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

THE WEATHER PREDICTION CENTER

COLLEGE PARK, MD

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HAWAII EXTENDED FORECAST DISCUSSION

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HAWAII EXTENDED FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
716 AM EDT TUE JUN 18 2013

VALID 00Z WED JUN 19 2013 - 00Z WED JUN 26 2013

THE MODELS AND ENSEMBLES CONTINUE TO REASONABLY AGREE THAT HIGH
PRESSURE CENTERED NORTHEAST OF HAWAII AND REINFORCING HIGH
PRESSURE TO THE NORTH OF THE STATE WILL SUPPORT MODERATE TO AT
TIMES LOCALLY BRISK ISLAND TRADES FOR MUCH OF THE UPCOMING WEEK. 
IN THIS PATTERN EXPECT MAINLY WINDWARD TERRAIN BASED SHOWERS. 
FORECAST SPREAD/UNCERTAINTY REMAINS ABOUT NORMAL THIS WEEK AND
PREFERENCE IS FOR A COMPOSITE MASS FIELD SOLUTION.

SCHICHTEL

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Last Updated: 716 AM EDT TUE JUN 18 2013

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