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000
FXHW60 PHFO 212032 CCA
AFDHFO

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
1030 AM HST SUN DEC 21 2014

CORRECTED TIME IN HEADER

.SYNOPSIS...
A RIDGE NEAR THE ISLANDS WILL BRING GENTLE SEA BREEZES AND
AFTERNOON CLOUDS TODAY...BUT RAINFALL WILL BE SPARSE. A SHEAR LINE
WILL MOVE SOUTHEAST OVER KAUAI THIS EVENING AND CONTINUE DOWN TO THE
BIG ISLAND BY WEDNESDAY MORNING. IT WILL BRING WIDESPREAD SHOWERS
AND STRONG TRADE WINDS. RAINFALL WILL BE MODEST AT FIRST BUT A
TROUGH ALOFT MAY PRODUCE LOCALLY HEAVY SHOWERS...OR EVEN
THUNDERSTORMS MONDAY NIGHT. RAINFALL AMOUNTS WILL TAPER OFF ON
CHRISTMAS EVE. TRADE WINDS WILL GRADUALLY WEAKEN THROUGH THE SECOND
HALF OF THE WEEK.

&&

.DISCUSSION...
OBSERVATIONS AROUND THE ISLANDS SHOW ISOLATED SHOWERS OVER THE
COASTAL WATERS AND MOSTLY DRY WEATHER OVER THE ISLAND WITH LIGHT AND
VARIABLE WINDS. SEA BREEZES ARE LIKELY TO DEVELOP THIS AFTERNOON AND
BRING INCREASING CLOUDS TO INTERIOR AREA...BUT THE ATMOSPHERE IS
RATHER DRY SO ANY RAINFALL SHOULD BE LIGHT.

THE COMPUTER MODELS ARE IN GOOD AGREEMENT SHOWING A FRONTAL CLOUD
BAND MOVING SOUTHEAST OVER KAUAI AROUND SUNSET AND CONTINUING ACROSS
THE OTHER ISLANDS THROUGH WEDNESDAY MORNING. THE FRONT WILL
TRANSITION TO A SHEAR LINE AS IT REACHES THE ISLANDS...WITH GENTLE
NORTH WINDS AHEAD OF THE SHEAR LINE AND STRONG NORTH TO NORTHEAST
WINDS BEHIND IT. THE CLOUD BAND WILL PRODUCE WIDESPREAD SHOWERS AS
IT MOVES OVER KAUAI COUNTY AND OAHU THROUGH MONDAY MORNING BUT THE
ATMOSPHERE WILL NOT BE UNSTABLE ENOUGH TO ALLOW EXCESSIVE RAINFALL.

A TROUGH ALOFT WILL BE MOVING SOUTHEAST ACROSS THE MAIN HAWAIIAN
ISLANDS AND A STRONG SHORTWAVE WILL BE DROPPING SOUTHEAST WITHIN THE
TROUGH MONDAY EVENING THROUGH TUESDAY MORNING. THIS FEATURE WILL
DESTABILIZE THE ATMOSPHERE AND GENERATE HEAVY RAIN AND POSSIBLY
THUNDERSTORMS OVER THE ISLANDS. THE ATMOSPHERE SHOULD STABILIZE
AGAIN TUESDAY NIGHT AS THE SHORT WAVE MOVES OFF TO THE EAST.

A STRONG HIGH WITH A CENTRAL PRESSURE NEAR 1030 MB WILL BE MOVING
EAST BEHIND THE FRONT. THE HIGH WILL BE NORTH OF THE MAIN HAWAIIAN
ISLANDS BY TUESDAY EVENING. A TIGHT PRESSURE GRADIENT BETWEEN THE
HIGH AND THE FRONT WILL PRODUCE STRONG NORTH TO NORTHEAST WINDS AND
COULD REQUIRE WIND ADVISORIES. THE TRADES WILL GRADUALLY SUBSIDE
THROUGH THE WEEK BUT WILL REMAIN LOCALLY BREEZY THROUGH CHRISTMAS
EVE.

&&

.AVIATION...
CLOUDS WILL INCREASE OVER INTERIOR AREAS THIS AFTERNOON BUT A STABLE
ATMOSPHERE WILL LIMIT CLOUD AND SHRA DEVELOPMENT...WITH ONLY ISOL
MVFR VIS/CIG EXPECTED. THE SHEAR LINE IS EXPECTED TO REACH KAUAI
AROUND 04Z BRINGING STRONG N TO NE WINDS AND WIDESPREAD MVFR
CEILINGS AND VIS WITH LOCALIZED IFR. AIRMETS FOR MT OBSC AND LOW
LEVEL TURB S THRU SW OF THE ISLANDS WILL LIKELY BE NEEDED. THE SHEAR
LINE IS EXPECTED TO REACH OAHU LATE TONIGHT AND MAUI COUNTY ON
MONDAY.

&&

.MARINE...
A NEW NORTHWEST SWELL REACHED BUOY 51101...NEAR NIHOA...AFTER
MIDNIGHT LAST NIGHT AND ROSE OVER 10 FEET BY 900 AM. SURF FROM THIS
SWELL WILL BUILD RAPIDLY ALONG NORTH AND WEST FACING SHORES THIS
AFTERNOON AND REACH WARNING LEVELS TONIGHT. A HIGH SURF WARNING IS
IN EFFECT FOR NORTH AND WEST FACING SHORES OF THE SMALLER ISLANDS
AND FOR WEST FACING SHORES OF THE BIG ISLAND. THE BIG NORTHWEST
SWELL WILL ALSO GENERATE SMALL CRAFT ADVISORY CONDITIONS OVER MOST
COASTAL WATERS DUE TO HAZARDOUS SEAS. A HIGH SURF ADVISORY ALSO
REMAINS IN EFFECT FOR EAST FACING SHORES OF THE BIG ISLAND THROUGH
600 PM TODAY.

WINDS OVER THE COASTAL WATERS WILL BE GENTLE AND VARIABLE TODAY.
STRONG NORTH TO NORTHEAST WINDS WILL MOVE OVER THE AREA STARTING
THIS EVENING. THERE WILL BE WIDESPREAD SMALL CRAFT ADVISORY STRENGTH
WINDS WITH NEAR-GALE FORCE WINDS IN THE CHANNELS WITH SOME GALES
POSSIBLE. WINDS WILL GRADUALLY SUBSIDE STARTING CHRISTMAS EVE.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
HIGH SURF WARNING UNTIL 600 AM TUESDAY FOR NORTH AND WEST FACING
SHORES OF NIIHAU KAUAI OAHU AND MOLOKAI AND FOR NORTH FACING SHORES
OF MAUI.

HIGH SURF WARNING FROM 1000 AM TODAY TO 600 AM TUESDAY FOR WEST
FACING SHORES OF THE BIG ISLAND.

HIGH SURF ADVISORY UNTIL 600 PM TODAY FOR EAST FACING SHORES OF
THE BIG ISLAND.

SMALL CRAFT ADVISORY UNTIL 600 AM TUESDAY FOR ALL HAWAIIAN WATERS
EXCEPT MAALAEA BAY.

&&

$$
DONALDSON







000
FXHW60 PHFO 212032 CCA
AFDHFO

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
1030 AM HST SUN DEC 21 2014

CORRECTED TIME IN HEADER

.SYNOPSIS...
A RIDGE NEAR THE ISLANDS WILL BRING GENTLE SEA BREEZES AND
AFTERNOON CLOUDS TODAY...BUT RAINFALL WILL BE SPARSE. A SHEAR LINE
WILL MOVE SOUTHEAST OVER KAUAI THIS EVENING AND CONTINUE DOWN TO THE
BIG ISLAND BY WEDNESDAY MORNING. IT WILL BRING WIDESPREAD SHOWERS
AND STRONG TRADE WINDS. RAINFALL WILL BE MODEST AT FIRST BUT A
TROUGH ALOFT MAY PRODUCE LOCALLY HEAVY SHOWERS...OR EVEN
THUNDERSTORMS MONDAY NIGHT. RAINFALL AMOUNTS WILL TAPER OFF ON
CHRISTMAS EVE. TRADE WINDS WILL GRADUALLY WEAKEN THROUGH THE SECOND
HALF OF THE WEEK.

&&

.DISCUSSION...
OBSERVATIONS AROUND THE ISLANDS SHOW ISOLATED SHOWERS OVER THE
COASTAL WATERS AND MOSTLY DRY WEATHER OVER THE ISLAND WITH LIGHT AND
VARIABLE WINDS. SEA BREEZES ARE LIKELY TO DEVELOP THIS AFTERNOON AND
BRING INCREASING CLOUDS TO INTERIOR AREA...BUT THE ATMOSPHERE IS
RATHER DRY SO ANY RAINFALL SHOULD BE LIGHT.

THE COMPUTER MODELS ARE IN GOOD AGREEMENT SHOWING A FRONTAL CLOUD
BAND MOVING SOUTHEAST OVER KAUAI AROUND SUNSET AND CONTINUING ACROSS
THE OTHER ISLANDS THROUGH WEDNESDAY MORNING. THE FRONT WILL
TRANSITION TO A SHEAR LINE AS IT REACHES THE ISLANDS...WITH GENTLE
NORTH WINDS AHEAD OF THE SHEAR LINE AND STRONG NORTH TO NORTHEAST
WINDS BEHIND IT. THE CLOUD BAND WILL PRODUCE WIDESPREAD SHOWERS AS
IT MOVES OVER KAUAI COUNTY AND OAHU THROUGH MONDAY MORNING BUT THE
ATMOSPHERE WILL NOT BE UNSTABLE ENOUGH TO ALLOW EXCESSIVE RAINFALL.

A TROUGH ALOFT WILL BE MOVING SOUTHEAST ACROSS THE MAIN HAWAIIAN
ISLANDS AND A STRONG SHORTWAVE WILL BE DROPPING SOUTHEAST WITHIN THE
TROUGH MONDAY EVENING THROUGH TUESDAY MORNING. THIS FEATURE WILL
DESTABILIZE THE ATMOSPHERE AND GENERATE HEAVY RAIN AND POSSIBLY
THUNDERSTORMS OVER THE ISLANDS. THE ATMOSPHERE SHOULD STABILIZE
AGAIN TUESDAY NIGHT AS THE SHORT WAVE MOVES OFF TO THE EAST.

A STRONG HIGH WITH A CENTRAL PRESSURE NEAR 1030 MB WILL BE MOVING
EAST BEHIND THE FRONT. THE HIGH WILL BE NORTH OF THE MAIN HAWAIIAN
ISLANDS BY TUESDAY EVENING. A TIGHT PRESSURE GRADIENT BETWEEN THE
HIGH AND THE FRONT WILL PRODUCE STRONG NORTH TO NORTHEAST WINDS AND
COULD REQUIRE WIND ADVISORIES. THE TRADES WILL GRADUALLY SUBSIDE
THROUGH THE WEEK BUT WILL REMAIN LOCALLY BREEZY THROUGH CHRISTMAS
EVE.

&&

.AVIATION...
CLOUDS WILL INCREASE OVER INTERIOR AREAS THIS AFTERNOON BUT A STABLE
ATMOSPHERE WILL LIMIT CLOUD AND SHRA DEVELOPMENT...WITH ONLY ISOL
MVFR VIS/CIG EXPECTED. THE SHEAR LINE IS EXPECTED TO REACH KAUAI
AROUND 04Z BRINGING STRONG N TO NE WINDS AND WIDESPREAD MVFR
CEILINGS AND VIS WITH LOCALIZED IFR. AIRMETS FOR MT OBSC AND LOW
LEVEL TURB S THRU SW OF THE ISLANDS WILL LIKELY BE NEEDED. THE SHEAR
LINE IS EXPECTED TO REACH OAHU LATE TONIGHT AND MAUI COUNTY ON
MONDAY.

&&

.MARINE...
A NEW NORTHWEST SWELL REACHED BUOY 51101...NEAR NIHOA...AFTER
MIDNIGHT LAST NIGHT AND ROSE OVER 10 FEET BY 900 AM. SURF FROM THIS
SWELL WILL BUILD RAPIDLY ALONG NORTH AND WEST FACING SHORES THIS
AFTERNOON AND REACH WARNING LEVELS TONIGHT. A HIGH SURF WARNING IS
IN EFFECT FOR NORTH AND WEST FACING SHORES OF THE SMALLER ISLANDS
AND FOR WEST FACING SHORES OF THE BIG ISLAND. THE BIG NORTHWEST
SWELL WILL ALSO GENERATE SMALL CRAFT ADVISORY CONDITIONS OVER MOST
COASTAL WATERS DUE TO HAZARDOUS SEAS. A HIGH SURF ADVISORY ALSO
REMAINS IN EFFECT FOR EAST FACING SHORES OF THE BIG ISLAND THROUGH
600 PM TODAY.

WINDS OVER THE COASTAL WATERS WILL BE GENTLE AND VARIABLE TODAY.
STRONG NORTH TO NORTHEAST WINDS WILL MOVE OVER THE AREA STARTING
THIS EVENING. THERE WILL BE WIDESPREAD SMALL CRAFT ADVISORY STRENGTH
WINDS WITH NEAR-GALE FORCE WINDS IN THE CHANNELS WITH SOME GALES
POSSIBLE. WINDS WILL GRADUALLY SUBSIDE STARTING CHRISTMAS EVE.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
HIGH SURF WARNING UNTIL 600 AM TUESDAY FOR NORTH AND WEST FACING
SHORES OF NIIHAU KAUAI OAHU AND MOLOKAI AND FOR NORTH FACING SHORES
OF MAUI.

HIGH SURF WARNING FROM 1000 AM TODAY TO 600 AM TUESDAY FOR WEST
FACING SHORES OF THE BIG ISLAND.

HIGH SURF ADVISORY UNTIL 600 PM TODAY FOR EAST FACING SHORES OF
THE BIG ISLAND.

SMALL CRAFT ADVISORY UNTIL 600 AM TUESDAY FOR ALL HAWAIIAN WATERS
EXCEPT MAALAEA BAY.

&&

$$
DONALDSON






000
FXHW60 PHFO 212031
AFDHFO

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
338 AM HST SUN DEC 21 2014

.SYNOPSIS...
A RIDGE NEAR THE ISLANDS WILL BRING GENTLE SEA BREEZES AND
AFTERNOON CLOUDS TODAY...BUT RAINFALL WILL BE SPARSE. A SHEAR LINE
WILL MOVE SOUTHEAST OVER KAUAI THIS EVENING AND CONTINUE DOWN TO THE
BIG ISLAND BY WEDNESDAY MORNING. IT WILL BRING WIDESPREAD SHOWERS
AND STRONG TRADE WINDS. RAINFALL WILL BE MODEST AT FIRST BUT A
TROUGH ALOFT MAY PRODUCE LOCALLY HEAVY SHOWERS...OR EVEN
THUNDERSTORMS MONDAY NIGHT. RAINFALL AMOUNTS WILL TAPER OFF ON
CHRISTMAS EVE. TRADE WINDS WILL GRADUALLY WEAKEN THROUGH THE SECOND
HALF OF THE WEEK.

&&

.DISCUSSION...
OBSERVATIONS AROUND THE ISLANDS SHOW ISOLATED SHOWERS OVER THE
COASTAL WATERS AND MOSTLY DRY WEATHER OVER THE ISLAND WITH LIGHT AND
VARIABLE WINDS. SEA BREEZES ARE LIKELY TO DEVELOP THIS AFTERNOON AND
BRING INCREASING CLOUDS TO INTERIOR AREA...BUT THE ATMOSPHERE IS
RATHER DRY SO ANY RAINFALL SHOULD BE LIGHT.

THE COMPUTER MODELS ARE IN GOOD AGREEMENT SHOWING A FRONTAL CLOUD
BAND MOVING SOUTHEAST OVER KAUAI AROUND SUNSET AND CONTINUING ACROSS
THE OTHER ISLANDS THROUGH WEDNESDAY MORNING. THE FRONT WILL
TRANSITION TO A SHEAR LINE AS IT REACHES THE ISLANDS...WITH GENTLE
NORTH WINDS AHEAD OF THE SHEAR LINE AND STRONG NORTH TO NORTHEAST
WINDS BEHIND IT. THE CLOUD BAND WILL PRODUCE WIDESPREAD SHOWERS AS
IT MOVES OVER KAUAI COUNTY AND OAHU THROUGH MONDAY MORNING BUT THE
ATMOSPHERE WILL NOT BE UNSTABLE ENOUGH TO ALLOW EXCESSIVE RAINFALL.

A TROUGH ALOFT WILL BE MOVING SOUTHEAST ACROSS THE MAIN HAWAIIAN
ISLANDS AND A STRONG SHORTWAVE WILL BE DROPPING SOUTHEAST WITHIN THE
TROUGH MONDAY EVENING THROUGH TUESDAY MORNING. THIS FEATURE WILL
DESTABILIZE THE ATMOSPHERE AND GENERATE HEAVY RAIN AND POSSIBLY
THUNDERSTORMS OVER THE ISLANDS. THE ATMOSPHERE SHOULD STABILIZE
AGAIN TUESDAY NIGHT AS THE SHORT WAVE MOVES OFF TO THE EAST.

A STRONG HIGH WITH A CENTRAL PRESSURE NEAR 1030 MB WILL BE MOVING
EAST BEHIND THE FRONT. THE HIGH WILL BE NORTH OF THE MAIN HAWAIIAN
ISLANDS BY TUESDAY EVENING. A TIGHT PRESSURE GRADIENT BETWEEN THE
HIGH AND THE FRONT WILL PRODUCE STRONG NORTH TO NORTHEAST WINDS AND
COULD REQUIRE WIND ADVISORIES. THE TRADES WILL GRADUALLY SUBSIDE
THROUGH THE WEEK BUT WILL REMAIN LOCALLY BREEZY THROUGH CHRISTMAS
EVE.

&&

.AVIATION...
CLOUDS WILL INCREASE OVER INTERIOR AREAS THIS AFTERNOON BUT A STABLE
ATMOSPHERE WILL LIMIT CLOUD AND SHRA DEVELOPMENT...WITH ONLY ISOL
MVFR VIS/CIG EXPECTED. THE SHEAR LINE IS EXPECTED TO REACH KAUAI
AROUND 04Z BRINGING STRONG N TO NE WINDS AND WIDESPREAD MVFR
CEILINGS AND VIS WITH LOCALIZED IFR. AIRMETS FOR MT OBSC AND LOW
LEVEL TURB S THRU SW OF THE ISLANDS WILL LIKELY BE NEEDED. THE SHEAR
LINE IS EXPECTED TO REACH OAHU LATE TONIGHT AND MAUI COUNTY ON
MONDAY.

&&

.MARINE...
A NEW NORTHWEST SWELL REACHED BUOY 51101...NEAR NIHOA...AFTER
MIDNIGHT LAST NIGHT AND ROSE OVER 10 FEET BY 900 AM. SURF FROM THIS
SWELL WILL BUILD RAPIDLY ALONG NORTH AND WEST FACING SHORES THIS
AFTERNOON AND REACH WARNING LEVELS TONIGHT. A HIGH SURF WARNING IS
IN EFFECT FOR NORTH AND WEST FACING SHORES OF THE SMALLER ISLANDS
AND FOR WEST FACING SHORES OF THE BIG ISLAND. THE BIG NORTHWEST
SWELL WILL ALSO GENERATE SMALL CRAFT ADVISORY CONDITIONS OVER MOST
COASTAL WATERS DUE TO HAZARDOUS SEAS. A HIGH SURF ADVISORY ALSO
REMAINS IN EFFECT FOR EAST FACING SHORES OF THE BIG ISLAND THROUGH
600 PM TODAY.

WINDS OVER THE COASTAL WATERS WILL BE GENTLE AND VARIABLE TODAY.
STRONG NORTH TO NORTHEAST WINDS WILL MOVE OVER THE AREA STARTING
THIS EVENING. THERE WILL BE WIDESPREAD SMALL CRAFT ADVISORY STRENGTH
WINDS WITH NEAR-GALE FORCE WINDS IN THE CHANNELS WITH SOME GALES
POSSIBLE. WINDS WILL GRADUALLY SUBSIDE STARTING CHRISTMAS EVE.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
HIGH SURF WARNING UNTIL 600 AM TUESDAY FOR NORTH AND WEST FACING
SHORES OF NIIHAU KAUAI OAHU AND MOLOKAI AND FOR NORTH FACING SHORES
OF MAUI.

HIGH SURF WARNING FROM 1000 AM TODAY TO 600 AM TUESDAY FOR WEST
FACING SHORES OF THE BIG ISLAND.

HIGH SURF ADVISORY UNTIL 600 PM TODAY FOR EAST FACING SHORES OF
THE BIG ISLAND.

SMALL CRAFT ADVISORY UNTIL 600 AM TUESDAY FOR ALL HAWAIIAN WATERS
EXCEPT MAALAEA BAY.

&&

$$
DONALDSON





000
FXHW60 PHFO 212031
AFDHFO

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
338 AM HST SUN DEC 21 2014

.SYNOPSIS...
A RIDGE NEAR THE ISLANDS WILL BRING GENTLE SEA BREEZES AND
AFTERNOON CLOUDS TODAY...BUT RAINFALL WILL BE SPARSE. A SHEAR LINE
WILL MOVE SOUTHEAST OVER KAUAI THIS EVENING AND CONTINUE DOWN TO THE
BIG ISLAND BY WEDNESDAY MORNING. IT WILL BRING WIDESPREAD SHOWERS
AND STRONG TRADE WINDS. RAINFALL WILL BE MODEST AT FIRST BUT A
TROUGH ALOFT MAY PRODUCE LOCALLY HEAVY SHOWERS...OR EVEN
THUNDERSTORMS MONDAY NIGHT. RAINFALL AMOUNTS WILL TAPER OFF ON
CHRISTMAS EVE. TRADE WINDS WILL GRADUALLY WEAKEN THROUGH THE SECOND
HALF OF THE WEEK.

&&

.DISCUSSION...
OBSERVATIONS AROUND THE ISLANDS SHOW ISOLATED SHOWERS OVER THE
COASTAL WATERS AND MOSTLY DRY WEATHER OVER THE ISLAND WITH LIGHT AND
VARIABLE WINDS. SEA BREEZES ARE LIKELY TO DEVELOP THIS AFTERNOON AND
BRING INCREASING CLOUDS TO INTERIOR AREA...BUT THE ATMOSPHERE IS
RATHER DRY SO ANY RAINFALL SHOULD BE LIGHT.

THE COMPUTER MODELS ARE IN GOOD AGREEMENT SHOWING A FRONTAL CLOUD
BAND MOVING SOUTHEAST OVER KAUAI AROUND SUNSET AND CONTINUING ACROSS
THE OTHER ISLANDS THROUGH WEDNESDAY MORNING. THE FRONT WILL
TRANSITION TO A SHEAR LINE AS IT REACHES THE ISLANDS...WITH GENTLE
NORTH WINDS AHEAD OF THE SHEAR LINE AND STRONG NORTH TO NORTHEAST
WINDS BEHIND IT. THE CLOUD BAND WILL PRODUCE WIDESPREAD SHOWERS AS
IT MOVES OVER KAUAI COUNTY AND OAHU THROUGH MONDAY MORNING BUT THE
ATMOSPHERE WILL NOT BE UNSTABLE ENOUGH TO ALLOW EXCESSIVE RAINFALL.

A TROUGH ALOFT WILL BE MOVING SOUTHEAST ACROSS THE MAIN HAWAIIAN
ISLANDS AND A STRONG SHORTWAVE WILL BE DROPPING SOUTHEAST WITHIN THE
TROUGH MONDAY EVENING THROUGH TUESDAY MORNING. THIS FEATURE WILL
DESTABILIZE THE ATMOSPHERE AND GENERATE HEAVY RAIN AND POSSIBLY
THUNDERSTORMS OVER THE ISLANDS. THE ATMOSPHERE SHOULD STABILIZE
AGAIN TUESDAY NIGHT AS THE SHORT WAVE MOVES OFF TO THE EAST.

A STRONG HIGH WITH A CENTRAL PRESSURE NEAR 1030 MB WILL BE MOVING
EAST BEHIND THE FRONT. THE HIGH WILL BE NORTH OF THE MAIN HAWAIIAN
ISLANDS BY TUESDAY EVENING. A TIGHT PRESSURE GRADIENT BETWEEN THE
HIGH AND THE FRONT WILL PRODUCE STRONG NORTH TO NORTHEAST WINDS AND
COULD REQUIRE WIND ADVISORIES. THE TRADES WILL GRADUALLY SUBSIDE
THROUGH THE WEEK BUT WILL REMAIN LOCALLY BREEZY THROUGH CHRISTMAS
EVE.

&&

.AVIATION...
CLOUDS WILL INCREASE OVER INTERIOR AREAS THIS AFTERNOON BUT A STABLE
ATMOSPHERE WILL LIMIT CLOUD AND SHRA DEVELOPMENT...WITH ONLY ISOL
MVFR VIS/CIG EXPECTED. THE SHEAR LINE IS EXPECTED TO REACH KAUAI
AROUND 04Z BRINGING STRONG N TO NE WINDS AND WIDESPREAD MVFR
CEILINGS AND VIS WITH LOCALIZED IFR. AIRMETS FOR MT OBSC AND LOW
LEVEL TURB S THRU SW OF THE ISLANDS WILL LIKELY BE NEEDED. THE SHEAR
LINE IS EXPECTED TO REACH OAHU LATE TONIGHT AND MAUI COUNTY ON
MONDAY.

&&

.MARINE...
A NEW NORTHWEST SWELL REACHED BUOY 51101...NEAR NIHOA...AFTER
MIDNIGHT LAST NIGHT AND ROSE OVER 10 FEET BY 900 AM. SURF FROM THIS
SWELL WILL BUILD RAPIDLY ALONG NORTH AND WEST FACING SHORES THIS
AFTERNOON AND REACH WARNING LEVELS TONIGHT. A HIGH SURF WARNING IS
IN EFFECT FOR NORTH AND WEST FACING SHORES OF THE SMALLER ISLANDS
AND FOR WEST FACING SHORES OF THE BIG ISLAND. THE BIG NORTHWEST
SWELL WILL ALSO GENERATE SMALL CRAFT ADVISORY CONDITIONS OVER MOST
COASTAL WATERS DUE TO HAZARDOUS SEAS. A HIGH SURF ADVISORY ALSO
REMAINS IN EFFECT FOR EAST FACING SHORES OF THE BIG ISLAND THROUGH
600 PM TODAY.

WINDS OVER THE COASTAL WATERS WILL BE GENTLE AND VARIABLE TODAY.
STRONG NORTH TO NORTHEAST WINDS WILL MOVE OVER THE AREA STARTING
THIS EVENING. THERE WILL BE WIDESPREAD SMALL CRAFT ADVISORY STRENGTH
WINDS WITH NEAR-GALE FORCE WINDS IN THE CHANNELS WITH SOME GALES
POSSIBLE. WINDS WILL GRADUALLY SUBSIDE STARTING CHRISTMAS EVE.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
HIGH SURF WARNING UNTIL 600 AM TUESDAY FOR NORTH AND WEST FACING
SHORES OF NIIHAU KAUAI OAHU AND MOLOKAI AND FOR NORTH FACING SHORES
OF MAUI.

HIGH SURF WARNING FROM 1000 AM TODAY TO 600 AM TUESDAY FOR WEST
FACING SHORES OF THE BIG ISLAND.

HIGH SURF ADVISORY UNTIL 600 PM TODAY FOR EAST FACING SHORES OF
THE BIG ISLAND.

SMALL CRAFT ADVISORY UNTIL 600 AM TUESDAY FOR ALL HAWAIIAN WATERS
EXCEPT MAALAEA BAY.

&&

$$
DONALDSON





  [top]

000
ATHW40 PHFO 211830
SIMHI

HAWAIIAN ISLANDS SATELLITE INTERPRETATION MESSAGE
NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI
1830 UTC SUN DEC 21 2014

BASED ON DATA THROUGH 1800 UTC DECEMBER 21 2014

A FRONTAL CLOUD BAND WAS JUST UNDER 200 MILES NORTHWEST OF KAUAI
THIS MORNING.  THE ACTUAL FRONT WAS ABOUT 260 MILES WEST NORTHWEST
OF KAUAI AT 8 AM THIS MORNING.  PREFRONTAL CLOUDS PRECEDED THE FRONT
AND THE MAIN CLOUD BAND.  THE FRONT WAS MOVING TOWARD THE ISLANDS
AROUND 15 MILES AN HOUR.

THE EAST EDGE OF THE ASSOCIATED CLOUD BAND WHICH INCLUDED THE
PREFRONTAL CLOUDS STRETCHED THROUGH 30N 157W TO 24N 163W TO 20N
180E.  THE BAND CONSISTED OF BROKEN TO OVERCAST LOW CLOUDS S OF 25N
LATITUDE AND OVERCAST LOW TO MID LEVEL CLOUDS BETWEEN 25N AND 30N.
THE BAND WAS MOSTLY BETWEEN 200 AND 225 MILES WIDE BETWEEN 20N AND
30N.  BEHIND THE FRONTAL BAND...NUMEROUS BUT WIDELY SEPARATED
PATCHES PATCHES OF SCATTERED TO BROKEN LOW CLOUDS WERE COMMON.

SKIES WERE MOSTLY CLEAR BETWEEN THE FRONT AND KAUAI.  BUT SEVERAL
LARGE CLUSTERS OF BROKEN TO OVERCAST LOW CLOUDS...A MIX OF
STRATOCUMULUS AND CUMULUS CLOUDS WERE SPREAD OUT ACROSS THE STATE
FROM THE KAUAI CHANNEL TO THE BIG ISLAND.  THESE CLOUDS FILLED MUCH
OF THE REGION BETWEEN 20N AND 20N BETWEEN 168W AND 140W.  THE LOW
CLOUDS WERE MOVING WEST INTO THE BIG ISLAND THEN SPLITTING WITH
SOME GOING NORTHWEST TO THE NORTH OF APUA POINT.  OTHER CLOUDS WERE
CONTINUING WEST TO THE SOUTH OF APUA POINT...THE EASTERNMOST POINT
ON THE BIG ISLAND.  THE CLOUDS EAST OF THE MAUI COUNTY AND OAHU
WERE FLOWING TOWARD THE NORTH.  BUT THOSE IN THE IMMEDIATE VICINITY
OF THOSE ISLANDS APPEARED TO BE FAIRLY STAGNANT.

AT 8 AM...SKIES WERE MOSTLY CLEAR OVER KAUAI...MAUI AND MOLOKAI AS
WELL AS OVER MOST OF THE BIG ISLAND.  SOME CLOUDY SKIES WERE NOTED
OVER ALL BUT THE EAST PART OF OAHU AND OVER THE EAST PART OF THE BIG
ISLAND...MAINLY THE PUNA DISTRICT.  LANAI WAS MOSTLY CLOUDY AS ONE
LARGE CLOUD CLUSTER SAT JUST SOUTHWEST OF THAT ISLAND.

$$






000
ATHW40 PHFO 211830
SIMHI

HAWAIIAN ISLANDS SATELLITE INTERPRETATION MESSAGE
NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI
1830 UTC SUN DEC 21 2014

BASED ON DATA THROUGH 1800 UTC DECEMBER 21 2014

A FRONTAL CLOUD BAND WAS JUST UNDER 200 MILES NORTHWEST OF KAUAI
THIS MORNING.  THE ACTUAL FRONT WAS ABOUT 260 MILES WEST NORTHWEST
OF KAUAI AT 8 AM THIS MORNING.  PREFRONTAL CLOUDS PRECEDED THE FRONT
AND THE MAIN CLOUD BAND.  THE FRONT WAS MOVING TOWARD THE ISLANDS
AROUND 15 MILES AN HOUR.

THE EAST EDGE OF THE ASSOCIATED CLOUD BAND WHICH INCLUDED THE
PREFRONTAL CLOUDS STRETCHED THROUGH 30N 157W TO 24N 163W TO 20N
180E.  THE BAND CONSISTED OF BROKEN TO OVERCAST LOW CLOUDS S OF 25N
LATITUDE AND OVERCAST LOW TO MID LEVEL CLOUDS BETWEEN 25N AND 30N.
THE BAND WAS MOSTLY BETWEEN 200 AND 225 MILES WIDE BETWEEN 20N AND
30N.  BEHIND THE FRONTAL BAND...NUMEROUS BUT WIDELY SEPARATED
PATCHES PATCHES OF SCATTERED TO BROKEN LOW CLOUDS WERE COMMON.

SKIES WERE MOSTLY CLEAR BETWEEN THE FRONT AND KAUAI.  BUT SEVERAL
LARGE CLUSTERS OF BROKEN TO OVERCAST LOW CLOUDS...A MIX OF
STRATOCUMULUS AND CUMULUS CLOUDS WERE SPREAD OUT ACROSS THE STATE
FROM THE KAUAI CHANNEL TO THE BIG ISLAND.  THESE CLOUDS FILLED MUCH
OF THE REGION BETWEEN 20N AND 20N BETWEEN 168W AND 140W.  THE LOW
CLOUDS WERE MOVING WEST INTO THE BIG ISLAND THEN SPLITTING WITH
SOME GOING NORTHWEST TO THE NORTH OF APUA POINT.  OTHER CLOUDS WERE
CONTINUING WEST TO THE SOUTH OF APUA POINT...THE EASTERNMOST POINT
ON THE BIG ISLAND.  THE CLOUDS EAST OF THE MAUI COUNTY AND OAHU
WERE FLOWING TOWARD THE NORTH.  BUT THOSE IN THE IMMEDIATE VICINITY
OF THOSE ISLANDS APPEARED TO BE FAIRLY STAGNANT.

AT 8 AM...SKIES WERE MOSTLY CLEAR OVER KAUAI...MAUI AND MOLOKAI AS
WELL AS OVER MOST OF THE BIG ISLAND.  SOME CLOUDY SKIES WERE NOTED
OVER ALL BUT THE EAST PART OF OAHU AND OVER THE EAST PART OF THE BIG
ISLAND...MAINLY THE PUNA DISTRICT.  LANAI WAS MOSTLY CLOUDY AS ONE
LARGE CLOUD CLUSTER SAT JUST SOUTHWEST OF THAT ISLAND.

$$





000
FXHW60 PHFO 211340
AFDHFO

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
338 AM HST SUN DEC 21 2014

.SYNOPSIS...
LIGHT WINDS WILL CONTINUE TODAY...ALLOWING FOR SEA BREEZES TO
RETURN THIS AFTERNOON AND GENERATING A FEW SHOWERS OVER LEEWARD AND
INTERIOR AREAS. A COLD FRONT WILL APPROACH THE ISLANDS FROM THE
NORTHWEST...BRINGING AN INCREASE IN SHOWERS STARTING LATER TONIGHT.
THERE IS POTENTIAL FOR HEAVY RAIN AND A FEW THUNDERSTORMS ACROSS THE
ALOHA STATE FROM MONDAY AFTERNOON THROUGH TUESDAY. STRONG NORTHERLY
WINDS WILL DEVELOP BEHIND THE FRONT BY MID WEEK.

&&

.DISCUSSION...
A FEW SHOWERS HAVE BEEN MOVING ACROSS WINDWARD AND MOUNTAIN AREAS
DURING THE EARLY MORNING HOURS...WITH SFC WINDS REMAINING GENERALLY
LIGHT. WINDS OVER THE BIG ISLAND ARE NOW VEERING TO A MORE SE FLOW.
AN UPPER LEVEL RIDGE OVER THE ALOHA STATE WILL HELP IN KEEPING A
RELATIVELY STABLE AIRMASS ALOFT WITH SHOWER ACTIVITY REMAINING LOW
TODAY. AT THE SFC...A BROAD HIGH FAR ENE OF THE ISLANDS WILL
CONTINUE TO MIGRATE E...WHICH WILL MAINTAIN WINDS ON THE LIGHT SIDE
TODAY AND TONIGHT.

MEANWHILE...A DEEPENING TROUGH FAR NW OF THE ISLAND CHAIN CONTINUES
TO GRADUALLY APPROACH THE ALOHA STATE...WITH AN ASSOCIATED COLD
FRONT ABOUT 250 MILES NW OF KAUAI ALSO MOVING TOWARDS THE ISLANDS.
WITH THIS OVERALL SYNOPTIC SETUP...EXPECT ANOTHER ROUND OF SEA
BREEZES DEVELOPING THIS AFTERNOON WITH CLOUDS AND SHOWERS AFFECTING
SOME LEEWARD AND INTERIOR AREAS. RAINFALL SHOULD REMAIN LIGHT.

THE TROUGH/LOW COMPLEX WILL APPROACH THE W EDGE OF THE ISLAND CHAIN
TONIGHT WITH SHOWER COVERAGE INCREASING ACROSS THE AREA...AND WITH
POSSIBLY ENOUGH UPPER LVL SUPPORT FOR SOME DEEP CONVECTION TO
DEVELOP. A COLDER AIRMASS ALOFT WILL ARRIVE WITH THE TROUGH AND
FURTHER DESTABILIZE THE ATMOSPHERE OVER THE ISLANDS. LATEST MODEL
ANALYSES SHOW 500 MB TEMPS DROPPING TO -12C TO -14C. HOWEVER...
COMPARED TO PREVIOUS RUNS...THE MOST RECENT TRENDS IN THE GLOBAL
MODEL SOLUTIONS SEEM LESS AGGRESSIVE IN TERMS OF OVERALL AVAILABLE
MOISTURE FOR SIGNIFICANT CONVECTION TO DEVELOP WITH THE FROPA. X-SEC
ANALYSES DEPICT A RATHER DRY SWATH OF AIR ABOVE 700 MB MON THROUGH
TUE. BUT THE TROUGH SHOULD PROVIDE ENOUGH INSTABILITY TO ERODE LOW
LVL INVERSIONS AND ALLOW FOR SOME VERTICAL DEVELOPMENT OF SHOWERS
AND ANY THUNDERSTORM CELLS THAT MAY FORM.

IN GENERAL...GFS AND ECMWF SHOW FAIR AGREEMENT IN TERMS OF THE
TIMING AND OVERALL SCENARIO...BRINGING A FROPA THROUGH THE ISLAND
CHAIN AND A CUTOFF LOW DEVELOPING NE OF THE ALOHA STATE MON THROUGH
TUE. SO FAR IT SEEMS THE HIGHEST IMPACTS WEATHERWISE ARE EXPECTED
OVER KAUAI COUNTY AND OAHU...WHERE THE HIGHEST POPS AND CHANCES FOR
LOCALIZED HEAVY RAINFALL COVERAGE RESIDE. THERE IS ALSO A SLIGHT
CHANCE OF THUNDERSTORMS FROM MON AFTERNOON TO TUE NIGHT.

STRONG NNE WINDS WILL ARRIVE IN THE WAKE OF THE FROPA BY MID
WEEK...THEN GRADUALLY RELAX THROUGH THE SECOND HALF OF THE WEEK.
WIND WILL FINALLY VEER TO A MORE TYPICAL NE FLOW NEXT WEEKEND AS
HIGH PRESSURE BUILDS NW OF THE ALOHA STATE.

&&

.AVIATION...
LIGHT WINDS WILL ALLOW SEA BREEZES TO DEVELOP OVER THE ISLANDS LATER
THIS MORNING...LEADING TO INCREASED CLOUDINESS OVER INTERIOR AREAS.
A STABLE ATMOSPHERE WILL LIMIT CLOUD AND SHRA DEVELOPMENT...WITH
ISOL MVFR VIS/CIG EXPECTED. IN THE MEAN TIME...A LIGHT BUT
PERSISTENT E/SE LOW-LEVEL FLOW OVER MOST AREAS WILL DELIVER ISOL
MVFR VIS/CIG IN SHRA TO WINDWARD AREAS OF THE ISLANDS...MAINLY FROM
OAHU TO THE BIG ISLAND. A FRONT ARRIVING FROM THE NW TONIGHT WILL
BRING INCREASING N TO NE WINDS AND MVFR VIS/CIG IN SHRA...AFFECTING
KAUAI INITIALLY...BEFORE SPREADING TO OAHU ON MONDAY. THE INCREASING
WINDS AND SHRA WILL LIKELY REQUIRE AIRMETS FOR LOW LEVEL TURBULENCE
TO THE LEE OF THE MOUNTAINS...AND MOUNTAIN OBSCURATION ALONG N
FACING SLOPES.

&&

.MARINE...
A LONG PERIOD NORTHWEST SWELL GENERATED BY A LARGE AND POWERFUL LOW
PRESSURE SYSTEM WILL BRING INCREASING SURF HEIGHTS TODAY...REACHING
WARNING LEVELS TONIGHT. A HIGH SURF WARNING IS IN EFFECT UNTIL
TUESDAY MORNING FOR NORTH AND WEST FACING SHORES OF THE SMALLER
ISLANDS...AND STARTING LATER THIS MORNING FOR WEST FACING SHORES OF
THE BIG ISLAND.

A HIGH SURF ADVISORY ALSO REMAINS IN EFFECT FOR EAST FACING SHORES
OF THE BIG ISLAND THROUGH 6 PM HST TODAY.

THIS INCREASING SWELL WILL ALSO GENERATE SMALL CRAFT ADVISORY
CONDITIONS OVER MOST COASTAL WATERS DUE TO HAZARDOUS SEAS.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
HIGH SURF WARNING UNTIL 6 AM HST TUESDAY FOR NORTH AND WEST FACING
SHORES OF NIIHAU KAUAI OAHU AND MOLOKAI AND FOR NORTH FACING SHORES
OF MAUI.

HIGH SURF WARNING FROM 10 AM HST TODAY TO 6 AM HST TUESDAY FOR WEST
FACING SHORES OF THE BIG ISLAND.

HIGH SURF ADVISORY UNTIL 6 PM HST TODAY FOR EAST FACING SHORES OF
THE BIG ISLAND.

SMALL CRAFT ADVISORY UNTIL 6 AM HST TUESDAY FOR ALL HAWAIIAN WATERS
EXCEPT MAALAEA BAY.

&&

$$

DISCUSSION/MARINE...REYNES
AVIATION...BIRCHARD







000
FXHW60 PHFO 211340
AFDHFO

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
338 AM HST SUN DEC 21 2014

.SYNOPSIS...
LIGHT WINDS WILL CONTINUE TODAY...ALLOWING FOR SEA BREEZES TO
RETURN THIS AFTERNOON AND GENERATING A FEW SHOWERS OVER LEEWARD AND
INTERIOR AREAS. A COLD FRONT WILL APPROACH THE ISLANDS FROM THE
NORTHWEST...BRINGING AN INCREASE IN SHOWERS STARTING LATER TONIGHT.
THERE IS POTENTIAL FOR HEAVY RAIN AND A FEW THUNDERSTORMS ACROSS THE
ALOHA STATE FROM MONDAY AFTERNOON THROUGH TUESDAY. STRONG NORTHERLY
WINDS WILL DEVELOP BEHIND THE FRONT BY MID WEEK.

&&

.DISCUSSION...
A FEW SHOWERS HAVE BEEN MOVING ACROSS WINDWARD AND MOUNTAIN AREAS
DURING THE EARLY MORNING HOURS...WITH SFC WINDS REMAINING GENERALLY
LIGHT. WINDS OVER THE BIG ISLAND ARE NOW VEERING TO A MORE SE FLOW.
AN UPPER LEVEL RIDGE OVER THE ALOHA STATE WILL HELP IN KEEPING A
RELATIVELY STABLE AIRMASS ALOFT WITH SHOWER ACTIVITY REMAINING LOW
TODAY. AT THE SFC...A BROAD HIGH FAR ENE OF THE ISLANDS WILL
CONTINUE TO MIGRATE E...WHICH WILL MAINTAIN WINDS ON THE LIGHT SIDE
TODAY AND TONIGHT.

MEANWHILE...A DEEPENING TROUGH FAR NW OF THE ISLAND CHAIN CONTINUES
TO GRADUALLY APPROACH THE ALOHA STATE...WITH AN ASSOCIATED COLD
FRONT ABOUT 250 MILES NW OF KAUAI ALSO MOVING TOWARDS THE ISLANDS.
WITH THIS OVERALL SYNOPTIC SETUP...EXPECT ANOTHER ROUND OF SEA
BREEZES DEVELOPING THIS AFTERNOON WITH CLOUDS AND SHOWERS AFFECTING
SOME LEEWARD AND INTERIOR AREAS. RAINFALL SHOULD REMAIN LIGHT.

THE TROUGH/LOW COMPLEX WILL APPROACH THE W EDGE OF THE ISLAND CHAIN
TONIGHT WITH SHOWER COVERAGE INCREASING ACROSS THE AREA...AND WITH
POSSIBLY ENOUGH UPPER LVL SUPPORT FOR SOME DEEP CONVECTION TO
DEVELOP. A COLDER AIRMASS ALOFT WILL ARRIVE WITH THE TROUGH AND
FURTHER DESTABILIZE THE ATMOSPHERE OVER THE ISLANDS. LATEST MODEL
ANALYSES SHOW 500 MB TEMPS DROPPING TO -12C TO -14C. HOWEVER...
COMPARED TO PREVIOUS RUNS...THE MOST RECENT TRENDS IN THE GLOBAL
MODEL SOLUTIONS SEEM LESS AGGRESSIVE IN TERMS OF OVERALL AVAILABLE
MOISTURE FOR SIGNIFICANT CONVECTION TO DEVELOP WITH THE FROPA. X-SEC
ANALYSES DEPICT A RATHER DRY SWATH OF AIR ABOVE 700 MB MON THROUGH
TUE. BUT THE TROUGH SHOULD PROVIDE ENOUGH INSTABILITY TO ERODE LOW
LVL INVERSIONS AND ALLOW FOR SOME VERTICAL DEVELOPMENT OF SHOWERS
AND ANY THUNDERSTORM CELLS THAT MAY FORM.

IN GENERAL...GFS AND ECMWF SHOW FAIR AGREEMENT IN TERMS OF THE
TIMING AND OVERALL SCENARIO...BRINGING A FROPA THROUGH THE ISLAND
CHAIN AND A CUTOFF LOW DEVELOPING NE OF THE ALOHA STATE MON THROUGH
TUE. SO FAR IT SEEMS THE HIGHEST IMPACTS WEATHERWISE ARE EXPECTED
OVER KAUAI COUNTY AND OAHU...WHERE THE HIGHEST POPS AND CHANCES FOR
LOCALIZED HEAVY RAINFALL COVERAGE RESIDE. THERE IS ALSO A SLIGHT
CHANCE OF THUNDERSTORMS FROM MON AFTERNOON TO TUE NIGHT.

STRONG NNE WINDS WILL ARRIVE IN THE WAKE OF THE FROPA BY MID
WEEK...THEN GRADUALLY RELAX THROUGH THE SECOND HALF OF THE WEEK.
WIND WILL FINALLY VEER TO A MORE TYPICAL NE FLOW NEXT WEEKEND AS
HIGH PRESSURE BUILDS NW OF THE ALOHA STATE.

&&

.AVIATION...
LIGHT WINDS WILL ALLOW SEA BREEZES TO DEVELOP OVER THE ISLANDS LATER
THIS MORNING...LEADING TO INCREASED CLOUDINESS OVER INTERIOR AREAS.
A STABLE ATMOSPHERE WILL LIMIT CLOUD AND SHRA DEVELOPMENT...WITH
ISOL MVFR VIS/CIG EXPECTED. IN THE MEAN TIME...A LIGHT BUT
PERSISTENT E/SE LOW-LEVEL FLOW OVER MOST AREAS WILL DELIVER ISOL
MVFR VIS/CIG IN SHRA TO WINDWARD AREAS OF THE ISLANDS...MAINLY FROM
OAHU TO THE BIG ISLAND. A FRONT ARRIVING FROM THE NW TONIGHT WILL
BRING INCREASING N TO NE WINDS AND MVFR VIS/CIG IN SHRA...AFFECTING
KAUAI INITIALLY...BEFORE SPREADING TO OAHU ON MONDAY. THE INCREASING
WINDS AND SHRA WILL LIKELY REQUIRE AIRMETS FOR LOW LEVEL TURBULENCE
TO THE LEE OF THE MOUNTAINS...AND MOUNTAIN OBSCURATION ALONG N
FACING SLOPES.

&&

.MARINE...
A LONG PERIOD NORTHWEST SWELL GENERATED BY A LARGE AND POWERFUL LOW
PRESSURE SYSTEM WILL BRING INCREASING SURF HEIGHTS TODAY...REACHING
WARNING LEVELS TONIGHT. A HIGH SURF WARNING IS IN EFFECT UNTIL
TUESDAY MORNING FOR NORTH AND WEST FACING SHORES OF THE SMALLER
ISLANDS...AND STARTING LATER THIS MORNING FOR WEST FACING SHORES OF
THE BIG ISLAND.

A HIGH SURF ADVISORY ALSO REMAINS IN EFFECT FOR EAST FACING SHORES
OF THE BIG ISLAND THROUGH 6 PM HST TODAY.

THIS INCREASING SWELL WILL ALSO GENERATE SMALL CRAFT ADVISORY
CONDITIONS OVER MOST COASTAL WATERS DUE TO HAZARDOUS SEAS.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
HIGH SURF WARNING UNTIL 6 AM HST TUESDAY FOR NORTH AND WEST FACING
SHORES OF NIIHAU KAUAI OAHU AND MOLOKAI AND FOR NORTH FACING SHORES
OF MAUI.

HIGH SURF WARNING FROM 10 AM HST TODAY TO 6 AM HST TUESDAY FOR WEST
FACING SHORES OF THE BIG ISLAND.

HIGH SURF ADVISORY UNTIL 6 PM HST TODAY FOR EAST FACING SHORES OF
THE BIG ISLAND.

SMALL CRAFT ADVISORY UNTIL 6 AM HST TUESDAY FOR ALL HAWAIIAN WATERS
EXCEPT MAALAEA BAY.

&&

$$

DISCUSSION/MARINE...REYNES
AVIATION...BIRCHARD








000
FXHW60 PHFO 211340
AFDHFO

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
338 AM HST SUN DEC 21 2014

.SYNOPSIS...
LIGHT WINDS WILL CONTINUE TODAY...ALLOWING FOR SEA BREEZES TO
RETURN THIS AFTERNOON AND GENERATING A FEW SHOWERS OVER LEEWARD AND
INTERIOR AREAS. A COLD FRONT WILL APPROACH THE ISLANDS FROM THE
NORTHWEST...BRINGING AN INCREASE IN SHOWERS STARTING LATER TONIGHT.
THERE IS POTENTIAL FOR HEAVY RAIN AND A FEW THUNDERSTORMS ACROSS THE
ALOHA STATE FROM MONDAY AFTERNOON THROUGH TUESDAY. STRONG NORTHERLY
WINDS WILL DEVELOP BEHIND THE FRONT BY MID WEEK.

&&

.DISCUSSION...
A FEW SHOWERS HAVE BEEN MOVING ACROSS WINDWARD AND MOUNTAIN AREAS
DURING THE EARLY MORNING HOURS...WITH SFC WINDS REMAINING GENERALLY
LIGHT. WINDS OVER THE BIG ISLAND ARE NOW VEERING TO A MORE SE FLOW.
AN UPPER LEVEL RIDGE OVER THE ALOHA STATE WILL HELP IN KEEPING A
RELATIVELY STABLE AIRMASS ALOFT WITH SHOWER ACTIVITY REMAINING LOW
TODAY. AT THE SFC...A BROAD HIGH FAR ENE OF THE ISLANDS WILL
CONTINUE TO MIGRATE E...WHICH WILL MAINTAIN WINDS ON THE LIGHT SIDE
TODAY AND TONIGHT.

MEANWHILE...A DEEPENING TROUGH FAR NW OF THE ISLAND CHAIN CONTINUES
TO GRADUALLY APPROACH THE ALOHA STATE...WITH AN ASSOCIATED COLD
FRONT ABOUT 250 MILES NW OF KAUAI ALSO MOVING TOWARDS THE ISLANDS.
WITH THIS OVERALL SYNOPTIC SETUP...EXPECT ANOTHER ROUND OF SEA
BREEZES DEVELOPING THIS AFTERNOON WITH CLOUDS AND SHOWERS AFFECTING
SOME LEEWARD AND INTERIOR AREAS. RAINFALL SHOULD REMAIN LIGHT.

THE TROUGH/LOW COMPLEX WILL APPROACH THE W EDGE OF THE ISLAND CHAIN
TONIGHT WITH SHOWER COVERAGE INCREASING ACROSS THE AREA...AND WITH
POSSIBLY ENOUGH UPPER LVL SUPPORT FOR SOME DEEP CONVECTION TO
DEVELOP. A COLDER AIRMASS ALOFT WILL ARRIVE WITH THE TROUGH AND
FURTHER DESTABILIZE THE ATMOSPHERE OVER THE ISLANDS. LATEST MODEL
ANALYSES SHOW 500 MB TEMPS DROPPING TO -12C TO -14C. HOWEVER...
COMPARED TO PREVIOUS RUNS...THE MOST RECENT TRENDS IN THE GLOBAL
MODEL SOLUTIONS SEEM LESS AGGRESSIVE IN TERMS OF OVERALL AVAILABLE
MOISTURE FOR SIGNIFICANT CONVECTION TO DEVELOP WITH THE FROPA. X-SEC
ANALYSES DEPICT A RATHER DRY SWATH OF AIR ABOVE 700 MB MON THROUGH
TUE. BUT THE TROUGH SHOULD PROVIDE ENOUGH INSTABILITY TO ERODE LOW
LVL INVERSIONS AND ALLOW FOR SOME VERTICAL DEVELOPMENT OF SHOWERS
AND ANY THUNDERSTORM CELLS THAT MAY FORM.

IN GENERAL...GFS AND ECMWF SHOW FAIR AGREEMENT IN TERMS OF THE
TIMING AND OVERALL SCENARIO...BRINGING A FROPA THROUGH THE ISLAND
CHAIN AND A CUTOFF LOW DEVELOPING NE OF THE ALOHA STATE MON THROUGH
TUE. SO FAR IT SEEMS THE HIGHEST IMPACTS WEATHERWISE ARE EXPECTED
OVER KAUAI COUNTY AND OAHU...WHERE THE HIGHEST POPS AND CHANCES FOR
LOCALIZED HEAVY RAINFALL COVERAGE RESIDE. THERE IS ALSO A SLIGHT
CHANCE OF THUNDERSTORMS FROM MON AFTERNOON TO TUE NIGHT.

STRONG NNE WINDS WILL ARRIVE IN THE WAKE OF THE FROPA BY MID
WEEK...THEN GRADUALLY RELAX THROUGH THE SECOND HALF OF THE WEEK.
WIND WILL FINALLY VEER TO A MORE TYPICAL NE FLOW NEXT WEEKEND AS
HIGH PRESSURE BUILDS NW OF THE ALOHA STATE.

&&

.AVIATION...
LIGHT WINDS WILL ALLOW SEA BREEZES TO DEVELOP OVER THE ISLANDS LATER
THIS MORNING...LEADING TO INCREASED CLOUDINESS OVER INTERIOR AREAS.
A STABLE ATMOSPHERE WILL LIMIT CLOUD AND SHRA DEVELOPMENT...WITH
ISOL MVFR VIS/CIG EXPECTED. IN THE MEAN TIME...A LIGHT BUT
PERSISTENT E/SE LOW-LEVEL FLOW OVER MOST AREAS WILL DELIVER ISOL
MVFR VIS/CIG IN SHRA TO WINDWARD AREAS OF THE ISLANDS...MAINLY FROM
OAHU TO THE BIG ISLAND. A FRONT ARRIVING FROM THE NW TONIGHT WILL
BRING INCREASING N TO NE WINDS AND MVFR VIS/CIG IN SHRA...AFFECTING
KAUAI INITIALLY...BEFORE SPREADING TO OAHU ON MONDAY. THE INCREASING
WINDS AND SHRA WILL LIKELY REQUIRE AIRMETS FOR LOW LEVEL TURBULENCE
TO THE LEE OF THE MOUNTAINS...AND MOUNTAIN OBSCURATION ALONG N
FACING SLOPES.

&&

.MARINE...
A LONG PERIOD NORTHWEST SWELL GENERATED BY A LARGE AND POWERFUL LOW
PRESSURE SYSTEM WILL BRING INCREASING SURF HEIGHTS TODAY...REACHING
WARNING LEVELS TONIGHT. A HIGH SURF WARNING IS IN EFFECT UNTIL
TUESDAY MORNING FOR NORTH AND WEST FACING SHORES OF THE SMALLER
ISLANDS...AND STARTING LATER THIS MORNING FOR WEST FACING SHORES OF
THE BIG ISLAND.

A HIGH SURF ADVISORY ALSO REMAINS IN EFFECT FOR EAST FACING SHORES
OF THE BIG ISLAND THROUGH 6 PM HST TODAY.

THIS INCREASING SWELL WILL ALSO GENERATE SMALL CRAFT ADVISORY
CONDITIONS OVER MOST COASTAL WATERS DUE TO HAZARDOUS SEAS.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
HIGH SURF WARNING UNTIL 6 AM HST TUESDAY FOR NORTH AND WEST FACING
SHORES OF NIIHAU KAUAI OAHU AND MOLOKAI AND FOR NORTH FACING SHORES
OF MAUI.

HIGH SURF WARNING FROM 10 AM HST TODAY TO 6 AM HST TUESDAY FOR WEST
FACING SHORES OF THE BIG ISLAND.

HIGH SURF ADVISORY UNTIL 6 PM HST TODAY FOR EAST FACING SHORES OF
THE BIG ISLAND.

SMALL CRAFT ADVISORY UNTIL 6 AM HST TUESDAY FOR ALL HAWAIIAN WATERS
EXCEPT MAALAEA BAY.

&&

$$

DISCUSSION/MARINE...REYNES
AVIATION...BIRCHARD








000
FXHW60 PHFO 211340
AFDHFO

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
338 AM HST SUN DEC 21 2014

.SYNOPSIS...
LIGHT WINDS WILL CONTINUE TODAY...ALLOWING FOR SEA BREEZES TO
RETURN THIS AFTERNOON AND GENERATING A FEW SHOWERS OVER LEEWARD AND
INTERIOR AREAS. A COLD FRONT WILL APPROACH THE ISLANDS FROM THE
NORTHWEST...BRINGING AN INCREASE IN SHOWERS STARTING LATER TONIGHT.
THERE IS POTENTIAL FOR HEAVY RAIN AND A FEW THUNDERSTORMS ACROSS THE
ALOHA STATE FROM MONDAY AFTERNOON THROUGH TUESDAY. STRONG NORTHERLY
WINDS WILL DEVELOP BEHIND THE FRONT BY MID WEEK.

&&

.DISCUSSION...
A FEW SHOWERS HAVE BEEN MOVING ACROSS WINDWARD AND MOUNTAIN AREAS
DURING THE EARLY MORNING HOURS...WITH SFC WINDS REMAINING GENERALLY
LIGHT. WINDS OVER THE BIG ISLAND ARE NOW VEERING TO A MORE SE FLOW.
AN UPPER LEVEL RIDGE OVER THE ALOHA STATE WILL HELP IN KEEPING A
RELATIVELY STABLE AIRMASS ALOFT WITH SHOWER ACTIVITY REMAINING LOW
TODAY. AT THE SFC...A BROAD HIGH FAR ENE OF THE ISLANDS WILL
CONTINUE TO MIGRATE E...WHICH WILL MAINTAIN WINDS ON THE LIGHT SIDE
TODAY AND TONIGHT.

MEANWHILE...A DEEPENING TROUGH FAR NW OF THE ISLAND CHAIN CONTINUES
TO GRADUALLY APPROACH THE ALOHA STATE...WITH AN ASSOCIATED COLD
FRONT ABOUT 250 MILES NW OF KAUAI ALSO MOVING TOWARDS THE ISLANDS.
WITH THIS OVERALL SYNOPTIC SETUP...EXPECT ANOTHER ROUND OF SEA
BREEZES DEVELOPING THIS AFTERNOON WITH CLOUDS AND SHOWERS AFFECTING
SOME LEEWARD AND INTERIOR AREAS. RAINFALL SHOULD REMAIN LIGHT.

THE TROUGH/LOW COMPLEX WILL APPROACH THE W EDGE OF THE ISLAND CHAIN
TONIGHT WITH SHOWER COVERAGE INCREASING ACROSS THE AREA...AND WITH
POSSIBLY ENOUGH UPPER LVL SUPPORT FOR SOME DEEP CONVECTION TO
DEVELOP. A COLDER AIRMASS ALOFT WILL ARRIVE WITH THE TROUGH AND
FURTHER DESTABILIZE THE ATMOSPHERE OVER THE ISLANDS. LATEST MODEL
ANALYSES SHOW 500 MB TEMPS DROPPING TO -12C TO -14C. HOWEVER...
COMPARED TO PREVIOUS RUNS...THE MOST RECENT TRENDS IN THE GLOBAL
MODEL SOLUTIONS SEEM LESS AGGRESSIVE IN TERMS OF OVERALL AVAILABLE
MOISTURE FOR SIGNIFICANT CONVECTION TO DEVELOP WITH THE FROPA. X-SEC
ANALYSES DEPICT A RATHER DRY SWATH OF AIR ABOVE 700 MB MON THROUGH
TUE. BUT THE TROUGH SHOULD PROVIDE ENOUGH INSTABILITY TO ERODE LOW
LVL INVERSIONS AND ALLOW FOR SOME VERTICAL DEVELOPMENT OF SHOWERS
AND ANY THUNDERSTORM CELLS THAT MAY FORM.

IN GENERAL...GFS AND ECMWF SHOW FAIR AGREEMENT IN TERMS OF THE
TIMING AND OVERALL SCENARIO...BRINGING A FROPA THROUGH THE ISLAND
CHAIN AND A CUTOFF LOW DEVELOPING NE OF THE ALOHA STATE MON THROUGH
TUE. SO FAR IT SEEMS THE HIGHEST IMPACTS WEATHERWISE ARE EXPECTED
OVER KAUAI COUNTY AND OAHU...WHERE THE HIGHEST POPS AND CHANCES FOR
LOCALIZED HEAVY RAINFALL COVERAGE RESIDE. THERE IS ALSO A SLIGHT
CHANCE OF THUNDERSTORMS FROM MON AFTERNOON TO TUE NIGHT.

STRONG NNE WINDS WILL ARRIVE IN THE WAKE OF THE FROPA BY MID
WEEK...THEN GRADUALLY RELAX THROUGH THE SECOND HALF OF THE WEEK.
WIND WILL FINALLY VEER TO A MORE TYPICAL NE FLOW NEXT WEEKEND AS
HIGH PRESSURE BUILDS NW OF THE ALOHA STATE.

&&

.AVIATION...
LIGHT WINDS WILL ALLOW SEA BREEZES TO DEVELOP OVER THE ISLANDS LATER
THIS MORNING...LEADING TO INCREASED CLOUDINESS OVER INTERIOR AREAS.
A STABLE ATMOSPHERE WILL LIMIT CLOUD AND SHRA DEVELOPMENT...WITH
ISOL MVFR VIS/CIG EXPECTED. IN THE MEAN TIME...A LIGHT BUT
PERSISTENT E/SE LOW-LEVEL FLOW OVER MOST AREAS WILL DELIVER ISOL
MVFR VIS/CIG IN SHRA TO WINDWARD AREAS OF THE ISLANDS...MAINLY FROM
OAHU TO THE BIG ISLAND. A FRONT ARRIVING FROM THE NW TONIGHT WILL
BRING INCREASING N TO NE WINDS AND MVFR VIS/CIG IN SHRA...AFFECTING
KAUAI INITIALLY...BEFORE SPREADING TO OAHU ON MONDAY. THE INCREASING
WINDS AND SHRA WILL LIKELY REQUIRE AIRMETS FOR LOW LEVEL TURBULENCE
TO THE LEE OF THE MOUNTAINS...AND MOUNTAIN OBSCURATION ALONG N
FACING SLOPES.

&&

.MARINE...
A LONG PERIOD NORTHWEST SWELL GENERATED BY A LARGE AND POWERFUL LOW
PRESSURE SYSTEM WILL BRING INCREASING SURF HEIGHTS TODAY...REACHING
WARNING LEVELS TONIGHT. A HIGH SURF WARNING IS IN EFFECT UNTIL
TUESDAY MORNING FOR NORTH AND WEST FACING SHORES OF THE SMALLER
ISLANDS...AND STARTING LATER THIS MORNING FOR WEST FACING SHORES OF
THE BIG ISLAND.

A HIGH SURF ADVISORY ALSO REMAINS IN EFFECT FOR EAST FACING SHORES
OF THE BIG ISLAND THROUGH 6 PM HST TODAY.

THIS INCREASING SWELL WILL ALSO GENERATE SMALL CRAFT ADVISORY
CONDITIONS OVER MOST COASTAL WATERS DUE TO HAZARDOUS SEAS.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
HIGH SURF WARNING UNTIL 6 AM HST TUESDAY FOR NORTH AND WEST FACING
SHORES OF NIIHAU KAUAI OAHU AND MOLOKAI AND FOR NORTH FACING SHORES
OF MAUI.

HIGH SURF WARNING FROM 10 AM HST TODAY TO 6 AM HST TUESDAY FOR WEST
FACING SHORES OF THE BIG ISLAND.

HIGH SURF ADVISORY UNTIL 6 PM HST TODAY FOR EAST FACING SHORES OF
THE BIG ISLAND.

SMALL CRAFT ADVISORY UNTIL 6 AM HST TUESDAY FOR ALL HAWAIIAN WATERS
EXCEPT MAALAEA BAY.

&&

$$

DISCUSSION/MARINE...REYNES
AVIATION...BIRCHARD







000
ATHW40 PHFO 211200
SIMHI

HAWAIIAN ISLANDS SATELLITE INTERPRETATION MESSAGE
NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI
1200 UTC SUN DEC 21 2014

BASED ON DATA THROUGH 1130 UTC DECEMBER 21 2014

MOST AREAS AROUND THE ALOHA STATE THIS EARLY MORNING ARE CLEAR TO
PARTLY CLOUDY.  HOWEVER...SMALL CLUSTERS OF BROKEN LOW CLOUDS HAVE
BEEN FORMING NOW AND AGAIN OVER OAHU...THE ISLES OF MAUI COUNTY...
AND PORTIONS OF WESTERN AND NORTHERN BIG ISLAND.  LOW CLOUD MOTION
IS FROM THE EAST-SOUTHEAST BETWEEN 20 AND 25 MPH NEAR THE BIG
ISLAND...AND VEERS TO THE SOUTHEAST NEAR 15 MPH MOVING UP THE CHAIN
TO OAHU.  LOW CLOUDS HAVE BEGUN TO DRIFT FROM THE NORTH OVER KAUAI
IN RESPONSE TO A FRONT THAT IS GETTING CLOSER TO THE ISLES.

SMALL PATCHES OF BROKEN LOW CLOUDINESS ARE NORTH OF THE STATE FROM
OAHU TO THE BIG ISLAND...AND SOUTH OF MAUI COUNTY.  SKIES ARE CLEAR
TO SCATTERED ELSEWHERE OVER THE ADJACENT COASTAL WATERS AS OF
BULLETIN TIME.

THE LEADING EDGE OF BROKEN TO OVERCAST SHOWERY LOW CLOUDS ASSOCIATED
WITH A FRONT...AS MENTIONED IN THE FIRST PARAGRAPH...IS CURRENTLY
ABOUT 285 MILES NORTHWEST OF KAUAI.  THE SYSTEM HAS BEEN PUSHING
EAST NEAR 20 MPH ALONG 30N OVER THE PAST SEVEN HOURS.  MOST OF THE
CLOUDINESS WITH THE BOUNDARY IS WEST AND NORTHWEST OF A LINE FROM
30N156.5W TO 25N163W TO 18N180.  AS OF THIS WRITING...THE BACK EDGE
OF THE FRONTAL CLOUD BAND IS ALONG A LINE FROM 30N162.5W TO
24.5N170W TO 21N180.

UNORGANIZED CONVECTION CONTINUES TO IGNITE ALONG THE INTERTROPICAL
CONVERGENCE ZONE FAR SOUTH OF HAWAII.  MOST OF THE SHOWERS AND
THUNDERSTORMS HAVE BEEN FIRING FROM 06N TO 08.5N EAST OF 152W.  THE
MOST INTENSE CELLS...HOWEVER...CLIMBING TO OVER 50 THOUSAND FEET...
HAVE BEEN OCCURRING 05N TO 07N BETWEEN 162W AND 167W.

$$

KINEL






000
ATHW40 PHFO 211200
SIMHI

HAWAIIAN ISLANDS SATELLITE INTERPRETATION MESSAGE
NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI
1200 UTC SUN DEC 21 2014

BASED ON DATA THROUGH 1130 UTC DECEMBER 21 2014

MOST AREAS AROUND THE ALOHA STATE THIS EARLY MORNING ARE CLEAR TO
PARTLY CLOUDY.  HOWEVER...SMALL CLUSTERS OF BROKEN LOW CLOUDS HAVE
BEEN FORMING NOW AND AGAIN OVER OAHU...THE ISLES OF MAUI COUNTY...
AND PORTIONS OF WESTERN AND NORTHERN BIG ISLAND.  LOW CLOUD MOTION
IS FROM THE EAST-SOUTHEAST BETWEEN 20 AND 25 MPH NEAR THE BIG
ISLAND...AND VEERS TO THE SOUTHEAST NEAR 15 MPH MOVING UP THE CHAIN
TO OAHU.  LOW CLOUDS HAVE BEGUN TO DRIFT FROM THE NORTH OVER KAUAI
IN RESPONSE TO A FRONT THAT IS GETTING CLOSER TO THE ISLES.

SMALL PATCHES OF BROKEN LOW CLOUDINESS ARE NORTH OF THE STATE FROM
OAHU TO THE BIG ISLAND...AND SOUTH OF MAUI COUNTY.  SKIES ARE CLEAR
TO SCATTERED ELSEWHERE OVER THE ADJACENT COASTAL WATERS AS OF
BULLETIN TIME.

THE LEADING EDGE OF BROKEN TO OVERCAST SHOWERY LOW CLOUDS ASSOCIATED
WITH A FRONT...AS MENTIONED IN THE FIRST PARAGRAPH...IS CURRENTLY
ABOUT 285 MILES NORTHWEST OF KAUAI.  THE SYSTEM HAS BEEN PUSHING
EAST NEAR 20 MPH ALONG 30N OVER THE PAST SEVEN HOURS.  MOST OF THE
CLOUDINESS WITH THE BOUNDARY IS WEST AND NORTHWEST OF A LINE FROM
30N156.5W TO 25N163W TO 18N180.  AS OF THIS WRITING...THE BACK EDGE
OF THE FRONTAL CLOUD BAND IS ALONG A LINE FROM 30N162.5W TO
24.5N170W TO 21N180.

UNORGANIZED CONVECTION CONTINUES TO IGNITE ALONG THE INTERTROPICAL
CONVERGENCE ZONE FAR SOUTH OF HAWAII.  MOST OF THE SHOWERS AND
THUNDERSTORMS HAVE BEEN FIRING FROM 06N TO 08.5N EAST OF 152W.  THE
MOST INTENSE CELLS...HOWEVER...CLIMBING TO OVER 50 THOUSAND FEET...
HAVE BEEN OCCURRING 05N TO 07N BETWEEN 162W AND 167W.

$$

KINEL





000
ATHW40 PHFO 211200
SIMHI

HAWAIIAN ISLANDS SATELLITE INTERPRETATION MESSAGE
NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI
1200 UTC SUN DEC 21 2014

BASED ON DATA THROUGH 1130 UTC DECEMBER 21 2014

MOST AREAS AROUND THE ALOHA STATE THIS EARLY MORNING ARE CLEAR TO
PARTLY CLOUDY.  HOWEVER...SMALL CLUSTERS OF BROKEN LOW CLOUDS HAVE
BEEN FORMING NOW AND AGAIN OVER OAHU...THE ISLES OF MAUI COUNTY...
AND PORTIONS OF WESTERN AND NORTHERN BIG ISLAND.  LOW CLOUD MOTION
IS FROM THE EAST-SOUTHEAST BETWEEN 20 AND 25 MPH NEAR THE BIG
ISLAND...AND VEERS TO THE SOUTHEAST NEAR 15 MPH MOVING UP THE CHAIN
TO OAHU.  LOW CLOUDS HAVE BEGUN TO DRIFT FROM THE NORTH OVER KAUAI
IN RESPONSE TO A FRONT THAT IS GETTING CLOSER TO THE ISLES.

SMALL PATCHES OF BROKEN LOW CLOUDINESS ARE NORTH OF THE STATE FROM
OAHU TO THE BIG ISLAND...AND SOUTH OF MAUI COUNTY.  SKIES ARE CLEAR
TO SCATTERED ELSEWHERE OVER THE ADJACENT COASTAL WATERS AS OF
BULLETIN TIME.

THE LEADING EDGE OF BROKEN TO OVERCAST SHOWERY LOW CLOUDS ASSOCIATED
WITH A FRONT...AS MENTIONED IN THE FIRST PARAGRAPH...IS CURRENTLY
ABOUT 285 MILES NORTHWEST OF KAUAI.  THE SYSTEM HAS BEEN PUSHING
EAST NEAR 20 MPH ALONG 30N OVER THE PAST SEVEN HOURS.  MOST OF THE
CLOUDINESS WITH THE BOUNDARY IS WEST AND NORTHWEST OF A LINE FROM
30N156.5W TO 25N163W TO 18N180.  AS OF THIS WRITING...THE BACK EDGE
OF THE FRONTAL CLOUD BAND IS ALONG A LINE FROM 30N162.5W TO
24.5N170W TO 21N180.

UNORGANIZED CONVECTION CONTINUES TO IGNITE ALONG THE INTERTROPICAL
CONVERGENCE ZONE FAR SOUTH OF HAWAII.  MOST OF THE SHOWERS AND
THUNDERSTORMS HAVE BEEN FIRING FROM 06N TO 08.5N EAST OF 152W.  THE
MOST INTENSE CELLS...HOWEVER...CLIMBING TO OVER 50 THOUSAND FEET...
HAVE BEEN OCCURRING 05N TO 07N BETWEEN 162W AND 167W.

$$

KINEL





000
ATHW40 PHFO 211200
SIMHI

HAWAIIAN ISLANDS SATELLITE INTERPRETATION MESSAGE
NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI
1200 UTC SUN DEC 21 2014

BASED ON DATA THROUGH 1130 UTC DECEMBER 21 2014

MOST AREAS AROUND THE ALOHA STATE THIS EARLY MORNING ARE CLEAR TO
PARTLY CLOUDY.  HOWEVER...SMALL CLUSTERS OF BROKEN LOW CLOUDS HAVE
BEEN FORMING NOW AND AGAIN OVER OAHU...THE ISLES OF MAUI COUNTY...
AND PORTIONS OF WESTERN AND NORTHERN BIG ISLAND.  LOW CLOUD MOTION
IS FROM THE EAST-SOUTHEAST BETWEEN 20 AND 25 MPH NEAR THE BIG
ISLAND...AND VEERS TO THE SOUTHEAST NEAR 15 MPH MOVING UP THE CHAIN
TO OAHU.  LOW CLOUDS HAVE BEGUN TO DRIFT FROM THE NORTH OVER KAUAI
IN RESPONSE TO A FRONT THAT IS GETTING CLOSER TO THE ISLES.

SMALL PATCHES OF BROKEN LOW CLOUDINESS ARE NORTH OF THE STATE FROM
OAHU TO THE BIG ISLAND...AND SOUTH OF MAUI COUNTY.  SKIES ARE CLEAR
TO SCATTERED ELSEWHERE OVER THE ADJACENT COASTAL WATERS AS OF
BULLETIN TIME.

THE LEADING EDGE OF BROKEN TO OVERCAST SHOWERY LOW CLOUDS ASSOCIATED
WITH A FRONT...AS MENTIONED IN THE FIRST PARAGRAPH...IS CURRENTLY
ABOUT 285 MILES NORTHWEST OF KAUAI.  THE SYSTEM HAS BEEN PUSHING
EAST NEAR 20 MPH ALONG 30N OVER THE PAST SEVEN HOURS.  MOST OF THE
CLOUDINESS WITH THE BOUNDARY IS WEST AND NORTHWEST OF A LINE FROM
30N156.5W TO 25N163W TO 18N180.  AS OF THIS WRITING...THE BACK EDGE
OF THE FRONTAL CLOUD BAND IS ALONG A LINE FROM 30N162.5W TO
24.5N170W TO 21N180.

UNORGANIZED CONVECTION CONTINUES TO IGNITE ALONG THE INTERTROPICAL
CONVERGENCE ZONE FAR SOUTH OF HAWAII.  MOST OF THE SHOWERS AND
THUNDERSTORMS HAVE BEEN FIRING FROM 06N TO 08.5N EAST OF 152W.  THE
MOST INTENSE CELLS...HOWEVER...CLIMBING TO OVER 50 THOUSAND FEET...
HAVE BEEN OCCURRING 05N TO 07N BETWEEN 162W AND 167W.

$$

KINEL






000
FXHW60 PHFO 210630
AFDHFO

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
830 PM HST SAT DEC 20 2014

.SYNOPSIS...
LIGHT SOUTHEASTERLY WINDS WILL CONTINUE THROUGH SUNDAY AND ALLOWING
FOR LAND AND SEA BREEZES TO DEVELOP. EXPECT GENERALLY BENIGN WEATHER
CONDITIONS THROUGH SUNDAY WITH A FEW SHOWERS DEVELOPING IN THE
AFTERNOON AS SEA BREEZES PUSH INLAND. THEN A COLD FRONT APPROACHES
THE ISLANDS FROM THE NORTHWEST...BRINGING AN INCREASE IN SHOWERS
STARTING SUNDAY NIGHT. THERE IS POTENTIAL FOR HEAVY RAIN AND A FEW
THUNDERSTORMS ACROSS THE ALOHA STATE FROM MONDAY AFTERNOON THROUGH
TUESDAY. STRONG NORTHERLY WINDS WILL DEVELOP BEHIND THE FRONT BY MID
WEEK.

&&

.DISCUSSION...
AT 8 PM HST RADAR DATA WAS SHOWING A FEW SMALL SHOWERS MOVING ACROSS
WINDWARD AND MOUNTAIN AREAS. SFC WINDS ARE GENERALLY LIGHT...WITH
STILL SOME E FLOW PREVAILING OVER THE BIG ISLAND.

FOR THE REST OF TONIGHT...AN UPPER LEVEL RIDGE WILL REMAIN IN PLACE
OVER THE ALOHA STATE...WHICH WILL HELP KEEPING A RELATIVELY STABLE
AIRMASS ALOFT WITH SHOWER ACTIVITY REMAINING LOW. AT THE SFC...A
BROAD HIGH FAR ENE OF THE ISLANDS WILL CONTINUE TO MIGRATE E...WITH
GENERALLY LIGHT SE/S FLOW CONTINUING THROUGH SUN.

MEANWHILE...A DEEPENING TROUGH IS LOCATED FAR NW OF THE ISLAND CHAIN
AND GRADUALLY APPROACHING THE AREA. AN ASSOCIATED COLD FRONT IS
ABOUT 580 MILES NW OF KAUAI AND ALSO MOVING TOWARDS THE ISLANDS.
WITH THIS OVERALL SYNOPTIC SETUP...EXPECT ANOTHER DAY OF SEA BREEZES
DEVELOPING SUN AFTERNOON WITH CLOUDS AND SHOWERS AFFECTING SOME
LEEWARD AND INTERIOR AREAS. RAINFALL SHOULD REMAIN LIGHT.

THE UPPER LEVEL TROUGH AND ITS ASSOCIATED SFC COLD FRONT WILL
APPROACH THE W EDGE OF THE ALOHA STATE BY SUN NIGHT. SHOWER COVERAGE
WILL INCREASE AS THE LEADING EDGE OF THE FRONT REACHES THE
AREA...WITH POSSIBLY ENOUGH UPPER LVL SUPPORT FOR SOME DEEP
CONVECTION TO DEVELOP. A COLDER AIRMASS ALOFT WILL ARRIVE WITH THE
TROUGH...FURTHER DESTABILIZING THE ATMOSPHERE OVER THE ISLANDS.
LATEST MODEL ANALYSES SHOW 500 MB TEMPS DROPPING TO -12C TO -14C.
HOWEVER...THE LATEST TRENDS IN THE GLOBAL MODEL SOLUTIONS ARE
BECOMING LESS AGGRESSIVE IN TERMS OF OVERALL AVAILABLE MOISTURE FOR
SIGNIFICANT CONVECTION TO DEVELOP WITH THE FROPA. X-SEC ANALYSES
DEPICT A RATHER DRY SWATH ABOVE 700 MB. BUT THE TROUGH SHOULD
PROVIDE ENOUGH INSTABILITY TO ERODE LOW LVL INVERSIONS AND ALLOW FOR
SOME VERTICAL DEVELOPMENT OF SHOWERS AND ANY THUNDERSTORM CELLS THAT
MAY FORM.

GLOBAL MODELS ARE SHOWING BETTER AGREEMENT IN TERMS OF TIMING AND
OVERALL SCENARIO...WITH BOTH GFS AND ECMWF SOLUTIONS DEPICTING A
FROPA THROUGH THE ISLAND CHAIN AND A CUTOFF LOW DEVELOPING NE OF THE
STATE MON THROUGH TUE. SO FAR IT SEEMS THE HIGHEST IMPACTS
WEATHERWISE ARE EXPECTED OVER KAUAI COUNTY AND OAHU...WHERE THE
HIGHEST POPS AND CHANCES FOR LOCALIZED HEAVY RAINFALL COVERAGE
RESIDE. THERE IS ALSO A SLIGHT CHANCE OF THUNDERSTORMS FROM MON
AFTERNOON TO TUE NIGHT.

STRONG NNE WINDS WILL ARRIVE IN THE WAKE OF THE FROPA BY MID
WEEK...THEN GRADUALLY RELAX THROUGH THE SECOND HALF OF THE WEEK.
WIND WILL FINALLY VEER TO A MORE TYPICAL NE FLOW NEXT WEEKEND AS
HIGH PRESSURE BUILDS NW OF THE ALOHA STATE.

&&

.AVIATION...
LIGHT WINDS WILL ALLOW LAND BREEZES TO CLEAR SKIES OVER THE SMALLER
ISLANDS TONIGHT THROUGH SUNDAY MORNING...WITH PREVAILING VFR.
MEANWHILE...WEAKENING BUT PERSISTENT TRADE WINDS NEAR THE BIG
ISLAND WILL CARRY A FEW SHRA OVER WINDWARD COASTS...SLOPES AND
ADJACENT WATERS...RESULTING IN ISOL MVFR CIG/VIS. LIGHT WINDS AND A
STABLE ISLAND ATMOSPHERE CONTINUING THROUGH SUNDAY WILL LEAD TO
AREAS OF INTERIOR CLOUDINESS BY SUNDAY AFTERNOON...WITH ISOL MVFR
CIG POSSIBLE OVER ALL ISLANDS. A FRONT ARRIVING FROM THE NW LATE IN
THE DAY WILL BRING INCREASING N TO NE WINDS AND MVFR VIS/CIG IN
SHRA...AFFECTING KAUAI INITIALLY TOMORROW EVENING.

&&

.MARINE...
A LONG PERIOD NORTHWEST SWELL GENERATED BY A LARGE AND POWERFUL LOW
PRESSURE SYSTEM IS EXPECTED TO BRING WARNING LEVEL SURF TO THE
ISLANDS ON SUNDAY. THIS SWELL WILL REMAIN IN PLACE THROUGH MONDAY
BEFORE GRADUALLY DIMINISHING. A HIGH SURF WARNING STARTS AT 4 AM
SUNDAY FOR NORTH AND WEST FACING SHORES OF THE SMALLER ISLANDS...
AND LATE SUNDAY MORNING FOR WEST FACING SHORES OF THE BIG ISLAND.

A HIGH SURF ADVISORY ALSO REMAINS IN EFFECT FOR EAST FACING SHORES
OF THE BIG ISLAND THROUGH SUNDAY.

THIS INCREASING SWELL WILL ALSO GENERATE SMALL CRAFT ADVISORY
CONDITIONS STARTING SUNDAY EARLY MORNING OVER MOST COASTAL WATERS
DUE TO HAZARDOUS SEAS.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
HIGH SURF WARNING FROM 4 AM HST SUNDAY TO 6 AM HST TUESDAY FOR NORTH
AND WEST FACING SHORES OF NIIHAU KAUAI OAHU AND MOLOKAI AND FOR
NORTH FACING SHORES OF MAUI.

HIGH SURF WARNING FROM 10 AM HST SUNDAY TO 6 AM HST TUESDAY FOR WEST
FACING SHORES OF THE BIG ISLAND.

HIGH SURF ADVISORY UNTIL 6 PM HST SUNDAY FOR EAST FACING SHORES OF
THE BIG ISLAND.

SMALL CRAFT ADVISORY FROM 4 AM SUNDAY TO 6 AM HST TUESDAY FOR ALL
HAWAIIAN WATERS EXCEPT MAALAEA BAY.

&&

$$

DISCUSSION/MARINE...REYNES
AVIATION...BIRCHARD






000
FXHW60 PHFO 210630
AFDHFO

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
830 PM HST SAT DEC 20 2014

.SYNOPSIS...
LIGHT SOUTHEASTERLY WINDS WILL CONTINUE THROUGH SUNDAY AND ALLOWING
FOR LAND AND SEA BREEZES TO DEVELOP. EXPECT GENERALLY BENIGN WEATHER
CONDITIONS THROUGH SUNDAY WITH A FEW SHOWERS DEVELOPING IN THE
AFTERNOON AS SEA BREEZES PUSH INLAND. THEN A COLD FRONT APPROACHES
THE ISLANDS FROM THE NORTHWEST...BRINGING AN INCREASE IN SHOWERS
STARTING SUNDAY NIGHT. THERE IS POTENTIAL FOR HEAVY RAIN AND A FEW
THUNDERSTORMS ACROSS THE ALOHA STATE FROM MONDAY AFTERNOON THROUGH
TUESDAY. STRONG NORTHERLY WINDS WILL DEVELOP BEHIND THE FRONT BY MID
WEEK.

&&

.DISCUSSION...
AT 8 PM HST RADAR DATA WAS SHOWING A FEW SMALL SHOWERS MOVING ACROSS
WINDWARD AND MOUNTAIN AREAS. SFC WINDS ARE GENERALLY LIGHT...WITH
STILL SOME E FLOW PREVAILING OVER THE BIG ISLAND.

FOR THE REST OF TONIGHT...AN UPPER LEVEL RIDGE WILL REMAIN IN PLACE
OVER THE ALOHA STATE...WHICH WILL HELP KEEPING A RELATIVELY STABLE
AIRMASS ALOFT WITH SHOWER ACTIVITY REMAINING LOW. AT THE SFC...A
BROAD HIGH FAR ENE OF THE ISLANDS WILL CONTINUE TO MIGRATE E...WITH
GENERALLY LIGHT SE/S FLOW CONTINUING THROUGH SUN.

MEANWHILE...A DEEPENING TROUGH IS LOCATED FAR NW OF THE ISLAND CHAIN
AND GRADUALLY APPROACHING THE AREA. AN ASSOCIATED COLD FRONT IS
ABOUT 580 MILES NW OF KAUAI AND ALSO MOVING TOWARDS THE ISLANDS.
WITH THIS OVERALL SYNOPTIC SETUP...EXPECT ANOTHER DAY OF SEA BREEZES
DEVELOPING SUN AFTERNOON WITH CLOUDS AND SHOWERS AFFECTING SOME
LEEWARD AND INTERIOR AREAS. RAINFALL SHOULD REMAIN LIGHT.

THE UPPER LEVEL TROUGH AND ITS ASSOCIATED SFC COLD FRONT WILL
APPROACH THE W EDGE OF THE ALOHA STATE BY SUN NIGHT. SHOWER COVERAGE
WILL INCREASE AS THE LEADING EDGE OF THE FRONT REACHES THE
AREA...WITH POSSIBLY ENOUGH UPPER LVL SUPPORT FOR SOME DEEP
CONVECTION TO DEVELOP. A COLDER AIRMASS ALOFT WILL ARRIVE WITH THE
TROUGH...FURTHER DESTABILIZING THE ATMOSPHERE OVER THE ISLANDS.
LATEST MODEL ANALYSES SHOW 500 MB TEMPS DROPPING TO -12C TO -14C.
HOWEVER...THE LATEST TRENDS IN THE GLOBAL MODEL SOLUTIONS ARE
BECOMING LESS AGGRESSIVE IN TERMS OF OVERALL AVAILABLE MOISTURE FOR
SIGNIFICANT CONVECTION TO DEVELOP WITH THE FROPA. X-SEC ANALYSES
DEPICT A RATHER DRY SWATH ABOVE 700 MB. BUT THE TROUGH SHOULD
PROVIDE ENOUGH INSTABILITY TO ERODE LOW LVL INVERSIONS AND ALLOW FOR
SOME VERTICAL DEVELOPMENT OF SHOWERS AND ANY THUNDERSTORM CELLS THAT
MAY FORM.

GLOBAL MODELS ARE SHOWING BETTER AGREEMENT IN TERMS OF TIMING AND
OVERALL SCENARIO...WITH BOTH GFS AND ECMWF SOLUTIONS DEPICTING A
FROPA THROUGH THE ISLAND CHAIN AND A CUTOFF LOW DEVELOPING NE OF THE
STATE MON THROUGH TUE. SO FAR IT SEEMS THE HIGHEST IMPACTS
WEATHERWISE ARE EXPECTED OVER KAUAI COUNTY AND OAHU...WHERE THE
HIGHEST POPS AND CHANCES FOR LOCALIZED HEAVY RAINFALL COVERAGE
RESIDE. THERE IS ALSO A SLIGHT CHANCE OF THUNDERSTORMS FROM MON
AFTERNOON TO TUE NIGHT.

STRONG NNE WINDS WILL ARRIVE IN THE WAKE OF THE FROPA BY MID
WEEK...THEN GRADUALLY RELAX THROUGH THE SECOND HALF OF THE WEEK.
WIND WILL FINALLY VEER TO A MORE TYPICAL NE FLOW NEXT WEEKEND AS
HIGH PRESSURE BUILDS NW OF THE ALOHA STATE.

&&

.AVIATION...
LIGHT WINDS WILL ALLOW LAND BREEZES TO CLEAR SKIES OVER THE SMALLER
ISLANDS TONIGHT THROUGH SUNDAY MORNING...WITH PREVAILING VFR.
MEANWHILE...WEAKENING BUT PERSISTENT TRADE WINDS NEAR THE BIG
ISLAND WILL CARRY A FEW SHRA OVER WINDWARD COASTS...SLOPES AND
ADJACENT WATERS...RESULTING IN ISOL MVFR CIG/VIS. LIGHT WINDS AND A
STABLE ISLAND ATMOSPHERE CONTINUING THROUGH SUNDAY WILL LEAD TO
AREAS OF INTERIOR CLOUDINESS BY SUNDAY AFTERNOON...WITH ISOL MVFR
CIG POSSIBLE OVER ALL ISLANDS. A FRONT ARRIVING FROM THE NW LATE IN
THE DAY WILL BRING INCREASING N TO NE WINDS AND MVFR VIS/CIG IN
SHRA...AFFECTING KAUAI INITIALLY TOMORROW EVENING.

&&

.MARINE...
A LONG PERIOD NORTHWEST SWELL GENERATED BY A LARGE AND POWERFUL LOW
PRESSURE SYSTEM IS EXPECTED TO BRING WARNING LEVEL SURF TO THE
ISLANDS ON SUNDAY. THIS SWELL WILL REMAIN IN PLACE THROUGH MONDAY
BEFORE GRADUALLY DIMINISHING. A HIGH SURF WARNING STARTS AT 4 AM
SUNDAY FOR NORTH AND WEST FACING SHORES OF THE SMALLER ISLANDS...
AND LATE SUNDAY MORNING FOR WEST FACING SHORES OF THE BIG ISLAND.

A HIGH SURF ADVISORY ALSO REMAINS IN EFFECT FOR EAST FACING SHORES
OF THE BIG ISLAND THROUGH SUNDAY.

THIS INCREASING SWELL WILL ALSO GENERATE SMALL CRAFT ADVISORY
CONDITIONS STARTING SUNDAY EARLY MORNING OVER MOST COASTAL WATERS
DUE TO HAZARDOUS SEAS.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
HIGH SURF WARNING FROM 4 AM HST SUNDAY TO 6 AM HST TUESDAY FOR NORTH
AND WEST FACING SHORES OF NIIHAU KAUAI OAHU AND MOLOKAI AND FOR
NORTH FACING SHORES OF MAUI.

HIGH SURF WARNING FROM 10 AM HST SUNDAY TO 6 AM HST TUESDAY FOR WEST
FACING SHORES OF THE BIG ISLAND.

HIGH SURF ADVISORY UNTIL 6 PM HST SUNDAY FOR EAST FACING SHORES OF
THE BIG ISLAND.

SMALL CRAFT ADVISORY FROM 4 AM SUNDAY TO 6 AM HST TUESDAY FOR ALL
HAWAIIAN WATERS EXCEPT MAALAEA BAY.

&&

$$

DISCUSSION/MARINE...REYNES
AVIATION...BIRCHARD







000
ATHW40 PHFO 210500
SIMHI

HAWAIIAN ISLANDS SATELLITE INTERPRETATION MESSAGE
NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI
0500 UTC SUN DEC 21 2014

BASED ON DATA THROUGH 0430 UTC DECEMBER 21 2014

LOW CLOUDS HAVE BEEN FAVORING MAUKA SECTIONS OF THE SMALLER ISLES
AND WEST MAUI...THE WEST-FACING SLOPES OF HALEAKALA IN EAST MAUI...
AND THE SOUTH KOHALA AND KONA SLOPES ON THE BIG ISLAND.  BROKEN LOW
CLOUDINESS HAS ALSO BEEN AFFECTING WINDWARD AREAS OF EACH ISLE FROM
TIME TO TIME.  SKIES ARE OTHERWISE CLEAR TO PARTLY CLOUDY OVER THE
ALOHA STATE THIS EARLY EVENING.  LOW CLOUD MOVEMENT IS FROM THE EAST
NEAR 25 MPH JUST EAST OF THE BIG ISLAND...AND VEERS TO THE SOUTHEAST
AND SLOWS TO NEAR 10 MPH MOVING UP THE CHAIN TO KAUAI.

CONDITIONS ARE CLEAR TO SCATTERED OVER THE ADJACENT COASTAL WATERS
AS OF BULLETIN TIME.

THE LEADING EDGE OF LOW CLOUDS JUST AHEAD OF A FRONT IS ABOUT 400
MILES NORTHWEST OF KAUAI...AND HAS BEEN HEADING EAST TO SOUTHEAST
NEAR 30 MPH ALONG 30N.  MOST OF THE BROKEN TO OVERCAST LOW CLOUDS
WITH THE SYSTEM ARE CURRENTLY NORTHWEST OF A LINE FROM 30N160W TO
23N170W TO 19N180...WITH THE BACK EDGE OF CLOUDINESS ALONG A LINE
FROM 30N166W TO 25.5N170W TO 21.5N180.

SHOWERS AND THUNDERSTORMS HAVE BEEN FIRING ALONG THE INTERTROPICAL
CONVERGENCE ZONE FAR SOUTH OF HAWAII.  MOST OF THE CONVECTION HAS
BEEN IGNITING FROM 04N TO 08.5N EAST OF 164W...AND FROM 04N TO 08N
BETWEEN 170W AND 178W.

$$

KINEL






000
ATHW40 PHFO 210500
SIMHI

HAWAIIAN ISLANDS SATELLITE INTERPRETATION MESSAGE
NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI
0500 UTC SUN DEC 21 2014

BASED ON DATA THROUGH 0430 UTC DECEMBER 21 2014

LOW CLOUDS HAVE BEEN FAVORING MAUKA SECTIONS OF THE SMALLER ISLES
AND WEST MAUI...THE WEST-FACING SLOPES OF HALEAKALA IN EAST MAUI...
AND THE SOUTH KOHALA AND KONA SLOPES ON THE BIG ISLAND.  BROKEN LOW
CLOUDINESS HAS ALSO BEEN AFFECTING WINDWARD AREAS OF EACH ISLE FROM
TIME TO TIME.  SKIES ARE OTHERWISE CLEAR TO PARTLY CLOUDY OVER THE
ALOHA STATE THIS EARLY EVENING.  LOW CLOUD MOVEMENT IS FROM THE EAST
NEAR 25 MPH JUST EAST OF THE BIG ISLAND...AND VEERS TO THE SOUTHEAST
AND SLOWS TO NEAR 10 MPH MOVING UP THE CHAIN TO KAUAI.

CONDITIONS ARE CLEAR TO SCATTERED OVER THE ADJACENT COASTAL WATERS
AS OF BULLETIN TIME.

THE LEADING EDGE OF LOW CLOUDS JUST AHEAD OF A FRONT IS ABOUT 400
MILES NORTHWEST OF KAUAI...AND HAS BEEN HEADING EAST TO SOUTHEAST
NEAR 30 MPH ALONG 30N.  MOST OF THE BROKEN TO OVERCAST LOW CLOUDS
WITH THE SYSTEM ARE CURRENTLY NORTHWEST OF A LINE FROM 30N160W TO
23N170W TO 19N180...WITH THE BACK EDGE OF CLOUDINESS ALONG A LINE
FROM 30N166W TO 25.5N170W TO 21.5N180.

SHOWERS AND THUNDERSTORMS HAVE BEEN FIRING ALONG THE INTERTROPICAL
CONVERGENCE ZONE FAR SOUTH OF HAWAII.  MOST OF THE CONVECTION HAS
BEEN IGNITING FROM 04N TO 08.5N EAST OF 164W...AND FROM 04N TO 08N
BETWEEN 170W AND 178W.

$$

KINEL





000
ATHW40 PHFO 210500
SIMHI

HAWAIIAN ISLANDS SATELLITE INTERPRETATION MESSAGE
NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI
0500 UTC SUN DEC 21 2014

BASED ON DATA THROUGH 0430 UTC DECEMBER 21 2014

LOW CLOUDS HAVE BEEN FAVORING MAUKA SECTIONS OF THE SMALLER ISLES
AND WEST MAUI...THE WEST-FACING SLOPES OF HALEAKALA IN EAST MAUI...
AND THE SOUTH KOHALA AND KONA SLOPES ON THE BIG ISLAND.  BROKEN LOW
CLOUDINESS HAS ALSO BEEN AFFECTING WINDWARD AREAS OF EACH ISLE FROM
TIME TO TIME.  SKIES ARE OTHERWISE CLEAR TO PARTLY CLOUDY OVER THE
ALOHA STATE THIS EARLY EVENING.  LOW CLOUD MOVEMENT IS FROM THE EAST
NEAR 25 MPH JUST EAST OF THE BIG ISLAND...AND VEERS TO THE SOUTHEAST
AND SLOWS TO NEAR 10 MPH MOVING UP THE CHAIN TO KAUAI.

CONDITIONS ARE CLEAR TO SCATTERED OVER THE ADJACENT COASTAL WATERS
AS OF BULLETIN TIME.

THE LEADING EDGE OF LOW CLOUDS JUST AHEAD OF A FRONT IS ABOUT 400
MILES NORTHWEST OF KAUAI...AND HAS BEEN HEADING EAST TO SOUTHEAST
NEAR 30 MPH ALONG 30N.  MOST OF THE BROKEN TO OVERCAST LOW CLOUDS
WITH THE SYSTEM ARE CURRENTLY NORTHWEST OF A LINE FROM 30N160W TO
23N170W TO 19N180...WITH THE BACK EDGE OF CLOUDINESS ALONG A LINE
FROM 30N166W TO 25.5N170W TO 21.5N180.

SHOWERS AND THUNDERSTORMS HAVE BEEN FIRING ALONG THE INTERTROPICAL
CONVERGENCE ZONE FAR SOUTH OF HAWAII.  MOST OF THE CONVECTION HAS
BEEN IGNITING FROM 04N TO 08.5N EAST OF 164W...AND FROM 04N TO 08N
BETWEEN 170W AND 178W.

$$

KINEL





000
ATHW40 PHFO 210500
SIMHI

HAWAIIAN ISLANDS SATELLITE INTERPRETATION MESSAGE
NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI
0500 UTC SUN DEC 21 2014

BASED ON DATA THROUGH 0430 UTC DECEMBER 21 2014

LOW CLOUDS HAVE BEEN FAVORING MAUKA SECTIONS OF THE SMALLER ISLES
AND WEST MAUI...THE WEST-FACING SLOPES OF HALEAKALA IN EAST MAUI...
AND THE SOUTH KOHALA AND KONA SLOPES ON THE BIG ISLAND.  BROKEN LOW
CLOUDINESS HAS ALSO BEEN AFFECTING WINDWARD AREAS OF EACH ISLE FROM
TIME TO TIME.  SKIES ARE OTHERWISE CLEAR TO PARTLY CLOUDY OVER THE
ALOHA STATE THIS EARLY EVENING.  LOW CLOUD MOVEMENT IS FROM THE EAST
NEAR 25 MPH JUST EAST OF THE BIG ISLAND...AND VEERS TO THE SOUTHEAST
AND SLOWS TO NEAR 10 MPH MOVING UP THE CHAIN TO KAUAI.

CONDITIONS ARE CLEAR TO SCATTERED OVER THE ADJACENT COASTAL WATERS
AS OF BULLETIN TIME.

THE LEADING EDGE OF LOW CLOUDS JUST AHEAD OF A FRONT IS ABOUT 400
MILES NORTHWEST OF KAUAI...AND HAS BEEN HEADING EAST TO SOUTHEAST
NEAR 30 MPH ALONG 30N.  MOST OF THE BROKEN TO OVERCAST LOW CLOUDS
WITH THE SYSTEM ARE CURRENTLY NORTHWEST OF A LINE FROM 30N160W TO
23N170W TO 19N180...WITH THE BACK EDGE OF CLOUDINESS ALONG A LINE
FROM 30N166W TO 25.5N170W TO 21.5N180.

SHOWERS AND THUNDERSTORMS HAVE BEEN FIRING ALONG THE INTERTROPICAL
CONVERGENCE ZONE FAR SOUTH OF HAWAII.  MOST OF THE CONVECTION HAS
BEEN IGNITING FROM 04N TO 08.5N EAST OF 164W...AND FROM 04N TO 08N
BETWEEN 170W AND 178W.

$$

KINEL






000
FXHW60 PHFO 210152
AFDHFO

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
400 PM HST SAT DEC 20 2014

.SYNOPSIS...
WEAKENING SOUTHEASTERLY FLOW WILL ALLOW FOR LAND AND SEA BREEZES TO
DEVELOP THROUGH SUNDAY. A COLD FRONT APPROACHING FROM THE NORTHWEST
WILL BRING AN INCREASE IN SHOWERS AS EARLY AS SUNDAY NIGHT TO KAUAI.
THERE IS THE POTENTIAL FOR HEAVY RAIN AND A FEW THUNDERSTORMS ACROSS
THE STATE FROM MONDAY AFTERNOON THROUGH TUESDAY. STRONG NORTHERLY
WINDS WILL DEVELOP BEHIND THE FRONT.

&&

.DISCUSSION...
WATER VAPOR IMAGERY SHOWS AN UPPER LEVEL HIGH NORTHEAST OF THE
STATE...WITH A RIDGE EXTENDING ACROSS THE ISLANDS. A SHARP TROUGH IS
LOCATED FAR TO THE NORTHWEST...MOVING TO THE SOUTHEAST AT 30 MPH. AT
THE SURFACE...A RIDGE IS LOCATED LESS THAN 200 MILES NORTH OF
KAUAI...AND THE APPROACHING COLD FRONT IS ABOUT 600 MILES NORTHWEST
OF KAUAI. 00Z RAOBS FROM HILO AND LIHUE SHOW STABLE INVERSIONS NEAR
6KFT. PRECIPITABLE WATERS ARE 0.8-0.9 INCHES...WHICH IS DRIER THAN
NORMAL FOR THIS TIME OF YEAR. EARLY AFTERNOON MIMIC TOTAL
PRECIPITABLE IMAGERY SHOWS VALUES OF 0.8-1.0 INCHES EXTENDING
SEVERAL HUNDRED MILES UPSTREAM TO THE EAST OF THE STATE...WITH TPW
VALUES OF 1.5-1.7 INCHES POOLING ALONG THE COLD FRONT TO THE
NORTHWEST.

WITH THE SURFACE RIDGE BEING SUPPRESSED SOUTHWARD BY THE APPROACHING
FRONT...LOW-LEVEL WINDS HAVE ALREADY TURNED SOUTHEASTERLY ACROSS THE
SMALLER ISLANDS AND ONSHORE SEA BREEZES DEVELOPED DURING THE DAY.
CLOUD MOTIONS SHOW EASTERLY WINDS STILL AFFECTING THE BIG ISLAND.
WINDS ARE EXPECTED TO WEAKEN FURTHER AS THE WESTERN EXTENT OF THE
RIDGE ERODES WITH THE APPROACH OF THE COLD FRONT. SURFACE PRESSURES
ACROSS THE STATE ARE ABOUT A MILLIBAR LOWER THAN 24 HOURS AGO. THE
LOCALLY DRIVEN SEA BREEZE/LAND BREEZE PATTERN WILL CONTINUE THROUGH
SUNDAY. THE STABLE AND DRY AIRMASS WILL KEEP RAINFALL GENERALLY
LIGHT...BUT WE WILL SEE AN INCREASE IN CLOUDS AND SHOWERS ACROSS
INTERIOR AND WEST/NORTHWEST SECTIONS DURING THE LATE
MORNING/AFTERNOON.

THE UPPER LEVEL TROUGH NORTHWEST OF THE STATE WILL PROPEL THE COLD
FRONT TOWARD KAUAI BY SUNDAY NIGHT. MOST OF THE UPPER LEVEL SUPPORT
WITH THIS FIRST TROUGH WILL PASS TO OUR NORTH...AND THE FRONT IS
EXPECTED TO LOSE SOME OF ITS PUSH. HOWEVER...ANOTHER PIECE OF ENERGY
WILL DIG DOWN THE BACK SIDE OF THE TROUGH AND AMPLIFY NEAR THE
ISLANDS...REINVIGORATING THE FRONT AND DRIVING IT FARTHER SOUTHEAST.
COLD AIR ASSOCIATED WITH THIS DIGGING TROUGH WILL ALSO DESTABILIZE
THE AIRMASS OVER THE ISLANDS. 500MB TEMPERATURES DROP TO -12C TO
-14C. MOISTURE WILL BE SOMEWHAT LIMITED...WITH CROSS SECTIONS ACROSS
THE ISLANDS SHOWING DRY AIR ABOVE 700MB. HOWEVER...MODEL FORECAST
SOUNDINGS SHOW THE SUBSIDENCE INVERSION ERODING...LEADING TO
UNSTABLE PROFILES AND RELATIVELY SATURATED LOW-LEVELS. DIFFERENCES
REMAIN BETWEEN THE GFS AND ECMWF...WITH THE GFS BEING MORE
CONSISTENT THROUGH THE EXTENDED FORECAST. THE 12Z ECMWF CUTS OFF
MUCH OF THE DIGGING ENERGY SOUTHWEST OF THE STATE WHILE THE GFS
KEEPS THE TROUGH MORE PROGRESSIVE. BY MID WEEK THE ECMWF TRENDS BACK
TOWARD THE GFS SOLUTION WITH THE PLACEMENT OF A CUTOFF LOW
DEVELOPING NORTHEAST OF THE STATE. OVERALL THE PATTERN HAS
STABILIZED ENOUGH THAT WE CAN START TO ADD A BETTER DELINEATION OF
HIGHER POPS AS THE FRONT/TROUGH SWING THROUGH THE STATE. KEPT THE
BROAD BRUSH OF SLIGHT CHANCE THUNDERSTORMS FOR A ROUGHLY 24 HOUR
PERIOD GENERALLY MONDAY NIGHT/TUESDAY.

STRONG NORTH TO NORTHEASTERLY WINDS ARE EXPECTED TO DEVELOP BEHIND
THE FRONT EARLY IN THE NEW WORK WEEK. THESE WINDS WILL GRADUALLY
RELAX THROUGH THE WEEK...BUT REMAIN GENERALLY OUT OF THE
NORTH-NORTHEAST DUE TO THE PRESENCE OF THE LOW THAT IS EXPECTED TO
BE NORTHEAST OF THE STATE. BY LATE IN THE WEEK THIS LOW WILL WEAKEN
AND ALLOW HIGH PRESSURE TO BUILD NORTHWEST OF THE STATE...WHICH WILL
ALLOW WINDS TO VEER TO A MORE NORTHEASTERLY DIRECTION.

&&

.AVIATION...
WEAK SOUTHEAST FLOW IS EXPECTED ACROSS THE WHOLE OF THE STATE
THROUGH TOMORROW AS THE COLD FRONT TO OUR DISTANT NORTHWEST BEGINS
ITS APPROACH. WEAK SEA BREEZES THIS AFTERNOON WILL BE REPLACED BY
WEAK LAND BREEZES OVERNIGHT ONLY TO REDEVELOP TOMORROW AFTERNOON.
CLOUD COVER THIS AFTERNOON IS FOCUSED OVER ISLAND INTERIORS BUT
SHOULD BECOME MORE DIFFUSE AFTER SUNSET. NEXT BAND OF TRADE WIND
SHOWERS COMING OUT OF THE SOUTHEAST SHOULD REACH THE BIG ISLAND AND
MAUI LATE THIS EVENING. THE AIRMASS SURROUNDING THE ISLANDS IS
RELATIVELY DRY AND THE SUBSIDENCE INVERSION RELATIVELY LOW. ANY
PRECIPITATION NEXT 24 HOURS SHOULD BE LIGHT. ISOLATED MVFR CONDS
POSSIBLE IN WINDWARD SIDE SHOWERS OVERNIGHT OTHERWISE VFR CONDS WILL
PREVAIL ALL AREAS.

&&

.MARINE...
A LONG PERIOD NORTHWEST SWELL GENERATED BY A LARGE AND POWERFUL LOW
PRESSURE SYSTEM IS EXPECTED TO BRING WARNING LEVEL SURF TO THE
ISLANDS ON SUNDAY. A JASON ALTIMETER PASS FROM LATE THIS MORNING
JUST NORTHWEST NORTHWEST OF THE CORE OF THE HIGHEST SEAS SUPPORTS
THE CURRENT WAVEWATCH III FORECAST. WW3 SHOWS A SWELL OF 12-13 FEET
REACHING BUOY 51101 AFTER MIDNIGHT TONIGHT. THIS SWELL WILL BUILD
ACROSS THE ISLANDS ON SUNDAY...THEN LINGER INTO MONDAY BEFORE
GRADUALLY DIMINISHING. HAVE ISSUED A HIGH SURF WARNING FOR NORTH AND
WEST FACING SHORES OF THE SMALLER ISLANDS. GIVEN THE LATER TIMING
FOR THE BIG ISLAND /SWELL ARRIVING SUNDAY NIGHT/ HAVE HELD OFF ON
INCLUDING THE WEST SIDE. HOWEVER...WAVEWATCH GUIDANCE OF 6 FEET/17
SECONDS OFF THE KONA COAST WILL ALSO LEAD TO WARNING LEVEL SURF
THERE AS WELL. GIVEN THE LARGE SWELL...WE HAVE ALSO ISSUED A SMALL
CRAFT ADVISORY FOR MOST COASTAL WATERS DUE TO HAZARDOUS SEAS.

LIFEGUARD REPORTS FROM THE BIG ISLAND INDICATE HIGH SURF CONDITIONS
ALONG EAST FACING SHORES. THE HILO BUOY HAS BEEN RELATIVELY STEADY
REPORTING COMBINED SEAS OF 9-10 FEET...AND THE MAJORITY OF THE
ENERGY IS FROM ABOUT 110 DEGREES AT 10 SECONDS. WAVEWATCH GUIDANCE
AT THAT DATA POINT INDICATES THIS SWELL WILL CONTINUE AT SIMILAR
LEVELS INTO SUNDAY BEFORE GRADUALLY DIMINISHING. A HIGH SURF
ADVISORY REMAINS IN EFFECT FOR EAST FACING SHORES THROUGH SUNDAY.
GIVEN THE SWELL DIRECTION OUT OF THE EAST-SOUTHEAST AND LOWER BUOY
READINGS/SURF OBSERVATIONS ACROSS THE REMAINING ISLANDS...HAVE
CONFINED THE ADVISORY TO THE BIG ISLAND.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
HIGH SURF WARNING FROM 4 AM SUNDAY TO 6 AM HST TUESDAY FOR NORTH AND
WEST FACING SHORES OF NIIHAU KAUAI OAHU AND MOLOKAI AND FOR NORTH
FACING SHORES OF MAUI.

HIGH SURF ADVISORY UNTIL 6 PM HST SUNDAY FOR EAST FACING SHORES OF
THE BIG ISLAND.

SMALL CRAFT ADVISORY FROM 4 AM SUNDAY TO 6 AM HST TUESDAY FOR ALL
HAWAIIAN WATERS EXCEPT MAALAEA BAY.

&&

$$

DISCUSSION/MARINE...BRAVENDER
AVIATION...BEDAL





000
FXHW60 PHFO 210152
AFDHFO

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
400 PM HST SAT DEC 20 2014

.SYNOPSIS...
WEAKENING SOUTHEASTERLY FLOW WILL ALLOW FOR LAND AND SEA BREEZES TO
DEVELOP THROUGH SUNDAY. A COLD FRONT APPROACHING FROM THE NORTHWEST
WILL BRING AN INCREASE IN SHOWERS AS EARLY AS SUNDAY NIGHT TO KAUAI.
THERE IS THE POTENTIAL FOR HEAVY RAIN AND A FEW THUNDERSTORMS ACROSS
THE STATE FROM MONDAY AFTERNOON THROUGH TUESDAY. STRONG NORTHERLY
WINDS WILL DEVELOP BEHIND THE FRONT.

&&

.DISCUSSION...
WATER VAPOR IMAGERY SHOWS AN UPPER LEVEL HIGH NORTHEAST OF THE
STATE...WITH A RIDGE EXTENDING ACROSS THE ISLANDS. A SHARP TROUGH IS
LOCATED FAR TO THE NORTHWEST...MOVING TO THE SOUTHEAST AT 30 MPH. AT
THE SURFACE...A RIDGE IS LOCATED LESS THAN 200 MILES NORTH OF
KAUAI...AND THE APPROACHING COLD FRONT IS ABOUT 600 MILES NORTHWEST
OF KAUAI. 00Z RAOBS FROM HILO AND LIHUE SHOW STABLE INVERSIONS NEAR
6KFT. PRECIPITABLE WATERS ARE 0.8-0.9 INCHES...WHICH IS DRIER THAN
NORMAL FOR THIS TIME OF YEAR. EARLY AFTERNOON MIMIC TOTAL
PRECIPITABLE IMAGERY SHOWS VALUES OF 0.8-1.0 INCHES EXTENDING
SEVERAL HUNDRED MILES UPSTREAM TO THE EAST OF THE STATE...WITH TPW
VALUES OF 1.5-1.7 INCHES POOLING ALONG THE COLD FRONT TO THE
NORTHWEST.

WITH THE SURFACE RIDGE BEING SUPPRESSED SOUTHWARD BY THE APPROACHING
FRONT...LOW-LEVEL WINDS HAVE ALREADY TURNED SOUTHEASTERLY ACROSS THE
SMALLER ISLANDS AND ONSHORE SEA BREEZES DEVELOPED DURING THE DAY.
CLOUD MOTIONS SHOW EASTERLY WINDS STILL AFFECTING THE BIG ISLAND.
WINDS ARE EXPECTED TO WEAKEN FURTHER AS THE WESTERN EXTENT OF THE
RIDGE ERODES WITH THE APPROACH OF THE COLD FRONT. SURFACE PRESSURES
ACROSS THE STATE ARE ABOUT A MILLIBAR LOWER THAN 24 HOURS AGO. THE
LOCALLY DRIVEN SEA BREEZE/LAND BREEZE PATTERN WILL CONTINUE THROUGH
SUNDAY. THE STABLE AND DRY AIRMASS WILL KEEP RAINFALL GENERALLY
LIGHT...BUT WE WILL SEE AN INCREASE IN CLOUDS AND SHOWERS ACROSS
INTERIOR AND WEST/NORTHWEST SECTIONS DURING THE LATE
MORNING/AFTERNOON.

THE UPPER LEVEL TROUGH NORTHWEST OF THE STATE WILL PROPEL THE COLD
FRONT TOWARD KAUAI BY SUNDAY NIGHT. MOST OF THE UPPER LEVEL SUPPORT
WITH THIS FIRST TROUGH WILL PASS TO OUR NORTH...AND THE FRONT IS
EXPECTED TO LOSE SOME OF ITS PUSH. HOWEVER...ANOTHER PIECE OF ENERGY
WILL DIG DOWN THE BACK SIDE OF THE TROUGH AND AMPLIFY NEAR THE
ISLANDS...REINVIGORATING THE FRONT AND DRIVING IT FARTHER SOUTHEAST.
COLD AIR ASSOCIATED WITH THIS DIGGING TROUGH WILL ALSO DESTABILIZE
THE AIRMASS OVER THE ISLANDS. 500MB TEMPERATURES DROP TO -12C TO
-14C. MOISTURE WILL BE SOMEWHAT LIMITED...WITH CROSS SECTIONS ACROSS
THE ISLANDS SHOWING DRY AIR ABOVE 700MB. HOWEVER...MODEL FORECAST
SOUNDINGS SHOW THE SUBSIDENCE INVERSION ERODING...LEADING TO
UNSTABLE PROFILES AND RELATIVELY SATURATED LOW-LEVELS. DIFFERENCES
REMAIN BETWEEN THE GFS AND ECMWF...WITH THE GFS BEING MORE
CONSISTENT THROUGH THE EXTENDED FORECAST. THE 12Z ECMWF CUTS OFF
MUCH OF THE DIGGING ENERGY SOUTHWEST OF THE STATE WHILE THE GFS
KEEPS THE TROUGH MORE PROGRESSIVE. BY MID WEEK THE ECMWF TRENDS BACK
TOWARD THE GFS SOLUTION WITH THE PLACEMENT OF A CUTOFF LOW
DEVELOPING NORTHEAST OF THE STATE. OVERALL THE PATTERN HAS
STABILIZED ENOUGH THAT WE CAN START TO ADD A BETTER DELINEATION OF
HIGHER POPS AS THE FRONT/TROUGH SWING THROUGH THE STATE. KEPT THE
BROAD BRUSH OF SLIGHT CHANCE THUNDERSTORMS FOR A ROUGHLY 24 HOUR
PERIOD GENERALLY MONDAY NIGHT/TUESDAY.

STRONG NORTH TO NORTHEASTERLY WINDS ARE EXPECTED TO DEVELOP BEHIND
THE FRONT EARLY IN THE NEW WORK WEEK. THESE WINDS WILL GRADUALLY
RELAX THROUGH THE WEEK...BUT REMAIN GENERALLY OUT OF THE
NORTH-NORTHEAST DUE TO THE PRESENCE OF THE LOW THAT IS EXPECTED TO
BE NORTHEAST OF THE STATE. BY LATE IN THE WEEK THIS LOW WILL WEAKEN
AND ALLOW HIGH PRESSURE TO BUILD NORTHWEST OF THE STATE...WHICH WILL
ALLOW WINDS TO VEER TO A MORE NORTHEASTERLY DIRECTION.

&&

.AVIATION...
WEAK SOUTHEAST FLOW IS EXPECTED ACROSS THE WHOLE OF THE STATE
THROUGH TOMORROW AS THE COLD FRONT TO OUR DISTANT NORTHWEST BEGINS
ITS APPROACH. WEAK SEA BREEZES THIS AFTERNOON WILL BE REPLACED BY
WEAK LAND BREEZES OVERNIGHT ONLY TO REDEVELOP TOMORROW AFTERNOON.
CLOUD COVER THIS AFTERNOON IS FOCUSED OVER ISLAND INTERIORS BUT
SHOULD BECOME MORE DIFFUSE AFTER SUNSET. NEXT BAND OF TRADE WIND
SHOWERS COMING OUT OF THE SOUTHEAST SHOULD REACH THE BIG ISLAND AND
MAUI LATE THIS EVENING. THE AIRMASS SURROUNDING THE ISLANDS IS
RELATIVELY DRY AND THE SUBSIDENCE INVERSION RELATIVELY LOW. ANY
PRECIPITATION NEXT 24 HOURS SHOULD BE LIGHT. ISOLATED MVFR CONDS
POSSIBLE IN WINDWARD SIDE SHOWERS OVERNIGHT OTHERWISE VFR CONDS WILL
PREVAIL ALL AREAS.

&&

.MARINE...
A LONG PERIOD NORTHWEST SWELL GENERATED BY A LARGE AND POWERFUL LOW
PRESSURE SYSTEM IS EXPECTED TO BRING WARNING LEVEL SURF TO THE
ISLANDS ON SUNDAY. A JASON ALTIMETER PASS FROM LATE THIS MORNING
JUST NORTHWEST NORTHWEST OF THE CORE OF THE HIGHEST SEAS SUPPORTS
THE CURRENT WAVEWATCH III FORECAST. WW3 SHOWS A SWELL OF 12-13 FEET
REACHING BUOY 51101 AFTER MIDNIGHT TONIGHT. THIS SWELL WILL BUILD
ACROSS THE ISLANDS ON SUNDAY...THEN LINGER INTO MONDAY BEFORE
GRADUALLY DIMINISHING. HAVE ISSUED A HIGH SURF WARNING FOR NORTH AND
WEST FACING SHORES OF THE SMALLER ISLANDS. GIVEN THE LATER TIMING
FOR THE BIG ISLAND /SWELL ARRIVING SUNDAY NIGHT/ HAVE HELD OFF ON
INCLUDING THE WEST SIDE. HOWEVER...WAVEWATCH GUIDANCE OF 6 FEET/17
SECONDS OFF THE KONA COAST WILL ALSO LEAD TO WARNING LEVEL SURF
THERE AS WELL. GIVEN THE LARGE SWELL...WE HAVE ALSO ISSUED A SMALL
CRAFT ADVISORY FOR MOST COASTAL WATERS DUE TO HAZARDOUS SEAS.

LIFEGUARD REPORTS FROM THE BIG ISLAND INDICATE HIGH SURF CONDITIONS
ALONG EAST FACING SHORES. THE HILO BUOY HAS BEEN RELATIVELY STEADY
REPORTING COMBINED SEAS OF 9-10 FEET...AND THE MAJORITY OF THE
ENERGY IS FROM ABOUT 110 DEGREES AT 10 SECONDS. WAVEWATCH GUIDANCE
AT THAT DATA POINT INDICATES THIS SWELL WILL CONTINUE AT SIMILAR
LEVELS INTO SUNDAY BEFORE GRADUALLY DIMINISHING. A HIGH SURF
ADVISORY REMAINS IN EFFECT FOR EAST FACING SHORES THROUGH SUNDAY.
GIVEN THE SWELL DIRECTION OUT OF THE EAST-SOUTHEAST AND LOWER BUOY
READINGS/SURF OBSERVATIONS ACROSS THE REMAINING ISLANDS...HAVE
CONFINED THE ADVISORY TO THE BIG ISLAND.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
HIGH SURF WARNING FROM 4 AM SUNDAY TO 6 AM HST TUESDAY FOR NORTH AND
WEST FACING SHORES OF NIIHAU KAUAI OAHU AND MOLOKAI AND FOR NORTH
FACING SHORES OF MAUI.

HIGH SURF ADVISORY UNTIL 6 PM HST SUNDAY FOR EAST FACING SHORES OF
THE BIG ISLAND.

SMALL CRAFT ADVISORY FROM 4 AM SUNDAY TO 6 AM HST TUESDAY FOR ALL
HAWAIIAN WATERS EXCEPT MAALAEA BAY.

&&

$$

DISCUSSION/MARINE...BRAVENDER
AVIATION...BEDAL






000
ATHW40 PHFO 210031
SIMHI

HAWAIIAN ISLANDS SATELLITE INTERPRETATION MESSAGE
NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI
0030 UTC SUN DEC 21 2014

BASED ON DATA THROUGH 0000 UTC DECEMBER 21 2014

A NORTH NORTHEAST TO SOUTH SOUTHWEST UPPER LEVEL TROUGH TO THE
NORTHWEST OF THE MAIN HAWAIIAN ISLANDS CONTINUES TO MOVE TOWARDS THE
ISLANDS THIS AFTERNOON. THE BASE OF THE TROUGH IS NEAR LISIANSKI
ATOLL...AND IS ABOUT 900 MILES NORTHWEST OF KAUAI AT 2 PM. THIS
UPPER LEVEL SYSTEM IS ASSOCIATED WITH AN APPROACHING SURFACE FRONT.
THE LEADING EDGE OF THE LAYERED CLOUD BAND ASSOCIATED WITH THE FRONT
LIES ALONG A LINE FROM 16N177E TO 23N171W TO 35N154W...AND
CONTINUES TO THE NORTH AND NORTHEAST. THE SOUTHERN END OF THE BAND
IS MOSTLY COMPRISED OF LOW CLOUDS...BUT NORTH OF 24N...THE BAND IS
COMPRISED OF LAYERED CLOUDS. THE LOW CLOUD BAND AT THE SOUTHERN END
IS ABOUT 200 MILES WIDE...WHILE THE LAYERED CLOUD BAND IS CLOSER TO
400 MILES WIDE.

LOW CLOUDS HAVE INCREASED OVER THE MAIN HAWAIIAN ISLANDS SINCE DAY
BREAK. THIS AFTERNOON FINDS CLOUDS COVERING MOST OF KAUAI AND
NIIHAU...WITH JUST A FEW CLOUDS OVER THE WATERS SURROUNDING KAUAI
COUNTY. ON OAHU...CLOUDS HAVE INCREASED OVER THE KOOLAU RANGE...AND
FORMED OVER THE WAIANAE RANGE...COVERING BOTH AT 2 PM. THE LOW
CLOUDS OVER EASTERN MOLOKAI THIS MORNING INCREASED IN COVERAGE OVER
THE LAST SEVERAL HOURS...AND NOW COVER THE EASTERN THIRD OF THE
ISLAND...WHILE ADDITIONAL CLOUDS HAVE FORMED OVER THE WESTERN END OF
THE ISLAND. CLOUDS HAVE FORMED OVER THE SOUTHERN HALF OF
LANAI...WHILE SCATTERED CLOUDS REMAIN OVER THE SOUTHERN COAST OF
KAHOOLAWE. ON MAUI...CLOUDS FORMED OVER THE WEST MAUI
MOUNTAINS...AND OVER THE WEST FACING SLOPES OF HALEAKALA.
MEANWHILE...THE CLOUDS OVER THE EAST FACING SLOPES OF HALEAKALA HAVE
THINNED...LEAVING SCATTERED CLOUDS OVER THE SLOPES FROM NAHIKU TO
HANA TO KIPAHULU.

ON THE BIG ISLAND...THE CLOUDS OVER THE SOUTH HILO AND PUNA
DISTRICTS THINNED SIGNIFICANTLY OVER THE LAST SEVERAL
HOURS...LEAVING FEW CLOUDS OVER THE SOUTH HILO DISTRICT...AND
SCATTERED CLOUDS OVER THE PUNA DISTRICT. MEANWHILE...CLOUDS HAVE
INCREASED OVER THE KAU...SOUTH KONA...NORTH KONA...SOUTH
KOHALA...AND NORTH KOHALA DISTRICTS. SOME OF THESE CLOUDS ARE
SPILLING OVER INTO THE HAMAKUA DISTRICT.

$$

MBALLARD





000
ATHW40 PHFO 210031
SIMHI

HAWAIIAN ISLANDS SATELLITE INTERPRETATION MESSAGE
NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI
0030 UTC SUN DEC 21 2014

BASED ON DATA THROUGH 0000 UTC DECEMBER 21 2014

A NORTH NORTHEAST TO SOUTH SOUTHWEST UPPER LEVEL TROUGH TO THE
NORTHWEST OF THE MAIN HAWAIIAN ISLANDS CONTINUES TO MOVE TOWARDS THE
ISLANDS THIS AFTERNOON. THE BASE OF THE TROUGH IS NEAR LISIANSKI
ATOLL...AND IS ABOUT 900 MILES NORTHWEST OF KAUAI AT 2 PM. THIS
UPPER LEVEL SYSTEM IS ASSOCIATED WITH AN APPROACHING SURFACE FRONT.
THE LEADING EDGE OF THE LAYERED CLOUD BAND ASSOCIATED WITH THE FRONT
LIES ALONG A LINE FROM 16N177E TO 23N171W TO 35N154W...AND
CONTINUES TO THE NORTH AND NORTHEAST. THE SOUTHERN END OF THE BAND
IS MOSTLY COMPRISED OF LOW CLOUDS...BUT NORTH OF 24N...THE BAND IS
COMPRISED OF LAYERED CLOUDS. THE LOW CLOUD BAND AT THE SOUTHERN END
IS ABOUT 200 MILES WIDE...WHILE THE LAYERED CLOUD BAND IS CLOSER TO
400 MILES WIDE.

LOW CLOUDS HAVE INCREASED OVER THE MAIN HAWAIIAN ISLANDS SINCE DAY
BREAK. THIS AFTERNOON FINDS CLOUDS COVERING MOST OF KAUAI AND
NIIHAU...WITH JUST A FEW CLOUDS OVER THE WATERS SURROUNDING KAUAI
COUNTY. ON OAHU...CLOUDS HAVE INCREASED OVER THE KOOLAU RANGE...AND
FORMED OVER THE WAIANAE RANGE...COVERING BOTH AT 2 PM. THE LOW
CLOUDS OVER EASTERN MOLOKAI THIS MORNING INCREASED IN COVERAGE OVER
THE LAST SEVERAL HOURS...AND NOW COVER THE EASTERN THIRD OF THE
ISLAND...WHILE ADDITIONAL CLOUDS HAVE FORMED OVER THE WESTERN END OF
THE ISLAND. CLOUDS HAVE FORMED OVER THE SOUTHERN HALF OF
LANAI...WHILE SCATTERED CLOUDS REMAIN OVER THE SOUTHERN COAST OF
KAHOOLAWE. ON MAUI...CLOUDS FORMED OVER THE WEST MAUI
MOUNTAINS...AND OVER THE WEST FACING SLOPES OF HALEAKALA.
MEANWHILE...THE CLOUDS OVER THE EAST FACING SLOPES OF HALEAKALA HAVE
THINNED...LEAVING SCATTERED CLOUDS OVER THE SLOPES FROM NAHIKU TO
HANA TO KIPAHULU.

ON THE BIG ISLAND...THE CLOUDS OVER THE SOUTH HILO AND PUNA
DISTRICTS THINNED SIGNIFICANTLY OVER THE LAST SEVERAL
HOURS...LEAVING FEW CLOUDS OVER THE SOUTH HILO DISTRICT...AND
SCATTERED CLOUDS OVER THE PUNA DISTRICT. MEANWHILE...CLOUDS HAVE
INCREASED OVER THE KAU...SOUTH KONA...NORTH KONA...SOUTH
KOHALA...AND NORTH KOHALA DISTRICTS. SOME OF THESE CLOUDS ARE
SPILLING OVER INTO THE HAMAKUA DISTRICT.

$$

MBALLARD






000
FXHW60 PHFO 202245 AAB
AFDHFO

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE HONOLULU HI
1245 PM HST SAT DEC 20 2014

.UPDATE...
LIFEGUARD REPORTS FROM THE BIG ISLAND INDICATE HIGH SURF CONDITIONS
ALONG EAST FACING SHORES. THE HILO BUOY HAS BEEN REPORTING COMBINED
SEAS AROUND 9 FEET...AND THE MAJORITY OF THE ENERGY IS FROM ABOUT
120 DEGREES AT 10 SECONDS. WAVEWATCH GUIDANCE AT THAT DATA POINT
INDICATES THIS SWELL WILL CONTINUE AT SIMILAR LEVELS INTO SUNDAY
BEFORE GRADUALLY DIMINISHING. HAVE UPDATED TO ISSUE A HIGH SURF
ADVISORY FOR EAST FACING SHORES OF THE BIG ISLAND THROUGH SUNDAY.
GIVEN THE SWELL DIRECTION OUT OF THE EAST-SOUTHEAST AND LOWER BUOY
READINGS/SURF OBSERVATIONS ACROSS THE REMAINING ISLANDS...HAVE
CONFINED THE ADVISORY TO THE BIG ISLAND.

&&

.SYNOPSIS...
WEAKENING SOUTHEASTERLY FLOW WILL ALLOW FOR LAND AND SEA BREEZES TO
DEVELOP THROUGH SUNDAY. A COLD FRONT APPROACHING FROM THE NORTHWEST
WILL BRING AN INCREASE IN SHOWERS AS EARLY AS SUNDAY NIGHT TO KAUAI.
THERE IS THE POTENTIAL FOR HEAVY RAIN AND A FEW THUNDERSTORMS ACROSS
THE STATE FROM MONDAY AFTERNOON THROUGH TUESDAY. STRONG NORTHERLY
WINDS WILL DEVELOP BEHIND THE FRONT.

&&

.DISCUSSION...
WATER VAPOR IMAGERY SHOWS AN UPPER LEVEL HIGH NORTHEAST OF THE
STATE...WITH A RIDGE EXTENDING ACROSS THE ISLANDS. A SHARP TROUGH IS
LOCATED FAR TO THE NORTHWEST...MOVING TO THE SOUTHEAST AT 30 MPH. AT
THE SURFACE...A RIDGE IS LOCATED LESS THAN 200 MILES NORTH OF
KAUAI...AND THE APPROACHING COLD FRONT IS ABOUT 700 MILES NORTHWEST
OF KAUAI. 12Z RAOBS SHOW STABLE INVERSIONS RANGING FROM 5KFT AT
LIHUE TO 7KFT AT HILO. PRECIPITABLE WATERS ARE ALSO 0.9-1.0
INCHES...WHICH IS DRIER THAN NORMAL FOR THIS TIME OF YEAR. EARLY
MORNING MIMIC TOTAL PRECIPITABLE IMAGERY SHOWS SIMILAR OR SLIGHTLY
DRIER AIR WITHIN A COUPLE HUNDRED MILES EAST OF THE STATE...WITH TPW
VALUES NEAR 1.5 INCHES POOLING ALONG THE COLD FRONT TO THE
NORTHWEST.

WITH THE SURFACE RIDGE BEING SUPPRESSED SOUTHWARD BY THE APPROACHING
FRONT...LOW-LEVEL WINDS HAVE ALREADY TURNED MORE SOUTHEASTERLY
ACROSS THE SMALLER ISLANDS. CLOUD MOTIONS SHOW EASTERLY WINDS STILL
AFFECTING THE BIG ISLAND. WINDS HAVE WEAKENED WITH THE RIDGE
NEARBY...AND WILL WEAKEN FURTHER AS THE WESTERN EXTENT OF THE RIDGE
ERODES WITH THE APPROACH OF THE COLD FRONT. SURFACE PRESSURES ACROSS
THE STATE HAVE ALREADY DROPPED ABOUT 2MB IN THE PAST 24 HOURS. WITH
THE SOUTHEASTERLY WIND DIRECTION...THE BIG ISLAND WILL ALSO BLOCK
SOME OF THE GRADIENT WIND FROM THE SMALLER ISLANDS...LEADING TO A
LOCALLY DRIVEN LAND AND SEA BREEZE PATTERN. THE STABLE AND DRY
AIRMASS WILL KEEP RAINFALL GENERALLY LIGHT...BUT WE WILL SEE AN
INCREASE IN CLOUDS AND SHOWERS ACROSS INTERIOR AND WEST/NORTHWEST
SECTIONS DURING THE LATE MORNING/AFTERNOON. THIS WILL BE THE CASE
BOTH TODAY AND ON SUNDAY...AS WINDS WILL REMAIN LIGHT OVER THE
ISLANDS.

WINDS ACROSS THE BIG ISLAND SUMMITS HAVE SHOWN A GRADUAL DOWNWARD
TREND THROUGH THE MORNING SO FAR. WHILE THE CFHT SENSOR HAS DROPPED
BELOW ADVISORY LEVELS FOR THE HIGHER ELEVATIONS...IT IS STILL
HOVERING AT UP TO 40 MPH. WE SHOULD BE ABLE TO DROP THE WIND
ADVISORY AS EXPECTED THIS MORNING.

THE UPPER LEVEL TROUGH NORTHWEST OF THE STATE WILL PROPEL THE COLD
FRONT TOWARD KAUAI BY SUNDAY NIGHT. MOST OF THE UPPER LEVEL SUPPORT
WITH THIS FIRST TROUGH WILL PASS TO OUR NORTH...AND THE FRONT IS
EXPECTED TO LOSE SOME OF ITS PUSH. HOWEVER...ANOTHER PIECE OF ENERGY
IS EXPECTED TO DIG DOWN THE BACK SIDE OF THE TROUGH AND AMPLIFY NEAR
THE ISLANDS...REINVIGORATING THE FRONT AND DRIVING IT FARTHER
SOUTHEAST. COLD AIR ASSOCIATED WITH THIS DIGGING TROUGH WILL ALSO
DESTABILIZE THE AIRMASS OVER THE ISLANDS. 500MB TEMPERATURES DROP TO
-12C TO -14C. MOISTURE WILL BE SOMEWHAT LIMITED...WITH CROSS
SECTIONS ACROSS THE ISLANDS SHOWING MOISTURE EXTENDING UP TO 700MB.
HOWEVER...MODEL FORECAST SOUNDINGS SHOW THE SUBSIDENCE INVERSION
ERODING...LEADING TO UNSTABLE PROFILES AND RELATIVELY SATURATED
LOW-LEVELS. DIFFERENCES REMAIN BETWEEN THE GFS AND ECMWF...WITH THE
GFS BEING MORE CONSISTENT THROUGH THE EXTENDED FORECAST. THE 12Z
ECMWF CUTS OFF MUCH OF THE DIGGING ENERGY SOUTHWEST OF THE STATE
WHILE THE GFS KEEPS THE TROUGH MORE PROGRESSIVE. BY MID WEEK THE
ECMWF TRENDS BACK TOWARD THE GFS SOLUTION WITH THE PLACEMENT OF A
CUTOFF LOW DEVELOPING NORTHEAST OF THE STATE. OVERALL THE PATTERN
HAS STABILIZED ENOUGH THAT CHANGES ARE NOT NEEDED FOR THE CURRENT
FORECAST...WHICH FEATURES A MENTION OF THUNDERSTORMS FROM MONDAY
AFTERNOON THROUGH TUESDAY NIGHT.

STRONG NORTHERLY WINDS ARE EXPECTED TO DEVELOP BEHIND THE FRONT
EARLY IN THE NEW WORK WEEK. THESE WINDS WILL GRADUALLY RELAX THROUGH
THE WEEK...BUT REMAIN GENERALLY OUT OF THE NORTH DUE TO THE PRESENCE
OF THE LOW THAT IS EXPECTED TO BE NORTHEAST OF THE STATE. BY LATE IN
THE WEEK THIS LOW WILL WEAKEN AND ALLOW HIGH PRESSURE TO BUILD
NORTHWEST OF THE STATE...WHICH WILL ALLOW WINDS TO VEER TO A MORE
NORTHEASTERLY DIRECTION.

&&

.AVIATION...
WEAK SOUTHEAST FLOW IS EXPECTED ACROSS THE WHOLE OF STATE TODAY AS
THE COLD FRONT TO OUR DISTANT NORTHWEST BEGINS ITS APPROACH. WEAK
EASTERLY TRADES THIS MORNING WILL BE REPLACED BY WEAK SEA BREEZES
THIS AFTERNOON AND WEAK LAND BREEZES LATE TONIGHT. MORNING
CLOUDINESS IS FOCUSED OVER WINDWARD SLOPES AND COASTS BUT AFTERNOON
AND EVENING CLOUDS WILL BECOME FOCUSED OVER ISLAND INTERIORS.
AIRMASS OVER THE ISLANDS TODAY IS RELATIVELY DRY AND THE SUBSIDENCE
INVERSION IS RELATIVELY LOW. ANY PRECIPITATION TODAY SHOULD BE LIGHT
AND VFR CONDS ARE EXPECTED TO PREVAIL THROUGH 24 HOURS. PARTIAL
CLEARING EXPECTED ALONG LEEWARD COASTS AFTER MIDNIGHT.

&&

.MARINE...
A LONG PERIOD NORTHWEST SWELL GENERATED BY A LARGE AND POWERFUL LOW
PRESSURE SYSTEM IS EXPECTED TO BRING WARNING LEVEL SURF TO THE
ISLANDS ON SUNDAY. A JASON ALTIMETER PASS FROM LAST NIGHT JUST
OUTSIDE THE CORE OF THE HIGHEST SEAS SUPPORTS THE CURRENT WAVEWATCH
III FORECAST. WW3 SHOWS A SWELL OF 12-13 FEET REACHING BUOY 51101
AFTER MIDNIGHT TONIGHT. THIS SWELL WILL BUILD ACROSS THE ISLANDS ON
SUNDAY...THEN LINGER INTO MONDAY BEFORE GRADUALLY DIMINISHING. HAVE
ISSUED A HIGH SURF WARNING FOR NORTH AND WEST FACING SHORES OF THE
SMALLER ISLANDS. GIVEN THE LATER TIMING FOR THE BIG ISLAND /SWELL
ARRIVING SUNDAY NIGHT/ HAVE HELD OFF ON INCLUDING THE WEST SIDE.
HOWEVER...WAVEWATCH GUIDANCE OF 6 FEET/17 SECONDS OFF THE KONA
COAST WILL ALSO LEAD TO WARNING LEVEL SURF THERE AS WELL. THE SWELL
THIS LARGE WILL ALSO LEAD TO SMALL CRAFT CONDITIONS ACROSS THE
COASTAL WATERS.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
HIGH SURF WARNING FROM 4 AM SUNDAY TO 6 AM HST TUESDAY FOR NORTH AND
WEST FACING SHORES OF NIIHAU KAUAI OAHU AND MOLOKAI AND FOR NORTH
FACING SHORES OF MAUI.

HIGH SURF ADVISORY UNTIL 6 PM HST SUNDAY FOR EAST FACING SHORES OF
THE BIG ISLAND.

&&

$$

DISCUSSION/MARINE...BRAVENDER
AVIATION...BEDAL







000
FXHW60 PHFO 202245 AAB
AFDHFO

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE HONOLULU HI
1245 PM HST SAT DEC 20 2014

.UPDATE...
LIFEGUARD REPORTS FROM THE BIG ISLAND INDICATE HIGH SURF CONDITIONS
ALONG EAST FACING SHORES. THE HILO BUOY HAS BEEN REPORTING COMBINED
SEAS AROUND 9 FEET...AND THE MAJORITY OF THE ENERGY IS FROM ABOUT
120 DEGREES AT 10 SECONDS. WAVEWATCH GUIDANCE AT THAT DATA POINT
INDICATES THIS SWELL WILL CONTINUE AT SIMILAR LEVELS INTO SUNDAY
BEFORE GRADUALLY DIMINISHING. HAVE UPDATED TO ISSUE A HIGH SURF
ADVISORY FOR EAST FACING SHORES OF THE BIG ISLAND THROUGH SUNDAY.
GIVEN THE SWELL DIRECTION OUT OF THE EAST-SOUTHEAST AND LOWER BUOY
READINGS/SURF OBSERVATIONS ACROSS THE REMAINING ISLANDS...HAVE
CONFINED THE ADVISORY TO THE BIG ISLAND.

&&

.SYNOPSIS...
WEAKENING SOUTHEASTERLY FLOW WILL ALLOW FOR LAND AND SEA BREEZES TO
DEVELOP THROUGH SUNDAY. A COLD FRONT APPROACHING FROM THE NORTHWEST
WILL BRING AN INCREASE IN SHOWERS AS EARLY AS SUNDAY NIGHT TO KAUAI.
THERE IS THE POTENTIAL FOR HEAVY RAIN AND A FEW THUNDERSTORMS ACROSS
THE STATE FROM MONDAY AFTERNOON THROUGH TUESDAY. STRONG NORTHERLY
WINDS WILL DEVELOP BEHIND THE FRONT.

&&

.DISCUSSION...
WATER VAPOR IMAGERY SHOWS AN UPPER LEVEL HIGH NORTHEAST OF THE
STATE...WITH A RIDGE EXTENDING ACROSS THE ISLANDS. A SHARP TROUGH IS
LOCATED FAR TO THE NORTHWEST...MOVING TO THE SOUTHEAST AT 30 MPH. AT
THE SURFACE...A RIDGE IS LOCATED LESS THAN 200 MILES NORTH OF
KAUAI...AND THE APPROACHING COLD FRONT IS ABOUT 700 MILES NORTHWEST
OF KAUAI. 12Z RAOBS SHOW STABLE INVERSIONS RANGING FROM 5KFT AT
LIHUE TO 7KFT AT HILO. PRECIPITABLE WATERS ARE ALSO 0.9-1.0
INCHES...WHICH IS DRIER THAN NORMAL FOR THIS TIME OF YEAR. EARLY
MORNING MIMIC TOTAL PRECIPITABLE IMAGERY SHOWS SIMILAR OR SLIGHTLY
DRIER AIR WITHIN A COUPLE HUNDRED MILES EAST OF THE STATE...WITH TPW
VALUES NEAR 1.5 INCHES POOLING ALONG THE COLD FRONT TO THE
NORTHWEST.

WITH THE SURFACE RIDGE BEING SUPPRESSED SOUTHWARD BY THE APPROACHING
FRONT...LOW-LEVEL WINDS HAVE ALREADY TURNED MORE SOUTHEASTERLY
ACROSS THE SMALLER ISLANDS. CLOUD MOTIONS SHOW EASTERLY WINDS STILL
AFFECTING THE BIG ISLAND. WINDS HAVE WEAKENED WITH THE RIDGE
NEARBY...AND WILL WEAKEN FURTHER AS THE WESTERN EXTENT OF THE RIDGE
ERODES WITH THE APPROACH OF THE COLD FRONT. SURFACE PRESSURES ACROSS
THE STATE HAVE ALREADY DROPPED ABOUT 2MB IN THE PAST 24 HOURS. WITH
THE SOUTHEASTERLY WIND DIRECTION...THE BIG ISLAND WILL ALSO BLOCK
SOME OF THE GRADIENT WIND FROM THE SMALLER ISLANDS...LEADING TO A
LOCALLY DRIVEN LAND AND SEA BREEZE PATTERN. THE STABLE AND DRY
AIRMASS WILL KEEP RAINFALL GENERALLY LIGHT...BUT WE WILL SEE AN
INCREASE IN CLOUDS AND SHOWERS ACROSS INTERIOR AND WEST/NORTHWEST
SECTIONS DURING THE LATE MORNING/AFTERNOON. THIS WILL BE THE CASE
BOTH TODAY AND ON SUNDAY...AS WINDS WILL REMAIN LIGHT OVER THE
ISLANDS.

WINDS ACROSS THE BIG ISLAND SUMMITS HAVE SHOWN A GRADUAL DOWNWARD
TREND THROUGH THE MORNING SO FAR. WHILE THE CFHT SENSOR HAS DROPPED
BELOW ADVISORY LEVELS FOR THE HIGHER ELEVATIONS...IT IS STILL
HOVERING AT UP TO 40 MPH. WE SHOULD BE ABLE TO DROP THE WIND
ADVISORY AS EXPECTED THIS MORNING.

THE UPPER LEVEL TROUGH NORTHWEST OF THE STATE WILL PROPEL THE COLD
FRONT TOWARD KAUAI BY SUNDAY NIGHT. MOST OF THE UPPER LEVEL SUPPORT
WITH THIS FIRST TROUGH WILL PASS TO OUR NORTH...AND THE FRONT IS
EXPECTED TO LOSE SOME OF ITS PUSH. HOWEVER...ANOTHER PIECE OF ENERGY
IS EXPECTED TO DIG DOWN THE BACK SIDE OF THE TROUGH AND AMPLIFY NEAR
THE ISLANDS...REINVIGORATING THE FRONT AND DRIVING IT FARTHER
SOUTHEAST. COLD AIR ASSOCIATED WITH THIS DIGGING TROUGH WILL ALSO
DESTABILIZE THE AIRMASS OVER THE ISLANDS. 500MB TEMPERATURES DROP TO
-12C TO -14C. MOISTURE WILL BE SOMEWHAT LIMITED...WITH CROSS
SECTIONS ACROSS THE ISLANDS SHOWING MOISTURE EXTENDING UP TO 700MB.
HOWEVER...MODEL FORECAST SOUNDINGS SHOW THE SUBSIDENCE INVERSION
ERODING...LEADING TO UNSTABLE PROFILES AND RELATIVELY SATURATED
LOW-LEVELS. DIFFERENCES REMAIN BETWEEN THE GFS AND ECMWF...WITH THE
GFS BEING MORE CONSISTENT THROUGH THE EXTENDED FORECAST. THE 12Z
ECMWF CUTS OFF MUCH OF THE DIGGING ENERGY SOUTHWEST OF THE STATE
WHILE THE GFS KEEPS THE TROUGH MORE PROGRESSIVE. BY MID WEEK THE
ECMWF TRENDS BACK TOWARD THE GFS SOLUTION WITH THE PLACEMENT OF A
CUTOFF LOW DEVELOPING NORTHEAST OF THE STATE. OVERALL THE PATTERN
HAS STABILIZED ENOUGH THAT CHANGES ARE NOT NEEDED FOR THE CURRENT
FORECAST...WHICH FEATURES A MENTION OF THUNDERSTORMS FROM MONDAY
AFTERNOON THROUGH TUESDAY NIGHT.

STRONG NORTHERLY WINDS ARE EXPECTED TO DEVELOP BEHIND THE FRONT
EARLY IN THE NEW WORK WEEK. THESE WINDS WILL GRADUALLY RELAX THROUGH
THE WEEK...BUT REMAIN GENERALLY OUT OF THE NORTH DUE TO THE PRESENCE
OF THE LOW THAT IS EXPECTED TO BE NORTHEAST OF THE STATE. BY LATE IN
THE WEEK THIS LOW WILL WEAKEN AND ALLOW HIGH PRESSURE TO BUILD
NORTHWEST OF THE STATE...WHICH WILL ALLOW WINDS TO VEER TO A MORE
NORTHEASTERLY DIRECTION.

&&

.AVIATION...
WEAK SOUTHEAST FLOW IS EXPECTED ACROSS THE WHOLE OF STATE TODAY AS
THE COLD FRONT TO OUR DISTANT NORTHWEST BEGINS ITS APPROACH. WEAK
EASTERLY TRADES THIS MORNING WILL BE REPLACED BY WEAK SEA BREEZES
THIS AFTERNOON AND WEAK LAND BREEZES LATE TONIGHT. MORNING
CLOUDINESS IS FOCUSED OVER WINDWARD SLOPES AND COASTS BUT AFTERNOON
AND EVENING CLOUDS WILL BECOME FOCUSED OVER ISLAND INTERIORS.
AIRMASS OVER THE ISLANDS TODAY IS RELATIVELY DRY AND THE SUBSIDENCE
INVERSION IS RELATIVELY LOW. ANY PRECIPITATION TODAY SHOULD BE LIGHT
AND VFR CONDS ARE EXPECTED TO PREVAIL THROUGH 24 HOURS. PARTIAL
CLEARING EXPECTED ALONG LEEWARD COASTS AFTER MIDNIGHT.

&&

.MARINE...
A LONG PERIOD NORTHWEST SWELL GENERATED BY A LARGE AND POWERFUL LOW
PRESSURE SYSTEM IS EXPECTED TO BRING WARNING LEVEL SURF TO THE
ISLANDS ON SUNDAY. A JASON ALTIMETER PASS FROM LAST NIGHT JUST
OUTSIDE THE CORE OF THE HIGHEST SEAS SUPPORTS THE CURRENT WAVEWATCH
III FORECAST. WW3 SHOWS A SWELL OF 12-13 FEET REACHING BUOY 51101
AFTER MIDNIGHT TONIGHT. THIS SWELL WILL BUILD ACROSS THE ISLANDS ON
SUNDAY...THEN LINGER INTO MONDAY BEFORE GRADUALLY DIMINISHING. HAVE
ISSUED A HIGH SURF WARNING FOR NORTH AND WEST FACING SHORES OF THE
SMALLER ISLANDS. GIVEN THE LATER TIMING FOR THE BIG ISLAND /SWELL
ARRIVING SUNDAY NIGHT/ HAVE HELD OFF ON INCLUDING THE WEST SIDE.
HOWEVER...WAVEWATCH GUIDANCE OF 6 FEET/17 SECONDS OFF THE KONA
COAST WILL ALSO LEAD TO WARNING LEVEL SURF THERE AS WELL. THE SWELL
THIS LARGE WILL ALSO LEAD TO SMALL CRAFT CONDITIONS ACROSS THE
COASTAL WATERS.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
HIGH SURF WARNING FROM 4 AM SUNDAY TO 6 AM HST TUESDAY FOR NORTH AND
WEST FACING SHORES OF NIIHAU KAUAI OAHU AND MOLOKAI AND FOR NORTH
FACING SHORES OF MAUI.

HIGH SURF ADVISORY UNTIL 6 PM HST SUNDAY FOR EAST FACING SHORES OF
THE BIG ISLAND.

&&

$$

DISCUSSION/MARINE...BRAVENDER
AVIATION...BEDAL







000
FXHW60 PHFO 202245 AAB
AFDHFO

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE HONOLULU HI
1245 PM HST SAT DEC 20 2014

.UPDATE...
LIFEGUARD REPORTS FROM THE BIG ISLAND INDICATE HIGH SURF CONDITIONS
ALONG EAST FACING SHORES. THE HILO BUOY HAS BEEN REPORTING COMBINED
SEAS AROUND 9 FEET...AND THE MAJORITY OF THE ENERGY IS FROM ABOUT
120 DEGREES AT 10 SECONDS. WAVEWATCH GUIDANCE AT THAT DATA POINT
INDICATES THIS SWELL WILL CONTINUE AT SIMILAR LEVELS INTO SUNDAY
BEFORE GRADUALLY DIMINISHING. HAVE UPDATED TO ISSUE A HIGH SURF
ADVISORY FOR EAST FACING SHORES OF THE BIG ISLAND THROUGH SUNDAY.
GIVEN THE SWELL DIRECTION OUT OF THE EAST-SOUTHEAST AND LOWER BUOY
READINGS/SURF OBSERVATIONS ACROSS THE REMAINING ISLANDS...HAVE
CONFINED THE ADVISORY TO THE BIG ISLAND.

&&

.SYNOPSIS...
WEAKENING SOUTHEASTERLY FLOW WILL ALLOW FOR LAND AND SEA BREEZES TO
DEVELOP THROUGH SUNDAY. A COLD FRONT APPROACHING FROM THE NORTHWEST
WILL BRING AN INCREASE IN SHOWERS AS EARLY AS SUNDAY NIGHT TO KAUAI.
THERE IS THE POTENTIAL FOR HEAVY RAIN AND A FEW THUNDERSTORMS ACROSS
THE STATE FROM MONDAY AFTERNOON THROUGH TUESDAY. STRONG NORTHERLY
WINDS WILL DEVELOP BEHIND THE FRONT.

&&

.DISCUSSION...
WATER VAPOR IMAGERY SHOWS AN UPPER LEVEL HIGH NORTHEAST OF THE
STATE...WITH A RIDGE EXTENDING ACROSS THE ISLANDS. A SHARP TROUGH IS
LOCATED FAR TO THE NORTHWEST...MOVING TO THE SOUTHEAST AT 30 MPH. AT
THE SURFACE...A RIDGE IS LOCATED LESS THAN 200 MILES NORTH OF
KAUAI...AND THE APPROACHING COLD FRONT IS ABOUT 700 MILES NORTHWEST
OF KAUAI. 12Z RAOBS SHOW STABLE INVERSIONS RANGING FROM 5KFT AT
LIHUE TO 7KFT AT HILO. PRECIPITABLE WATERS ARE ALSO 0.9-1.0
INCHES...WHICH IS DRIER THAN NORMAL FOR THIS TIME OF YEAR. EARLY
MORNING MIMIC TOTAL PRECIPITABLE IMAGERY SHOWS SIMILAR OR SLIGHTLY
DRIER AIR WITHIN A COUPLE HUNDRED MILES EAST OF THE STATE...WITH TPW
VALUES NEAR 1.5 INCHES POOLING ALONG THE COLD FRONT TO THE
NORTHWEST.

WITH THE SURFACE RIDGE BEING SUPPRESSED SOUTHWARD BY THE APPROACHING
FRONT...LOW-LEVEL WINDS HAVE ALREADY TURNED MORE SOUTHEASTERLY
ACROSS THE SMALLER ISLANDS. CLOUD MOTIONS SHOW EASTERLY WINDS STILL
AFFECTING THE BIG ISLAND. WINDS HAVE WEAKENED WITH THE RIDGE
NEARBY...AND WILL WEAKEN FURTHER AS THE WESTERN EXTENT OF THE RIDGE
ERODES WITH THE APPROACH OF THE COLD FRONT. SURFACE PRESSURES ACROSS
THE STATE HAVE ALREADY DROPPED ABOUT 2MB IN THE PAST 24 HOURS. WITH
THE SOUTHEASTERLY WIND DIRECTION...THE BIG ISLAND WILL ALSO BLOCK
SOME OF THE GRADIENT WIND FROM THE SMALLER ISLANDS...LEADING TO A
LOCALLY DRIVEN LAND AND SEA BREEZE PATTERN. THE STABLE AND DRY
AIRMASS WILL KEEP RAINFALL GENERALLY LIGHT...BUT WE WILL SEE AN
INCREASE IN CLOUDS AND SHOWERS ACROSS INTERIOR AND WEST/NORTHWEST
SECTIONS DURING THE LATE MORNING/AFTERNOON. THIS WILL BE THE CASE
BOTH TODAY AND ON SUNDAY...AS WINDS WILL REMAIN LIGHT OVER THE
ISLANDS.

WINDS ACROSS THE BIG ISLAND SUMMITS HAVE SHOWN A GRADUAL DOWNWARD
TREND THROUGH THE MORNING SO FAR. WHILE THE CFHT SENSOR HAS DROPPED
BELOW ADVISORY LEVELS FOR THE HIGHER ELEVATIONS...IT IS STILL
HOVERING AT UP TO 40 MPH. WE SHOULD BE ABLE TO DROP THE WIND
ADVISORY AS EXPECTED THIS MORNING.

THE UPPER LEVEL TROUGH NORTHWEST OF THE STATE WILL PROPEL THE COLD
FRONT TOWARD KAUAI BY SUNDAY NIGHT. MOST OF THE UPPER LEVEL SUPPORT
WITH THIS FIRST TROUGH WILL PASS TO OUR NORTH...AND THE FRONT IS
EXPECTED TO LOSE SOME OF ITS PUSH. HOWEVER...ANOTHER PIECE OF ENERGY
IS EXPECTED TO DIG DOWN THE BACK SIDE OF THE TROUGH AND AMPLIFY NEAR
THE ISLANDS...REINVIGORATING THE FRONT AND DRIVING IT FARTHER
SOUTHEAST. COLD AIR ASSOCIATED WITH THIS DIGGING TROUGH WILL ALSO
DESTABILIZE THE AIRMASS OVER THE ISLANDS. 500MB TEMPERATURES DROP TO
-12C TO -14C. MOISTURE WILL BE SOMEWHAT LIMITED...WITH CROSS
SECTIONS ACROSS THE ISLANDS SHOWING MOISTURE EXTENDING UP TO 700MB.
HOWEVER...MODEL FORECAST SOUNDINGS SHOW THE SUBSIDENCE INVERSION
ERODING...LEADING TO UNSTABLE PROFILES AND RELATIVELY SATURATED
LOW-LEVELS. DIFFERENCES REMAIN BETWEEN THE GFS AND ECMWF...WITH THE
GFS BEING MORE CONSISTENT THROUGH THE EXTENDED FORECAST. THE 12Z
ECMWF CUTS OFF MUCH OF THE DIGGING ENERGY SOUTHWEST OF THE STATE
WHILE THE GFS KEEPS THE TROUGH MORE PROGRESSIVE. BY MID WEEK THE
ECMWF TRENDS BACK TOWARD THE GFS SOLUTION WITH THE PLACEMENT OF A
CUTOFF LOW DEVELOPING NORTHEAST OF THE STATE. OVERALL THE PATTERN
HAS STABILIZED ENOUGH THAT CHANGES ARE NOT NEEDED FOR THE CURRENT
FORECAST...WHICH FEATURES A MENTION OF THUNDERSTORMS FROM MONDAY
AFTERNOON THROUGH TUESDAY NIGHT.

STRONG NORTHERLY WINDS ARE EXPECTED TO DEVELOP BEHIND THE FRONT
EARLY IN THE NEW WORK WEEK. THESE WINDS WILL GRADUALLY RELAX THROUGH
THE WEEK...BUT REMAIN GENERALLY OUT OF THE NORTH DUE TO THE PRESENCE
OF THE LOW THAT IS EXPECTED TO BE NORTHEAST OF THE STATE. BY LATE IN
THE WEEK THIS LOW WILL WEAKEN AND ALLOW HIGH PRESSURE TO BUILD
NORTHWEST OF THE STATE...WHICH WILL ALLOW WINDS TO VEER TO A MORE
NORTHEASTERLY DIRECTION.

&&

.AVIATION...
WEAK SOUTHEAST FLOW IS EXPECTED ACROSS THE WHOLE OF STATE TODAY AS
THE COLD FRONT TO OUR DISTANT NORTHWEST BEGINS ITS APPROACH. WEAK
EASTERLY TRADES THIS MORNING WILL BE REPLACED BY WEAK SEA BREEZES
THIS AFTERNOON AND WEAK LAND BREEZES LATE TONIGHT. MORNING
CLOUDINESS IS FOCUSED OVER WINDWARD SLOPES AND COASTS BUT AFTERNOON
AND EVENING CLOUDS WILL BECOME FOCUSED OVER ISLAND INTERIORS.
AIRMASS OVER THE ISLANDS TODAY IS RELATIVELY DRY AND THE SUBSIDENCE
INVERSION IS RELATIVELY LOW. ANY PRECIPITATION TODAY SHOULD BE LIGHT
AND VFR CONDS ARE EXPECTED TO PREVAIL THROUGH 24 HOURS. PARTIAL
CLEARING EXPECTED ALONG LEEWARD COASTS AFTER MIDNIGHT.

&&

.MARINE...
A LONG PERIOD NORTHWEST SWELL GENERATED BY A LARGE AND POWERFUL LOW
PRESSURE SYSTEM IS EXPECTED TO BRING WARNING LEVEL SURF TO THE
ISLANDS ON SUNDAY. A JASON ALTIMETER PASS FROM LAST NIGHT JUST
OUTSIDE THE CORE OF THE HIGHEST SEAS SUPPORTS THE CURRENT WAVEWATCH
III FORECAST. WW3 SHOWS A SWELL OF 12-13 FEET REACHING BUOY 51101
AFTER MIDNIGHT TONIGHT. THIS SWELL WILL BUILD ACROSS THE ISLANDS ON
SUNDAY...THEN LINGER INTO MONDAY BEFORE GRADUALLY DIMINISHING. HAVE
ISSUED A HIGH SURF WARNING FOR NORTH AND WEST FACING SHORES OF THE
SMALLER ISLANDS. GIVEN THE LATER TIMING FOR THE BIG ISLAND /SWELL
ARRIVING SUNDAY NIGHT/ HAVE HELD OFF ON INCLUDING THE WEST SIDE.
HOWEVER...WAVEWATCH GUIDANCE OF 6 FEET/17 SECONDS OFF THE KONA
COAST WILL ALSO LEAD TO WARNING LEVEL SURF THERE AS WELL. THE SWELL
THIS LARGE WILL ALSO LEAD TO SMALL CRAFT CONDITIONS ACROSS THE
COASTAL WATERS.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
HIGH SURF WARNING FROM 4 AM SUNDAY TO 6 AM HST TUESDAY FOR NORTH AND
WEST FACING SHORES OF NIIHAU KAUAI OAHU AND MOLOKAI AND FOR NORTH
FACING SHORES OF MAUI.

HIGH SURF ADVISORY UNTIL 6 PM HST SUNDAY FOR EAST FACING SHORES OF
THE BIG ISLAND.

&&

$$

DISCUSSION/MARINE...BRAVENDER
AVIATION...BEDAL







000
FXHW60 PHFO 202245 AAB
AFDHFO

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE HONOLULU HI
1245 PM HST SAT DEC 20 2014

.UPDATE...
LIFEGUARD REPORTS FROM THE BIG ISLAND INDICATE HIGH SURF CONDITIONS
ALONG EAST FACING SHORES. THE HILO BUOY HAS BEEN REPORTING COMBINED
SEAS AROUND 9 FEET...AND THE MAJORITY OF THE ENERGY IS FROM ABOUT
120 DEGREES AT 10 SECONDS. WAVEWATCH GUIDANCE AT THAT DATA POINT
INDICATES THIS SWELL WILL CONTINUE AT SIMILAR LEVELS INTO SUNDAY
BEFORE GRADUALLY DIMINISHING. HAVE UPDATED TO ISSUE A HIGH SURF
ADVISORY FOR EAST FACING SHORES OF THE BIG ISLAND THROUGH SUNDAY.
GIVEN THE SWELL DIRECTION OUT OF THE EAST-SOUTHEAST AND LOWER BUOY
READINGS/SURF OBSERVATIONS ACROSS THE REMAINING ISLANDS...HAVE
CONFINED THE ADVISORY TO THE BIG ISLAND.

&&

.SYNOPSIS...
WEAKENING SOUTHEASTERLY FLOW WILL ALLOW FOR LAND AND SEA BREEZES TO
DEVELOP THROUGH SUNDAY. A COLD FRONT APPROACHING FROM THE NORTHWEST
WILL BRING AN INCREASE IN SHOWERS AS EARLY AS SUNDAY NIGHT TO KAUAI.
THERE IS THE POTENTIAL FOR HEAVY RAIN AND A FEW THUNDERSTORMS ACROSS
THE STATE FROM MONDAY AFTERNOON THROUGH TUESDAY. STRONG NORTHERLY
WINDS WILL DEVELOP BEHIND THE FRONT.

&&

.DISCUSSION...
WATER VAPOR IMAGERY SHOWS AN UPPER LEVEL HIGH NORTHEAST OF THE
STATE...WITH A RIDGE EXTENDING ACROSS THE ISLANDS. A SHARP TROUGH IS
LOCATED FAR TO THE NORTHWEST...MOVING TO THE SOUTHEAST AT 30 MPH. AT
THE SURFACE...A RIDGE IS LOCATED LESS THAN 200 MILES NORTH OF
KAUAI...AND THE APPROACHING COLD FRONT IS ABOUT 700 MILES NORTHWEST
OF KAUAI. 12Z RAOBS SHOW STABLE INVERSIONS RANGING FROM 5KFT AT
LIHUE TO 7KFT AT HILO. PRECIPITABLE WATERS ARE ALSO 0.9-1.0
INCHES...WHICH IS DRIER THAN NORMAL FOR THIS TIME OF YEAR. EARLY
MORNING MIMIC TOTAL PRECIPITABLE IMAGERY SHOWS SIMILAR OR SLIGHTLY
DRIER AIR WITHIN A COUPLE HUNDRED MILES EAST OF THE STATE...WITH TPW
VALUES NEAR 1.5 INCHES POOLING ALONG THE COLD FRONT TO THE
NORTHWEST.

WITH THE SURFACE RIDGE BEING SUPPRESSED SOUTHWARD BY THE APPROACHING
FRONT...LOW-LEVEL WINDS HAVE ALREADY TURNED MORE SOUTHEASTERLY
ACROSS THE SMALLER ISLANDS. CLOUD MOTIONS SHOW EASTERLY WINDS STILL
AFFECTING THE BIG ISLAND. WINDS HAVE WEAKENED WITH THE RIDGE
NEARBY...AND WILL WEAKEN FURTHER AS THE WESTERN EXTENT OF THE RIDGE
ERODES WITH THE APPROACH OF THE COLD FRONT. SURFACE PRESSURES ACROSS
THE STATE HAVE ALREADY DROPPED ABOUT 2MB IN THE PAST 24 HOURS. WITH
THE SOUTHEASTERLY WIND DIRECTION...THE BIG ISLAND WILL ALSO BLOCK
SOME OF THE GRADIENT WIND FROM THE SMALLER ISLANDS...LEADING TO A
LOCALLY DRIVEN LAND AND SEA BREEZE PATTERN. THE STABLE AND DRY
AIRMASS WILL KEEP RAINFALL GENERALLY LIGHT...BUT WE WILL SEE AN
INCREASE IN CLOUDS AND SHOWERS ACROSS INTERIOR AND WEST/NORTHWEST
SECTIONS DURING THE LATE MORNING/AFTERNOON. THIS WILL BE THE CASE
BOTH TODAY AND ON SUNDAY...AS WINDS WILL REMAIN LIGHT OVER THE
ISLANDS.

WINDS ACROSS THE BIG ISLAND SUMMITS HAVE SHOWN A GRADUAL DOWNWARD
TREND THROUGH THE MORNING SO FAR. WHILE THE CFHT SENSOR HAS DROPPED
BELOW ADVISORY LEVELS FOR THE HIGHER ELEVATIONS...IT IS STILL
HOVERING AT UP TO 40 MPH. WE SHOULD BE ABLE TO DROP THE WIND
ADVISORY AS EXPECTED THIS MORNING.

THE UPPER LEVEL TROUGH NORTHWEST OF THE STATE WILL PROPEL THE COLD
FRONT TOWARD KAUAI BY SUNDAY NIGHT. MOST OF THE UPPER LEVEL SUPPORT
WITH THIS FIRST TROUGH WILL PASS TO OUR NORTH...AND THE FRONT IS
EXPECTED TO LOSE SOME OF ITS PUSH. HOWEVER...ANOTHER PIECE OF ENERGY
IS EXPECTED TO DIG DOWN THE BACK SIDE OF THE TROUGH AND AMPLIFY NEAR
THE ISLANDS...REINVIGORATING THE FRONT AND DRIVING IT FARTHER
SOUTHEAST. COLD AIR ASSOCIATED WITH THIS DIGGING TROUGH WILL ALSO
DESTABILIZE THE AIRMASS OVER THE ISLANDS. 500MB TEMPERATURES DROP TO
-12C TO -14C. MOISTURE WILL BE SOMEWHAT LIMITED...WITH CROSS
SECTIONS ACROSS THE ISLANDS SHOWING MOISTURE EXTENDING UP TO 700MB.
HOWEVER...MODEL FORECAST SOUNDINGS SHOW THE SUBSIDENCE INVERSION
ERODING...LEADING TO UNSTABLE PROFILES AND RELATIVELY SATURATED
LOW-LEVELS. DIFFERENCES REMAIN BETWEEN THE GFS AND ECMWF...WITH THE
GFS BEING MORE CONSISTENT THROUGH THE EXTENDED FORECAST. THE 12Z
ECMWF CUTS OFF MUCH OF THE DIGGING ENERGY SOUTHWEST OF THE STATE
WHILE THE GFS KEEPS THE TROUGH MORE PROGRESSIVE. BY MID WEEK THE
ECMWF TRENDS BACK TOWARD THE GFS SOLUTION WITH THE PLACEMENT OF A
CUTOFF LOW DEVELOPING NORTHEAST OF THE STATE. OVERALL THE PATTERN
HAS STABILIZED ENOUGH THAT CHANGES ARE NOT NEEDED FOR THE CURRENT
FORECAST...WHICH FEATURES A MENTION OF THUNDERSTORMS FROM MONDAY
AFTERNOON THROUGH TUESDAY NIGHT.

STRONG NORTHERLY WINDS ARE EXPECTED TO DEVELOP BEHIND THE FRONT
EARLY IN THE NEW WORK WEEK. THESE WINDS WILL GRADUALLY RELAX THROUGH
THE WEEK...BUT REMAIN GENERALLY OUT OF THE NORTH DUE TO THE PRESENCE
OF THE LOW THAT IS EXPECTED TO BE NORTHEAST OF THE STATE. BY LATE IN
THE WEEK THIS LOW WILL WEAKEN AND ALLOW HIGH PRESSURE TO BUILD
NORTHWEST OF THE STATE...WHICH WILL ALLOW WINDS TO VEER TO A MORE
NORTHEASTERLY DIRECTION.

&&

.AVIATION...
WEAK SOUTHEAST FLOW IS EXPECTED ACROSS THE WHOLE OF STATE TODAY AS
THE COLD FRONT TO OUR DISTANT NORTHWEST BEGINS ITS APPROACH. WEAK
EASTERLY TRADES THIS MORNING WILL BE REPLACED BY WEAK SEA BREEZES
THIS AFTERNOON AND WEAK LAND BREEZES LATE TONIGHT. MORNING
CLOUDINESS IS FOCUSED OVER WINDWARD SLOPES AND COASTS BUT AFTERNOON
AND EVENING CLOUDS WILL BECOME FOCUSED OVER ISLAND INTERIORS.
AIRMASS OVER THE ISLANDS TODAY IS RELATIVELY DRY AND THE SUBSIDENCE
INVERSION IS RELATIVELY LOW. ANY PRECIPITATION TODAY SHOULD BE LIGHT
AND VFR CONDS ARE EXPECTED TO PREVAIL THROUGH 24 HOURS. PARTIAL
CLEARING EXPECTED ALONG LEEWARD COASTS AFTER MIDNIGHT.

&&

.MARINE...
A LONG PERIOD NORTHWEST SWELL GENERATED BY A LARGE AND POWERFUL LOW
PRESSURE SYSTEM IS EXPECTED TO BRING WARNING LEVEL SURF TO THE
ISLANDS ON SUNDAY. A JASON ALTIMETER PASS FROM LAST NIGHT JUST
OUTSIDE THE CORE OF THE HIGHEST SEAS SUPPORTS THE CURRENT WAVEWATCH
III FORECAST. WW3 SHOWS A SWELL OF 12-13 FEET REACHING BUOY 51101
AFTER MIDNIGHT TONIGHT. THIS SWELL WILL BUILD ACROSS THE ISLANDS ON
SUNDAY...THEN LINGER INTO MONDAY BEFORE GRADUALLY DIMINISHING. HAVE
ISSUED A HIGH SURF WARNING FOR NORTH AND WEST FACING SHORES OF THE
SMALLER ISLANDS. GIVEN THE LATER TIMING FOR THE BIG ISLAND /SWELL
ARRIVING SUNDAY NIGHT/ HAVE HELD OFF ON INCLUDING THE WEST SIDE.
HOWEVER...WAVEWATCH GUIDANCE OF 6 FEET/17 SECONDS OFF THE KONA
COAST WILL ALSO LEAD TO WARNING LEVEL SURF THERE AS WELL. THE SWELL
THIS LARGE WILL ALSO LEAD TO SMALL CRAFT CONDITIONS ACROSS THE
COASTAL WATERS.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
HIGH SURF WARNING FROM 4 AM SUNDAY TO 6 AM HST TUESDAY FOR NORTH AND
WEST FACING SHORES OF NIIHAU KAUAI OAHU AND MOLOKAI AND FOR NORTH
FACING SHORES OF MAUI.

HIGH SURF ADVISORY UNTIL 6 PM HST SUNDAY FOR EAST FACING SHORES OF
THE BIG ISLAND.

&&

$$

DISCUSSION/MARINE...BRAVENDER
AVIATION...BEDAL







000
FXHW60 PHFO 202123 AAA
AFDHFO

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE HONOLULU HI
1123 AM HST SAT DEC 20 2014

.UPDATE...
UPDATED HAZARD SECTION TO DROP THE WIND ADVISORY AND ADD HIGH SURF
WARNING.

&&

.SYNOPSIS...
WEAKENING SOUTHEASTERLY FLOW WILL ALLOW FOR LAND AND SEA BREEZES TO
DEVELOP THROUGH SUNDAY. A COLD FRONT APPROACHING FROM THE NORTHWEST
WILL BRING AN INCREASE IN SHOWERS AS EARLY AS SUNDAY NIGHT TO KAUAI.
THERE IS THE POTENTIAL FOR HEAVY RAIN AND A FEW THUNDERSTORMS ACROSS
THE STATE FROM MONDAY AFTERNOON THROUGH TUESDAY. STRONG NORTHERLY
WINDS WILL DEVELOP BEHIND THE FRONT.

&&

.DISCUSSION...
WATER VAPOR IMAGERY SHOWS AN UPPER LEVEL HIGH NORTHEAST OF THE
STATE...WITH A RIDGE EXTENDING ACROSS THE ISLANDS. A SHARP TROUGH IS
LOCATED FAR TO THE NORTHWEST...MOVING TO THE SOUTHEAST AT 30 MPH. AT
THE SURFACE...A RIDGE IS LOCATED LESS THAN 200 MILES NORTH OF
KAUAI...AND THE APPROACHING COLD FRONT IS ABOUT 700 MILES NORTHWEST
OF KAUAI. 12Z RAOBS SHOW STABLE INVERSIONS RANGING FROM 5KFT AT
LIHUE TO 7KFT AT HILO. PRECIPITABLE WATERS ARE ALSO 0.9-1.0
INCHES...WHICH IS DRIER THAN NORMAL FOR THIS TIME OF YEAR. EARLY
MORNING MIMIC TOTAL PRECIPITABLE IMAGERY SHOWS SIMILAR OR SLIGHTLY
DRIER AIR WITHIN A COUPLE HUNDRED MILES EAST OF THE STATE...WITH TPW
VALUES NEAR 1.5 INCHES POOLING ALONG THE COLD FRONT TO THE
NORTHWEST.

WITH THE SURFACE RIDGE BEING SUPPRESSED SOUTHWARD BY THE APPROACHING
FRONT...LOW-LEVEL WINDS HAVE ALREADY TURNED MORE SOUTHEASTERLY
ACROSS THE SMALLER ISLANDS. CLOUD MOTIONS SHOW EASTERLY WINDS STILL
AFFECTING THE BIG ISLAND. WINDS HAVE WEAKENED WITH THE RIDGE
NEARBY...AND WILL WEAKEN FURTHER AS THE WESTERN EXTENT OF THE RIDGE
ERODES WITH THE APPROACH OF THE COLD FRONT. SURFACE PRESSURES ACROSS
THE STATE HAVE ALREADY DROPPED ABOUT 2MB IN THE PAST 24 HOURS. WITH
THE SOUTHEASTERLY WIND DIRECTION...THE BIG ISLAND WILL ALSO BLOCK
SOME OF THE GRADIENT WIND FROM THE SMALLER ISLANDS...LEADING TO A
LOCALLY DRIVEN LAND AND SEA BREEZE PATTERN. THE STABLE AND DRY
AIRMASS WILL KEEP RAINFALL GENERALLY LIGHT...BUT WE WILL SEE AN
INCREASE IN CLOUDS AND SHOWERS ACROSS INTERIOR AND WEST/NORTHWEST
SECTIONS DURING THE LATE MORNING/AFTERNOON. THIS WILL BE THE CASE
BOTH TODAY AND ON SUNDAY...AS WINDS WILL REMAIN LIGHT OVER THE
ISLANDS.

WINDS ACROSS THE BIG ISLAND SUMMITS HAVE SHOWN A GRADUAL DOWNWARD
TREND THROUGH THE MORNING SO FAR. WHILE THE CFHT SENSOR HAS DROPPED
BELOW ADVISORY LEVELS FOR THE HIGHER ELEVATIONS...IT IS STILL
HOVERING AT UP TO 40 MPH. WE SHOULD BE ABLE TO DROP THE WIND
ADVISORY AS EXPECTED THIS MORNING.

THE UPPER LEVEL TROUGH NORTHWEST OF THE STATE WILL PROPEL THE COLD
FRONT TOWARD KAUAI BY SUNDAY NIGHT. MOST OF THE UPPER LEVEL SUPPORT
WITH THIS FIRST TROUGH WILL PASS TO OUR NORTH...AND THE FRONT IS
EXPECTED TO LOSE SOME OF ITS PUSH. HOWEVER...ANOTHER PIECE OF ENERGY
IS EXPECTED TO DIG DOWN THE BACK SIDE OF THE TROUGH AND AMPLIFY NEAR
THE ISLANDS...REINVIGORATING THE FRONT AND DRIVING IT FARTHER
SOUTHEAST. COLD AIR ASSOCIATED WITH THIS DIGGING TROUGH WILL ALSO
DESTABILIZE THE AIRMASS OVER THE ISLANDS. 500MB TEMPERATURES DROP TO
-12C TO -14C. MOISTURE WILL BE SOMEWHAT LIMITED...WITH CROSS
SECTIONS ACROSS THE ISLANDS SHOWING MOISTURE EXTENDING UP TO 700MB.
HOWEVER...MODEL FORECAST SOUNDINGS SHOW THE SUBSIDENCE INVERSION
ERODING...LEADING TO UNSTABLE PROFILES AND RELATIVELY SATURATED
LOW-LEVELS. DIFFERENCES REMAIN BETWEEN THE GFS AND ECMWF...WITH THE
GFS BEING MORE CONSISTENT THROUGH THE EXTENDED FORECAST. THE 12Z
ECMWF CUTS OFF MUCH OF THE DIGGING ENERGY SOUTHWEST OF THE STATE
WHILE THE GFS KEEPS THE TROUGH MORE PROGRESSIVE. BY MID WEEK THE
ECMWF TRENDS BACK TOWARD THE GFS SOLUTION WITH THE PLACEMENT OF A
CUTOFF LOW DEVELOPING NORTHEAST OF THE STATE. OVERALL THE PATTERN
HAS STABILIZED ENOUGH THAT CHANGES ARE NOT NEEDED FOR THE CURRENT
FORECAST...WHICH FEATURES A MENTION OF THUNDERSTORMS FROM MONDAY
AFTERNOON THROUGH TUESDAY NIGHT.

STRONG NORTHERLY WINDS ARE EXPECTED TO DEVELOP BEHIND THE FRONT
EARLY IN THE NEW WORK WEEK. THESE WINDS WILL GRADUALLY RELAX THROUGH
THE WEEK...BUT REMAIN GENERALLY OUT OF THE NORTH DUE TO THE PRESENCE
OF THE LOW THAT IS EXPECTED TO BE NORTHEAST OF THE STATE. BY LATE IN
THE WEEK THIS LOW WILL WEAKEN AND ALLOW HIGH PRESSURE TO BUILD
NORTHWEST OF THE STATE...WHICH WILL ALLOW WINDS TO VEER TO A MORE
NORTHEASTERLY DIRECTION.

&&

.AVIATION...
WEAK SOUTHEAST FLOW IS EXPECTED ACROSS THE WHOLE OF STATE TODAY AS
THE COLD FRONT TO OUR DISTANT NORTHWEST BEGINS ITS APPROACH. WEAK
EASTERLY TRADES THIS MORNING WILL BE REPLACED BY WEAK SEA BREEZES
THIS AFTERNOON AND WEAK LAND BREEZES LATE TONIGHT. MORNING
CLOUDINESS IS FOCUSED OVER WINDWARD SLOPES AND COASTS BUT AFTERNOON
AND EVENING CLOUDS WILL BECOME FOCUSED OVER ISLAND INTERIORS.
AIRMASS OVER THE ISLANDS TODAY IS RELATIVELY DRY AND THE SUBSIDENCE
INVERSION IS RELATIVELY LOW. ANY PRECIPITATION TODAY SHOULD BE LIGHT
AND VFR CONDS ARE EXPECTED TO PREVAIL THROUGH 24 HOURS. PARTIAL
CLEARING EXPECTED ALONG LEEWARD COASTS AFTER MIDNIGHT.

&&

.MARINE...
A LONG PERIOD NORTHWEST SWELL GENERATED BY A LARGE AND POWERFUL LOW
PRESSURE SYSTEM IS EXPECTED TO BRING WARNING LEVEL SURF TO THE
ISLANDS ON SUNDAY. A JASON ALTIMETER PASS FROM LAST NIGHT JUST
OUTSIDE THE CORE OF THE HIGHEST SEAS SUPPORTS THE CURRENT WAVEWATCH
III FORECAST. WW3 SHOWS A SWELL OF 12-13 FEET REACHING BUOY 51101
AFTER MIDNIGHT TONIGHT. THIS SWELL WILL BUILD ACROSS THE ISLANDS ON
SUNDAY...THEN LINGER INTO MONDAY BEFORE GRADUALLY DIMINISHING. HAVE
ISSUED A HIGH SURF WARNING FOR NORTH AND WEST FACING SHORES OF THE
SMALLER ISLANDS. GIVEN THE LATER TIMING FOR THE BIG ISLAND /SWELL
ARRIVING SUNDAY NIGHT/ HAVE HELD OFF ON INCLUDING THE WEST SIDE.
HOWEVER...WAVEWATCH GUIDANCE OF 6 FEET/17 SECONDS OFF THE KONA
COAST WILL ALSO LEAD TO WARNING LEVEL SURF THERE AS WELL. THE SWELL
THIS LARGE WILL ALSO LEAD TO SMALL CRAFT CONDITIONS ACROSS THE
COASTAL WATERS.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
HIGH SURF WARNING FROM 4 AM SUNDAY TO 6 AM HST TUESDAY FOR NORTH AND
WEST FACING SHORES OF NIIHAU KAUAI OAHU AND MOLOKAI AND FOR NORTH
FACING SHORES OF MAUI.

&&

$$

DISCUSSION/MARINE...BRAVENDER
AVIATION...BEDAL






000
FXHW60 PHFO 202123 AAA
AFDHFO

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE HONOLULU HI
1123 AM HST SAT DEC 20 2014

.UPDATE...
UPDATED HAZARD SECTION TO DROP THE WIND ADVISORY AND ADD HIGH SURF
WARNING.

&&

.SYNOPSIS...
WEAKENING SOUTHEASTERLY FLOW WILL ALLOW FOR LAND AND SEA BREEZES TO
DEVELOP THROUGH SUNDAY. A COLD FRONT APPROACHING FROM THE NORTHWEST
WILL BRING AN INCREASE IN SHOWERS AS EARLY AS SUNDAY NIGHT TO KAUAI.
THERE IS THE POTENTIAL FOR HEAVY RAIN AND A FEW THUNDERSTORMS ACROSS
THE STATE FROM MONDAY AFTERNOON THROUGH TUESDAY. STRONG NORTHERLY
WINDS WILL DEVELOP BEHIND THE FRONT.

&&

.DISCUSSION...
WATER VAPOR IMAGERY SHOWS AN UPPER LEVEL HIGH NORTHEAST OF THE
STATE...WITH A RIDGE EXTENDING ACROSS THE ISLANDS. A SHARP TROUGH IS
LOCATED FAR TO THE NORTHWEST...MOVING TO THE SOUTHEAST AT 30 MPH. AT
THE SURFACE...A RIDGE IS LOCATED LESS THAN 200 MILES NORTH OF
KAUAI...AND THE APPROACHING COLD FRONT IS ABOUT 700 MILES NORTHWEST
OF KAUAI. 12Z RAOBS SHOW STABLE INVERSIONS RANGING FROM 5KFT AT
LIHUE TO 7KFT AT HILO. PRECIPITABLE WATERS ARE ALSO 0.9-1.0
INCHES...WHICH IS DRIER THAN NORMAL FOR THIS TIME OF YEAR. EARLY
MORNING MIMIC TOTAL PRECIPITABLE IMAGERY SHOWS SIMILAR OR SLIGHTLY
DRIER AIR WITHIN A COUPLE HUNDRED MILES EAST OF THE STATE...WITH TPW
VALUES NEAR 1.5 INCHES POOLING ALONG THE COLD FRONT TO THE
NORTHWEST.

WITH THE SURFACE RIDGE BEING SUPPRESSED SOUTHWARD BY THE APPROACHING
FRONT...LOW-LEVEL WINDS HAVE ALREADY TURNED MORE SOUTHEASTERLY
ACROSS THE SMALLER ISLANDS. CLOUD MOTIONS SHOW EASTERLY WINDS STILL
AFFECTING THE BIG ISLAND. WINDS HAVE WEAKENED WITH THE RIDGE
NEARBY...AND WILL WEAKEN FURTHER AS THE WESTERN EXTENT OF THE RIDGE
ERODES WITH THE APPROACH OF THE COLD FRONT. SURFACE PRESSURES ACROSS
THE STATE HAVE ALREADY DROPPED ABOUT 2MB IN THE PAST 24 HOURS. WITH
THE SOUTHEASTERLY WIND DIRECTION...THE BIG ISLAND WILL ALSO BLOCK
SOME OF THE GRADIENT WIND FROM THE SMALLER ISLANDS...LEADING TO A
LOCALLY DRIVEN LAND AND SEA BREEZE PATTERN. THE STABLE AND DRY
AIRMASS WILL KEEP RAINFALL GENERALLY LIGHT...BUT WE WILL SEE AN
INCREASE IN CLOUDS AND SHOWERS ACROSS INTERIOR AND WEST/NORTHWEST
SECTIONS DURING THE LATE MORNING/AFTERNOON. THIS WILL BE THE CASE
BOTH TODAY AND ON SUNDAY...AS WINDS WILL REMAIN LIGHT OVER THE
ISLANDS.

WINDS ACROSS THE BIG ISLAND SUMMITS HAVE SHOWN A GRADUAL DOWNWARD
TREND THROUGH THE MORNING SO FAR. WHILE THE CFHT SENSOR HAS DROPPED
BELOW ADVISORY LEVELS FOR THE HIGHER ELEVATIONS...IT IS STILL
HOVERING AT UP TO 40 MPH. WE SHOULD BE ABLE TO DROP THE WIND
ADVISORY AS EXPECTED THIS MORNING.

THE UPPER LEVEL TROUGH NORTHWEST OF THE STATE WILL PROPEL THE COLD
FRONT TOWARD KAUAI BY SUNDAY NIGHT. MOST OF THE UPPER LEVEL SUPPORT
WITH THIS FIRST TROUGH WILL PASS TO OUR NORTH...AND THE FRONT IS
EXPECTED TO LOSE SOME OF ITS PUSH. HOWEVER...ANOTHER PIECE OF ENERGY
IS EXPECTED TO DIG DOWN THE BACK SIDE OF THE TROUGH AND AMPLIFY NEAR
THE ISLANDS...REINVIGORATING THE FRONT AND DRIVING IT FARTHER
SOUTHEAST. COLD AIR ASSOCIATED WITH THIS DIGGING TROUGH WILL ALSO
DESTABILIZE THE AIRMASS OVER THE ISLANDS. 500MB TEMPERATURES DROP TO
-12C TO -14C. MOISTURE WILL BE SOMEWHAT LIMITED...WITH CROSS
SECTIONS ACROSS THE ISLANDS SHOWING MOISTURE EXTENDING UP TO 700MB.
HOWEVER...MODEL FORECAST SOUNDINGS SHOW THE SUBSIDENCE INVERSION
ERODING...LEADING TO UNSTABLE PROFILES AND RELATIVELY SATURATED
LOW-LEVELS. DIFFERENCES REMAIN BETWEEN THE GFS AND ECMWF...WITH THE
GFS BEING MORE CONSISTENT THROUGH THE EXTENDED FORECAST. THE 12Z
ECMWF CUTS OFF MUCH OF THE DIGGING ENERGY SOUTHWEST OF THE STATE
WHILE THE GFS KEEPS THE TROUGH MORE PROGRESSIVE. BY MID WEEK THE
ECMWF TRENDS BACK TOWARD THE GFS SOLUTION WITH THE PLACEMENT OF A
CUTOFF LOW DEVELOPING NORTHEAST OF THE STATE. OVERALL THE PATTERN
HAS STABILIZED ENOUGH THAT CHANGES ARE NOT NEEDED FOR THE CURRENT
FORECAST...WHICH FEATURES A MENTION OF THUNDERSTORMS FROM MONDAY
AFTERNOON THROUGH TUESDAY NIGHT.

STRONG NORTHERLY WINDS ARE EXPECTED TO DEVELOP BEHIND THE FRONT
EARLY IN THE NEW WORK WEEK. THESE WINDS WILL GRADUALLY RELAX THROUGH
THE WEEK...BUT REMAIN GENERALLY OUT OF THE NORTH DUE TO THE PRESENCE
OF THE LOW THAT IS EXPECTED TO BE NORTHEAST OF THE STATE. BY LATE IN
THE WEEK THIS LOW WILL WEAKEN AND ALLOW HIGH PRESSURE TO BUILD
NORTHWEST OF THE STATE...WHICH WILL ALLOW WINDS TO VEER TO A MORE
NORTHEASTERLY DIRECTION.

&&

.AVIATION...
WEAK SOUTHEAST FLOW IS EXPECTED ACROSS THE WHOLE OF STATE TODAY AS
THE COLD FRONT TO OUR DISTANT NORTHWEST BEGINS ITS APPROACH. WEAK
EASTERLY TRADES THIS MORNING WILL BE REPLACED BY WEAK SEA BREEZES
THIS AFTERNOON AND WEAK LAND BREEZES LATE TONIGHT. MORNING
CLOUDINESS IS FOCUSED OVER WINDWARD SLOPES AND COASTS BUT AFTERNOON
AND EVENING CLOUDS WILL BECOME FOCUSED OVER ISLAND INTERIORS.
AIRMASS OVER THE ISLANDS TODAY IS RELATIVELY DRY AND THE SUBSIDENCE
INVERSION IS RELATIVELY LOW. ANY PRECIPITATION TODAY SHOULD BE LIGHT
AND VFR CONDS ARE EXPECTED TO PREVAIL THROUGH 24 HOURS. PARTIAL
CLEARING EXPECTED ALONG LEEWARD COASTS AFTER MIDNIGHT.

&&

.MARINE...
A LONG PERIOD NORTHWEST SWELL GENERATED BY A LARGE AND POWERFUL LOW
PRESSURE SYSTEM IS EXPECTED TO BRING WARNING LEVEL SURF TO THE
ISLANDS ON SUNDAY. A JASON ALTIMETER PASS FROM LAST NIGHT JUST
OUTSIDE THE CORE OF THE HIGHEST SEAS SUPPORTS THE CURRENT WAVEWATCH
III FORECAST. WW3 SHOWS A SWELL OF 12-13 FEET REACHING BUOY 51101
AFTER MIDNIGHT TONIGHT. THIS SWELL WILL BUILD ACROSS THE ISLANDS ON
SUNDAY...THEN LINGER INTO MONDAY BEFORE GRADUALLY DIMINISHING. HAVE
ISSUED A HIGH SURF WARNING FOR NORTH AND WEST FACING SHORES OF THE
SMALLER ISLANDS. GIVEN THE LATER TIMING FOR THE BIG ISLAND /SWELL
ARRIVING SUNDAY NIGHT/ HAVE HELD OFF ON INCLUDING THE WEST SIDE.
HOWEVER...WAVEWATCH GUIDANCE OF 6 FEET/17 SECONDS OFF THE KONA
COAST WILL ALSO LEAD TO WARNING LEVEL SURF THERE AS WELL. THE SWELL
THIS LARGE WILL ALSO LEAD TO SMALL CRAFT CONDITIONS ACROSS THE
COASTAL WATERS.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
HIGH SURF WARNING FROM 4 AM SUNDAY TO 6 AM HST TUESDAY FOR NORTH AND
WEST FACING SHORES OF NIIHAU KAUAI OAHU AND MOLOKAI AND FOR NORTH
FACING SHORES OF MAUI.

&&

$$

DISCUSSION/MARINE...BRAVENDER
AVIATION...BEDAL





000
FXHW60 PHFO 202023
AFDHFO

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
1000 AM HST SAT DEC 20 2014

.SYNOPSIS...
WEAKENING SOUTHEASTERLY FLOW WILL ALLOW FOR LAND AND SEA BREEZES TO
DEVELOP THROUGH SUNDAY. A COLD FRONT APPROACHING FROM THE NORTHWEST
WILL BRING AN INCREASE IN SHOWERS AS EARLY AS SUNDAY NIGHT TO KAUAI.
THERE IS THE POTENTIAL FOR HEAVY RAIN AND A FEW THUNDERSTORMS ACROSS
THE STATE FROM MONDAY AFTERNOON THROUGH TUESDAY. STRONG NORTHERLY
WINDS WILL DEVELOP BEHIND THE FRONT.

&&

.DISCUSSION...
WATER VAPOR IMAGERY SHOWS AN UPPER LEVEL HIGH NORTHEAST OF THE
STATE...WITH A RIDGE EXTENDING ACROSS THE ISLANDS. A SHARP TROUGH IS
LOCATED FAR TO THE NORTHWEST...MOVING TO THE SOUTHEAST AT 30 MPH. AT
THE SURFACE...A RIDGE IS LOCATED LESS THAN 200 MILES NORTH OF
KAUAI...AND THE APPROACHING COLD FRONT IS ABOUT 700 MILES NORTHWEST
OF KAUAI. 12Z RAOBS SHOW STABLE INVERSIONS RANGING FROM 5KFT AT
LIHUE TO 7KFT AT HILO. PRECIPITABLE WATERS ARE ALSO 0.9-1.0
INCHES...WHICH IS DRIER THAN NORMAL FOR THIS TIME OF YEAR. EARLY
MORNING MIMIC TOTAL PRECIPITABLE IMAGERY SHOWS SIMILAR OR SLIGHTLY
DRIER AIR WITHIN A COUPLE HUNDRED MILES EAST OF THE STATE...WITH TPW
VALUES NEAR 1.5 INCHES POOLING ALONG THE COLD FRONT TO THE
NORTHWEST.

WITH THE SURFACE RIDGE BEING SUPPRESSED SOUTHWARD BY THE APPROACHING
FRONT...LOW-LEVEL WINDS HAVE ALREADY TURNED MORE SOUTHEASTERLY
ACROSS THE SMALLER ISLANDS. CLOUD MOTIONS SHOW EASTERLY WINDS STILL
AFFECTING THE BIG ISLAND. WINDS HAVE WEAKENED WITH THE RIDGE
NEARBY...AND WILL WEAKEN FURTHER AS THE WESTERN EXTENT OF THE RIDGE
ERODES WITH THE APPROACH OF THE COLD FRONT. SURFACE PRESSURES ACROSS
THE STATE HAVE ALREADY DROPPED ABOUT 2MB IN THE PAST 24 HOURS. WITH
THE SOUTHEASTERLY WIND DIRECTION...THE BIG ISLAND WILL ALSO BLOCK
SOME OF THE GRADIENT WIND FROM THE SMALLER ISLANDS...LEADING TO A
LOCALLY DRIVEN LAND AND SEA BREEZE PATTERN. THE STABLE AND DRY
AIRMASS WILL KEEP RAINFALL GENERALLY LIGHT...BUT WE WILL SEE AN
INCREASE IN CLOUDS AND SHOWERS ACROSS INTERIOR AND WEST/NORTHWEST
SECTIONS DURING THE LATE MORNING/AFTERNOON. THIS WILL BE THE CASE
BOTH TODAY AND ON SUNDAY...AS WINDS WILL REMAIN LIGHT OVER THE
ISLANDS.

WINDS ACROSS THE BIG ISLAND SUMMITS HAVE SHOWN A GRADUAL DOWNWARD
TREND THROUGH THE MORNING SO FAR. WHILE THE CFHT SENSOR HAS DROPPED
BELOW ADVISORY LEVELS FOR THE HIGHER ELEVATIONS...IT IS STILL
HOVERING AT UP TO 40 MPH. WE SHOULD BE ABLE TO DROP THE WIND
ADVISORY AS EXPECTED THIS MORNING.

THE UPPER LEVEL TROUGH NORTHWEST OF THE STATE WILL PROPEL THE COLD
FRONT TOWARD KAUAI BY SUNDAY NIGHT. MOST OF THE UPPER LEVEL SUPPORT
WITH THIS FIRST TROUGH WILL PASS TO OUR NORTH...AND THE FRONT IS
EXPECTED TO LOSE SOME OF ITS PUSH. HOWEVER...ANOTHER PIECE OF ENERGY
IS EXPECTED TO DIG DOWN THE BACK SIDE OF THE TROUGH AND AMPLIFY NEAR
THE ISLANDS...REINVIGORATING THE FRONT AND DRIVING IT FARTHER
SOUTHEAST. COLD AIR ASSOCIATED WITH THIS DIGGING TROUGH WILL ALSO
DESTABILIZE THE AIRMASS OVER THE ISLANDS. 500MB TEMPERATURES DROP TO
-12C TO -14C. MOISTURE WILL BE SOMEWHAT LIMITED...WITH CROSS
SECTIONS ACROSS THE ISLANDS SHOWING MOISTURE EXTENDING UP TO 700MB.
HOWEVER...MODEL FORECAST SOUNDINGS SHOW THE SUBSIDENCE INVERSION
ERODING...LEADING TO UNSTABLE PROFILES AND RELATIVELY SATURATED
LOW-LEVELS. DIFFERENCES REMAIN BETWEEN THE GFS AND ECMWF...WITH THE
GFS BEING MORE CONSISTENT THROUGH THE EXTENDED FORECAST. THE 12Z
ECMWF CUTS OFF MUCH OF THE DIGGING ENERGY SOUTHWEST OF THE STATE
WHILE THE GFS KEEPS THE TROUGH MORE PROGRESSIVE. BY MID WEEK THE
ECMWF TRENDS BACK TOWARD THE GFS SOLUTION WITH THE PLACEMENT OF A
CUTOFF LOW DEVELOPING NORTHEAST OF THE STATE. OVERALL THE PATTERN
HAS STABILIZED ENOUGH THAT CHANGES ARE NOT NEEDED FOR THE CURRENT
FORECAST...WHICH FEATURES A MENTION OF THUNDERSTORMS FROM MONDAY
AFTERNOON THROUGH TUESDAY NIGHT.

STRONG NORTHERLY WINDS ARE EXPECTED TO DEVELOP BEHIND THE FRONT
EARLY IN THE NEW WORK WEEK. THESE WINDS WILL GRADUALLY RELAX THROUGH
THE WEEK...BUT REMAIN GENERALLY OUT OF THE NORTH DUE TO THE PRESENCE
OF THE LOW THAT IS EXPECTED TO BE NORTHEAST OF THE STATE. BY LATE IN
THE WEEK THIS LOW WILL WEAKEN AND ALLOW HIGH PRESSURE TO BUILD
NORTHWEST OF THE STATE...WHICH WILL ALLOW WINDS TO VEER TO A MORE
NORTHEASTERLY DIRECTION.

&&

.AVIATION...
WEAK SOUTHEAST FLOW IS EXPECTED ACROSS THE WHOLE OF STATE TODAY AS
THE COLD FRONT TO OUR DISTANT NORTHWEST BEGINS ITS APPROACH. WEAK
EASTERLY TRADES THIS MORNING WILL BE REPLACED BY WEAK SEA BREEZES
THIS AFTERNOON AND WEAK LAND BREEZES LATE TONIGHT. MORNING
CLOUDINESS IS FOCUSED OVER WINDWARD SLOPES AND COASTS BUT AFTERNOON
AND EVENING CLOUDS WILL BECOME FOCUSED OVER ISLAND INTERIORS.
AIRMASS OVER THE ISLANDS TODAY IS RELATIVELY DRY AND THE SUBSIDENCE
INVERSION IS RELATIVELY LOW. ANY PRECIPITATION TODAY SHOULD BE LIGHT
AND VFR CONDS ARE EXPECTED TO PREVAIL THROUGH 24 HOURS. PARTIAL
CLEARING EXPECTED ALONG LEEWARD COASTS AFTER MIDNIGHT.

&&

.MARINE...
A LONG PERIOD NORTHWEST SWELL GENERATED BY A LARGE AND POWERFUL LOW
PRESSURE SYSTEM IS EXPECTED TO BRING WARNING LEVEL SURF TO THE
ISLANDS ON SUNDAY. A JASON ALTIMETER PASS FROM LAST NIGHT JUST
OUTSIDE THE CORE OF THE HIGHEST SEAS SUPPORTS THE CURRENT WAVEWATCH
III FORECAST. WW3 SHOWS A SWELL NEAR 12 FEET REACHING BUOY 51101
AFTER MIDNIGHT TONIGHT. THIS SWELL WILL BUILD ACROSS THE ISLANDS ON
SUNDAY...THEN LINGER INTO MONDAY BEFORE GRADUALLY DIMINISHING. A
HIGH SURF WARNING WILL BE ISSUED FOR NORTH AND WEST FACING SHORES.
THE SWELL THIS LARGE WILL ALSO LEAD TO SMALL CRAFT CONDITIONS ACROSS
THE COASTAL WATERS.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY THROUGH NOON HST TODAY FOR THE BIG ISLAND SUMMITS.

&&

$$

DISCUSSION/MARINE...BRAVENDER
AVIATION...BEDAL





000
FXHW60 PHFO 202023
AFDHFO

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
1000 AM HST SAT DEC 20 2014

.SYNOPSIS...
WEAKENING SOUTHEASTERLY FLOW WILL ALLOW FOR LAND AND SEA BREEZES TO
DEVELOP THROUGH SUNDAY. A COLD FRONT APPROACHING FROM THE NORTHWEST
WILL BRING AN INCREASE IN SHOWERS AS EARLY AS SUNDAY NIGHT TO KAUAI.
THERE IS THE POTENTIAL FOR HEAVY RAIN AND A FEW THUNDERSTORMS ACROSS
THE STATE FROM MONDAY AFTERNOON THROUGH TUESDAY. STRONG NORTHERLY
WINDS WILL DEVELOP BEHIND THE FRONT.

&&

.DISCUSSION...
WATER VAPOR IMAGERY SHOWS AN UPPER LEVEL HIGH NORTHEAST OF THE
STATE...WITH A RIDGE EXTENDING ACROSS THE ISLANDS. A SHARP TROUGH IS
LOCATED FAR TO THE NORTHWEST...MOVING TO THE SOUTHEAST AT 30 MPH. AT
THE SURFACE...A RIDGE IS LOCATED LESS THAN 200 MILES NORTH OF
KAUAI...AND THE APPROACHING COLD FRONT IS ABOUT 700 MILES NORTHWEST
OF KAUAI. 12Z RAOBS SHOW STABLE INVERSIONS RANGING FROM 5KFT AT
LIHUE TO 7KFT AT HILO. PRECIPITABLE WATERS ARE ALSO 0.9-1.0
INCHES...WHICH IS DRIER THAN NORMAL FOR THIS TIME OF YEAR. EARLY
MORNING MIMIC TOTAL PRECIPITABLE IMAGERY SHOWS SIMILAR OR SLIGHTLY
DRIER AIR WITHIN A COUPLE HUNDRED MILES EAST OF THE STATE...WITH TPW
VALUES NEAR 1.5 INCHES POOLING ALONG THE COLD FRONT TO THE
NORTHWEST.

WITH THE SURFACE RIDGE BEING SUPPRESSED SOUTHWARD BY THE APPROACHING
FRONT...LOW-LEVEL WINDS HAVE ALREADY TURNED MORE SOUTHEASTERLY
ACROSS THE SMALLER ISLANDS. CLOUD MOTIONS SHOW EASTERLY WINDS STILL
AFFECTING THE BIG ISLAND. WINDS HAVE WEAKENED WITH THE RIDGE
NEARBY...AND WILL WEAKEN FURTHER AS THE WESTERN EXTENT OF THE RIDGE
ERODES WITH THE APPROACH OF THE COLD FRONT. SURFACE PRESSURES ACROSS
THE STATE HAVE ALREADY DROPPED ABOUT 2MB IN THE PAST 24 HOURS. WITH
THE SOUTHEASTERLY WIND DIRECTION...THE BIG ISLAND WILL ALSO BLOCK
SOME OF THE GRADIENT WIND FROM THE SMALLER ISLANDS...LEADING TO A
LOCALLY DRIVEN LAND AND SEA BREEZE PATTERN. THE STABLE AND DRY
AIRMASS WILL KEEP RAINFALL GENERALLY LIGHT...BUT WE WILL SEE AN
INCREASE IN CLOUDS AND SHOWERS ACROSS INTERIOR AND WEST/NORTHWEST
SECTIONS DURING THE LATE MORNING/AFTERNOON. THIS WILL BE THE CASE
BOTH TODAY AND ON SUNDAY...AS WINDS WILL REMAIN LIGHT OVER THE
ISLANDS.

WINDS ACROSS THE BIG ISLAND SUMMITS HAVE SHOWN A GRADUAL DOWNWARD
TREND THROUGH THE MORNING SO FAR. WHILE THE CFHT SENSOR HAS DROPPED
BELOW ADVISORY LEVELS FOR THE HIGHER ELEVATIONS...IT IS STILL
HOVERING AT UP TO 40 MPH. WE SHOULD BE ABLE TO DROP THE WIND
ADVISORY AS EXPECTED THIS MORNING.

THE UPPER LEVEL TROUGH NORTHWEST OF THE STATE WILL PROPEL THE COLD
FRONT TOWARD KAUAI BY SUNDAY NIGHT. MOST OF THE UPPER LEVEL SUPPORT
WITH THIS FIRST TROUGH WILL PASS TO OUR NORTH...AND THE FRONT IS
EXPECTED TO LOSE SOME OF ITS PUSH. HOWEVER...ANOTHER PIECE OF ENERGY
IS EXPECTED TO DIG DOWN THE BACK SIDE OF THE TROUGH AND AMPLIFY NEAR
THE ISLANDS...REINVIGORATING THE FRONT AND DRIVING IT FARTHER
SOUTHEAST. COLD AIR ASSOCIATED WITH THIS DIGGING TROUGH WILL ALSO
DESTABILIZE THE AIRMASS OVER THE ISLANDS. 500MB TEMPERATURES DROP TO
-12C TO -14C. MOISTURE WILL BE SOMEWHAT LIMITED...WITH CROSS
SECTIONS ACROSS THE ISLANDS SHOWING MOISTURE EXTENDING UP TO 700MB.
HOWEVER...MODEL FORECAST SOUNDINGS SHOW THE SUBSIDENCE INVERSION
ERODING...LEADING TO UNSTABLE PROFILES AND RELATIVELY SATURATED
LOW-LEVELS. DIFFERENCES REMAIN BETWEEN THE GFS AND ECMWF...WITH THE
GFS BEING MORE CONSISTENT THROUGH THE EXTENDED FORECAST. THE 12Z
ECMWF CUTS OFF MUCH OF THE DIGGING ENERGY SOUTHWEST OF THE STATE
WHILE THE GFS KEEPS THE TROUGH MORE PROGRESSIVE. BY MID WEEK THE
ECMWF TRENDS BACK TOWARD THE GFS SOLUTION WITH THE PLACEMENT OF A
CUTOFF LOW DEVELOPING NORTHEAST OF THE STATE. OVERALL THE PATTERN
HAS STABILIZED ENOUGH THAT CHANGES ARE NOT NEEDED FOR THE CURRENT
FORECAST...WHICH FEATURES A MENTION OF THUNDERSTORMS FROM MONDAY
AFTERNOON THROUGH TUESDAY NIGHT.

STRONG NORTHERLY WINDS ARE EXPECTED TO DEVELOP BEHIND THE FRONT
EARLY IN THE NEW WORK WEEK. THESE WINDS WILL GRADUALLY RELAX THROUGH
THE WEEK...BUT REMAIN GENERALLY OUT OF THE NORTH DUE TO THE PRESENCE
OF THE LOW THAT IS EXPECTED TO BE NORTHEAST OF THE STATE. BY LATE IN
THE WEEK THIS LOW WILL WEAKEN AND ALLOW HIGH PRESSURE TO BUILD
NORTHWEST OF THE STATE...WHICH WILL ALLOW WINDS TO VEER TO A MORE
NORTHEASTERLY DIRECTION.

&&

.AVIATION...
WEAK SOUTHEAST FLOW IS EXPECTED ACROSS THE WHOLE OF STATE TODAY AS
THE COLD FRONT TO OUR DISTANT NORTHWEST BEGINS ITS APPROACH. WEAK
EASTERLY TRADES THIS MORNING WILL BE REPLACED BY WEAK SEA BREEZES
THIS AFTERNOON AND WEAK LAND BREEZES LATE TONIGHT. MORNING
CLOUDINESS IS FOCUSED OVER WINDWARD SLOPES AND COASTS BUT AFTERNOON
AND EVENING CLOUDS WILL BECOME FOCUSED OVER ISLAND INTERIORS.
AIRMASS OVER THE ISLANDS TODAY IS RELATIVELY DRY AND THE SUBSIDENCE
INVERSION IS RELATIVELY LOW. ANY PRECIPITATION TODAY SHOULD BE LIGHT
AND VFR CONDS ARE EXPECTED TO PREVAIL THROUGH 24 HOURS. PARTIAL
CLEARING EXPECTED ALONG LEEWARD COASTS AFTER MIDNIGHT.

&&

.MARINE...
A LONG PERIOD NORTHWEST SWELL GENERATED BY A LARGE AND POWERFUL LOW
PRESSURE SYSTEM IS EXPECTED TO BRING WARNING LEVEL SURF TO THE
ISLANDS ON SUNDAY. A JASON ALTIMETER PASS FROM LAST NIGHT JUST
OUTSIDE THE CORE OF THE HIGHEST SEAS SUPPORTS THE CURRENT WAVEWATCH
III FORECAST. WW3 SHOWS A SWELL NEAR 12 FEET REACHING BUOY 51101
AFTER MIDNIGHT TONIGHT. THIS SWELL WILL BUILD ACROSS THE ISLANDS ON
SUNDAY...THEN LINGER INTO MONDAY BEFORE GRADUALLY DIMINISHING. A
HIGH SURF WARNING WILL BE ISSUED FOR NORTH AND WEST FACING SHORES.
THE SWELL THIS LARGE WILL ALSO LEAD TO SMALL CRAFT CONDITIONS ACROSS
THE COASTAL WATERS.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY THROUGH NOON HST TODAY FOR THE BIG ISLAND SUMMITS.

&&

$$

DISCUSSION/MARINE...BRAVENDER
AVIATION...BEDAL





000
FXHW60 PHFO 202023
AFDHFO

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
1000 AM HST SAT DEC 20 2014

.SYNOPSIS...
WEAKENING SOUTHEASTERLY FLOW WILL ALLOW FOR LAND AND SEA BREEZES TO
DEVELOP THROUGH SUNDAY. A COLD FRONT APPROACHING FROM THE NORTHWEST
WILL BRING AN INCREASE IN SHOWERS AS EARLY AS SUNDAY NIGHT TO KAUAI.
THERE IS THE POTENTIAL FOR HEAVY RAIN AND A FEW THUNDERSTORMS ACROSS
THE STATE FROM MONDAY AFTERNOON THROUGH TUESDAY. STRONG NORTHERLY
WINDS WILL DEVELOP BEHIND THE FRONT.

&&

.DISCUSSION...
WATER VAPOR IMAGERY SHOWS AN UPPER LEVEL HIGH NORTHEAST OF THE
STATE...WITH A RIDGE EXTENDING ACROSS THE ISLANDS. A SHARP TROUGH IS
LOCATED FAR TO THE NORTHWEST...MOVING TO THE SOUTHEAST AT 30 MPH. AT
THE SURFACE...A RIDGE IS LOCATED LESS THAN 200 MILES NORTH OF
KAUAI...AND THE APPROACHING COLD FRONT IS ABOUT 700 MILES NORTHWEST
OF KAUAI. 12Z RAOBS SHOW STABLE INVERSIONS RANGING FROM 5KFT AT
LIHUE TO 7KFT AT HILO. PRECIPITABLE WATERS ARE ALSO 0.9-1.0
INCHES...WHICH IS DRIER THAN NORMAL FOR THIS TIME OF YEAR. EARLY
MORNING MIMIC TOTAL PRECIPITABLE IMAGERY SHOWS SIMILAR OR SLIGHTLY
DRIER AIR WITHIN A COUPLE HUNDRED MILES EAST OF THE STATE...WITH TPW
VALUES NEAR 1.5 INCHES POOLING ALONG THE COLD FRONT TO THE
NORTHWEST.

WITH THE SURFACE RIDGE BEING SUPPRESSED SOUTHWARD BY THE APPROACHING
FRONT...LOW-LEVEL WINDS HAVE ALREADY TURNED MORE SOUTHEASTERLY
ACROSS THE SMALLER ISLANDS. CLOUD MOTIONS SHOW EASTERLY WINDS STILL
AFFECTING THE BIG ISLAND. WINDS HAVE WEAKENED WITH THE RIDGE
NEARBY...AND WILL WEAKEN FURTHER AS THE WESTERN EXTENT OF THE RIDGE
ERODES WITH THE APPROACH OF THE COLD FRONT. SURFACE PRESSURES ACROSS
THE STATE HAVE ALREADY DROPPED ABOUT 2MB IN THE PAST 24 HOURS. WITH
THE SOUTHEASTERLY WIND DIRECTION...THE BIG ISLAND WILL ALSO BLOCK
SOME OF THE GRADIENT WIND FROM THE SMALLER ISLANDS...LEADING TO A
LOCALLY DRIVEN LAND AND SEA BREEZE PATTERN. THE STABLE AND DRY
AIRMASS WILL KEEP RAINFALL GENERALLY LIGHT...BUT WE WILL SEE AN
INCREASE IN CLOUDS AND SHOWERS ACROSS INTERIOR AND WEST/NORTHWEST
SECTIONS DURING THE LATE MORNING/AFTERNOON. THIS WILL BE THE CASE
BOTH TODAY AND ON SUNDAY...AS WINDS WILL REMAIN LIGHT OVER THE
ISLANDS.

WINDS ACROSS THE BIG ISLAND SUMMITS HAVE SHOWN A GRADUAL DOWNWARD
TREND THROUGH THE MORNING SO FAR. WHILE THE CFHT SENSOR HAS DROPPED
BELOW ADVISORY LEVELS FOR THE HIGHER ELEVATIONS...IT IS STILL
HOVERING AT UP TO 40 MPH. WE SHOULD BE ABLE TO DROP THE WIND
ADVISORY AS EXPECTED THIS MORNING.

THE UPPER LEVEL TROUGH NORTHWEST OF THE STATE WILL PROPEL THE COLD
FRONT TOWARD KAUAI BY SUNDAY NIGHT. MOST OF THE UPPER LEVEL SUPPORT
WITH THIS FIRST TROUGH WILL PASS TO OUR NORTH...AND THE FRONT IS
EXPECTED TO LOSE SOME OF ITS PUSH. HOWEVER...ANOTHER PIECE OF ENERGY
IS EXPECTED TO DIG DOWN THE BACK SIDE OF THE TROUGH AND AMPLIFY NEAR
THE ISLANDS...REINVIGORATING THE FRONT AND DRIVING IT FARTHER
SOUTHEAST. COLD AIR ASSOCIATED WITH THIS DIGGING TROUGH WILL ALSO
DESTABILIZE THE AIRMASS OVER THE ISLANDS. 500MB TEMPERATURES DROP TO
-12C TO -14C. MOISTURE WILL BE SOMEWHAT LIMITED...WITH CROSS
SECTIONS ACROSS THE ISLANDS SHOWING MOISTURE EXTENDING UP TO 700MB.
HOWEVER...MODEL FORECAST SOUNDINGS SHOW THE SUBSIDENCE INVERSION
ERODING...LEADING TO UNSTABLE PROFILES AND RELATIVELY SATURATED
LOW-LEVELS. DIFFERENCES REMAIN BETWEEN THE GFS AND ECMWF...WITH THE
GFS BEING MORE CONSISTENT THROUGH THE EXTENDED FORECAST. THE 12Z
ECMWF CUTS OFF MUCH OF THE DIGGING ENERGY SOUTHWEST OF THE STATE
WHILE THE GFS KEEPS THE TROUGH MORE PROGRESSIVE. BY MID WEEK THE
ECMWF TRENDS BACK TOWARD THE GFS SOLUTION WITH THE PLACEMENT OF A
CUTOFF LOW DEVELOPING NORTHEAST OF THE STATE. OVERALL THE PATTERN
HAS STABILIZED ENOUGH THAT CHANGES ARE NOT NEEDED FOR THE CURRENT
FORECAST...WHICH FEATURES A MENTION OF THUNDERSTORMS FROM MONDAY
AFTERNOON THROUGH TUESDAY NIGHT.

STRONG NORTHERLY WINDS ARE EXPECTED TO DEVELOP BEHIND THE FRONT
EARLY IN THE NEW WORK WEEK. THESE WINDS WILL GRADUALLY RELAX THROUGH
THE WEEK...BUT REMAIN GENERALLY OUT OF THE NORTH DUE TO THE PRESENCE
OF THE LOW THAT IS EXPECTED TO BE NORTHEAST OF THE STATE. BY LATE IN
THE WEEK THIS LOW WILL WEAKEN AND ALLOW HIGH PRESSURE TO BUILD
NORTHWEST OF THE STATE...WHICH WILL ALLOW WINDS TO VEER TO A MORE
NORTHEASTERLY DIRECTION.

&&

.AVIATION...
WEAK SOUTHEAST FLOW IS EXPECTED ACROSS THE WHOLE OF STATE TODAY AS
THE COLD FRONT TO OUR DISTANT NORTHWEST BEGINS ITS APPROACH. WEAK
EASTERLY TRADES THIS MORNING WILL BE REPLACED BY WEAK SEA BREEZES
THIS AFTERNOON AND WEAK LAND BREEZES LATE TONIGHT. MORNING
CLOUDINESS IS FOCUSED OVER WINDWARD SLOPES AND COASTS BUT AFTERNOON
AND EVENING CLOUDS WILL BECOME FOCUSED OVER ISLAND INTERIORS.
AIRMASS OVER THE ISLANDS TODAY IS RELATIVELY DRY AND THE SUBSIDENCE
INVERSION IS RELATIVELY LOW. ANY PRECIPITATION TODAY SHOULD BE LIGHT
AND VFR CONDS ARE EXPECTED TO PREVAIL THROUGH 24 HOURS. PARTIAL
CLEARING EXPECTED ALONG LEEWARD COASTS AFTER MIDNIGHT.

&&

.MARINE...
A LONG PERIOD NORTHWEST SWELL GENERATED BY A LARGE AND POWERFUL LOW
PRESSURE SYSTEM IS EXPECTED TO BRING WARNING LEVEL SURF TO THE
ISLANDS ON SUNDAY. A JASON ALTIMETER PASS FROM LAST NIGHT JUST
OUTSIDE THE CORE OF THE HIGHEST SEAS SUPPORTS THE CURRENT WAVEWATCH
III FORECAST. WW3 SHOWS A SWELL NEAR 12 FEET REACHING BUOY 51101
AFTER MIDNIGHT TONIGHT. THIS SWELL WILL BUILD ACROSS THE ISLANDS ON
SUNDAY...THEN LINGER INTO MONDAY BEFORE GRADUALLY DIMINISHING. A
HIGH SURF WARNING WILL BE ISSUED FOR NORTH AND WEST FACING SHORES.
THE SWELL THIS LARGE WILL ALSO LEAD TO SMALL CRAFT CONDITIONS ACROSS
THE COASTAL WATERS.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY THROUGH NOON HST TODAY FOR THE BIG ISLAND SUMMITS.

&&

$$

DISCUSSION/MARINE...BRAVENDER
AVIATION...BEDAL





000
FXHW60 PHFO 202023
AFDHFO

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
1000 AM HST SAT DEC 20 2014

.SYNOPSIS...
WEAKENING SOUTHEASTERLY FLOW WILL ALLOW FOR LAND AND SEA BREEZES TO
DEVELOP THROUGH SUNDAY. A COLD FRONT APPROACHING FROM THE NORTHWEST
WILL BRING AN INCREASE IN SHOWERS AS EARLY AS SUNDAY NIGHT TO KAUAI.
THERE IS THE POTENTIAL FOR HEAVY RAIN AND A FEW THUNDERSTORMS ACROSS
THE STATE FROM MONDAY AFTERNOON THROUGH TUESDAY. STRONG NORTHERLY
WINDS WILL DEVELOP BEHIND THE FRONT.

&&

.DISCUSSION...
WATER VAPOR IMAGERY SHOWS AN UPPER LEVEL HIGH NORTHEAST OF THE
STATE...WITH A RIDGE EXTENDING ACROSS THE ISLANDS. A SHARP TROUGH IS
LOCATED FAR TO THE NORTHWEST...MOVING TO THE SOUTHEAST AT 30 MPH. AT
THE SURFACE...A RIDGE IS LOCATED LESS THAN 200 MILES NORTH OF
KAUAI...AND THE APPROACHING COLD FRONT IS ABOUT 700 MILES NORTHWEST
OF KAUAI. 12Z RAOBS SHOW STABLE INVERSIONS RANGING FROM 5KFT AT
LIHUE TO 7KFT AT HILO. PRECIPITABLE WATERS ARE ALSO 0.9-1.0
INCHES...WHICH IS DRIER THAN NORMAL FOR THIS TIME OF YEAR. EARLY
MORNING MIMIC TOTAL PRECIPITABLE IMAGERY SHOWS SIMILAR OR SLIGHTLY
DRIER AIR WITHIN A COUPLE HUNDRED MILES EAST OF THE STATE...WITH TPW
VALUES NEAR 1.5 INCHES POOLING ALONG THE COLD FRONT TO THE
NORTHWEST.

WITH THE SURFACE RIDGE BEING SUPPRESSED SOUTHWARD BY THE APPROACHING
FRONT...LOW-LEVEL WINDS HAVE ALREADY TURNED MORE SOUTHEASTERLY
ACROSS THE SMALLER ISLANDS. CLOUD MOTIONS SHOW EASTERLY WINDS STILL
AFFECTING THE BIG ISLAND. WINDS HAVE WEAKENED WITH THE RIDGE
NEARBY...AND WILL WEAKEN FURTHER AS THE WESTERN EXTENT OF THE RIDGE
ERODES WITH THE APPROACH OF THE COLD FRONT. SURFACE PRESSURES ACROSS
THE STATE HAVE ALREADY DROPPED ABOUT 2MB IN THE PAST 24 HOURS. WITH
THE SOUTHEASTERLY WIND DIRECTION...THE BIG ISLAND WILL ALSO BLOCK
SOME OF THE GRADIENT WIND FROM THE SMALLER ISLANDS...LEADING TO A
LOCALLY DRIVEN LAND AND SEA BREEZE PATTERN. THE STABLE AND DRY
AIRMASS WILL KEEP RAINFALL GENERALLY LIGHT...BUT WE WILL SEE AN
INCREASE IN CLOUDS AND SHOWERS ACROSS INTERIOR AND WEST/NORTHWEST
SECTIONS DURING THE LATE MORNING/AFTERNOON. THIS WILL BE THE CASE
BOTH TODAY AND ON SUNDAY...AS WINDS WILL REMAIN LIGHT OVER THE
ISLANDS.

WINDS ACROSS THE BIG ISLAND SUMMITS HAVE SHOWN A GRADUAL DOWNWARD
TREND THROUGH THE MORNING SO FAR. WHILE THE CFHT SENSOR HAS DROPPED
BELOW ADVISORY LEVELS FOR THE HIGHER ELEVATIONS...IT IS STILL
HOVERING AT UP TO 40 MPH. WE SHOULD BE ABLE TO DROP THE WIND
ADVISORY AS EXPECTED THIS MORNING.

THE UPPER LEVEL TROUGH NORTHWEST OF THE STATE WILL PROPEL THE COLD
FRONT TOWARD KAUAI BY SUNDAY NIGHT. MOST OF THE UPPER LEVEL SUPPORT
WITH THIS FIRST TROUGH WILL PASS TO OUR NORTH...AND THE FRONT IS
EXPECTED TO LOSE SOME OF ITS PUSH. HOWEVER...ANOTHER PIECE OF ENERGY
IS EXPECTED TO DIG DOWN THE BACK SIDE OF THE TROUGH AND AMPLIFY NEAR
THE ISLANDS...REINVIGORATING THE FRONT AND DRIVING IT FARTHER
SOUTHEAST. COLD AIR ASSOCIATED WITH THIS DIGGING TROUGH WILL ALSO
DESTABILIZE THE AIRMASS OVER THE ISLANDS. 500MB TEMPERATURES DROP TO
-12C TO -14C. MOISTURE WILL BE SOMEWHAT LIMITED...WITH CROSS
SECTIONS ACROSS THE ISLANDS SHOWING MOISTURE EXTENDING UP TO 700MB.
HOWEVER...MODEL FORECAST SOUNDINGS SHOW THE SUBSIDENCE INVERSION
ERODING...LEADING TO UNSTABLE PROFILES AND RELATIVELY SATURATED
LOW-LEVELS. DIFFERENCES REMAIN BETWEEN THE GFS AND ECMWF...WITH THE
GFS BEING MORE CONSISTENT THROUGH THE EXTENDED FORECAST. THE 12Z
ECMWF CUTS OFF MUCH OF THE DIGGING ENERGY SOUTHWEST OF THE STATE
WHILE THE GFS KEEPS THE TROUGH MORE PROGRESSIVE. BY MID WEEK THE
ECMWF TRENDS BACK TOWARD THE GFS SOLUTION WITH THE PLACEMENT OF A
CUTOFF LOW DEVELOPING NORTHEAST OF THE STATE. OVERALL THE PATTERN
HAS STABILIZED ENOUGH THAT CHANGES ARE NOT NEEDED FOR THE CURRENT
FORECAST...WHICH FEATURES A MENTION OF THUNDERSTORMS FROM MONDAY
AFTERNOON THROUGH TUESDAY NIGHT.

STRONG NORTHERLY WINDS ARE EXPECTED TO DEVELOP BEHIND THE FRONT
EARLY IN THE NEW WORK WEEK. THESE WINDS WILL GRADUALLY RELAX THROUGH
THE WEEK...BUT REMAIN GENERALLY OUT OF THE NORTH DUE TO THE PRESENCE
OF THE LOW THAT IS EXPECTED TO BE NORTHEAST OF THE STATE. BY LATE IN
THE WEEK THIS LOW WILL WEAKEN AND ALLOW HIGH PRESSURE TO BUILD
NORTHWEST OF THE STATE...WHICH WILL ALLOW WINDS TO VEER TO A MORE
NORTHEASTERLY DIRECTION.

&&

.AVIATION...
WEAK SOUTHEAST FLOW IS EXPECTED ACROSS THE WHOLE OF STATE TODAY AS
THE COLD FRONT TO OUR DISTANT NORTHWEST BEGINS ITS APPROACH. WEAK
EASTERLY TRADES THIS MORNING WILL BE REPLACED BY WEAK SEA BREEZES
THIS AFTERNOON AND WEAK LAND BREEZES LATE TONIGHT. MORNING
CLOUDINESS IS FOCUSED OVER WINDWARD SLOPES AND COASTS BUT AFTERNOON
AND EVENING CLOUDS WILL BECOME FOCUSED OVER ISLAND INTERIORS.
AIRMASS OVER THE ISLANDS TODAY IS RELATIVELY DRY AND THE SUBSIDENCE
INVERSION IS RELATIVELY LOW. ANY PRECIPITATION TODAY SHOULD BE LIGHT
AND VFR CONDS ARE EXPECTED TO PREVAIL THROUGH 24 HOURS. PARTIAL
CLEARING EXPECTED ALONG LEEWARD COASTS AFTER MIDNIGHT.

&&

.MARINE...
A LONG PERIOD NORTHWEST SWELL GENERATED BY A LARGE AND POWERFUL LOW
PRESSURE SYSTEM IS EXPECTED TO BRING WARNING LEVEL SURF TO THE
ISLANDS ON SUNDAY. A JASON ALTIMETER PASS FROM LAST NIGHT JUST
OUTSIDE THE CORE OF THE HIGHEST SEAS SUPPORTS THE CURRENT WAVEWATCH
III FORECAST. WW3 SHOWS A SWELL NEAR 12 FEET REACHING BUOY 51101
AFTER MIDNIGHT TONIGHT. THIS SWELL WILL BUILD ACROSS THE ISLANDS ON
SUNDAY...THEN LINGER INTO MONDAY BEFORE GRADUALLY DIMINISHING. A
HIGH SURF WARNING WILL BE ISSUED FOR NORTH AND WEST FACING SHORES.
THE SWELL THIS LARGE WILL ALSO LEAD TO SMALL CRAFT CONDITIONS ACROSS
THE COASTAL WATERS.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY THROUGH NOON HST TODAY FOR THE BIG ISLAND SUMMITS.

&&

$$

DISCUSSION/MARINE...BRAVENDER
AVIATION...BEDAL





000
FXHW60 PHFO 201330
AFDHFO

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
330 AM HST SAT DEC 20 2014

.SYNOPSIS...
LIGHTER SOUTHEAST FLOW TODAY WILL ALLOW FOR LAND AND SEA BREEZES TO
DEVELOP AS A COLD FRONT AND UPPER TROUGH APPROACH FROM THE
NORTHWEST. SHOWERS WILL INCREASE STARTING LATE SUNDAY NIGHT WITH THE
POTENTIAL FOR HEAVY RAIN AND A FEW THUNDERSTORMS MONDAY AFTERNOON
THROUGH TUESDAY. STRONG NORTHERLY WINDS WILL THEN DEVELOP BY MID
WEEK.

&&

.DISCUSSION...
DRY WEATHER PATTERN CONTINUES THIS MORNING ACROSS THE ALOHA STATE AS
SFC HIGH PRESSURE NE OF THE ISLANDS MIGRATES E. A FEW SMALL SHOWERS
CAN BE OBSERVED UPSTREAM OF THE ISLANDS...WHICH WILL MAINLY AFFECT
WINDWARD AND MOUNTAIN AREAS AT TIMES. MEANWHILE...A WEAK
POSITIVELY-TILTED UPPER LVL TROUGH REMAINS OVER THE AREA WITH AN
ASSOCIATED JET STREAM PRODUCING A LINE OF CIRRUS CLOUDS JUST S OF
THE BIG ISLAND. THIS TROUGH IS ALSO KEEPING TIGHTER PRESSURE
GRADIENTS OVER THE BIG ISLAND AT SUMMIT LEVEL...PRODUCING STRONG
WINDS NEAR THE TOPS OF MAUNA LOA AND MAUNA KEA. THUS...A WIND
ADVISORY HAS BEEN ISSUED FOR THE BIG ISLAND SUMMITS UNTIL NOON
TODAY.

AS THE SFC HIGH MIGRATES E AND FURTHER AWAY FROM THE ISLAND
CHAIN...THE TRADES WILL BECOME LIGHT TODAY. MODELS ALSO SHOW A
STRONG SFC COLD FRONT APPROACHING THE ISLANDS ON SUN...WHICH SEEMS
TO HAVE GOOD UPPER LEVEL SUPPORT FROM A SHARP TROUGH ALSO MOVING
TOWARDS THE AREA. AS THIS TROUGH/FRONT COMPLEX MOVES CLOSER...THE
WINDS TODAY WILL BECOME SE AND GENERALLY LIGHT WITH WARMER AND HUMID
CONDITIONS EXPECTED THROUGH THIS EVENING. SOME VOG FROM THE BIG
ISLAND MAY REACH MAUI COUNTY TODAY AND SUN...BUT CHANCES ARE LOW AT
THIS TIME AS WINDS AROUND THE BIG ISLAND MAY REMAIN MORE EASTERLY.
THIS SYNOPTIC SETUP WILL ALLOW FOR SEA/LAND BREEZE CIRCULATIONS TO
DEVELOP TODAY AND PROBABLY AGAIN ON SUN...WITH CLOUDS AND SHOWERS
FORMING OVER LEEWARD AND INTERIOR AREAS EACH AFTERNOON AND EARLY
EVENING. BUT ANY SHOWERS THAT FORM WILL LIKELY REMAIN SHALLOW AND
PRODUCE LIGHT RAIN IN GENERAL AS A WEAK RIDGE ALOFT WILL DEVELOP
LATER TODAY AND REMAIN IN PLACE THROUGH SUN.

MODELS CONTINUE TO SHOW FAIR AGREEMENT REGARDING THE FORECAST
SOLUTION THROUGH EARLY TUE...DEPICTING THE COLD FRONT REACHING KAUAI
LATE SUN NIGHT AND INTO MON MORNING...AND A COLDER AIRMASS MOVING
ALOFT AS THE UPPER TROUGH ARRIVES LATE MON. EXPECT WIDESPREAD
SHOWERS...LOCALLY HEAVY RAIN AND POTENTIAL FOR THUNDERSTORM ACTIVITY
FROM MON AFTERNOON THROUGH TUE. THE TROUGH AXIS SEEMS TO MOVE ACROSS
KAUAI COUNTY SOMETIME LATE MON NIGHT...WITH 500 MB TEMPS COOLING
DOWN TO AROUND -15 TO -17 DEGREES CELSIUS. THUS...THE FORECAST WILL
CONTINUE TO CARRY SLIGHT CHANCES OF THUNDERSTORMS MON NIGHT AND
TUE...AND THE OVERALL COVERAGE HAS BEEN ADJUSTED TO INCLUDE VERY
MUCH THE ENTIRE AREA MON NIGHT.

DIFFERENCES REMAIN BETWEEN GLOBAL MODELS AS GFS DEVELOPS A CUTOFF
LOW AND MOVES IT OVER THE E HALF OF THE ISLAND CHAIN TUE AND TUE
NIGHT...WHILE ECMWF KEEPS THIS LOW N OF THE ISLANDS DURING THE SAME
TIME FRAME. THE FINAL OUTCOME OF THIS SCENARIO WILL CERTAINLY HAVE A
SIGNIFICANT IMPACT...SO FOR NOW WILL KEEP THE FORECAST CLOSER TO
ECMWF AND WILL ADJUST ACCORDINGLY.

BEST CHANCES FOR LOCALLY HEAVY RAIN AND THUNDERSTORMS RESIDE OVER
THE W HALF OF THE ISLAND CHAIN MON NIGHT AND TUE. THERE WILL BE
POTENTIAL FOR A FEW CELLS TO BECOME STRONG. ALSO...AS THE UPPER LOW
MOVES CLOSER TO THE BIG ISLAND...THE POTENTIAL FOR SNOW OVER THE
SUMMITS WILL INCREASE...MAINLY FROM MON NIGHT THROUGH TUE.

MODELS SHOW STRONG NE WINDS ESTABLISHING ACROSS THE AREA IN THE WAKE
OF THE FROPA...STARTING AROUND KAUAI COUNTY LATE SUN NIGHT...THEN
SPREADING DOWN THE REST OF THE ISLAND CHAIN BY TUE NIGHT AND
PREVAILING THROUGH THE SECOND HALF OF NEXT WEEK.

&&

.AVIATION...
WITH A FRONT APPROACHING AND HIGH PRESSURE NORTH OF THE ISLANDS
BEING PUSHED EASTWARD...TRADES WILL BE REPLACED WITH A LIGHTER
SOUTHEAST WIND TODAY. MAY SEE LAND/SEA BREEZES FROM TIME TO TIME.
THUS EXPECT MORE INTERIOR CLOUDINESS DURING THE NEXT COUPLE OF
AFTERNOONS ALONG WITH CLEARING AT NIGHT. BOTTOM LINE...EXPECT
MOSTLY VFR CONDITIONS TO PREVAIL TODAY.


&&

.MARINE...
THE CURRENT NORTHWEST SWELL WILL CONTINUE TO LOWER THROUGH TONIGHT.
A LARGER NORTHWEST SWELL IS EXPECTED TO ARRIVE ON SUNDAY AND WILL
LIKELY BUILD TO HIGH SURF WARNING LEVELS FOR NORTH AND WEST FACING
SHORES BY LATE IN THE DAY. THIS SWELL SHOULD HAVE ENOUGH WESTERLY
COMPONENT TO IMPACT THE WEST SIDE OF THE BIG ISLAND...LIKELY
REACHING WARNING LEVELS FOR KONA SUNDAY NIGHT THROUGH MONDAY NIGHT.

THE EAST-SOUTHEAST WINDS ARE BECOMING LIGHT AS A COLD FRONT
APPROACHES THE ALOHA STATE FROM THE NORTHWEST. WINDS WILL REMAIN
LIGHT ON SUNDAY AS THE NORTHWEST SWELL BUILDS...BUT NORTH TO
NORTHEAST WINDS WILL DRASTICALLY INCREASE SUNDAY NIGHT INTO MONDAY
AS THE SWELL PEAKS.

THE SMALL CRAFT ADVISORY /SCA/ FOR OUR TYPICAL WINDY ZONES IS NO
LONGER IN EFFECT.


&&

.HFO WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY THROUGH NOON HST TODAY FOR THE BIG ISLAND SUMMITS.

&&

$$

REYNES









000
FXHW60 PHFO 201330
AFDHFO

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
330 AM HST SAT DEC 20 2014

.SYNOPSIS...
LIGHTER SOUTHEAST FLOW TODAY WILL ALLOW FOR LAND AND SEA BREEZES TO
DEVELOP AS A COLD FRONT AND UPPER TROUGH APPROACH FROM THE
NORTHWEST. SHOWERS WILL INCREASE STARTING LATE SUNDAY NIGHT WITH THE
POTENTIAL FOR HEAVY RAIN AND A FEW THUNDERSTORMS MONDAY AFTERNOON
THROUGH TUESDAY. STRONG NORTHERLY WINDS WILL THEN DEVELOP BY MID
WEEK.

&&

.DISCUSSION...
DRY WEATHER PATTERN CONTINUES THIS MORNING ACROSS THE ALOHA STATE AS
SFC HIGH PRESSURE NE OF THE ISLANDS MIGRATES E. A FEW SMALL SHOWERS
CAN BE OBSERVED UPSTREAM OF THE ISLANDS...WHICH WILL MAINLY AFFECT
WINDWARD AND MOUNTAIN AREAS AT TIMES. MEANWHILE...A WEAK
POSITIVELY-TILTED UPPER LVL TROUGH REMAINS OVER THE AREA WITH AN
ASSOCIATED JET STREAM PRODUCING A LINE OF CIRRUS CLOUDS JUST S OF
THE BIG ISLAND. THIS TROUGH IS ALSO KEEPING TIGHTER PRESSURE
GRADIENTS OVER THE BIG ISLAND AT SUMMIT LEVEL...PRODUCING STRONG
WINDS NEAR THE TOPS OF MAUNA LOA AND MAUNA KEA. THUS...A WIND
ADVISORY HAS BEEN ISSUED FOR THE BIG ISLAND SUMMITS UNTIL NOON
TODAY.

AS THE SFC HIGH MIGRATES E AND FURTHER AWAY FROM THE ISLAND
CHAIN...THE TRADES WILL BECOME LIGHT TODAY. MODELS ALSO SHOW A
STRONG SFC COLD FRONT APPROACHING THE ISLANDS ON SUN...WHICH SEEMS
TO HAVE GOOD UPPER LEVEL SUPPORT FROM A SHARP TROUGH ALSO MOVING
TOWARDS THE AREA. AS THIS TROUGH/FRONT COMPLEX MOVES CLOSER...THE
WINDS TODAY WILL BECOME SE AND GENERALLY LIGHT WITH WARMER AND HUMID
CONDITIONS EXPECTED THROUGH THIS EVENING. SOME VOG FROM THE BIG
ISLAND MAY REACH MAUI COUNTY TODAY AND SUN...BUT CHANCES ARE LOW AT
THIS TIME AS WINDS AROUND THE BIG ISLAND MAY REMAIN MORE EASTERLY.
THIS SYNOPTIC SETUP WILL ALLOW FOR SEA/LAND BREEZE CIRCULATIONS TO
DEVELOP TODAY AND PROBABLY AGAIN ON SUN...WITH CLOUDS AND SHOWERS
FORMING OVER LEEWARD AND INTERIOR AREAS EACH AFTERNOON AND EARLY
EVENING. BUT ANY SHOWERS THAT FORM WILL LIKELY REMAIN SHALLOW AND
PRODUCE LIGHT RAIN IN GENERAL AS A WEAK RIDGE ALOFT WILL DEVELOP
LATER TODAY AND REMAIN IN PLACE THROUGH SUN.

MODELS CONTINUE TO SHOW FAIR AGREEMENT REGARDING THE FORECAST
SOLUTION THROUGH EARLY TUE...DEPICTING THE COLD FRONT REACHING KAUAI
LATE SUN NIGHT AND INTO MON MORNING...AND A COLDER AIRMASS MOVING
ALOFT AS THE UPPER TROUGH ARRIVES LATE MON. EXPECT WIDESPREAD
SHOWERS...LOCALLY HEAVY RAIN AND POTENTIAL FOR THUNDERSTORM ACTIVITY
FROM MON AFTERNOON THROUGH TUE. THE TROUGH AXIS SEEMS TO MOVE ACROSS
KAUAI COUNTY SOMETIME LATE MON NIGHT...WITH 500 MB TEMPS COOLING
DOWN TO AROUND -15 TO -17 DEGREES CELSIUS. THUS...THE FORECAST WILL
CONTINUE TO CARRY SLIGHT CHANCES OF THUNDERSTORMS MON NIGHT AND
TUE...AND THE OVERALL COVERAGE HAS BEEN ADJUSTED TO INCLUDE VERY
MUCH THE ENTIRE AREA MON NIGHT.

DIFFERENCES REMAIN BETWEEN GLOBAL MODELS AS GFS DEVELOPS A CUTOFF
LOW AND MOVES IT OVER THE E HALF OF THE ISLAND CHAIN TUE AND TUE
NIGHT...WHILE ECMWF KEEPS THIS LOW N OF THE ISLANDS DURING THE SAME
TIME FRAME. THE FINAL OUTCOME OF THIS SCENARIO WILL CERTAINLY HAVE A
SIGNIFICANT IMPACT...SO FOR NOW WILL KEEP THE FORECAST CLOSER TO
ECMWF AND WILL ADJUST ACCORDINGLY.

BEST CHANCES FOR LOCALLY HEAVY RAIN AND THUNDERSTORMS RESIDE OVER
THE W HALF OF THE ISLAND CHAIN MON NIGHT AND TUE. THERE WILL BE
POTENTIAL FOR A FEW CELLS TO BECOME STRONG. ALSO...AS THE UPPER LOW
MOVES CLOSER TO THE BIG ISLAND...THE POTENTIAL FOR SNOW OVER THE
SUMMITS WILL INCREASE...MAINLY FROM MON NIGHT THROUGH TUE.

MODELS SHOW STRONG NE WINDS ESTABLISHING ACROSS THE AREA IN THE WAKE
OF THE FROPA...STARTING AROUND KAUAI COUNTY LATE SUN NIGHT...THEN
SPREADING DOWN THE REST OF THE ISLAND CHAIN BY TUE NIGHT AND
PREVAILING THROUGH THE SECOND HALF OF NEXT WEEK.

&&

.AVIATION...
WITH A FRONT APPROACHING AND HIGH PRESSURE NORTH OF THE ISLANDS
BEING PUSHED EASTWARD...TRADES WILL BE REPLACED WITH A LIGHTER
SOUTHEAST WIND TODAY. MAY SEE LAND/SEA BREEZES FROM TIME TO TIME.
THUS EXPECT MORE INTERIOR CLOUDINESS DURING THE NEXT COUPLE OF
AFTERNOONS ALONG WITH CLEARING AT NIGHT. BOTTOM LINE...EXPECT
MOSTLY VFR CONDITIONS TO PREVAIL TODAY.


&&

.MARINE...
THE CURRENT NORTHWEST SWELL WILL CONTINUE TO LOWER THROUGH TONIGHT.
A LARGER NORTHWEST SWELL IS EXPECTED TO ARRIVE ON SUNDAY AND WILL
LIKELY BUILD TO HIGH SURF WARNING LEVELS FOR NORTH AND WEST FACING
SHORES BY LATE IN THE DAY. THIS SWELL SHOULD HAVE ENOUGH WESTERLY
COMPONENT TO IMPACT THE WEST SIDE OF THE BIG ISLAND...LIKELY
REACHING WARNING LEVELS FOR KONA SUNDAY NIGHT THROUGH MONDAY NIGHT.

THE EAST-SOUTHEAST WINDS ARE BECOMING LIGHT AS A COLD FRONT
APPROACHES THE ALOHA STATE FROM THE NORTHWEST. WINDS WILL REMAIN
LIGHT ON SUNDAY AS THE NORTHWEST SWELL BUILDS...BUT NORTH TO
NORTHEAST WINDS WILL DRASTICALLY INCREASE SUNDAY NIGHT INTO MONDAY
AS THE SWELL PEAKS.

THE SMALL CRAFT ADVISORY /SCA/ FOR OUR TYPICAL WINDY ZONES IS NO
LONGER IN EFFECT.


&&

.HFO WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY THROUGH NOON HST TODAY FOR THE BIG ISLAND SUMMITS.

&&

$$

REYNES










000
FXHW60 PHFO 200630
AFDHFO

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
830 PM HST FRI DEC 19 2014

.SYNOPSIS...
CURRENT MODERATE TRADE WINDS WILL DECREASE ON SATURDAY. THIS WILL
ALLOW FOR LAND AND SEA BREEZES TO DEVELOP THIS WEEKEND...AS A COLD
FRONT AND UPPER TROUGH APPROACH FROM THE NORTHWEST. SHOWERS WILL
INCREASE STARTING LATE SUNDAY NIGHT WITH THE POTENTIAL FOR HEAVY
RAIN AND A FEW THUNDERSTORMS MONDAY EVENING INTO TUESDAY. STRONG
NORTHERLY WINDS WILL THEN DEVELOP BY MID WEEK.

&&

.DISCUSSION...
GENERALLY DRIER CONDITIONS PREVAIL ACROSS THE ALOHA STATE THIS
EVENING WITH A SFC HIGH PRESSURE SYSTEM NE OF THE MAIN HAWAIIAN
ISLANDS PROVIDING A MODERATE TRADE WIND PATTERN. A FEW SMALL SHOWERS
UPSTREAM OF THE ISLANDS WILL MAINLY AFFECT WINDWARD AND MOUNTAIN
AREAS AT TIMES THROUGH THE REST OF TONIGHT. MEANWHILE...A WEAK
POSITIVELY-TILTED UPPER LVL TROUGH REMAINS OVER THE AREA WITH AN
ASSOCIATED JET STREAM PRODUCING A LINE OF CIRRUS CLOUDS JUST S OF
THE BIG ISLAND.

MODELS SHOW THE SFC HIGH MIGRATING E DURING THE WEEKEND...WITH THE
TRADES BECOMING LIGHT ON SAT. MODELS ALSO SHOW A STRONG SFC COLD
FRONT APPROACHING THE ISLANDS ON SUN...WHICH SEEMS TO HAVE UPPER
LEVEL SUPPORT IN THE FORM OF A SHARP TROUGH ALSO MOVING TOWARDS THE
AREA. AS THIS TROUGH/FRONT COMPLEX MOVES CLOSER...THE WINDS ON SAT
WILL BECOME SE AND GENERALLY LIGHT WITH WARMER AND HUMID CONDITIONS
EXPECTED ALL DAY. SOME VOG FROM THE BIG ISLAND MAY REACH MAUI COUNTY
ON SAT AND SUN...BUT CHANCES ARE LOW AT THIS TIME AS WINDS AROUND
THE BIG ISLAND MAY REMAIN MORE EASTERLY. THIS SYNOPTIC SETUP WILL
ALLOW FOR SEA/LAND BREEZE CIRCULATIONS TO DEVELOP SATURDAY...AND
PROBABLY AGAIN ON SUN...WITH CLOUDS AND SHOWERS FORMING OVER LEEWARD
AND INTERIOR AREAS EACH AFTERNOON AND EARLY EVENING. BUT ANY SHOWERS
THAT FORM WILL LIKELY REMAIN SHALLOW AND PRODUCE LIGHT RAIN IN
GENERAL AS A WEAK RIDGE WILL PREVAIL ALOFT DURING THE NEXT COUPLE OF
DAYS.

MODELS SHOW FAIR AGREEMENT IN THEIR SOLUTIONS THROUGH EARLY TUE NEXT
WEEK...DEPICTING THE COLD FRONT REACHING KAUAI LATE SUN NIGHT AND
INTO MON MORNING...AND A COLDER AIRMASS MOVING ALOFT AS THE UPPER
TROUGH ARRIVES LATE MON. THE TROUGH SHOULD PROVIDE GOOD DYNAMIC
SUPPORT FOR WIDESPREAD SHOWERS...LOCALLY HEAVY RAIN AND POTENTIAL
FOR THUNDERSTORM ACTIVITY. THE TROUGH AXIS SEEMS TO MOVE ACROSS
KAUAI COUNTY SOMETIME LATE MON NIGHT...WITH 500 MB TEMPS COOLING
DOWN TO NEAR -16 OR -17 DEGREES CELSIUS. THUS...THE FORECAST WILL
CONTINUE TO CARRY SLIGHT CHANCES OF THUNDERSTORMS MON NIGHT AND
TUE...BUT OVERALL COVERAGE MAY BE ADJUSTED AS NEW MODEL GUIDANCE
BECOMES AVAILABLE.

LATEST GFS SOLUTION DEVELOPS A CUTOFF LOW SYSTEM AND MOVES IT OVER
THE E HALF OF THE ISLAND CHAIN ON TUE AND TUE NIGHT...WHILE ECMWF
KEEPS THIS LOW N OF THE ISLANDS DURING THE SAME TIME FRAME. THE
FINAL OUTCOME OF THIS SCENARIO WILL CERTAINLY HAVE A SIGNIFICANT
IMPACT...SO FOR NOW WILL KEEP THE FORECAST CLOSER TO ECMWF AND WILL
ADJUST ACCORDINGLY.

BEST CHANCES FOR LOCALLY HEAVY RAIN AND A FEW THUNDERSTORMS RESIDE
OVER THE W HALF OF THE ISLAND CHAIN MON NIGHT AND TUE. THERE WILL
BE POTENTIAL FOR A FEW CELLS TO BECOME STRONG. ALSO...AS THE UPPER
LOW MOVES CLOSER TO THE BIG ISLAND...THE POTENTIAL FOR SNOW OVER THE
SUMMITS WILL INCREASE...MAINLY FROM MON NIGHT THROUGH TUE.

MODELS SHOW STRONG NE WINDS ESTABLISHING ACROSS THE AREA IN THE WAKE
OF THE FROPA...STARTING AROUND KAUAI COUNTY LATE SUN NIGHT...THEN
SPREADING DOWN THE REST OF THE ISLAND CHAIN BY TUE NIGHT AND
PREVAILING THROUGH THE SECOND HALF OF NEXT WEEK.

&&

.AVIATION...
WITH A FRONT APPROACHING AND HIGH PRESSURE NORTH OF THE ISLANDS
BEING PUSHED EASTWARD...TRADES WILL BE REPLACED WITH A MORE
SOUTHEAST WIND FLOW INTO SATURDAY. BUT THE FRONT WILL BE WEAKENING
AS IT NEARS THE STATE THUS INSTEAD OF STRONG SE WINDS...MAY SEE MORE
LAND/SEA BREEZES FROM TIME TO TIME. THUS EXPECT MORE INTERIOR
CLOUDINESS DURING THE AFTERNOONS ALONG WITH CLEARING AT NIGHT WITH
SLIGHTLY LESS WINDWARD CLOUDINESS. BOTTOM LINE...EXPECT MOSTLY VFR
CONDITIONS TO PREVAIL INTO SATURDAY.


&&

.MARINE...
THE CURRENT NORTHWEST SWELL WILL CONTINUE TO LOWER THROUGH
SATURDAY NIGHT. A LARGER NORTHWEST SWELL IS EXPECTED TO ARRIVE ON
SUNDAY AND WILL LIKELY BUILD TO HIGH SURF WARNING LEVEL HEIGHTS
FOR NORTH AND WEST FACING SHORES BY LATE IN THE DAY. THIS SWELL
SHOULD HAVE ENOUGH WESTERLY COMPONENT TO IMPACT THE WEST SIDE OF
THE BIG ISLAND...LIKELY REACHING WARNING LEVELS FOR KONA SUNDAY
NIGHT THROUGH MONDAY NIGHT.

THE EAST-SOUTHEAST WINDS WILL CONTINUE TO DECREASE THROUGH THE REST
OF TONIGHT AND BECOME LIGHT ON SATURDAY AS A COLD FRONT APPROACHES
THE ALOHA STATE FROM THE NORTHWEST. WINDS WILL REMAIN LIGHT ON
SUNDAY AS THE NORTHWEST SWELL BUILDS...BUT NORTH TO NORTHEAST WINDS
WILL DRASTICALLY INCREASE SUNDAY NIGHT INTO MONDAY AS THE SWELL
PEAKS.

A SMALL CRAFT ADVISORY /SCA/ IS IN EFFECT THROUGH 6 AM SATURDAY
FOR OUR TYPICAL WINDY ZONES AROUND MAUI COUNTY AND THE BIG
ISLAND...EXCEPT FOR MAALAEA BAY DUE TO THE EAST-SOUTHEAST WIND
DIRECTION. THE SCA WILL LIKELY BE DROPPED SATURDAY MORNING.


&&

.HFO WATCHES/WARNINGS/ADVISORIES...
SMALL CRAFT ADVISORY UNTIL 6 AM HST SATURDAY FOR MAUI COUNTY
WINDWARD WATERS-PAILOLO CHANNEL-ALENUIHAHA CHANNEL-BIG ISLAND
WINDWARD WATERS-BIG ISLAND LEEWARD WATERS-BIG ISLAND SOUTHEAST
WATERS.


&&

$$

REYNES








000
FXHW60 PHFO 200630
AFDHFO

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
830 PM HST FRI DEC 19 2014

.SYNOPSIS...
CURRENT MODERATE TRADE WINDS WILL DECREASE ON SATURDAY. THIS WILL
ALLOW FOR LAND AND SEA BREEZES TO DEVELOP THIS WEEKEND...AS A COLD
FRONT AND UPPER TROUGH APPROACH FROM THE NORTHWEST. SHOWERS WILL
INCREASE STARTING LATE SUNDAY NIGHT WITH THE POTENTIAL FOR HEAVY
RAIN AND A FEW THUNDERSTORMS MONDAY EVENING INTO TUESDAY. STRONG
NORTHERLY WINDS WILL THEN DEVELOP BY MID WEEK.

&&

.DISCUSSION...
GENERALLY DRIER CONDITIONS PREVAIL ACROSS THE ALOHA STATE THIS
EVENING WITH A SFC HIGH PRESSURE SYSTEM NE OF THE MAIN HAWAIIAN
ISLANDS PROVIDING A MODERATE TRADE WIND PATTERN. A FEW SMALL SHOWERS
UPSTREAM OF THE ISLANDS WILL MAINLY AFFECT WINDWARD AND MOUNTAIN
AREAS AT TIMES THROUGH THE REST OF TONIGHT. MEANWHILE...A WEAK
POSITIVELY-TILTED UPPER LVL TROUGH REMAINS OVER THE AREA WITH AN
ASSOCIATED JET STREAM PRODUCING A LINE OF CIRRUS CLOUDS JUST S OF
THE BIG ISLAND.

MODELS SHOW THE SFC HIGH MIGRATING E DURING THE WEEKEND...WITH THE
TRADES BECOMING LIGHT ON SAT. MODELS ALSO SHOW A STRONG SFC COLD
FRONT APPROACHING THE ISLANDS ON SUN...WHICH SEEMS TO HAVE UPPER
LEVEL SUPPORT IN THE FORM OF A SHARP TROUGH ALSO MOVING TOWARDS THE
AREA. AS THIS TROUGH/FRONT COMPLEX MOVES CLOSER...THE WINDS ON SAT
WILL BECOME SE AND GENERALLY LIGHT WITH WARMER AND HUMID CONDITIONS
EXPECTED ALL DAY. SOME VOG FROM THE BIG ISLAND MAY REACH MAUI COUNTY
ON SAT AND SUN...BUT CHANCES ARE LOW AT THIS TIME AS WINDS AROUND
THE BIG ISLAND MAY REMAIN MORE EASTERLY. THIS SYNOPTIC SETUP WILL
ALLOW FOR SEA/LAND BREEZE CIRCULATIONS TO DEVELOP SATURDAY...AND
PROBABLY AGAIN ON SUN...WITH CLOUDS AND SHOWERS FORMING OVER LEEWARD
AND INTERIOR AREAS EACH AFTERNOON AND EARLY EVENING. BUT ANY SHOWERS
THAT FORM WILL LIKELY REMAIN SHALLOW AND PRODUCE LIGHT RAIN IN
GENERAL AS A WEAK RIDGE WILL PREVAIL ALOFT DURING THE NEXT COUPLE OF
DAYS.

MODELS SHOW FAIR AGREEMENT IN THEIR SOLUTIONS THROUGH EARLY TUE NEXT
WEEK...DEPICTING THE COLD FRONT REACHING KAUAI LATE SUN NIGHT AND
INTO MON MORNING...AND A COLDER AIRMASS MOVING ALOFT AS THE UPPER
TROUGH ARRIVES LATE MON. THE TROUGH SHOULD PROVIDE GOOD DYNAMIC
SUPPORT FOR WIDESPREAD SHOWERS...LOCALLY HEAVY RAIN AND POTENTIAL
FOR THUNDERSTORM ACTIVITY. THE TROUGH AXIS SEEMS TO MOVE ACROSS
KAUAI COUNTY SOMETIME LATE MON NIGHT...WITH 500 MB TEMPS COOLING
DOWN TO NEAR -16 OR -17 DEGREES CELSIUS. THUS...THE FORECAST WILL
CONTINUE TO CARRY SLIGHT CHANCES OF THUNDERSTORMS MON NIGHT AND
TUE...BUT OVERALL COVERAGE MAY BE ADJUSTED AS NEW MODEL GUIDANCE
BECOMES AVAILABLE.

LATEST GFS SOLUTION DEVELOPS A CUTOFF LOW SYSTEM AND MOVES IT OVER
THE E HALF OF THE ISLAND CHAIN ON TUE AND TUE NIGHT...WHILE ECMWF
KEEPS THIS LOW N OF THE ISLANDS DURING THE SAME TIME FRAME. THE
FINAL OUTCOME OF THIS SCENARIO WILL CERTAINLY HAVE A SIGNIFICANT
IMPACT...SO FOR NOW WILL KEEP THE FORECAST CLOSER TO ECMWF AND WILL
ADJUST ACCORDINGLY.

BEST CHANCES FOR LOCALLY HEAVY RAIN AND A FEW THUNDERSTORMS RESIDE
OVER THE W HALF OF THE ISLAND CHAIN MON NIGHT AND TUE. THERE WILL
BE POTENTIAL FOR A FEW CELLS TO BECOME STRONG. ALSO...AS THE UPPER
LOW MOVES CLOSER TO THE BIG ISLAND...THE POTENTIAL FOR SNOW OVER THE
SUMMITS WILL INCREASE...MAINLY FROM MON NIGHT THROUGH TUE.

MODELS SHOW STRONG NE WINDS ESTABLISHING ACROSS THE AREA IN THE WAKE
OF THE FROPA...STARTING AROUND KAUAI COUNTY LATE SUN NIGHT...THEN
SPREADING DOWN THE REST OF THE ISLAND CHAIN BY TUE NIGHT AND
PREVAILING THROUGH THE SECOND HALF OF NEXT WEEK.

&&

.AVIATION...
WITH A FRONT APPROACHING AND HIGH PRESSURE NORTH OF THE ISLANDS
BEING PUSHED EASTWARD...TRADES WILL BE REPLACED WITH A MORE
SOUTHEAST WIND FLOW INTO SATURDAY. BUT THE FRONT WILL BE WEAKENING
AS IT NEARS THE STATE THUS INSTEAD OF STRONG SE WINDS...MAY SEE MORE
LAND/SEA BREEZES FROM TIME TO TIME. THUS EXPECT MORE INTERIOR
CLOUDINESS DURING THE AFTERNOONS ALONG WITH CLEARING AT NIGHT WITH
SLIGHTLY LESS WINDWARD CLOUDINESS. BOTTOM LINE...EXPECT MOSTLY VFR
CONDITIONS TO PREVAIL INTO SATURDAY.


&&

.MARINE...
THE CURRENT NORTHWEST SWELL WILL CONTINUE TO LOWER THROUGH
SATURDAY NIGHT. A LARGER NORTHWEST SWELL IS EXPECTED TO ARRIVE ON
SUNDAY AND WILL LIKELY BUILD TO HIGH SURF WARNING LEVEL HEIGHTS
FOR NORTH AND WEST FACING SHORES BY LATE IN THE DAY. THIS SWELL
SHOULD HAVE ENOUGH WESTERLY COMPONENT TO IMPACT THE WEST SIDE OF
THE BIG ISLAND...LIKELY REACHING WARNING LEVELS FOR KONA SUNDAY
NIGHT THROUGH MONDAY NIGHT.

THE EAST-SOUTHEAST WINDS WILL CONTINUE TO DECREASE THROUGH THE REST
OF TONIGHT AND BECOME LIGHT ON SATURDAY AS A COLD FRONT APPROACHES
THE ALOHA STATE FROM THE NORTHWEST. WINDS WILL REMAIN LIGHT ON
SUNDAY AS THE NORTHWEST SWELL BUILDS...BUT NORTH TO NORTHEAST WINDS
WILL DRASTICALLY INCREASE SUNDAY NIGHT INTO MONDAY AS THE SWELL
PEAKS.

A SMALL CRAFT ADVISORY /SCA/ IS IN EFFECT THROUGH 6 AM SATURDAY
FOR OUR TYPICAL WINDY ZONES AROUND MAUI COUNTY AND THE BIG
ISLAND...EXCEPT FOR MAALAEA BAY DUE TO THE EAST-SOUTHEAST WIND
DIRECTION. THE SCA WILL LIKELY BE DROPPED SATURDAY MORNING.


&&

.HFO WATCHES/WARNINGS/ADVISORIES...
SMALL CRAFT ADVISORY UNTIL 6 AM HST SATURDAY FOR MAUI COUNTY
WINDWARD WATERS-PAILOLO CHANNEL-ALENUIHAHA CHANNEL-BIG ISLAND
WINDWARD WATERS-BIG ISLAND LEEWARD WATERS-BIG ISLAND SOUTHEAST
WATERS.


&&

$$

REYNES









000
FXHW60 PHFO 200208
AFDHFO

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
408 PM HST FRI DEC 19 2014

.SYNOPSIS...
TRADES WILL WEAKEN TO A LAND AND SEA BREEZE PATTERN THIS WEEKEND
AS A COLD FRONT AND UPPER TROUGH APPROACH FROM THE NORTHWEST.
NORTH TO NORTHEAST WINDS AND RAINFALL WILL INCREASE LATE SUNDAY
NIGHT WITH THE POTENTIAL FOR HEAVY RAIN AND THUNDERSTORMS MONDAY
EVENING INTO TUESDAY.

&&

.DISCUSSION...
SATELLITE IMAGERY SHOWS A POSITIVELY-TILTED UPPER LEVEL TROUGH
OVER HAWAII WITH A WEST TO EAST ORIENTED JET STREAM RUNNING JUST
SOUTH OF THE BIG ISLAND INDICATED BY A SWATH OF CIRRUS CLOUDS. AT
THE SURFACE...HIGH PRESSURE IS CENTERED TO THE EAST-NORTHEAST OF
THE STATE PRODUCING MODERATE EAST-SOUTHEAST WINDS...WITH THE
STRONGEST WINDS NEAR MAUI COUNTY AND THE BIG ISLAND. RADAR AND
WEATHER OBSERVATIONS ARE SHOWING TRACE AMOUNTS OF SHOWERS THIS
AFTERNOON.

THE SURFACE HIGH IS EXPECTED TO MOVE EAST...AWAY FROM
HAWAII...TONIGHT AND WILL RESULT IN PROGRESSIVELY LESS INFLUENCE
ON OUR WINDS. MEANWHILE...A STRONG COLD FRONT IS APPROXIMATELY
1300 MILES NORTHWEST OF KAUAI MOVING TOWARD US. THE FRONT IS
SUPPORTED BY AN UPPER TROUGH WHICH WILL STAY WITH IT AS APPROACHES
THE HAWAIIAN ISLANDS. WINDS WILL WEAKEN AND VEER SOUTHEASTERLY ON
SATURDAY AHEAD OF THIS SYSTEM...RESULTING IN A SHIFT TO MORE WARM
AND MUGGY CONDITIONS THIS WEEKEND. WINDS WILL LIKELY STAY TOO
EASTERLY NEAR THE BIG ISLAND TO BRING VOG UP TO THE SMALLER
ISLANDS. THE WEAKENING FLOW WILL ALSO ALLOW A SEA AND LAND BREEZE
PATTERN TO SET UP SATURDAY AND SUNDAY...RESULTING IN DAYTIME CLOUD
BUILD UPS OVER THE ISLANDS AND CLEARING OUT AT NIGHT. WEAK RIDGING
ALOFT AND GENERALLY DRY CONDITIONS OVER THE STATE THIS WEEKEND
WILL KEEP THE AFTERNOON SHOWER ACTIVITY ON THE LIGHT SIDE.

THE COLD FRONT WILL ARRIVE ON KAUAI LATE SUNDAY NIGHT / EARLY
MONDAY MORNING...FOLLOWED BY THE COLD POOL ALOFT FROM THE UPPER TROUGH
MONDAY EVENING. NORTHEAST SURFACE WINDS WILL DRASTICALLY STRENGTHEN ALONG
THE FRONTAL BOUNDARY BEGINNING ON KAUAI LATE SUNDAY NIGHT...SPREADING
EASTWARD DOWN THE ISLAND CHAIN THROUGH TUESDAY NIGHT.

WITH SIGNIFICANT SUPPORT FROM THE LOW / TROUGH ALOFT...THE FRONT
WILL HAVE THE OPPORTUNITY TO PRODUCE LOCALLY HEAVY RAIN AND
THUNDERSTORMS. THE GFS AND ECMWF MODELS ARE IN FAIR AGREEMENT
THROUGH TUESDAY MORNING...BUT BEGIN TO DIVERGE SOLUTIONS IN TERMS OF
PLACEMENT OF THIS UPPER LEVEL FEATURE.

BOTH MODELS BRING THE TROUGH AXIS ACROSS KAUAI MONDAY
NIGHT...WITH 500 MB TEMPERATURES NEAR -16 DEGREES CELSIUS FOR THE
GFS AND -17 DEGREES CELSIUS FOR THE ECMWF. THE GFS FORMS A CUT OFF
LOW AND BRINGS IT OVER THE BIG ISLAND ON TUESDAY AND TUESDAY
NIGHT...WHILE THE ECMWF LIFTS THE LOW TO THE NORTH OF THE STATE.
GIVEN THE STRONG DIVERGENCE IN SOLUTIONS...IT IS HARD TO SAY WITH
MUCH CERTAINTY RIGHT NOW WHERE THE IMPACTS OF INSTABILITY CAUSED
BY THE UPPER LOW WILL OCCUR.

FOR NOW...IT LOOKS LIKE THE NORTHWESTERN END OF THE STATE...NAMELY
KAUAI AND OAHU...WOULD HAVE THE BEST CHANCES FOR THUNDERSTORMS AND
HEAVY RAINFALL MONDAY NIGHT AND TUESDAY. THE STRONG VERTICAL WIND
SHEAR WILL IMPROVE THE VENTILATION OF ANY THUNDERSTORMS THAT DO
DEVELOP...POTENTIALLY ALLOWING SOME TO BECOME SEVERE...THOUGH
REMAINS A BIT EARLY TO CONSIDER A SEVERE THUNDERSTORM WATCH. IF
THE GFS SOLUTION HOLDS...AND THE UPPER LOW TRACKS OVER THE BIG
ISLAND...IT WOULD DRAW UP DEEP MOISTURE BRINGING THE POTENTIAL FOR SNOW
OVER THE SUMMITS OF MAUNA KEA AND MAUNA LOA MONDAY NIGHT THROUGH
TUESDAY.

AS MENTIONED...THERE STILL A BIT OF DISCREPANCY BETWEEN LONG RANGE
MODEL SOLUTIONS. WE WILL CONTINUE TO MONITOR FOR BETTER AGREEMENT
AND FORECAST CONFIDENCE DURING THE SECOND HALF OF NEXT WEEK.


&&

.AVIATION...
WITH A FRONT APPROACHING AND HIGH PRESSURE NORTH OF THE ISLANDS
BEING PUSHED EASTWARD...TRADES WILL BE REPLACED WITH A MORE
SOUTHEAST WIND FLOW INTO SATURDAY. BUT THE FRONT WILL BE WEAKENING
AS IT NEARS THE STATE THUS INSTEAD OF STRONG SE WINDS...MAY SEE MORE
LAND/SEA BREEZES FROM TIME TO TIME. THUS EXPECT MORE INTERIOR
CLOUDINESS DURING THE AFTERNOONS ALONG WITH CLEARING AT NIGHT WITH
SLIGHTLY LESS WINDWARD CLOUDINESS. BOTTOM LINE...EXPECT MOSTLY VFR
CONDITIONS TO PREVAIL INTO SATURDAY.


&&

.MARINE...
THE CURRENT NORTHWEST SWELL WILL CONTINUE TO LOWER THROUGH
SATURDAY NIGHT. A LARGER NORTHWEST SWELL IS EXPECTED TO ARRIVE ON
SUNDAY AND WILL LIKELY BUILD TO HIGH SURF WARNING LEVEL HEIGHTS
FOR NORTH AND WEST FACING SHORES BY LATE IN THE DAY. THIS SWELL
SHOULD HAVE ENOUGH WESTERLY COMPONENT TO IMPACT THE WEST SIDE OF
THE BIG ISLAND...LIKELY REACHING WARNING LEVELS FOR KONA SUNDAY
NIGHT THROUGH MONDAY NIGHT.

EAST-SOUTHEAST WINDS ARE EXPECTED TO TAPER OFF TONIGHT AS A COLD FRONT
APPROACHES THE STATE FROM THE NORTHWEST. THE FRONT WILL PUSH THE
SUBTROPICAL HIGH NORTHEAST OF THE STATE FURTHER AWAY TO THE EAST.
WINDS WILL REMAIN LIGHT ON SUNDAY AS THE NORTHWEST SWELL
BUILDS...BUT NORTH TO NORTHEAST WINDS WILL DRASTICALLY INCREASE
SUNDAY NIGHT INTO MONDAY AS THE SWELL PEAKS.

A SMALL CRAFT ADVISORY /SCA/ IS IN EFFECT THROUGH 6 AM SATURDAY
FOR OUR TYPICAL WINDY ZONES AROUND MAUI COUNTY AND THE BIG
ISLAND...EXCEPT FOR MAALEA BAY DUE TO THE EAST-SOUTHEAST WIND
DIRECTION. THE SCA WILL LIKELY BE DROPPED SATURDAY MORNING.


&&

.HFO WATCHES/WARNINGS/ADVISORIES...
SMALL CRAFT ADVISORY UNTIL 6 AM HST SATURDAY FOR MAUI COUNTY
WINDWARD WATERS-PAILOLO CHANNEL-ALENUIHAHA CHANNEL-BIG ISLAND
WINDWARD WATERS-BIG ISLAND LEEWARD WATERS-BIG ISLAND SOUTHEAST
WATERS.


&&

$$

DISCUSSION/MARINE...FOSTER
AVIATION...FUJII




000
FXHW60 PHFO 200208
AFDHFO

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
408 PM HST FRI DEC 19 2014

.SYNOPSIS...
TRADES WILL WEAKEN TO A LAND AND SEA BREEZE PATTERN THIS WEEKEND
AS A COLD FRONT AND UPPER TROUGH APPROACH FROM THE NORTHWEST.
NORTH TO NORTHEAST WINDS AND RAINFALL WILL INCREASE LATE SUNDAY
NIGHT WITH THE POTENTIAL FOR HEAVY RAIN AND THUNDERSTORMS MONDAY
EVENING INTO TUESDAY.

&&

.DISCUSSION...
SATELLITE IMAGERY SHOWS A POSITIVELY-TILTED UPPER LEVEL TROUGH
OVER HAWAII WITH A WEST TO EAST ORIENTED JET STREAM RUNNING JUST
SOUTH OF THE BIG ISLAND INDICATED BY A SWATH OF CIRRUS CLOUDS. AT
THE SURFACE...HIGH PRESSURE IS CENTERED TO THE EAST-NORTHEAST OF
THE STATE PRODUCING MODERATE EAST-SOUTHEAST WINDS...WITH THE
STRONGEST WINDS NEAR MAUI COUNTY AND THE BIG ISLAND. RADAR AND
WEATHER OBSERVATIONS ARE SHOWING TRACE AMOUNTS OF SHOWERS THIS
AFTERNOON.

THE SURFACE HIGH IS EXPECTED TO MOVE EAST...AWAY FROM
HAWAII...TONIGHT AND WILL RESULT IN PROGRESSIVELY LESS INFLUENCE
ON OUR WINDS. MEANWHILE...A STRONG COLD FRONT IS APPROXIMATELY
1300 MILES NORTHWEST OF KAUAI MOVING TOWARD US. THE FRONT IS
SUPPORTED BY AN UPPER TROUGH WHICH WILL STAY WITH IT AS APPROACHES
THE HAWAIIAN ISLANDS. WINDS WILL WEAKEN AND VEER SOUTHEASTERLY ON
SATURDAY AHEAD OF THIS SYSTEM...RESULTING IN A SHIFT TO MORE WARM
AND MUGGY CONDITIONS THIS WEEKEND. WINDS WILL LIKELY STAY TOO
EASTERLY NEAR THE BIG ISLAND TO BRING VOG UP TO THE SMALLER
ISLANDS. THE WEAKENING FLOW WILL ALSO ALLOW A SEA AND LAND BREEZE
PATTERN TO SET UP SATURDAY AND SUNDAY...RESULTING IN DAYTIME CLOUD
BUILD UPS OVER THE ISLANDS AND CLEARING OUT AT NIGHT. WEAK RIDGING
ALOFT AND GENERALLY DRY CONDITIONS OVER THE STATE THIS WEEKEND
WILL KEEP THE AFTERNOON SHOWER ACTIVITY ON THE LIGHT SIDE.

THE COLD FRONT WILL ARRIVE ON KAUAI LATE SUNDAY NIGHT / EARLY
MONDAY MORNING...FOLLOWED BY THE COLD POOL ALOFT FROM THE UPPER TROUGH
MONDAY EVENING. NORTHEAST SURFACE WINDS WILL DRASTICALLY STRENGTHEN ALONG
THE FRONTAL BOUNDARY BEGINNING ON KAUAI LATE SUNDAY NIGHT...SPREADING
EASTWARD DOWN THE ISLAND CHAIN THROUGH TUESDAY NIGHT.

WITH SIGNIFICANT SUPPORT FROM THE LOW / TROUGH ALOFT...THE FRONT
WILL HAVE THE OPPORTUNITY TO PRODUCE LOCALLY HEAVY RAIN AND
THUNDERSTORMS. THE GFS AND ECMWF MODELS ARE IN FAIR AGREEMENT
THROUGH TUESDAY MORNING...BUT BEGIN TO DIVERGE SOLUTIONS IN TERMS OF
PLACEMENT OF THIS UPPER LEVEL FEATURE.

BOTH MODELS BRING THE TROUGH AXIS ACROSS KAUAI MONDAY
NIGHT...WITH 500 MB TEMPERATURES NEAR -16 DEGREES CELSIUS FOR THE
GFS AND -17 DEGREES CELSIUS FOR THE ECMWF. THE GFS FORMS A CUT OFF
LOW AND BRINGS IT OVER THE BIG ISLAND ON TUESDAY AND TUESDAY
NIGHT...WHILE THE ECMWF LIFTS THE LOW TO THE NORTH OF THE STATE.
GIVEN THE STRONG DIVERGENCE IN SOLUTIONS...IT IS HARD TO SAY WITH
MUCH CERTAINTY RIGHT NOW WHERE THE IMPACTS OF INSTABILITY CAUSED
BY THE UPPER LOW WILL OCCUR.

FOR NOW...IT LOOKS LIKE THE NORTHWESTERN END OF THE STATE...NAMELY
KAUAI AND OAHU...WOULD HAVE THE BEST CHANCES FOR THUNDERSTORMS AND
HEAVY RAINFALL MONDAY NIGHT AND TUESDAY. THE STRONG VERTICAL WIND
SHEAR WILL IMPROVE THE VENTILATION OF ANY THUNDERSTORMS THAT DO
DEVELOP...POTENTIALLY ALLOWING SOME TO BECOME SEVERE...THOUGH
REMAINS A BIT EARLY TO CONSIDER A SEVERE THUNDERSTORM WATCH. IF
THE GFS SOLUTION HOLDS...AND THE UPPER LOW TRACKS OVER THE BIG
ISLAND...IT WOULD DRAW UP DEEP MOISTURE BRINGING THE POTENTIAL FOR SNOW
OVER THE SUMMITS OF MAUNA KEA AND MAUNA LOA MONDAY NIGHT THROUGH
TUESDAY.

AS MENTIONED...THERE STILL A BIT OF DISCREPANCY BETWEEN LONG RANGE
MODEL SOLUTIONS. WE WILL CONTINUE TO MONITOR FOR BETTER AGREEMENT
AND FORECAST CONFIDENCE DURING THE SECOND HALF OF NEXT WEEK.


&&

.AVIATION...
WITH A FRONT APPROACHING AND HIGH PRESSURE NORTH OF THE ISLANDS
BEING PUSHED EASTWARD...TRADES WILL BE REPLACED WITH A MORE
SOUTHEAST WIND FLOW INTO SATURDAY. BUT THE FRONT WILL BE WEAKENING
AS IT NEARS THE STATE THUS INSTEAD OF STRONG SE WINDS...MAY SEE MORE
LAND/SEA BREEZES FROM TIME TO TIME. THUS EXPECT MORE INTERIOR
CLOUDINESS DURING THE AFTERNOONS ALONG WITH CLEARING AT NIGHT WITH
SLIGHTLY LESS WINDWARD CLOUDINESS. BOTTOM LINE...EXPECT MOSTLY VFR
CONDITIONS TO PREVAIL INTO SATURDAY.


&&

.MARINE...
THE CURRENT NORTHWEST SWELL WILL CONTINUE TO LOWER THROUGH
SATURDAY NIGHT. A LARGER NORTHWEST SWELL IS EXPECTED TO ARRIVE ON
SUNDAY AND WILL LIKELY BUILD TO HIGH SURF WARNING LEVEL HEIGHTS
FOR NORTH AND WEST FACING SHORES BY LATE IN THE DAY. THIS SWELL
SHOULD HAVE ENOUGH WESTERLY COMPONENT TO IMPACT THE WEST SIDE OF
THE BIG ISLAND...LIKELY REACHING WARNING LEVELS FOR KONA SUNDAY
NIGHT THROUGH MONDAY NIGHT.

EAST-SOUTHEAST WINDS ARE EXPECTED TO TAPER OFF TONIGHT AS A COLD FRONT
APPROACHES THE STATE FROM THE NORTHWEST. THE FRONT WILL PUSH THE
SUBTROPICAL HIGH NORTHEAST OF THE STATE FURTHER AWAY TO THE EAST.
WINDS WILL REMAIN LIGHT ON SUNDAY AS THE NORTHWEST SWELL
BUILDS...BUT NORTH TO NORTHEAST WINDS WILL DRASTICALLY INCREASE
SUNDAY NIGHT INTO MONDAY AS THE SWELL PEAKS.

A SMALL CRAFT ADVISORY /SCA/ IS IN EFFECT THROUGH 6 AM SATURDAY
FOR OUR TYPICAL WINDY ZONES AROUND MAUI COUNTY AND THE BIG
ISLAND...EXCEPT FOR MAALEA BAY DUE TO THE EAST-SOUTHEAST WIND
DIRECTION. THE SCA WILL LIKELY BE DROPPED SATURDAY MORNING.


&&

.HFO WATCHES/WARNINGS/ADVISORIES...
SMALL CRAFT ADVISORY UNTIL 6 AM HST SATURDAY FOR MAUI COUNTY
WINDWARD WATERS-PAILOLO CHANNEL-ALENUIHAHA CHANNEL-BIG ISLAND
WINDWARD WATERS-BIG ISLAND LEEWARD WATERS-BIG ISLAND SOUTHEAST
WATERS.


&&

$$

DISCUSSION/MARINE...FOSTER
AVIATION...FUJII





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