High Surf in Hawaii, April 13 to 17, 2008

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
400 AM HST SUN APR 13 2008

.SYNOPSIS...
STRONG HIGH PRESSURE NORTH OF THE STATE WILL MAINTAIN BREEZY TRADE
WINDS THROUGH TUESDAY. SHOWERS WILL AFFECT MAINLY WINDWARD AND MAUKA
AREAS...AND MAY DRIFT TO THE LEE AREAS OF THE SMALLER ISLANDS AT
TIMES. AN UPPER TROUGH WEST OF THE ISLANDS CONTINUES TO PRODUCE
SOME HIGH CLOUDS OVER PORTIONS OF THE STATE. A SURFACE TROUGH IS
FORECAST TO DEVELOP NORTHWEST OF THE STATE BEGINNING LATE TUESDAY
INTO WEDNESDAY...RESULTING IN LIGHTER WINDS.

&&

.DISCUSSION...
PATCHES OF LOW CLOUDS HAVE REACHED WINDWARD MAUI AND BIG ISLAND
THIS MORNING...BRINGING SOME SHOWERS. ELSEWHERE IT HAS BEEN QUIET
WEATHER WISE...WITH ONLY FEW PASSING CLOUDS AND SHOWERS. HENCE NOT
MUCH PRECIPITATION WAS REPORTED IN THE LATEST RAINFALL SUMMARY.
THERE ARE STILL MORE SCATTERED CLOUDS JUST EAST OF THE
ISLANDS...AND THESE WILL AFFECT THE STATE LATER THIS MORNING.
MORNING LIHUE AND HILO SOUNDINGS ACTUALLY HINT A WEAK INVERSION WITH
THE BASE AT ABOUT 6K FEET. DO EXPECT THIS TO CHANGE AS MORE LOW
LEVEL MOISTURE PASSES THE ISLANDS LATER TODAY. HIGH CLOUDS CONTINUE
TO COVER KAUAI AND NIIHAU THIS MORNING...AND SHOULD INCREASE
EASTWARD THROUGH THE REST OF MORNING AS THE PERSISTENT UPPER
LEVEL TROUGH WEST OF THE STATE CONTINUE TO PRODUCE THESE HIGH CLOUDS.

STRONG HIGH PRESSURE SYSTEM WILL BE NORTH OF THE MAIN HAWAIIAN
ISLANDS FOR THE NEXT FEW DAYS...BRINGING BREEZY TRADE WINDS TO MOST
OF THE STATE. THERE IS A WEAKENING NEARLY STATIONARY SHEAR LINE
NORTH OF THE ISLANDS AND IT IS KEEPING THE STRONGEST WINDS NORTH OF
THE ISLANDS. AT ANY RATE...TRADE WIND WEATHER IS TO PREVAIL OVER
THE REGION THROUGH NEXT FEW DAYS...WITH PASSING CLOUDS AND SHOWERS
AFFECTING MAINLY THE WINDWARD AND MAUKA AREAS. WINDS WILL BE STRONG
ENOUGH TO CARRY SOME SHOWERS TO THE LEE AREAS OF THE SMALLER
ISLANDS AS WELL.

A SURFACE TROUGH OF LOW PRESSURE IS EXPECTED TO DEVELOP WEST OF THE
ISLANDS BY LATE TUESDAY INTO WEDNESDAY. THE WINDS WILL TURN MORE
SOUTHERLY OVER THE SMALLER ISLANDS AND BECOMING LIGHTER...WHILE BIG
ISLAND SHOULD REMAIN MORE IN THE TRADE WIND REGIME. HAVE KEPT THE
HAZE OFF THE SMALLER ISLANDS AT THIS POINT IN THE FORECAST
PACKAGE...AS IT IS POSSIBLE THAT THE VOLCANIC EMISSION WILL TAKE A
MORE EASTERLY DIRECTION BEFORE TURNING NORTH. ON THE OTHER HAND...AM
NOT SURPRISED IF SOME OF THE EMISSION REACHING THE WESTERN ISLANDS.
FORECAST CHARTS INDICATE AIR MASS WILL BE UNSTABLE THOUGH NOT MUCH
ORGANIZED LOW LEVEL MOISTURE IS EXPECTED...EXCEPT FOR KAUAI
VICINITY. THUS IT IS POSSIBLE FOR HEAVIER SHOWERS TO
DEVELOP...SPECIALLY WINDWARD AND MOUNTAIN AREAS AS WELL AS KAUAI
VICINITY.

FORECAST CHARTS INDICATE THIS TROUGH WILL WEAKEN ENOUGH TOWARDS THE
NEXT WEEK FOR TRADE WINDS TO RETURN TO ALL ISLANDS. LOOKS LIKE THE
TYPICAL TRADE WIND WEATHER WILL RETURN THEN.

&&

.MARINE...
HAVE POSTED SMALL CRAFT ADVISORY FOR ALMOST ALL WATERS AND CHANNEL
EXCEPT MAUI COUNTY AND OAHU LEEWARD WATERS DUE TO INCREASING WIND
AND SEAS. THE BREEZY TRADES WILL ALSO LIKELY PRODUCE ADVISORY LEVEL
ROUGH SURF ALONG EAST FACING SHORES BY LATER TODAY. A SERIES OF
SMALL SWELLS WILL AFFECT NORTH FACING SHORES OVER THE NEXT SEVERAL
DAYS WITH THE PRIMARILY SWELL DIRECTION SWINGING AROUND FROM THE
NORTHWEST TO THE NORTH NORTHEAST WITH TIME. THESE NORTH SWELLS MAY
ALSO CAUSE HARBOR SURGES FOR THE NORTH FACING HARBORS...PARTICULARLY
KAHULUI AND HILO.

A PAIR OF SOUTH SWELLS ARE STILL EXPECTED THIS WEEK...BRINGING SMALL
TO MODERATE SURF TUESDAY AND WEDNESDAY...AND LARGER SURF THURSDAY
AND FRIDAY.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
SMALL CRAFT ADVISORY TILL 6 AM HST MONDAY FOR ALL COASTAL WATERS AND
CHANNELS EXCEPT MAUI COUNTY AND OAHU LEEWARD WATERS.

&&

HUI