High Surf in Hawaii, February 15 to 27, 2013

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
330 AM HST FRI FEB 15 2013

.SYNOPSIS...
TRADE WINDS WILL GRADUALLY INCREASE THROUGH MIDWEEK NEXT WEEK 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 LATER TODAY 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 REMAIN AT OR ABOVE 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.

UPPER RIDGING WHICH HAS KEPT OUR AIRMASS RATHER STABLE 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.

AN AREA OF INCREASED MOISTURE A FEW HUNDRED MILES TO THE EAST OF THE
STATE WILL MOVE OVER US TODAY AND SATURDAY...RESULTING IN INCREASED
WINDWARD AND MAUKA SHOWERS. THE BIG ISLAND WILL SEE THESE INCREASED
SHOWERS FIRST LATER TODAY. 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 TO LEEWARD
AREAS OF THE SMALLER ISLANDS AT TIMES.

&&

.MARINE...
A SMALL CRAFT ADVISORY REMAINS 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 NORTHWEST SWELL WILL PEAK TODAY...PRODUCING SURF AT ADVISORY
LEVELS ALONG EXPOSED SHORES...THEN LOWER SLOWLY TONIGHT 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 UNTIL 6 AM HST SATURDAY FOR NORTH AND WEST FACING
SHORES OF NIIHAU KAUAI OAHU AND MOLOKAI...AND FOR NORTH FACING
SHORES OF MAUI.

&&

POWELL