FXHW60 PHFO 070606
AFDHFO
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
830 PM HST SUN DEC 6 2009
.SYNOPSIS...
COOL NORTHWESTERLY WINDS AND A FEW SHOWERS WILL SWEEP ACROSS THE
STATE TONIGHT INTO MONDAY...BUT WEAK TRADES WILL RETURN BY
WEDNESDAY. THE TRADES WILL WEAKEN BY FRIDAY...AND THEN TURN INTO
SOUTHEASTERLIES AS A FRONT APPROACHES THE STATE OVER THE WEEKEND.
&&
.DISCUSSION...
THE DISSIPATING BAND ASSOCIATED WITH A WEAKENING COLD FRONT STILL
APPROACHED KAUAI FROM THE NORTHWEST AND NORTH...BUT THE
SOUTHEASTWARD PROGRESS OF THIS FEATURE SLOWED AS IT NEARED THE
STAGNATION POINT IN THE SURFACE WIND FIELD CURRENTLY LOCATED EAST OF
THE MAIN HAWAIIAN ISLANDS. OBSERVATIONS ACROSS THE STATE REPORTED
LIGHT AND VARIABLE WIND CONDITIONS AHEAD OF THE FRONT...WITH
SEASONALLY FEEBLE SEA BREEZES JUST STARTING TO TRANSITION TO LAND
BREEZES. WEAK CONVERGENCE SILL SUPPORTED A PRE-FRONTAL BAND THAT
CLOAKED MUCH OF THE BIG ISLAND IN CLOUD LAYERS...BUT THIS FEATURE
ALSO SHIFTED SOUTHEAST SLOWLY AS THE MAIN FRONTAL BAND APPROACHED...
SUGGESTING SOME CLEARING ACROSS THE THE BIG ISLAND OVERNIGHT.
RAINFALL ACROSS THE STATE WAS LIGHT TO SPARSE...AND THE FRONTAL BAND
IS NOT EXPECTED TO DROP MUCH RAIN EITHER. ALTHOUGH THE INVERSION WAS
HIGH AND WEAK NEAR THE BIG ISLAND...WITH A DEEP SURFACE MOIST
LAYER...NEAR KAUAI THE INVERSION BASE WAS LOWER THAN USUAL...HINTING
AT THE GENERALLY STABLE AIR MASS UNDER A BROAD RIDGE ALOFT. ALTHOUGH
AT HIGHER LATITUDES THE NORTH PACIFIC DISPLAYED A PROGRESSIVE
PATTERN OF LONG WAVES...MOST OF THIS ACTIVITY REMAINED WELL NORTH OF
THE STATE.
GUIDANCE GENERALLY AGREES THAT THE SUBTROPICAL RIDGE WILL REBUILD
QUICKLY AFTER THE FRONT DISSIPATES...BRINGING TRADES BACK TO THE
ISLANDS...BUT THE RIDGE WILL BE DISPLACED SOUTH SOON BY ANOTHER
APPROACHING FRONT...KEEPING THE TRADES LIGHT LOCALLY. THIS SECOND
FRONT IS EXPECTED TO DISSIPATE NORTH OF THE STATE AROUND FRIDAY...
THUS LIMITING ITS EFFECT ON THE ISLANDS TO ANOTHER PERIOD OF SLACK
WINDS FROM THURSDAY INTO FRIDAY. GUIDANCE PREDICTS A THIRD...
STRONGER FRONT TO TURN THE WEAK TRADES AROUND INTO SOUTHEASTERLIES
OVER THE WEEKEND...AND THEN TO REACH KAUAI SUNDAY NIGHT...THOUGH
WITHOUT BRINGING MUCH RAINFALL.
&&
.MARINE...
HEIGHT AND PERIOD DATA INDICATE THAT DANGEROUSLY LARGE SWELL WILL
REACH THE ISLANDS TONIGHT...PRODUCING DESTRUCTIVE SURF THROUGH
WEDNESDAY. ALSO OF NOTE...A HIGH TIDE NEAR TWO FEET WILL OCCUR LATE
TONIGHT AND EARLY MONDAY MORNING...INCREASING THE CHANCE OF SURF
WASHING OVER ROADS AND PROPERTY ALONG THE IMMEDIATE COAST.
A HIGH SURF WARNING IS IN EFFECT FOR MOST OF THE ISLANDS.
A SMALL CRAFT ADVISORY ALSO IS IN EFFECT FOR MOST COASTAL WATERS FOR
THE LARGE NORTHWEST SWELL.
&&
.HFO WATCHES/WARNINGS/ADVISORIES...
HIGH SURF WARNING UNTIL 6 PM HST WEDNESDAY FOR NIIHAU-KAUAI
WINDWARD-KAUAI LEEWARD-WAIANAE COAST-OAHU NORTH SHORE-OAHU
KOOLAU-OLOMANA-MOLOKAI-MAUI WINDWARD WEST-MAUI LEEWARD WEST-MAUI
CENTRAL VALLEY-WINDWARD HALEAKALA-KONA-BIG ISLAND NORTH AND EAST-
KOHALA.
SMALL CRAFT ADVISORY FROM 6 AM MONDAY TO 6 PM HST WEDNESDAY FOR
BIG ISLAND LEEWARD WATERS-BIG ISLAND SOUTHEAST WATERS.
SMALL CRAFT ADVISORY UNTIL 6 PM HST WEDNESDAY FOR KAUAI
NORTHWEST WATERS-KAUAI WINDWARD WATERS-KAUAI LEEWARD WATERS-
KAUAI CHANNEL-OAHU WINDWARD WATERS-OAHU LEEWARD WATERS-KAIWI
CHANNEL-MAUI COUNTY WINDWARD WATERS-MAUI COUNTY LEEWARD WATERS-
ALENUIHAHA CHANNEL-BIG ISLAND WINDWARD WATERS.
&&
$$
RYSHKO
