FXHW60 PHFO 210635

AFDHFO



AREA FORECAST DISCUSSION

NATIONAL WEATHER SERVICE HONOLULU HI

830 PM HST SAT MAR 20 2010



.SYNOPSIS...

TRADE WINDS WILL WEAKEN SUNDAY AS A SURFACE HIGH FAR NORTH NORTHEAST

MOVES EAST. WINDS WILL BE LIGHT AND VARIABLE MONDAY. WETTER WEATHER 

IS EXPECTED MONDAY EVENING AND TUESDAY WITH A CHANCE OF HEAVY 

SHOWERS AS THE AIR MASS BECOMES UNSTABLE. LIGHT TO MODERATE TRADES 

WILL RETURN BY THE MIDDLE OF NEXT WEEK.



&&



.DISCUSSION...

SCATTERED LOW CLOUDS MOVE ACROSS THE ISLANDS THIS EVENING UNDER 

TRADE WIND FLOW. THERE ARE SOME EMBEDDED SHOWERS WITH THE 

CLOUDS...THOUGH RAINFALL AMOUNTS ARE SOMEWHAT LIMITED AS THE WIND 

CARRIES THE SHOWERS AWAY RATHER SWIFTLY. THERE IS AN EXTENSIVE AREA 

OF LOW CLOUDS A LITTLE UPSTREAM EAST OF THE BIG ISLAND THIS EVENING. 

THIS WILL REACH THE WINDWARD BIG ISLAND LATER TONIGHT...BRINGING 

MORE SHOWERS. THE SHOWERS MAY SPREAD TO THE REST OF THE ISLAND CHAIN 

OVERNIGHT INTO EARLY SUNDAY. TRADE WIND WEATHER WILL CONTINUE 

SUNDAY...AS A HIGH PRESSURE FAR NORTH NORTHWEST OF THE ISLANDS IS 

STILL THE MAIN WEATHER FEATURE AFFECTING THE ISLAND WEATHER.



TRADE WIND WEATHER WILL TAKE A BREAK ON MONDAY AS THE SURFACE HIGH 

MOVES AWAY FAR EAST IN RESPONSE TO THE PASSING OF A COLD FRONT FAR 

NORTH OF THE ISLAND. A SURFACE TROUGH WILL EXTEND FROM THIS FRONT TO 

NEAR THE MAIN HAWAIIAN ISLANDS MONDAY. WINDS WILL BECOME LIGHT DUE 

TO THE CLOSE PRESENT OF THE TROUGH...AND MAY TURN SOUTHEAST WITH 

AFTERNOON SEA BREEZES LIKELY. IN THE MEAN TIME...AN UPPER TROUGH IS 

ALSO EXPECTED TO ADVANCE TOWARDS THE AREA. IT WILL LEAD TO THE AIR 

MASS OVER THE ISLANDS BECOMING SOMEWHAT UNSTABLE. A CONVECTIVE 

WEATHER PATTERN WILL DEVELOP...WITH ENHANCED CLOUDS AND 

SHOWERS...ESPECIALLY DURING AFTERNOONS AND EVENINGS MONDAY AND 

TUESDAY. THERE IS ALSO A BETTER CHANCE OF LOCALLY HEAVY SHOWERS TO 

OCCUR.



THE UPPER TROUGH IS EXPECTED TO WEAKEN SOMEWHAT AS IT MOVES OVER THE 

ISLANDS TUESDAY....BUT WILL LINGER IN THE ISLAND VICINITY THROUGH 

REST OF THE WEEK. AT THE SURFACE...A HIGH PRESSURE RIDGE WILL 

REESTABLISH FAR NORTH OF THE ISLANDS AS WELL. THUS LOOK FOR A RETURN 

OF MORE TYPICAL TRADE WINDS AS WELL AS TRADE WIND WEATHER TO THE 

ISLANDS LATER PART OF NEXT WEEK.



&&



.MARINE...

CURRENT SOUTH SWELL IS EXPECTED TO PEAK OVERNIGHT...THEN SLOWLY 

SUBSIDE SUNDAY AFTERNOON THROUGH TUESDAY. A HIGH SURF ADVISORY 

REMAINS IN EFFECT FOR SOUTH FACING SHORES OF ALL ISLANDS. THE NEXT 

LARGE NORTHWEST SWELL IS EXPECTED TUESDAY...AND MAY BE BRING ABOVE 

ADVISORY LEVEL SURF FOR THE NORTH AND WEST FACING SHORES.



A SMALL CRAFT ADVISORY REMAINS IN EFFECT FOR THE USUAL WINDY COASTAL 

AREAS AROUND MAUI AND SOUTHEAST OF THE BIG ISLAND AS THE LIGHT TO 

MODERATE TRADE WINDS CONTINUE.



&&



.HFO WATCHES/WARNINGS/ADVISORIES...

SMALL CRAFT ADVISORY UNTIL 6 PM HST SUNDAY FOR MAALAEA BAY-PAILOLO 

CHANNEL-ALENUIHAHA CHANNEL.



HIGH SURF ADVISORY UNTIL 6 PM HST SUNDAY FOR SOUTH FACING SHORES OF 

ALL ISLANDS. 



&&



$$



HUI