000
FXHW60 PHFO 200555
AFDHFO

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
830 PM HST WED JUN 19 2013

.SYNOPSIS...
LIGHT TO MODERATE TRADE WINDS WILL STRENGTHEN OVER THE WEEKEND...AND
THEN DIMINISH INTO THE MIDDLE OF NEXT WEEK. RAINFALL ACROSS THE
STATE WILL BE MAINLY LIGHT...AND LIMITED TO LEE SLOPES OF THE BIG
ISLAND EACH AFTERNOON...AND WINDWARD SLOPES OF MOST ISLANDS ALL DAY.

&&

.DISCUSSION...
SURFACE OBSERVATIONS AROUND THE MAIN HAWAIIAN ISLANDS REPORTED LIGHT
TO MODERATE TRADE WINDS. SOUNDING DATA SHOWED LITTLE MOMENTUM
THROUGH THE DEPTH OF THE NEAR-SURFACE MIXED LAYER...AND PRESSURE
TRENDS SUGGESTED A SLIGHT DECREASE IN WIND SPEED THROUGH THE SHORT
RUN. RAINFALL ACROSS THE STATE WAS LIGHT OVERALL...WITH MOST
MEASURABLE ACCUMULATION LIMITED TO WINDWARD KAUAI AND LEE SLOPES OF
THE BIG ISLAND. SOUNDING MEASUREMENTS AND SATELLITE ESTIMATES OF
PRECIPITABLE WATER SHOWED AN AIR MASS WITH FAIRLY TYPICAL HUMIDITY
FOR THE SEASON. ALOFT...BROAD BUT WEAK RIDGING PREVAILED OVER THE
EAST HALF OF THE ARCHIPELAGO...WHILE SHALLOW TROUGHING LANGUISHED
OVER THE WEST HALF.

GUIDANCE SOLIDLY AGREED THAT THE MAIN CHANGES THROUGH THE FORECAST
PERIOD WILL CONSIST OF SHIFTS IN THE POSITION OF DEEP-LAYER RIDGING
OVER THE STATE. THROUGH THIS COMING WEEKEND...THE RIDGE ALOFT WILL
STRENGTHEN AND MIGRATE WEST...GRADUALLY INCREASING SUPPORT FOR THE
SUBTROPICAL RIDGE AT THE SURFACE TO THE NORTH OF THE ISLANDS.
THUS...BY AROUND FRIDAY NIGHT THE TRADE WINDS WILL START TO SPEED
UP NOTICEABLY. BY SUNDAY NIGHT OR MONDAY...THE RIDGE ALOFT WILL BE
STRONGER THAN EVER...BUT SHIFTED SO FAR NORTHWEST THAT TROUGHING
FROM THE NORTHEAST WILL START TO ERODE THE SURFACE RIDGE INSTEAD...
LEADING TO A GENERAL DECREASE IN WIND SPEEDS INTO THE MIDDLE OF NEXT
WEEK.

THROUGHOUT THE WHOLE PERIOD...STABILITY WILL REMAIN HIGH ENOUGH THAT
MOST RAINFALL WILL RESULT FROM OROGRAPHIC FORCING ALONG WINDWARD
SLOPES. ABUNDANT SUNSHINE ALSO WILL DRIVE SEA-BREEZE CUMULUS
DEVELOPMENT OVER LEE SLOPES OF THE BIG ISLAND...THOUGH SUBSIDENCE
AND A SHORTAGE OF MOISTURE WILL TEND TO LIMIT THIS ACTIVITY.

&&

.AVIATION...
EXPECT LITTLE SIGNIFICANT CHANGE IN AVIATION WEATHER ACROSS THE MAIN
HAWAIIAN ISLANDS THROUGH THURSDAY MORNING. CONDITIONS WILL REMAIN
MOSTLY VFR...EXCEPT FOR BRIEF PERIODS OF MVFR CEILINGS DUE TO LOW
CLOUDS OVER SOME WINDWARD AND MAUKA AREAS...INCLUDING PHTO.

&&

.MARINE...
CONDITIONS WILL REMAIN CLOSE TO THE CRITERIA FOR A SMALL CRAFT
ADVISORY OVER TYPICALLY WINDY WATERS AROUND THE BIG ISLAND AND MAUI
THROUGH FRIDAY. THE ADVISORY LIKELY WILL BE NEEDED AS WIND SPEEDS
INCREASE INTO THE WEEKEND.

NO SIGNIFICANT SWELLS ARE IN STORE. MODERATE AND ROUGH SURF WILL
PERSIST ALONG WINDWARD SHORES. SMALL BACKGROUND SOUTH SWELLS WILL
HOLD FOR THE NEXT FEW DAYS...FOLLOWED BY A MODERATE SOUTHEAST SWELL
FROM SUNDAY INTO EARLY NEXT WEEK. A MODERATE SOUTH SOUTHWEST SWELL
IS POSSIBLE BY THE MIDDLE OF NEXT WEEK. NORTH-FACING SHORES SHOULD
ALSO SEE A SMALL NORTHWEST SWELL MONDAY THROUGH WEDNESDAY.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$

AVIATION...HOUSTON
REST...RYSHKO

000
ATHW40 PHFO 200530
SIMHI

HAWAIIAN ISLANDS SATELLITE INTERPRETATION MESSAGE
NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI
0530 UTC THU JUN 20 2013

BASED ON DATA THROUGH 0500 UTC JUNE 20 2013

WATER VAPOR IMAGERY...SHOWING FEATURES ABOVE ABOUT 24000
FEET...SHOWS AN UPPER TROUGH ORIENTED NORTHEAST TO SOUTHWEST JUST
WEST OF THE MAIN HAWAIIAN ISLANDS. WITH AN AXIS EXTENDING ROUGHLY
THROUGH 30N150W AND 20N165W...THIS FEATURE HAS MOVED VERY LITTLE
OVER THE PAST 24 HOURS. A RAGGED 300 TO 400 MILE WIDE BAND OF BROKEN
HIGH CLOUDS EAST OF A LINE FROM 30N146W TO 20N151W TO 13N164W MARKS
THE EASTERN FLANK OF THIS UPPER TROUGH.

AT LOW LEVELS...A BROAD ANTICYCLONIC CIRCULATION DOMINATES FLOW
SOUTH OF 35N ACROSS THE PACIFIC FROM THE MAINLAND TO THE DATELINE.
CENTERED NEAR 32N140W...THIS CIRCULATION...ACTUALLY A SUBTROPICAL
HIGH...HAS AN ASSOCIATED RIDGE EXTENDING WEST FROM THE CENTER
THROUGH 30N170W AND 30N180W. LOW LEVEL FLOW IS GENERALLY FROM EAST
TO WEST TO THE SOUTH OF THE RIDGE AXIS...INCLUDING ACROSS THE MAIN
HAWAIIAN ISLANDS AND LOCAL WATERS. TRADE WIND CONVERGENCE ALONG THE
SOUTHERN FRINGE OF THE ANTICYCLONIC CIRCULATION CONTINUES TO PRODUCE
BROKEN TO OVERCAST LAYERED CLOUDS WITH ISOLATED TO SCATTERED
CUMULONIMBUS...CB...FROM 05N TO 11N BETWEEN 145W AND 160W. SCATTERED
TO NUMEROUS CB ARE NOTED WEST OF 168W BETWEEN 04N AND 09N.

LOW CLOUD COVER ACROSS THE MAIN HAWAIIAN ISLANDS FOLLOWS A TRADE
WIND PATTERN...WITH COVERAGE FAVORING WINDWARD AND MAUKA AREAS.
BROKEN LOW CLOUDS COVER MAUKA SECTIONS OF KAUAI...ALTHOUGH THIS
COVERAGE IS DECREASING RAPIDLY. PATCHY BROKEN LOW CLOUDS COVER THE
KOOLAU SUMMITS ON OAHU AND THE EASTERN THIRD OF MOLOKAI. BROKEN TO
OVERCAST LOW CLOUDS COVER WINDWARD HALEAKALA SLOPES ON MAUI AS WELL
AS WINDWARD SLOPES OF THE WEST MAUI MOUNTAINS. PATCHY BROKEN LOW
CLOUDS COVER WINDWARD BIG ISLAND SLOPES...WHILE DAYTIME HEATING AND
RETURN FLOW HAVE SPAWNED THE USUAL OVERCAST LOW CLOUD COVERAGE
ACROSS KAU SLOPES AND KONA SLOPES SOUTH OF KAILUA-KONA. A FIELD OF
BROKEN LOW CLOUDS IS APPROACHING THE BIG ISLAND FROM THE EAST...BUT
OTHERWISE LOCAL WATERS HAVE GENERALLY SCATTERED LOW CLOUDS.
SATELLITE LOOP SHOWS LOW CLOUDS ARE MOVING ACROSS LOCAL WATERS
TOWARD THE WEST AT 15 TO 20 MPH.

$$
POWELL

000
FXHW60 PHFO 200116
AFDHFO

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
400 PM HST WED JUN 19 2013

.SYNOPSIS...
A SURFACE RIDGE SEVERAL HUNDRED MILES NORTH OF THE STATE WILL
DRIVE MODERATE TO LOCALLY BREEZY TRADE WINDS THROUGH THE WEEK. A
TYPICAL SUMMERTIME RAINFALL PATTERN WILL FOCUS MODEST RAINFALL OVER
WINDWARD SLOPES OF ALL ISLANDS...WHILE LEEWARD BIG ISLAND SLOPES
SEE A FEW AFTERNOON SHOWERS.

&&

.DISCUSSION...
MODERATE TRADE WINDS WILL HOLD DURING THE NEXT COUPLE OF DAYS...
WITH LOCALLY BREEZY WINDS SETTLING IN FOR THE WEEKEND. A NEARLY
STATIONARY SURFACE RIDGE ABOUT 550 MILES NORTH OF THE ISLANDS IS
DRIVING THE TRADE WIND FLOW. A COLD FRONT APPROACHING FROM THE
NORTHWEST IS WEAKENING THE RIDGE SLIGHTLY...AND THE PRESSURE
GRADIENT BETWEEN BUOYS 51101 AND 51003 REMAINS DOWN ABOUT 1 MB SINCE
YESTERDAY. THE FRONT WILL PASS TO THE NORTH OVER THE NEXT COUPLE OF
DAYS...WEAKENING THE PRESSURE GRADIENT OVER THE STATE A LITTLE MORE
AND CAUSING TRADES TO DECLINE JUST A NOTCH. THE RIDGE WILL
STRENGTHEN ON FRIDAY INTO THE WEEKEND...CAUSING WINDS TO BECOME
LOCALLY BREEZY AGAIN.

EXPECT A RATHER TYPICAL...TRADE WIND RAINFALL PATTERN TO CONTINUE
TO FOCUS MODEST SHOWERS OVER WINDWARD SLOPES. AFTERNOON SOUNDINGS...
AS WELL AS RECENT AIRCRAFT DATA...SHOW LOW TO MID LEVEL RIDGING
MAINTAINING STABLE CONDITIONS WITH AN INVERSION IN THE 6500 TO 7500
FOOT RANGE AND PRECIPITABLE WATER VALUES AROUND THE JUNE AVERAGE.
MODELS HINT AT LITTLE CHANGE DURING THE NEXT COUPLE OF DAYS. AN
UPPER LEVEL TROUGH OVERHEAD IS NOT STRONG ENOUGH TO PRODUCE ANY LOW
LEVEL INSTABILITY OVER THE ISLANDS...BUT IT WILL CONTINUE TO PRODUCE
HIGH CLOUDS SKIRTING JUST EAST OF THE STATE. RIDGING ALOFT WILL
BUILD IN FROM THE EAST DURING THE WEEKEND...POSSIBLY DECREASING
POPS. IN ADDITION...AS THE UPPER TROUGH DEPARTS TO THE WEST...WE
COULD SEE PERIODS OF HIGH CLOUDS SPREADING OVER THE ISLANDS.

IN THE EXTENDED...TRADES ARE EXPECTED TO DROP SLIGHTLY DURING THE
FIRST HALF OF THE NEW WORK WEEK AS A DEEPENING LOW IN THE FAR
NORTHEAST PACIFIC WEAKENS THE RIDGE TO OUR NORTH. THE FRONT
ASSOCIATED WITH THE LOW WILL DISSIPATE WELL BEFORE REACHING THE
ISLANDS...BUT MODELS ARE HINTING THAT REMNANT MOISTURE COULD STALL
NEAR KAUAI ON WEDNESDAY. WE ARE NOT CONFIDENT IN ANY SIGNIFICANT
INCREASE IN SHOWERS.

&&

.AVIATION...
VFR WILL PREVAIL ACROSS MOST OF THE STATE. EXPECT ISOL MVFR CIGS
OVER WINDWARD SLOPES AND POSSIBLY PHTO...MAINLY AT NIGHT.

&&

.MARINE...
WITH WINDS DOWN A NOTCH...THE SMALL CRAFT ADVISORY...SCA...HAS BEEN
DROPPED...BUT IT WON/T STAY DOWN FOR LONG. BORDERLINE CONDITIONS
WILL PREVAIL OVER THE TYPICALLY WINDY WATERS AROUND THE BIG ISLAND
AND MAUI THROUGH THURSDAY AND POSSIBLY INTO FRIDAY. THE SCA FLAG
WILL BE HOISTED AGAIN FOR THESE WATERS ON FRIDAY OR SATURDAY AS
TRADES REBUILD FOR THE WEEKEND.

NO SIGNIFICANT SWELLS ARE IN STORE. MODERATE AND ROUGH SURF WILL
PERSIST ALONG WINDWARD SHORES. SMALL BACKGROUND SOUTH SWELLS WILL
HOLD FOR THE NEXT FEW DAYS...FOLLOWED BY A MODERATE SOUTHEAST SWELL
FOR SUNDAY INTO EARLY NEXT WEEK. A MODERATE SOUTH SOUTHWEST SWELL IS
POSSIBLE BY THE MIDDLE OF NEXT WEEK. NORTH FACING SHORES SHOULD ALSO
SEE A SMALL NORTHWEST SWELL MONDAY THROUGH WEDNESDAY.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$
WROE

000
ATHW40 PHFO 200025
SIMHI

HAWAIIAN ISLANDS SATELLITE INTERPRETATION MESSAGE
NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI
0030 UTC THU JUN 20 2013

BASED ON DATA THROUGH 0000 UTC JUNE 20 2013

WATER VAPOR IMAGERY INDICATED AN UPPER LEVEL TROUGH CONTINUED OVER
MOST OF THE AREA THIS AFTERNOON WITH RIDGES OF HIGH PRESSURE JUST
GRAZING 140W AND 180. THE TROUGH ITSELF WAS RELATIVELY DRY WITH
JUST HIGH CLOUDS BEING ADVECTED NORTHEASTWARD OUT OF THE INTER
TROPICAL CONVERGENCE ZONE. THESE CIRRUS CLOUDS WERE MOVING TO THE
NORTHEAST AROUND 80 MILES PER HOURS. THESE BROKEN TO OVERCAST CLOUDS
WERE LOCATED SOUTH AND EAST OF A CURVE FROM 10N177W TO THE BIG
ISLAND TO 22N151W TO 27N151W TO 30N148W. AS FOR THE UPPER LEVEL
RIDGE NOSING INTO THE EXTREME NORTHWEST PORTION OF THE AREA...A FEW
THIN CIRRUS CLOUDS HAVE DEVELOPED OVER KURE ATOLL TO PEARL AND
HERMES ATOLL. AND FOR THE OTHER UPPER LEVEL RIDGE WITH ITS
NORTH-SOUTH ORIENTED AXIS LOCATED EAST OF 140W...IT HAS MAINLY
RESULTED IN THE DISSIPATION OF THE CIRRUS CLOUDS MOVING TOWARD IT
IN THE FLOW OF THE TROUGH.

IN THE MID TO LOWER LAYERS...AREAS OF STRATOCUMULUS CLOUDS WERE
SCATTERED ACROSS THE NORTH-CENTRAL PACIFIC OCEAN WITH THE LARGEST
AREA TO THE EAST OF THE MAIN HAWAIIAN ISLANDS. HOWEVER...THE LOW
CLOUDS WERE OBSCURED BY THE CIRRUS. THE STRATOCUMULI WERE MOVING TO
THE WEST AROUND 15 MILES PER HOUR AND HAD TOPS BETWEEN 8000 AND
11000 FEET.

IN THE VICINITY OF THE MAIN HAWAIIAN ISLANDS AT 0000Z...NIIHAU AND
KAUAI WERE MOSTLY CLOUDY. ON OAHU THE KOOLAU AND WAIANAE MOUNTAINS
WERE CLOUDY WHILE THE CENTRAL VALLEY WAS MOSTLY SUNNY. MOLOKAI WAS
CLOUDY ON THE NORTHEAST AND SOUTHWEST PORTIONS OF THE ISLAND WHILE
THE REMAINDER WAS MOSTLY SUNNY. LANAI WAS PARTLY SUNNY...EXCEPT ON
THE SOUTHERN PORTION WHERE IT WAS MOSTLY CLOUDY. KAHOOLAWE WAS
SUNNY. MAUI WAS MOSTLY CLOUDY OVER THE HIGHER TERRAIN WHILE THE
COASTAL AREAS WERE MOSTLY SUNNY. ON THE BIG ISLAND...IT WAS MOSTLY
CLOUDY...EXCEPT FOR THE COASTAL AREAS IN THE KOHALA DISTRICTS WHERE
IT WAS MOSTLY SUNNY.

$$

EVANS

000
FXHW60 PHFO 191936
AFDHFO

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
1000 AM HST WED JUN 19 2013

.SYNOPSIS...
A SURFACE RIDGE SEVERAL HUNDRED MILES NORTH OF THE STATE WILL
DRIVE MODERATE TO LOCALLY BREEZY TRADE WINDS THROUGH THE WEEK. A
TYPICAL SUMMERTIME RAINFALL PATTERN WILL FOCUS MODEST RAINFALL OVER
WINDWARD SLOPES OF ALL ISLANDS...WHILE LEEWARD BIG ISLAND SLOPES
SEE A FEW AFTERNOON SHOWERS.

&&

.DISCUSSION...
MODERATE TRADE WINDS WILL HOLD DURING THE NEXT COUPLE OF DAYS...
WITH LOCALLY BREEZY WINDS SETTLING IN FOR THE WEEKEND. A SURFACE
RIDGE ABOUT 550 MILES NORTH OF THE ISLANDS IS DRIVING THE TRADE
WINDS. A COLD FRONT APPROACHING FROM THE NORTHWEST IS WEAKENING THE
RIDGE SLIGHTLY...AND THE PRESSURE GRADIENT BETWEEN BUOYS 51101 AND
51003 HAS DECLINED BY NEARLY 1 MB SINCE THIS TIME YESTERDAY. THE
FRONT WILL PASS TO THE NORTH OVER THE NEXT COUPLE OF DAYS...
WEAKENING THE PRESSURE GRADIENT OVER THE STATE A LITTLE MORE AND
CAUSING TRADES TO DECLINE JUST A NOTCH. THE RIDGE WILL STRENGTHEN
ON FRIDAY INTO THE WEEKEND...CAUSING WINDS TO BECOME LOCALLY BREEZY
AGAIN.

EXPECT A RATHER TYPICAL...TRADE WIND RAINFALL PATTERN TO FOCUS
SHOWERS OVER WINDWARD SLOPES. RANDOM POCKETS OF SHOWERS MOVING ALONG
THE TRADE WIND FLOW WILL LIKELY LEAD TO SHORT TERM TWEAKING OF THE
POPS. MORNING SOUNDING AND RECENT AIRCRAFT DATA SHOW LOW TO MID
LEVEL RIDGING MAINTAINING STABLE CONDITIONS WITH AN INVERSION MAINLY
IN THE 7000 TO 8000 FOOT RANGE. AN UPPER LEVEL TROUGH OVERHEAD IS
NOT STRONG ENOUGH TO PRODUCE ANY LOW LEVEL INSTABILITY OVER THE
ISLANDS...BUT IT WILL CONTINUE TO PRODUCE HIGH CLOUDS EAST OF THE
STATE. RIDGING ALOFT WILL BUILD IN FROM THE EAST DURING THE
WEEKEND...POSSIBLY DECREASING POPS. IN ADDITION...AS THE UPPER
TROUGH DEPARTS TO THE WEST...WE COULD SEE PERIODS OF HIGH CLOUDS
SPREADING OVER THE ISLANDS.

&&

.AVIATION...
VFR WILL PREVAIL ACROSS MOST OF THE STATE. EXPECT ISOL MVFR CIGS
OVER WINDWARD SLOPES AND POSSIBLY PHTO...MAINLY AT NIGHT.

&&

.MARINE...
A SMALL CRAFT ADVISORY...SCA...IS IN EFFECT THROUGH THIS AFTERNOON
FOR LOCALLY STRONG TRADE WINDS AND ROUGH SEAS IN THE TYPICALLY
WINDY AREAS AROUND MAUI COUNTY AND THE BIG ISLAND. WITH A SLIGHT
DECLINE IN WINDS EXPECTED IN THE SHORT TERM...WE WILL LIKELY BE ABLE
TO DROP THE SCA FOR A DAY OR TWO. SCA CONDITIONS WILL REDEVELOP
ACROSS THE SAME AREAS ON FRIDAY OR SATURDAY.

NO SIGNIFICANT SWELLS ARE IN STORE. MODERATE AND ROUGH SURF WILL
PERSIST ALONG WINDWARD SHORES. SMALL BACKGROUND SOUTH SWELLS WILL
HOLD FOR THE NEXT FEW DAYS...FOLLOWED BY A MODERATE SOUTHEAST SWELL
FOR SUNDAY INTO EARLY NEXT WEEK. A MODERATE SOUTH SOUTHWEST SWELL IS
POSSIBLE BY THE MIDDLE OF NEXT WEEK. NORTH FACING SHORES WILL ALSO
LIKELY SEE A SMALL NORTHWEST SWELL MONDAY THROUGH WEDNESDAY.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
SMALL CRAFT ADVISORY UNTIL 600 PM HST TODAY FOR MAALAEA BAY...THE
WATERS SOUTH OF THE BIG ISLAND...AND THE PAILOLO AND ALENUIHAHA
CHANNELS.

&&

$$
WROE

000
ATHW40 PHFO 191825
SIMHI

HAWAIIAN ISLANDS SATELLITE INTERPRETATION MESSAGE
NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI
1830 UTC WED JUN 19 2013

BASED ON DATA THROUGH 1800 UTC JUNE 19 2013

INITIAL VISIBLE SECTOR IMAGES OF THE DAY SHOW SCATTERED TO BROKEN
LOW CLOUDS OVER THE EAST HALF OF KAUAI AND OVER THE WINDWARD SLOPES
OF THE KOOLAU RANGE ON OAHU. MAUI COUNTY HAS BROKEN LOW CLOUDS OVER
EAST MAUI FROM KEANAE TO HANA AND OVER EAST MOLOKAI FROM KAMALO TO
HALAWA VALLEY. OVER THE BIG ISLAND...BROKEN TO OVERCAST LOW CLOUDS
COVER THE EASTERN SLOPES FROM LAUPAHOEHOE TO PAHALA. A SMALLER AREA
OF BROKEN LOW CLOUDS IS OVER THE WEST SIDE ROUGHLY FROM PUAKO TO
KEAHOLE POINT. REMAINING AREAS OF THE STATE ARE MOSTLY CLOUD-FREE.

OFFSHORE WATERS NORTHEAST AND SOUTHWEST OF THE STATE HAVE BROKEN LOW
CLOUDS MOVING TOWARD THE WEST AT 15 TO 20 MILES PER HOUR. THE CLOUDS
OVER THE NORTHEAST WATERS ARE MORE SHOWERY IN APPEARANCE AND RADAR
DATA SHOW A FEW EMBEDDED LIGHT TO MODERATE RAINFALL CORES.

WATER VAPOR IMAGES SHOW A BROAD AND POORLY DEFINED UPPER LEVEL
TROUGH OVER HAWAIIAN ISLANDS. UW-CIMSS/NESDIS WIND DATA INDICATE
THAT THE TROUGH AXIS RUNS FROM ABOUT 30N 159W THROUGH 10N 175W.
BROKEN TO OVERCAST HIGH CLOUDS...OR CIRRUS...ASSOCIATED WITH THE
TROUGH EXTEND EAST OF A LINE FROM 30N 149W TO 20N 153W TO 14N 174W.

FAR TO THE SOUTH...THE INTERTROPICAL CONVERGENCE ZONE REMAINS SOUTH
OF 10N.  BASED ON INFRARED AND NASA TRMM SATELLITE DATA...MOST OF
THE THUNDERSTORM ACTIVITY FROM LAST NIGHT HAS DISSIPATED EXCEPT FOR
SOME CELLS BETWEEN 05N AND 10N BETWEEN 145W AND 155W.
HOWEVER...THERE IS STILL A CONSIDERABLE AMOUNT OF HIGH CLOUDS FROM
THE ABOVE MENTIONED UPPER LEVEL TROUGHS AND DEBRIS FROM EARLIER
THUNDERSTORMS.

$$

KODAMA

000
FXHW60 PHFO 191330
AFDHFO

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
330 AM HST WED JUN 19 2013

.SYNOPSIS...
EXPECT TRADE WIND WEATHER TO CONTINUE THROUGH THE FORECAST
PERIOD...THANKS TO PERSISTENT HIGH PRESSURE TO OUR NORTH. CLOUDS AND
SHOWERS WILL FAVOR WINDWARD AND MAUKA AREAS...MAINLY AT NIGHT AND
DURING THE MORNING HOURS. LEEWARD AREAS OF THE BIG ISLAND WILL SEE
INCREASED CLOUDS AND SHOWERS EACH AFTERNOON AND EVENING.

&&

.DISCUSSION...
A 1026 MB HIGH NEAR 33N142W...FAR NORTHEAST OF THE MAIN HAWAIIAN
ISLANDS...HAS AN ASSOCIATED RIDGE WHICH EXTENDS WEST THROUGH
30N170W. THIS RIDGE IS ABOUT 600 MILES NORTH OF THE MAIN HAWAIIAN
ISLANDS AND EASTERLY TRADE WINDS DOMINATE ACROSS LOCAL WATERS.
SATELLITE LOOP SHOWS CLOUD COVER ACROSS LOCAL WATERS HAS INCREASED
SINCE LAST EVENING...WITH BROKEN TO OVERCAST LOW CLOUDS EMBEDDED
WITHIN TRADE FLOW ACROSS WINDWARD WATERS AND LARGE BROKEN LOW CLOUD
PATCHES NOTED ACROSS LEEWARD WATERS. THESE CLOUDS ALSO COVER
WINDWARD AND MAUKA SECTIONS OF THE ISLANDS. RETURN FLOW KEEPS THICK
CLOUD COVER ACROSS LEEWARD AND KAU SECTIONS OF THE BIG ISLAND THIS
MORNING EVEN WITHOUT THE ASSISTANCE OF DAYTIME HEATING. SKY GRIDS
HAVE BEEN CHANGED CHANGED TO ACCOUNT FOR THIS INCREASED CLOUD COVER.
RADAR SHOWS ISOLATED TO SCATTERED LIGHT SHOWERS...WITH ALMOST ALL OF
THIS ACTIVITY TAKING PLACE OVER WATER. LATEST SOUNDINGS SHOW A
STRONG INVERSION AT AROUND 7800 FEET...CAPPING THE DEPTH OF
CONVECTION AND KEEPING TOTAL RAINFALL LIGHT. WATER VAPOR LOOP SHOWS
BROAD UPPER TROUGHING WEST OF THE ISLANDS...WITH AN AREA OF
SCATTERED TO BROKEN HIGH CLOUDS JUST SOUTHEAST THROUGH EAST OF THE
ISLANDS MARKING ITS EASTERN FLANK.

MODELS SHOW THE ATMOSPHERE BECOMING DRIER...WITH LOW-LEVEL MOISTURE
GETTING SHALLOWER OVER THE NEXT 24 HOURS. RAINFALL WILL LIKELY
BECOME QUITE SPARSE LATER TODAY THROUGH FRIDAY. WITH TRADE WINDS
CONTINUING...THIS SPARSE RAINFALL WILL BE CONCENTRATED OVER WINDWARD
AREAS. MODELS ALSO CONTINUE TO SHOW A BIG LOW DEVELOPING NEAR THE
ALEUTIANS OVER THE NEXT COUPLE OF DAYS...WITH THE SUBTROPICAL RIDGE
TO ITS SOUTH WEAKENING AND SHIFTING SOUTHWARD. THAT SHOULD WEAKEN
THE PRESSURE GRADIENT OVER THE ISLANDS AND CAUSE TRADE WIND SPEEDS
TO DROP OFF A BIT TONIGHT THROUGH THURSDAY NIGHT. THE RIDGE WILL
REBUILD BY THE WEEKEND AND TRADES WILL LIKELY BECOME LOCALLY BREEZY
AGAIN.

&&

.AVIATION...
EXPECT LITTLE SIGNIFICANT CHANGE IN AVIATION WEATHER AROUND THE MAIN
HAWAIIAN ISLANDS TODAY. CONDITIONS WILL REMAIN MOSTLY VFR...EXCEPT
FOR BRIEF PERIODS OF MVFR CEILINGS AND/OR VISIBILITIES OVER SOME
WINDWARD AND MAUKA AREAS IN LOW CLOUDS AND SHRA.

DATA FROM THE VAD WIND PROFILES APPEAR TO BE SHOWING VALUES LESS
THAN THE THRESHOLD WHICH MIGHT INDICATE TEMPO MODERATE LOW-LEVEL
MECHANICAL TURBULENCE MAY OCCUR LEEWARD OF THE MOUNTAINS ON THE
ISLANDS. THEREFORE...WE DO NOT ANTICIPATE ISSUING AN AIRMET FOR
LOW-LEVEL TURBULENCE THIS MORNING.

&&

.MARINE...
A SMALL CRAFT ADVISORY...SCA...IS IN EFFECT THROUGH THIS AFTERNOON
FOR LOCALLY STRONG TRADE WINDS AND ROUGH SEAS IN THE WINDIER AREAS
AROUND MAUI AND THE BIG ISLAND. WINDS WILL SUBSIDE SLIGHTLY TONIGHT
THROUGH THURSDAY NIGHT...PROBABLY ENOUGH TO ALLOW US TO DROP THE SCA
FOR A DAY OR TWO. A SCA IS LIKELY TO GO BACK UP AGAIN FRIDAY.

SURF WILL BE GENERALLY SMALL EXCEPT FOR MODERATE SURF ALONG EAST
SHORES DUE TO THE TRADE WINDS. A SMALL SOUTHEAST SWELL MAY AFFECT
THE BIG ISLAND STARTING SUNDAY...BUT THE BIG ISLAND WILL LIKELY
BLOCK MOST OF THE SWELL FROM REACHING THE REST OF THE ISLANDS.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
SMALL CRAFT ADVISORY UNTIL 600 PM HST TODAY FOR MAALAEA BAY...THE
WATERS SOUTH OF THE BIG ISLAND...AND THE PAILOLO AND ALENUIHAHA
CHANNELS.

&&

$$
PUBLIC/MARINE...POWELL
AVIATION...HOUSTON

000
ATHW40 PHFO 191200
SIMHI

HAWAIIAN ISLANDS SATELLITE INTERPRETATION MESSAGE
NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI
1200 UTC WED JUN 19 2013

BASED ON DATA THROUGH 1130 UTC JUNE 19 2013

LOW CLOUDS...SOME WITH EMBEDDED SHOWERS...ARE MAINLY CONCENTRATED
OVER WINDWARD AND MAUKA SECTIONS ON THE INDIVIDUAL ISLES THIS EARLY
MORNING.  THIS IS ESPECIALLY THE CASE ON THE BIG ISLAND...IN
WINDWARD EAST MAUI...AND OVER THE KOOLAU RANGE ON OAHU. LOW CEILINGS
ARE ALSO PREVALENT OVER COASTAL AND UPSLOPE AREAS OF KONA ON THE BIG
ISLAND...AND...FROM TIME TO TIME...IN LEEWARD PORTIONS OF THE
SMALLER ISLES AND WEST MAUI.  LOW CLOUD MOVEMENT IS FROM THE EAST TO
SLIGHTLY NORTH OF EAST AT 20 TO 25 MPH ACROSS THE ALOHA STATE.

IMMEDIATELY NORTH CLOCKWISE THROUGH SOUTHEAST...AND JUST WEST...OF
THE BIG ISLAND ARE BROKEN TO OVERCAST LOW CLOUDS.  BROKEN SHOWERY
LOW CLOUDS ARE PASSING BY NORTH OF OAHU AND MAUI COUNTY.  AND PLUME
CLOUDINESS IS PRODUCING CEILINGS SOUTH OF OAHU...AND SOUTHWEST AND
WEST OF KAUAI.  SKIES ARE CLEAR TO SCATTERED ELSEWHERE OVER THE
ADJACENT COASTAL WATERS.

AN UPPER TROUGH...ABOVE 25 THOUSAND FEET...HAS CHANGED VERY LITTLE
OVER THE PAST SEVEN HOURS...ACCORDING TO THE LATEST WATER VAPOR
IMAGES.  IT IS ORIENTED NORTHEAST TO SOUTHWEST...AND ITS AXIS IS
ALONG A LINE FROM 30N155W TO 23N163W TO 20N173W.  A JET STREAM IS
SOUTH AND SOUTHEAST OF THE TROUGH...AND ITS AXIS IS ROUGHLY ALONG A
LINE FROM 20N180 TO 16N170W TO 17N160W TO A POINT ABOUT 100 MILES
SOUTHEAST OF THE BIG ISLAND TO 26N150W.  THE JET IS CARRYING VARIOUS
AMOUNTS OF CIRRUS CLOUDS AS IT HEADS EAST AND THEN NORTHEAST.

CONVECTION CONTINUES TO ROIL THE ATMOSPHERE ALONG THE INTERTROPICAL
CONVERGENCE ZONE FAR SOUTH OF HAWAII.  MOST OF THESE UNORGANIZED
SHOWERS AND THUNDERSTORMS ARE LOCATED FROM 05N TO 10.5N BETWEEN 140W
AND 166W.

$$

KINEL

000
FXHW60 PHFO 190635
AFDHFO

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
830 PM HST TUE JUN 18 2013

.SYNOPSIS...
EXPECT TRADE WIND WEATHER TO CONTINUE THROUGH THE FORECAST
PERIOD...THANKS TO PERSISTENT HIGH PRESSURE TO OUR NORTH. CLOUDS AND
SHOWERS WILL FAVOR WINDWARD AND MAUKA AREAS...MAINLY AT NIGHT AND
DURING THE MORNING HOURS. LEEWARD AREAS OF THE BIG ISLAND WILL SEE
INCREASED CLOUDS AND SHOWERS EACH AFTERNOON AND EVENING.

&&

.DISCUSSION...
A 1028 MB HIGH NEAR 33N144W...FAR NORTHEAST OF THE MAIN HAWAIIAN
ISLANDS...HAS AN ASSOCIATED RIDGE WHICH EXTENDS WEST THROUGH
30N170W. THIS RIDGE IS ABOUT 600 MILES NORTH OF THE MAIN HAWAIIAN
ISLANDS AND EASTERLY TRADE WINDS DOMINATE ACROSS LOCAL WATERS.
SATELLITE LOOP SHOWS PATCHY BROKEN LOW CLOUDS EMBEDDED WITHIN TRADE
FLOW ACROSS WINDWARD WATERS. THESE CLOUDS ALSO COVER WINDWARD AND
MAUKA SECTIONS OF THE ISLANDS. RETURN FLOW AND AFTERNOON HEATING
KEEP THICK CLOUD COVER ACROSS LEEWARD AND KAU SECTIONS OF THE BIG
ISLAND THIS EVENING. HOWEVER...UNLIKE WINDWARD CLOUD COVER...WE
EXPECT LEEWARD BIG ISLAND CLOUD COVER WILL DECREASE OVERNIGHT. RADAR
SHOWS ISOLATED TO SCATTERED LIGHT SHOWERS. AFTERNOON SOUNDINGS SHOW
A STRONG INVERSION AT AROUND 7200 FEET...CAPPING THE DEPTH OF
CONVECTION AND KEEPING SHOWERS FAIRLY LIGHT. WATER VAPOR LOOP SHOWS
BROAD UPPER TROUGHING WEST OF THE ISLANDS...WITH AN AREA OF BROKEN
HIGH CLOUDS JUST EAST OF THE ISLANDS MARKING ITS EASTERN FLANK.

MODELS SHOW THE ATMOSPHERE BECOMING DRIER...WITH LOW-LEVEL MOISTURE
GETTING SHALLOWER OVER THE NEXT 24 HOURS. RAINFALL WILL LIKELY
BECOME QUITE SPARSE WEDNESDAY THROUGH FRIDAY. WITH TRADE WINDS
CONTINUING...THIS SPARSE RAINFALL WILL BE CONCENTRATED OVER WINDWARD
AREAS. MODELS ALSO CONTINUE TO SHOW A BIG LOW DEVELOPING NEAR THE
ALEUTIANS OVER THE NEXT COUPLE OF DAYS...WITH THE SUBTROPICAL RIDGE
TO ITS SOUTH WEAKENING AND SHIFTING SOUTHWARD. THAT SHOULD WEAKEN
THE PRESSURE GRADIENT OVER THE ISLANDS AND CAUSE TRADE WIND SPEEDS
TO DROP OFF A BIT WEDNESDAY NIGHT THROUGH THURSDAY NIGHT. THE RIDGE
WILL REBUILD BY THE WEEKEND AND TRADES WILL LIKELY BECOME LOCALLY
BREEZY AGAIN.

&&

.AVIATION...
THERE SHOULD BE LITTLE CHANGE IN AVIATION WEATHER AROUND THE MAIN
HAWAIIAN ISLANDS THROUGH EARLY WEDNESDAY MORNING. CONDITIONS WILL
REMAIN MOSTLY VFR...EXCEPT FOR BRIEF PERIODS OF MVFR CEILINGS OVER
SOME WINDWARD AND MAUKA AREAS.

&&

.MARINE...
A SMALL CRAFT ADVISORY...SCA...IS IN EFFECT THROUGH WEDNESDAY
AFTERNOON FOR LOCALLY STRONG TRADE WINDS AND ROUGH SEAS IN THE
WINDIER AREAS AROUND MAUI AND THE BIG ISLAND. WINDS WILL SUBSIDE
SLIGHTLY WEDNESDAY NIGHT THROUGH THURSDAY NIGHT...PROBABLY ENOUGH TO
ALLOW US TO DROP THE SCA FOR A DAY OR TWO. A SCA IS LIKELY TO GO
BACK UP AGAIN FRIDAY.

SURF WILL BE GENERALLY SMALL EXCEPT FOR MODERATE SURF ALONG EAST
SHORES DUE TO THE TRADE WINDS. A SMALL SOUTHEAST SWELL MAY AFFECT
THE BIG ISLAND STARTING SUNDAY...BUT THE BIG ISLAND WILL LIKELY
BLOCK MOST OF THE SWELL FROM REACHING THE REST OF THE ISLANDS.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
SMALL CRAFT ADVISORY UNTIL 600 PM HST WEDNESDAY FOR MAALAEA BAY...
THE WATERS SOUTH OF THE BIG ISLAND...AND THE PAILOLO AND ALENUIHAHA
CHANNELS.

&&

$$
PUBLIC/MARINE...POWELL
AVIATION...HOUSTON

000
ATHW40 PHFO 190500
SIMHI

HAWAIIAN ISLANDS SATELLITE INTERPRETATION MESSAGE
NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI
0500 UTC WED JUN 19 2013

BASED ON DATA THROUGH 0430 UTC JUNE 19 2013

MOST OF THE BIG ISLAND IS BROKEN TO OVERCAST BELOW 8000 FEET THIS
EARLY EVENING.  ONLY SMALL SECTIONS OF NORTH KOHALA...HAMAKUA...AND
KAU ARE SEEING CLEAR TO PARTLY CLOUDY SKIES AS OF BULLETIN TIME.

LOW CEILINGS ARE PREVALENT IN WINDWARD AND MAUKA AREAS OF THE OTHER
ISLES...INCLUDING THE SOUTH- AND WEST-FACING SLOPES OF HALEAKALA IN
EAST MAUI.  LEEWARD AREAS OF THE SMALLER ISLANDS AND WEST MAUI ARE
PARTLY CLOUDY PREDOMINANTLY...WITH ONLY OCCASIONAL BROKEN CONDITIONS.
LOW CLOUD MOTION IS FROM THE EAST AT 20 TO 25 MPH ACROSS THE ALOHA
STATE.

PATCHES OF BROKEN LOW CLOUDINESS ARE JUST NORTH CLOCKWISE THROUGH
EAST OF MAUI AND HEADING WEST ON THE PREVAILING TRADE FLOW.  PLUME
CLOUDS ARE GENERATING CEILINGS...AT LEAST FROM TIME TO TIME...WEST
OF THE BIG ISLAND...SOUTHWEST OF MAUI COUNTY...AND WEST OF KAUAI.
SKIES ARE OTHERWISE CLEAR TO SCATTERED OVER THE ADJACENT COASTAL
WATERS.

LOOKING AT THE MOST RECENT WATER VAPOR IMAGES...AN UPPER TROUGH...
WHOSE AXIS IS ORIENTED NORTHEAST TO SOUTHWEST AND IS ROUGHLY ALONG A
LINE FROM 30N156W TO 22N165W TO 20N176W...IS NEARLY STATIONARY.  THE
TROUGH IS HELPING TO PRODUCE SHOWERS AND ISOLATED THUNDERSTORM FROM
17N TO 20N BETWEEN 168W AND 172W.  TO THE SOUTH AND SOUTHEAST OF THE
TROUGH IS A JET STREAM WHOSE AXIS IS ALONG A LINE FROM 19N180 TO
16N170W TO 16N160W TO A POINT ABOUT 75 MILES SOUTHEAST OF THE BIG
ISLAND TO 27N150W.  VARIOUS AMOUNTS OF HIGH CLOUDS ARE BEING CARRIED
ALONG WITH THE JET...WITH THE GREATEST CONCENTRATION FLOWING FROM
SOUTHWEST TO NORTHEAST IN THE AREA TO THE EAST AND NORTHEAST OF THE
BIG ISLAND.

UNORGANIZED CONVECTION IS FIRING FAR SOUTH OF HAWAII ALONG THE
INTERTROPICAL CONVERGENCE ZONE.  IT HAS DECREASED IN INTENSITY OVER
THE PAST FEW HOURS.  MOST OF THE ACTIVITY IS LOCATED FROM 05N TO 10N
BETWEEN 140W AND 169W.

$$

KINEL

000
FXHW60 PHFO 190144
AFDHFO

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
400 PM HST TUE JUN 18 2013

.SYNOPSIS...
TYPICALLY QUIET JUNE WEATHER WILL CONTINUE AS SPRING GIVES WAY TO
SUMMER. HIGH PRESSURE TO THE NORTH WILL KEEP TRADE WINDS BLOWING.
SHOWERS WILL BE FOCUSED OVER WINDWARD AREAS...AND THESE SHOWERS WILL
BE MOST ACTIVE DURING THE NIGHTS AND MORNINGS. THERE MAY ALSO BE
SOME AFTERNOON SHOWERS OVER LEEWARD AREAS OF THE BIG ISLAND AND
MAUI...BUT RAINFALL WILL BE LIGHT.

&&

.DISCUSSION...
SUMMER WILL START THURSDAY EVENING AT 705 PM HST. THIS IS USUALLY
THE DRIEST TIME OF YEAR FOR MOST AREAS OF THE MAIN HAWAIIAN ISLANDS.
SATELLITE AND RADAR LOOPS AND SURFACE OBSERVATIONS SHOW TYPICALLY
QUIET WEATHER THIS EVENING. THERE ARE PATCHY SCATTERED TO BROKEN
LOW CLOUDS OVER THE ISLANDS WITH SCATTERED LOW CLOUDS UPSTREAM.
RADARS SHOW ONLY ISOLATED LIGHT SHOWERS MOVING OVER THE ISLANDS FROM
THE EAST IN THE LOCALLY BREEZY TRADEWIND FLOW.

THE COMPUTER MODELS SHOW THE ATMOSPHERE BECOMING DRIER AND THE
LOW-LEVEL MOISTURE GETTING SHALLOWER OVER THE NEXT 24 HOURS...SO
RAINFALL IS LIKELY TO BE QUITE SPARSE TOMORROW THROUGH FRIDAY. WITH
TRADE WINDS CONTINUING...WHAT RAINFALL WE DO GET WILL BE
CONCENTRATED OVER WINDWARD AREAS. CLIMATOLOGY SHOWS A SUMMERTIME
PEAK IN RAINFALL OVER SOUTH KONA...BUT IT LOOKS AS IF THE LEEWARD
SIDE OF THE BIG ISLAND WILL REMAIN QUITE DRY.

COMPUTER MODELS CONTINUE TO SHOW A BIG LOW DEVELOPING UP NEAR THE
ALEUTIANS OVER THE NEXT COUPLE OF DAYS AND SHOW THE SUBTROPICAL
RIDGE WEAKENING AND SHIFTING SOUTH. THAT SHOULD WEAKEN THE PRESSURE
GRADIENT OVER THE ISLANDS AND CAUSE TRADE-WIND SPEEDS TO DROP OFF A
BIT WEDNESDAY NIGHT THROUGH THURSDAY NIGHT. THE RIDGE WILL RE-BUILD
BY THE WEEKEND AND TRADES WILL LIKELY BECOME LOCALLY BREEZY AGAIN.

&&

.AVIATION...
THERE SHOULD BE LITTLE CHANGE IN AVIATION WEATHER AROUND THE MAIN
HAWAIIAN ISLANDS THROUGH AT LEAST THE NEXT 24 HOURS. CONDITIONS WILL
REMAIN MOSTLY VFR EXCEPT FOR ISOLATED MVFR CEILINGS OVER WINDWARD
AND MOUNTAIN AREAS.

&&

.MARINE...
A SMALL CRAFT ADVISORY...SCA...IS NOW UP THROUGH EARLY WEDNESDAY
EVENING FOR LOCALLY STRONG TRADE WINDS AND ROUGH SEAS IN THE WINDIER
AREAS AROUND MAUI AND THE BIG ISLAND. WINDS WILL SUBSIDE SLIGHTLY
WEDNESDAY NIGHT THROUGH THURSDAY NIGHT...PROBABLY ENOUGH TO ALLOW US
TO DROP THE SCA FOR A DAY OR TWO. A SCA IS LIKELY TO GO BACK UP
AGAIN FRIDAY.

SURF WILL BE GENERALLY SMALL EXCEPT FOR MODERATE SURF ALONG EAST
SHORES DUE TO THE TRADE WINDS. A SMALL SOUTHEAST SWELL MAY AFFECT
THE BIG ISLAND STARTING SUNDAY...BUT THE BIG ISLAND WILL LIKELY
BLOCK MOST OF THE SWELL FROM REACHING THE REST OF THE ISLANDS.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
SMALL CRAFT ADVISORY UNTIL 600 PM HST WEDNESDAY FOR MAALAEA BAY...
THE WATERS SOUTH OF THE BIG ISLAND...AND THE PAILOLO AND ALENUIHAHA
CHANNELS.

&&

$$
DONALDSON

000
FXHW60 PHFO 181951
AFDHFO

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
1000 AM HST TUE JUN 18 2013

.SYNOPSIS...
TYPICALLY QUIET JUNE WEATHER WILL CONTINUE AS SPRING GIVES WAY TO
SUMMER. HIGH PRESSURE TO THE NORTH WILL KEEP TRADE WINDS BLOWING.
SHOWERS WILL BE FOCUSED OVER WINDWARD AREAS...AND THESE SHOWERS WILL
BE MOST ACTIVE DURING THE NIGHTS AND MORNINGS. THERE MAY ALSO BE
SOME AFTERNOON SHOWERS OVER LEEWARD AREAS OF THE BIG ISLAND AND MAUI.

&&

.DISCUSSION...
SUMMER WILL START THURSDAY EVENING AT 705 PM HST. THIS IS USUALLY
THE DRIEST TIME OF YEAR FOR MOST AREAS OF THE MAIN HAWAIIAN ISLANDS.
SATELLITE AND RADAR LOOPS AND SURFACE OBSERVATIONS SHOW TYPICALLY
QUIET WEATHER THIS MORNING. THERE ARE PATCHY BROKEN LOW CLOUDS OVER
WINDWARD AREAS AND SCATTERED LOW CLOUDS OVER LEEWARD AREAS. LOW
CLOUDS ARE SCATTERED TO BROKEN UPSTREAM TO THE EAST OF THE ISLANDS
AND RADARS SHOW SCATTERED...LIGHT TO MODERATE SHOWERS ARE MOVING
OVER THE ISLANDS FROM THE EAST IN THE LOCALLY BREEZY TRADEWIND FLOW.

THE COMPUTER MODELS SHOW THE ATMOSPHERE BECOMING DRIER AND THE
LOW-LEVEL MOISTURE GETTING SHALLOWER OVER THE NEXT 24 HOURS.
RAINFALL IS LIKELY TO BE QUITE SPARSE TOMORROW THROUGH FRIDAY. WITH
TRADE WINDS CONTINUING...WHAT RAINFALL WE DO GET WILL BE
CONCENTRATED OVER WINDWARD AREAS. CLIMATOLOGY SHOWS A SUMMERTIME
PEAK IN RAINFALL OVER SOUTH KONA...BUT IT LOOKS AS IF THE LEEWARD
SIDE OF THE BIG ISLAND WILL REMAIN QUITE DRY.

THE COMPUTER MODELS ALL SHOW A BIG...DEEP LOW DEVELOPING UP NEAR THE
ALEUTIANS OVER THE NEXT COUPLE OF DAYS AND SHOW THE SUBTROPICAL
RIDGE WEAKENING AND SHIFTING SOUTH. THAT SHOULD WEAKEN THE PRESSURE
GRADIENT OVER THE ISLANDS AND CAUSE TRADE-WIND SPEEDS TO DROP OFF A
BIT WEDNESDAY THROUGH FRIDAY. THE RIDGE WILL RE-BUILD BY THE WEEKEND
AND TRADES WILL LIKELY BECOME LOCALLY BREEZY AGAIN.

&&

.AVIATION...
THERE SHOULD BE LITTLE CHANGE IN AVIATION WEATHER AROUND THE MAIN
HAWAIIAN ISLANDS THROUGH AT LEAST THE NEXT 24 HOURS. CONDITIONS WILL
REMAIN MOSTLY VFR EXCEPT FOR ISOLATED MVFR CEILINGS OVER WINDWARD
AND MOUNTAIN AREAS.

&&

.MARINE...
A SMALL CRAFT ADVISORY...SCA...IS UP THROUGH EARLY WEDNESDAY
MORNING FOR LOCALLY STRONG TRADE WINDS AND ROUGH SEAS IN THE WINDIER
AREAS AROUND MAUI AND THE BIG ISLAND. WINDS WILL SUBSIDE SLIGHTLY
WEDNESDAY THROUGH FRIDAY...PROBABLY ENOUGH TO ALLOW US TO DROP THE
SCA FOR A COUPLE OF DAYS. A SCA IS LIKELY TO GO BACK UP AGAIN BY
FRIDAY NIGHT.

SURF WILL BE GENERALLY SMALL EXCEPT FOR MODERATE SURF ALONG EAST
SHORES DUE TO THE TRADE WINDS. A SMALL SOUTHEAST SWELL MAY AFFECT
THE BIG ISLAND STARTING SUNDAY...BUT THE BIG ISLAND WILL LIKELY
BLOCK MOST OF THE SWELL FROM REACHING THE REST OF THE ISLANDS.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
SMALL CRAFT ADVISORY UNTIL 600 AM HST WEDNESDAY FOR MAALAEA BAY...
THE WATERS SOUTH OF THE BIG ISLAND...AND THE PAILOLO AND ALENUIHAHA
CHANNELS.

&&

$$
DONALDSON

000
FXHW60 PHFO 181415
AFDHFO

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
345 AM HST TUE JUN 18 2013

.SYNOPSIS...
A TRADE WIND WEATHER REGIME WILL CONTINUE INTO THE UPCOMING WEEKEND
WITH SHOWERS FAVORING MAINLY THE WINDWARD AND MOUNTAIN AREAS...
ESPECIALLY DURING THE NIGHTS AND MORNINGS.

&&

.DISCUSSION...
A BROAD SURFACE HIGH PRESSURE SYSTEM LOCATED 1100 MILES NORTHEAST
OF THE ISLANDS IS FORECAST TO REMAIN IN THAT VICINITY INTO THE
UPCOMING WEEKEND. THUS...ISLANDS WILL CONTINUE TO BENEFIT THE
COOLING TRADES THAT THE HIGH PRODUCES. THE STRENGTH OF THE TRADES
IS SLATED TO EASE OFF SLIGHTLY BY WEDNESDAY NIGHT INTO THE MODERATE
RANGE...BUT IT WILL REBOUND INTO THE LOCALLY STRONG ABOUT THE FRIDAY
NIGHT TIME FRAME. THIS WEAKENING OF THE TRADES COMES ABOUT AS THE
HIGH AND ASSOCIATED RIDGE ARE BEING TESTED BY A FRONT THAT WILL NOT
INFLUENCE THE ISLANDS. THE FRONT WEAKENS...AND BOTH RIDGE AND HIGH
REBUILD LATE IN THE WEEK RESULTING IN THE STRONGER TRADES OVER THE
WEEKEND...AND PERHAPS DAYS THEREAFTER.

NO REAL SIGNIFICANT CHANGE IN THE NEXT 48 HOURS. THE DEPTH OF THE
MARINE LAYER IS SLATED TO TOP 8000 FEET. THE LAYER WILL BE
MOIST...AND WITH OROGRAPHIC INFLUENCE AND BREEZY TRADES...THE END
RESULT IS PASSING SHOWERS FAVORING THE NIGHTS AND MORNINGS. THE
SOURCE OF THIS LOW LEVEL MOISTURE LIES JUST UPWIND OF THE BIG ISLAND
AND MAUI...AS PART OF A LARGE CLOUD MASS COVERING A SWATH OF AREA
BETWEEN THE ISLANDS AND WEST COAST. THE CLOUD MASS STARTS OFF AS
STABLE STRATUS OFF THE WEST COAST BUT BECOME UNSTABLE CUMULUS JUST
UPWIND OF THE ISLANDS.

SOME GOOD NEWS INSIGHT. THE GFS SOLUTION IS POINTING TO A SHALLOWER
MARINE LAYER WITH THE INVERSION LOWERING TO 5 TO 7 THOUSAND FEET BY
THURSDAY NIGHT...THANKS TO A STRONGER MID LEVEL RIDGE. THE MARINE
LAYER IS EXPECTED TO BE SLIGHTLY DRIER...SO WITH THAT SAID...WE ARE
LOOKING AT A DRIER TRADE WIND REGIME THE SECOND HALF OF THE WEEK
THAT MAY LAST INTO THE UPCOMING WEEKEND. THERE WILL STILL BE
SHOWERS...JUST FEWER.

HIGH LEVEL CIRRUS IS PRESENT OVER THE BIG ISLAND THIS MORNING THANKS
TO AN UPPER LOW NEAR KAUAI AND SOUTHERLY WINDS TO THE EAST OF IT
CARRYING MOISTURE NORTHWARD FROM THE LOWER LATITUDES. BUT AS THIS
LOW FILLS LATER TODAY...THE CIRRUS SHOULD BE MOVING OUT.

&&

.MARINE...
THE SMALL CRAFT ADVISORY /SCA/ IS IN EFFECT TO UNTIL 6 AM HST
WEDNESDAY FOR THE WINDIER PLACES AROUND MAUI AND THE BIG ISLAND.
THE SCA WILL BE MONITORED CLOSELY IF IT NEEDS TO BE EXTENDED.
BUT THE TRADES ARE EXPECTED TO EASE SLIGHTLY BY WEDNESDAY NIGHT
ALLOWING THE SCA TO BE DROPPED. THE TRADES ARE EXPECTED TO FIRM UP
BY THE WEEKEND...WITH POSSIBLE SCA CONDITIONS RETURNING TO THE
WINDIER COASTAL WATERS AROUND MAUI AND THE BIG ISLAND. MODERATE SURF
ALONG EAST SHORES DUE TO THE TRADE WINDS.


&&

AVIATION...
THERE WILL AREAS OF MVFR CEILINGS FAVORING THE WINDWARD AND MOUNTAIN
AREAS OF THE LARGER ISLANDS THIS MORNING...AND BRIEF MVFR CEILINGS
AND VIS WITH THE SHOWERS RIDING IN WITH THE TRADES. SOME OF THE
SHOWERS WILL BE FREQUENTING THE AREAS IMMEDIATELY SOUTH OF THE
MOUNTAIN RANGES OF THE SMALLER ISLANDS.

.HFO WATCHES/WARNINGS/ADVISORIES...
SMALL CRAFT ADVISORY UNTIL 6 AM HST WEDNESDAY FOR MAALAEA BAY...THE
PAILOLO AND ALENUIHAHA CHANNELS...AND WATERS SOUTH OF THE BIG ISLAND.


&&

$$

LAU