037 
FXHW60 PHFO 150630
AFDHFO

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
830 PM HST THU FEB 14 2013

.SYNOPSIS...
TRADE WINDS WILL GRADUALLY INCREASE OVER THE NEXT SEVERAL DAYS AND 
BECOME RATHER BREEZY AS HIGH PRESSURE BUILDS IN TO THE NORTH OF THE 
STATE. CLOUDS AND SHOWERS WILL FAVOR WINDWARD AND MAUKA AREAS...WITH 
ONLY ISOLATED SHOWERS EXPECTED OVER LEEWARD LOCATIONS. SHOWERS MAY 
INCREASE ACROSS THE SMALLER ISLANDS THIS WEEKEND AS AN UPPER LEVEL 
TROUGH APPROACHES. SHOWERS WILL INCREASE ACROSS WINDWARD PORTIONS OF 
THE BIG ISLAND BEGINNING FRIDAY AS AN AREA OF MOISTURE EMBEDDED IN 
THE TRADES ARRIVES.

&&

.DISCUSSION...
SURFACE HIGH PRESSURE WILL GRADUALLY STRENGTHEN TO OUR NORTH 
THROUGH THE WEEKEND...THEN CONTINUE STRENGTHENING INTO THE MIDDLE 
OF NEXT WEEK. TRADE WIND SPEEDS WILL INCREASE TO SMALL CRAFT 
ADVISORY LEVELS ACROSS LOCAL WATERS THROUGH MUCH OF THE FORECAST 
PERIOD...WITH WINDIER CHANNELS AND WATERS POSSIBLY REQUIRING GALE 
WARNINGS EARLY NEXT WEEK. 

RIDGING ALOFT WILL KEEP OUR AIRMASS RATHER STABLE THROUGH TONIGHT. 
THIS UPPER RIDGE WILL WEAKEN OVER THE NEXT COUPLE OF DAYS AND SHIFT 
NORTHWARD. AN UPPER LEVEL LOW IS FORECAST TO DEVELOP TO THE EAST 
NORTHEAST OF THE STATE WITH ITS ASSOCIATED TROUGH AXIS EXTENDING 
WESTWARD TO A POSITION JUST SOUTH OF THE BIG ISLAND. THIS WILL CAUSE 
A SLIGHT DESTABILIZATION OF THE ATMOSPHERE...MAINLY OVER THE EAST 
END OF THE STATE. EARLY NEXT WEEK...THE UPPER LOW IS FORECAST TO 
DRIFT A BIT TO THE NORTHWEST ALONG WITH ITS ASSOCIATED TROUGH AXIS. 
THIS WILL CAUSE THE INSTABILITY TO SHIFT TO THE NORTHWEST AS WELL. 
THE LOW AND TROUGH ARE THEN EXPECTED TO LINGER AROUND THE AREA INTO 
THE MIDDLE OF NEXT WEEK.

EXPECT RATHER DRY CONDITIONS TO CONTINUE TONIGHT AND...FOR THE 
SMALLER ISLANDS...THROUGH FRIDAY. AN AREA OF INCREASED MOISTURE A 
FEW HUNDRED MILES TO THE EAST OF THE STATE WILL MOVE OVER US FRIDAY 
AND SATURDAY...RESULTING IN INCREASED WINDWARD AND MAUKA SHOWERS. 
THE BIG ISLAND WILL SEE THESE INCREASED SHOWERS FIRST. WITH THE 
UPPER TROUGH IN OUR VICINITY EARLY NEXT WEEK...PASSING SHOWERS WILL 
CONTINUE TO FAVOR WINDWARD AND MAUKA AREAS. SHOWER COVERAGE AND 
INTENSITY WILL BE HIGHLY DEPENDENT ON MOISTURE AVAILABILITY WITHIN 
THE TRADE FLOW. WITH THE STRONGER TRADE WINDS...ISOLATED SHOWERS 
WILL MAKE IT OVER SOME LEEWARD AREAS OF THE SMALLER ISLANDS AT 
TIMES. 

&&

.MARINE...
A SMALL CRAFT ADVISORY IS IN EFFECT FOR ALL HAWAIIAN WATERS DUE TO 
EITHER HIGH COMBINED SEAS OR FOR STRENGTHENING TRADE WINDS...OR FOR 
BOTH. WHILE THIS ADVISORY IS IN EFFECT THROUGH SATURDAY 
AFTERNOON...IT MAY NEED TO BE EXTENDED INTO EARLY NEXT WEEK. WINDS 
MAY BECOME STRONG ENOUGH EARLY NEXT WEEK TO REQUIRE GALE WARNINGS 
FOR THE WINDIEST AREAS SUCH AS THE ALENUIHAHA CHANNEL. 

A NEW NORTHWEST SWELL WILL BUILD IN TONIGHT...PEAK ON FRIDAY AT 
ADVISORY LEVELS...THEN LOWER SLOWLY FRIDAY NIGHT AND SATURDAY. A 
SLIGHTLY LARGER AND LONGER PERIOD NORTHWEST SWELL WILL BEGIN TO 
ARRIVE LATE SATURDAY...PEAK ON SUNDAY AT HIGH END ADVISORY 
LEVELS...THEN LOWER SLOWLY MONDAY AND TUESDAY. THE STRENGTHENING 
TRADE WINDS WILL LIKELY CAUSE ADVISORY LEVEL SURF ALONG EAST FACING 
SHORES OVER THE WEEKEND AND INTO EARLY NEXT WEEK. 

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
SMALL CRAFT ADVISORY UNTIL 6 PM HST SATURDAY FOR ALL HAWAIIAN 
COASTAL WATERS.

HIGH SURF ADVISORY FROM MIDNIGHT TONIGHT TO 6 AM HST SATURDAY FOR 
NORTH AND WEST FACING SHORES OF NIIHAU KAUAI OAHU AND MOLOKAI...AND 
FOR NORTH FACING SHORES OF MAUI.

&&

$$

POWELL