ARE EXPECTED TO RAMP UP
TO BOARDERLINE HIGH WIND WARNING CRITERIA LATER THIS AFTERNOON.
THUS, A HIGH WIND WARNING AND A WINTER STORM WARNING REMAIN IN
EFFECT THROUGH TO 6 AM HST TUESDAY.
STRENGTHENING SOUTHEAST WINDS TODAY COULD WARRANT THE ISSUANCE OF
A WIND ADVISORY FOR LOW-LEVEL ELEVATIONS ALONG RIDGES AND PEAKS.
WILL CONTINUE TO MONITOR ALL AVAILABLE OBSERVATIONS THROUGHOUT THE
DAY.
THE THREAT OF HEAVY RAIN AND THUNDERSTORMS WILL DRASTICALLY
DECREASE TUESDAY AS THE UPPER LEVEL LOW WEAKENS AND THE SURFACE
TROUGH SHIFTS WEST OF THE STATE. SOUTHEAST WINDS WILL ALSO
GRADUALLY EASE TUESDAY THROUGH WEDNESDAY TO LIGHT TO BREEZY
LEVELS. WEATHER CONDITIONS WILL CONTINUE TO REMAIN SOMEWHAT
UNSETTLED THROUGH WEDNESDAY DUE TO THE WEAKENING UPPER LEVEL LOW
STILL LINGERING NEAR THE STATE. LOW LEVEL WINDS WILL CONTINUE TO
REMAIN OUT OF THE EAST TO SOUTHEAST DIRECTION, WHICH WILL CONTINUE
TO FAVOR SHOWERS OVER WINDWARD BIG ISLAND AND POSSIBLE KAUAI.
SOME LOCALLY HEAVY SHOWERS WILL CONTINUE TO REMAIN POSSIBLE ON
WEDNESDAY. STARTING THURSDAY, A FRONT PASSING NORTH OF THE STATE
WILL CAUSE THE WINDS TO WEAKEN AND VEER FURTHER TO THE SOUTHEAST
DIRECTION. WITH THE LIGHT WINDS IN PLACE ON THURSDAY, WE COULD SEE
SEA BREEZES DEVELOP DURING THE DAY, WHICH WILL ALLOW FOR
AFTERNOON CLOUDS AND SCATTERED SHOWERS. OVERALL, CONDITIONS SHOULD
BE STABILIZING ON THURSDAY WHICH SHOULD KEEP ANY SHOWERS ON THE
LIGHTER SIDE.
FROM FRIDAY AND BEYOND, THERE IS STILL QUITE A BIT OF UNCERTAINTY
IN THE LONG RANGE FORECAST. BOTH THE GFS AND ECMWF SHOW AN AREA OF
LOW PRESSURE DEVELOPING NORTH OF THE STATE, BUT THEY DIFFER IN
LOCATION AND INTENSITY. THE GLOBAL ENSEMBLE MEMBERS SEEM TO FAVOR
SHOWERS OVER THE WESTERN HALF OF THE STATE. FOR NOW THE FORECAST
REFLECTS SCATTERED SHOWERS OVER THE WESTERN HALF OF THE STATE, BUT
WE COULD SEE SHOWER COVERAGE INCREASE DEPENDING ON THE DEVELOPMENT
OF THE LOW. BEYOND SATURDAY, LONG RANGE MODELS ARE SHOWING A COLD
FRONT PUSHING THROUGH THE STATE EARLY NEXT WEEK.
AVIATION
UNSETTLED WEATHER WILL CONTINUE TO IMPACT PRIMARILY WINDWARD AND
MAUKA AREAS TODAY AND TONIGHT. PERIOD OF MVFR AND/OR IFR
CONDITIONS WILL IMPACT THESE AREA, WHILE PRIMARILY VFR CONDITIONS
PREVAIL IN LEEWARD AREAS. EASTERLY TRADE WINDS WILL INCREASE
ACROSS THE ISLANDS TODAY, BECOMING BREEZY AND GUSTY IN MOST AREAS
THIS MORNING.
AIRMET SIERRA REMAINS IN EFFECT FOR MOUNTAIN OBSCURATION OVER
WINDWARD AREAS OF ALL ISLANDS. THESE CONDITIONS WILL LIKELY
PERSIST THROUGH THE DAY. AIRMET TANGO REMAINS IN EFFECT FOR MID TO
UPPER LEVEL TURBULENCE, WHICH WILL LIKELY PERSIST FOR MUCH OF THE
DAY AS WELL. AIRMET ZULU IS ALSO IN EFFECT FOR LIGHT TO MODERATE
RIME ICING ACROSS THE ENTIRE STATE.
MARINE
A TROUGH WEST OF THE OFFSHORE WATERS WILL CONTINUE TO BRING
SCATTERED TO NUMEROUS SHOWERS AND ISOLATED THUNDERSTORMS TO THE
COASTAL WATERS THROUGH MID-WEEK. STRONG TO LOCALLY GALE FORCE
WINDS WILL HOLD THROUGH TUESDAY, THEN BEGIN TO WEAKEN. A GALE
WARNING REMAINS IN EFFECT FOR THE ALENUIHAHA CHANNEL THROUGH EARLY
TUESDAY. A SMALL CRAFT ADVISORY FOR BOTH WINDS AND SEAS REMAINS
IN EFFECT FOR THE REMAINING WATERS THROUGH AT LEAST TUESDAY
EVENING.
A MODERATE, MEDIUM PERIOD, NORTH NORTHEAST (020-030 DEGREE) SWELL
WILL VEER TO A MORE EAST NORTHEASTERLY DIRECTION THROUGH TUESDAY.
THEREFORE, MODERATE SURF ALONG NORTH FACING BEACHES IS EXPECTED TO
DECLINE. THE NEXT SMALL, LONG PERIOD, NORTHWEST (310 DEGREE)
SWELL WILL BUILD LATE TUESDAY AND HOLD THROUGH FRIDAY.
AN EASTERLY WIND FETCH GENERATED BY LOWERING PRESSURES SOUTH AND
WEST OF THE ISLANDS WILL SIGNIFICANTLY INCREASE EASTERLY WIND
WAVE SWELL THROUGH EARLY WEDNESDAY. THIS EAST SWELL WILL IMPACT
MOST EASTERN FACING SHORES OF ALL ISLANDS. THUS, A HIGH SURF
ADVISORY WILL REMAIN IN EFFECT FOR ALL EAST-FACING SHORES THROUGH
EARLY WEDNESDAY MORNING.
THE COASTAL FLOOD STATEMENT WILL CONTINUE THROUGH LATE TONIGHT.
EXPECT MINOR FLOODING OF LOW LYING COASTAL AREAS DURING THE EARLY
MORNING HIGH TIDES.
HFO WATCHES/WARNINGS/ADVISORIES
FLOOD WATCH THROUGH THIS 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 SURF ADVISORY UNTIL 6 AM HST WEDNESDAY FOR OLOMANA-KAUAI
EAST-KAUAI SOUTH-EAST HONOLULU-KOOLAU WINDWARD-MOLOKAI WINDWARD-
MOLOKAI SOUTHEAST-WINDWARD HALEAKALA-KIPAHULU-SOUTH HALEAKALA-
BIG ISLAND SOUTHEAST-BIG ISLAND EAST-BIG ISLAND NORTH.
WINTER STORM WARNING UNTIL 6 AM HST TUESDAY FOR BIG ISLAND
SUMMITS.
HIGH WIND WARNING UNTIL 6 AM HST TUESDAY FOR BIG ISLAND SUMMITS.
SMALL CRAFT ADVISORY UNTIL 6 PM HST TUESDAY FOR KAUAI NORTHWEST
WATERS-KAUAI WINDWARD WATERS-KAUAI LEEWARD WATERS-KAUAI CHANNEL-
OAHU WINDWARD WATERS-OAHU LEEWARD WATERS-KAIWI CHANNEL-MAUI
COUNTY WINDWARD WATERS-MAUI COUNTY LEEWARD WATERS-MAALAEA BAY-
PAILOLO CHANNEL-BIG ISLAND WINDWARD WATERS-BIG ISLAND LEEWARD
WATERS-BIG ISLAND SOUTHEAST WATERS.
GALE WARNING UNTIL 6 AM HST TUESDAY FOR ALENUIHAHA CHANNEL.
DISCUSSION...ALMANZA/EXTENDED GK
AVIATION...JELSEMA
MARINE...THOMAS
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