High Wind in Hawaii, December 3, 2012

AREA FORECAST DISCUSSION...UPDATE
NATIONAL WEATHER SERVICE HONOLULU HI
1030 PM HST SUN DEC 2 2012

UPDATED AVIATION SECTION

.SYNOPSIS...
STRONG UPPER LEVEL SOUTHWEST WINDS WILL CONTINUE TO BRING HIGH
CLOUDS OVER THE ALOHA STATE THROUGH EARLY MONDAY. MOST OF THE CLOUDS
WILL MOVE EAST OF THE STATE BY MONDAY AFTERNOON. PASSING SHOWERS
WILL AFFECT NIIHAU AND KAUAI TONIGHT...AND SOME BRIEF SHOWERS MAY
REACH OAHU ON MONDAY. A COLD FRONT APPROACHES KAUAI ON TUESDAY WITH
INCREASING CHANCES OF SHOWERS...MAINLY WEST OF MAUI COUNTY THROUGH
LATE WEDNESDAY. LIGHT TRADES ARE THEN EXPECTED TO RETURN FOR THE END
OF THE WORK WEEK.

&&

.DISCUSSION...
A TROUGH/LOW COMPLEX REMAINS FAR NW OF THE MAIN HAWAIIAN ISLANDS
WITH A DECAYING FRONT NEARLY STATIONARY JUST NW OF KAUAI.
MEANWHILE...SFC RIDGING EAST OF THE STATE IS STILL EXTENDING INTO
THE BIG ISLAND AND MAUI COUNTY...AND SHOULD REMAIN IN PLACE DURING
THE NEXT COUPLE OF DAYS. THE FRONT...OR WHATEVER IS LEFT OF IT...IS
EXPECTED TO SLOWLY PUSH EASTWARD AND MAYBE REACHING OAHU ON MONDAY
BEFORE DISSIPATING OR LIFTING NORTH.

AN UPPER LVL TROUGH EXTENDS SOUTH OF AN UPPER LOW NEAR 170W AND
BRINGING STRONG SW WINDS ACROSS THE AREA ALOFT. THESE WINDS WILL
CONTINUE TO CARRY MID/UPPER LVL CLOUD COVER OVER THE ISLANDS
TONIGHT. THEN ON MONDAY...THE HIGH CLOUDS WILL DECREASE AS THE FLOW
ALOFT SWITCHES TO THE WEST AND PUSHES THE MAIN CANOPY OF CLOUDS
FURTHER TO THE EAST OF THE ISLANDS.

SOME SHOWERS MAY AFFECT NIIHAU AND KAUAI TONIGHT AS A NARROW BAND OF
RAIN IS STILL LINGERING JUST WEST OF THOSE ISLANDS AND VERY SLOWLY
MIGRATING EAST. ELSEWHERE...AN ISOLATED SHOWER OR TWO MAY DEVELOP
OVERNIGHT...BUT FOR THE MOST PART NO SIGNIFICANT PRECIPITATION IS
EXPECTED EAST OF KAUAI THROUGH MONDAY. STRONG SW FLOW ALOFT WILL
ALSO JUSTIFY KEEPING A WIND ADVISORY IN EFFECT FOR THE MOUNTAIN
SUMMITS UNTIL 6 SM HST TOMORROW.

SURFACE RIDGE OVER THE BIG ISLAND AND MAUI COUNTY WILL GRADUALLY
MOVE NORTHWARD BY LATE MONDAY AND INTO TUESDAY WHILE THE TROUGH
ALOFT TO THE WEST WILL LIFT OUT TO THE NE. THEN MODEL GUIDANCE BRING
A SECOND UPPER LVL TROUGH...WHICH SETTLES AROUND 170W ON TUESDAY.
THIS
WILL BRING BACK STRONG SW WINDS ALOFT WITH INCREASING HIGH CLOUD
COVER AGAIN INCREASING ACROSS THE ALOHA STATE.

ANOTHER FRONTAL BOUNDARY IS SHOWN BY GUIDANCE APPROACHING KAUAI FROM
THE NW ON TUESDAY AS A COUPLE OF LOWS ROTATE AROUND THE MAIN TROUGH
TO THE NW OF THE STATE. THE AIRMASS OVER THE AREA SEEM TO REMAIN
STABLE ENOUGH TO KEEP CHANCES FOR THUNDERSTORM ACTIVITY LOW...BUT
THE SITUATION WILL BE CLOSELY MONITORED IN CASE CONDITIONS CHANGE
SIGNIFICANTLY IN UPCOMING MODEL GUIDANCE.

FOR THE SECOND HALF OF NEXT WEEK...LIGHT TRADE WINDS AND GENERALLY
PARTLY CLOUDY SKIES SHOULD RETURN ACROSS MUCH OF THE AREA WITH LOW
CLOUDS AND SHOWERS FAVORING WINDWARD AND MAUKA SECTIONS.

&&

.MARINE...
A LARGE NORTHWEST SWELL IS NOW ARRIVING...FOR WHICH A HIGH SURF
ADVISORY IS IN EFFECT INCLUDING NORTH AND WEST FACING SHORES OF
NIIHAU KAUAI AND MOLOKAI...AND NORTH FACING SHORES OF OAHU UNTIL 6
PM HST MONDAY.

ALSO...A SMALL CRAFT ADVISORY IS IN EFFECT FOR ALL KAUAI WATERS...
INCLUDING KAUAI CHANNEL...UNTIL 6 PM HST MONDAY. CONDITIONS SHOULD
THEN BEGIN SUBSIDING ON MONDAY EVENING.

&&

.AVIATION...
VFR CONDITIONS WILL PREVAIL AT THE TAF SITES THROUGH THE PERIOD. A
NARROW BAND OF CLOUD/SHRA MOVING E NEAR NIIHAU AND KAUAI THIS
EVENING LIKELY CONTAINS MVFR CIG/VIS...AND MAY BRING A BRIEF PERIOD
OF MVFR CONDITIONS TO PHLI AROUND 09Z. THIS BAND IS EXPECTED TO
SLOWLY WEAKEN NEAR KAUAI THROUGH EARLY MORNING. ALTHOUGH SOME LIGHT
RIME REPORTS WERE RECEIVED EARLIER IN THE DAY...MID AND HIGH LEVEL
MOISTURE IS DIMINISHING...AND THIS TREND IS FORECAST TO CONTINUE
OVER THE NEXT 12 TO 24 HOURS.

AN AIRMET HAS BEEN ISSUED FOR MOD TURB BLW 150 TO THE N AND E OF THE
MTN OF ISLANDS FROM MAUI TO KAUAI AS LATEST RADAR VAD WIND PROFILES
INDICATE WSW WINDS UP TO 30 KT IN THE LOWER LEVELS. GUIDANCE SHOWS
THESE WINDS DIMINISHING BY LATE MONDAY.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
HIGH SURF ADVISORY UNTIL 6 PM HST MONDAY FOR NIIHAU-KAUAI
WINDWARD-KAUAI LEEWARD-OAHU NORTH SHORE-OAHU KOOLAU-MOLOKAI.

WIND ADVISORY UNTIL 6 AM HST MONDAY FOR HALEAKALA SUMMIT-BIG
ISLAND SUMMITS.

SMALL CRAFT ADVISORY UNTIL 6 PM HST MONDAY FOR KAUAI NORTHWEST
WATERS-KAUAI WINDWARD WATERS-KAUAI LEEWARD WATERS-KAUAI CHANNEL.

&&

DISCUSSION/MARINE...REYNES
AVIATION...BIRCHARD