Weather Service Report


553 
FXHW60 PHFO 280652
AFDHFO

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
830 PM HST WED AUG 27 2014

.SYNOPSIS...
TRADE WINDS WILL SLOWLY WEAKEN OVERNIGHT INTO THURSDAY. LIGHT TRADE 
WINDS WILL ALLOW AFTERNOON SEA BREEZES TO DEVELOP OVER LEEWARD AREAS 
THROUGH THE WEEKEND...WITH SOME AFTERNOON AND EVENING CLOUDS AND 
SHOWERS OVER LEEWARD AND INTERIOR AREAS...FOLLOWED BY NIGHTTIME 
CLEARING. TRADE WINDS MAY STRENGTHEN SOMEWHAT NEXT WEEK.

&&

.DISCUSSION...
MODERATE TRADE WINDS CONTINUE THIS EVENING AS A HIGH PRESSURE 
REMAINS FAR NORTH OF THE ISLANDS. PASSING SHOWERS EMBEDDED IN THE 
TRADE WIND FLOW WILL AFFECT MAINLY WINDWARD AND MOUNTAIN AREAS. 
ALTHOUGH AIR MASS IS MARGINALLY STABLE IN THE ISLAND VICINITY...AS 
REVEALED BY AFTERNOON SOUNDINGS FROM HILO AND LIHUE...RADAR DATA 
INDICATE THESE SHOWERS WILL BE HEAVY ENOUGH TO BE MEASURABLE. EXPECT 
TYPICAL TRADE WIND WEATHER TO LAST THROUGH REST OF THIS EVENING INTO 
EARLY THURSDAY MORNING.

A CHANGE IN THE WEATHER IS COMING...AS THE HIGH FAR NORTH WEAKENS 
WHILE A LOW PRESSURE SYSTEM FROM THE EAST PACIFIC PASSES NORTH OF 
THE STATE IN THE NEXT FEW DAYS. WINDS WILL BECOME LIGHT ENOUGH TO 
ALLOW LAND AND SEA BREEZES TO DEVELOP DURING NIGHTS AND DAYS. 
A MORE CONVECTIVE WEATHER PATTERN IS EXPECTED  OVER THE STATE WITH 
CLOUDS AND SHOWERS OVER THE ISLANDS IN THE AFTERNOON AND EARLY 
EVENING HOURS UNDER THE CONVERGING SEA BREEZES WHILE SOME CLEARING 
WILL OCCUR OVER THE ISLANDS AT NIGHT UNDER THE DIVERGING LAND 
BREEZES. AIR MASS IS FORECAST TO REMAIN SOMEWHAT STABLE IN THE 
ISLAND VICINITY AS THERE WILL BE UPPER LEVEL RIDGING...THUS 
ATMOSPHERIC CONDITIONS WILL BE UNFAVORABLE FOR HEAVIER 
PRECIPITATION TO DEVELOP.

THIS CONVECTIVE WEATHER PATTERN LOOKS TO STAY AT LEAST THROUGH THE 
REST OF THE WEEK INTO EARLY NEXT WEEK. FORECAST MODELS HINT THE 
DEVELOPMENT OF A LOW PRESSURE SYSTEM FAR NORTH NORTHWEST OF THE 
ISLANDS EARLY NEXT WEEK. STRONGER TRADE WINDS MAY RETURN TO THE 
ISLANDS...THOUGH THAT DEPENDS ON HOW FAR THIS LOW PRESSURE SYSTEM 
WILL ACTUALLY BE. THE CURRENT EXTENDED FORECAST LOOKS OKAY FOR NOW.

&&

.AVIATION...
VFR CONDITIONS PREVAIL AT ALL TAF SITES AND ARE EXPECTED TO CONTINUE 
OVERNIGHT INTO EARLY THURSDAY. WINDWARD AND MOUNTAIN AREAS WILL 
LIKELY EXPERIENCE BRIEF MVFR CEILING CONDITIONS DUE TO PASSING LOW 
CLOUDS...WHILE BRIEF MVFR CEILING CONDITIONS MAY AFFECT THE KONA AND 
KAU SLOPES THROUGH THE REST OF THIS EVENING DUE TO LINGERING LOW 
CLOUDS.

NO AIRMET IS ANTICIPATED.

&&

.MARINE...
AN ABNORMALLY LONG-PERIOD SWELL FROM HURRICANE MARIE WILL ARRIVE
OVERNIGHT AND BUILD THROUGH THURSDAY NIGHT. THIS SWELL WILL BRING 
ADVISORY LEVEL SURF TO EAST FACING SHORES THURSDAY AND FRIDAY. WHILE 
SURF HEIGHTS ARE NOT EXPECTED TO BE EXCEPTIONALLY HIGH...LONG PERIOD 
SWELL ENERGY FROM THE EAST IS SOMEWHAT UNUSUAL...AND MAY LEAD TO 
NORMALLY SHELTERED WINDWARD LOCALES SEEING LARGER LONG PERIOD WAVES 
AND STRONG CURRENTS.

ALSO...A MODERATE SOUTH SWELL WILL ARRIVE TONIGHT...AND BUILD 
THROUGH THURSDAY...BRINGING ADVISORY LEVEL SURF ALONG SOUTH FACING 
SHORES THURSDAY AND FRIDAY. STRONG CURRENTS WILL DEVELOP IN SOME 
AREAS DUE THE INTERACTION BETWEEN THESE TWO SWELLS. THE SURF FROM 
BOTH SWELLS WILL SLOWLY DECLINE OVER THE WEEKEND.

AS WINDS DIMINISH FURTHER...NO SMALL CRAFT WIND CONDITIONS ARE 
EXPECTED THROUGH THE HOLIDAY WEEKEND. HOWEVER...THE LONG PERIOD 
EASTERLY AND SOUTHERLY SWELL MENTIONED ABOVE COULD BRING CONFUSED 
SEAS FOR AREAS EXPOSED TO BOTH SWELLS.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
HIGH SURF ADVISORY FROM 6 AM THURSDAY TO 6 AM HST SATURDAY FOR 
NIIHAU-KAUAI WINDWARD-KAUAI LEEWARD-OAHU SOUTH SHORE-WAIANAE 
COAST-OAHU KOOLAU-OLOMANA-MOLOKAI-LANAI MAKAI-KAHOOLAWE-MAUI 
WINDWARD WEST-MAUI LEEWARD WEST-MAUI CENTRAL VALLEY-WINDWARD 
HALEAKALA-LEEWARD HALEAKALA-KONA-SOUTH BIG ISLAND-BIG ISLAND 
NORTH AND EAST.


&&

$$

HUI



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