High Surf Advisory 6, NWS Honolulu, HI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
345 PM HST WED JAN 15 2014

.SYNOPSIS...
VARIABLE WINDS WILL PREVAIL OVER THE NEXT SEVERAL DAYS AS A SERIES
OF WEAK FRONTS AFFECT THE AREA TOMORROW MORNING...THEN AGAIN SUNDAY
NIGHT. A MUCH STRONGER COLD FRONT MAY BRING HEAVY RAIN AND A CHANCE
OF THUNDERSTORMS AGAIN BY THE MIDDLE OF NEXT WEEK. A PROLONGED
PERIOD OF HIGH SURF AND DANGEROUS BEACH CONDITIONS IS EXPECTED
THROUGH NEXT WEEK.

&&

.DISCUSSION...
THE FORECAST REASONING FROM EARLIER IN THE SHIFT REMAINS UNCHANGED
THIS AFTERNOON OTHER THAN SOME MINOR CHANGES TO ACCOUNT FOR
SATELLITE/RADAR AND SUBTLE CHANGES IN MODEL TRENDS. THE FRONT TO
THE NORTHWEST IS NEARING TERN ISLAND AND WILL REACH KAUAI BY
THURSDAY MORNING. THE FRONT WILL MAKE LITTLE EASTWARD PROGRESSION AS
THE PARENT LOW LIFTS QUICKLY NORTHWARD TOWARDS ALASKA ALONG THE
WESTERN PERIPHERY OF THE HIGH AMPLITUDE EASTERN PACIFIC RIDGE IN
PLACE. THIS WILL BRING INCREASED LIGHT RAINFALL TO KAUAI AND
OAHU...AND PERHAPS WESTERN MAUI COUNTY TOMORROW...DIMINISHING AS IT
WASHES OUT INTO FRIDAY.

CONFIDENCE REMAINS MODERATE IN THE LONGER TERM FORECAST. THE ZONAL
JET EXITING THE ASIAN COAST WILL CONTINUE TO SUPPORT PROGRESSIVE
FLOW OVER THE WESTERN AND CENTRAL PACIFIC SIGNALING WEAK FRONTAL
PASSAGES AND DISRUPTED TRADES LOCALLY THROUGH THE MIDDLE OF NEXT
WEEK. ANOTHER SIMILAR WEAK FRONT WILL NEAR KAUAI SUNDAY NIGHT AND
DISSIPATE QUICKLY INTO MONDAY PROVIDING LITTLE OR NO SIGNIFICANT
CHANGE TO THE WELL ESTABLISHED BENIGN AND STABLE LIGHT WIND PATTERN.

THE GFS/ECMWF ARE IN FAIR AGREEMENT DEPICTING A STRONGER SHORTWAVE
EXITING THE ASIAN COAST OVER THE WEEKEND. THIS WILL PROVIDE MORE
AMPLITUDE TO THE AFOREMENTIONED ZONAL JET ALLOWING FOR A SLOWER
MOVING BLOCKING PATTERN TO DEVELOP NEXT WEEK. THIS WILL YIELD A
SLOWER MOVING OCCLUSION NORTH OF HAWAII INCREASING THE LIKLIHOOD OF
A SIGNIFICANT FRONT WITH BETTER DYNAMIC SUPPORT REACHING THE STATE
WEDNESDAY-THURSDAY NEXT WEEK. CHANCES FOR HEAVY RAIN...
THUNDERSTORMS AND SUMMIT WEATHER WILL INCREASE TOWARDS THE MIDDLE
OF NEXT WEEK.

STRONG NORTHWESTERLY FLOW AND A MODIFIED YET DRIER AIRMASS WILL
ADVECT ACROSS THE STATE BEHIND THE FRONT AS IT PASSES WEDNESDAY
THROUGH THURSDAY. DRY SUNNY AND COOLER WEATHER COUPLED WITH
VEERING/EASING NORTHERLY WINDS WILL FOLLOW FOR FRIDAY INTO THE
WEEKEND.

&&

.AVIATION...
BROAD WEAK SOUTHWEST SYNOPTIC FLOW AT THE SURFACE WILL CONTINUE TO
ADVECT WIDELY SCATTERED TCU SHOWERS ACROSS THE FORECAST
AREA...ESPECIALLY THE NORTHERN ISLANDS. AIRMET SIERRA FOR MOUNTAIN
OBSCURATION ON KAUAI FORECAST TO END EARLY THIS EVENING...BUT MAY
NEED TO BE EXTENDED IF TRAINING CONTINUES. SEA BREEZE PATTERNS
PREDOMINATE ON THE BIG ISLAND AND NEARLY COMPLETE CLEARING IS
EXPECTED AFTER MIDNIGHT. BRISK SEA BREEZES ALL ISLANDS THIS
AFTERNOON WILL GIVE WAY TO GENTLER LAND BREEZES SHORTLY AFTER
SUNSET.

STARTING TOMORROW...EXPECT CLOUDIER SKIES AND AN INCREASED CHANCE OF
PRECIPITATION. MOUNTAIN OBSCURATIONS LIKELY ON KAUAI IN THE
MORNING...POTENTIALLY SPREADING TO OAHU IN THE AFTERNOON.

&&

.MARINE...
HAWAII IS IN THE BEGINNING STAGES OF A LONG RUN OF HIGH SURF FROM
THE NORTHWEST. SURF WILL REMAIN ELEVATED OVERNIGHT BUILDING QUICKLY
TO WARNING LEVELS TOMORROW AFTERNOON AND EVENING. HIGH SURF WARNINGS
ARE POSTED INCLUDING ADVISORIES FOR THE NORTH AND WEST FACING BIG
ISLAND. THE HIGHEST SURF WILL OCCUR THURSDAY NIGHT AND FRIDAY WITH
ADDITIONAL LARGE PULSES LATER IN THE WEEKEND. THE HIGHEST SURF WILL
HIT DURING THE PREDAWN HOURS THURSDAY NIGHT/FRIDAY MORNING
COINCIDING WITH THE HIGH TIDE. THIS WILL INCREASE CHANCES FOR
SIGNIFICANT BEACH EROSION AND RUN-UP DURING THESE HOURS. ADDITIONAL
LARGE SURF IS EXPECTED OVER THE WEEKEND AND NEXT WEEK SO THE
WARNINGS AND ADVISORY NUMBERS AND EXPIRATIONS WILL TAKE ADJUSTMENTS
AS THE SWELL FILLS IN. THE SURF FORECAST PRODUCT HAS BEEN UPDATED
SO PLEASE CHECK IT OUT FOR GREATER DETAIL ON THE POTENTIAL LARGE
SWELL FOR THE MIDDLE OF NEXT WEEK.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
HIGH SURF WARNING UNTIL 6 PM HST FRIDAY FOR NIIHAU-KAUAI
WINDWARD-KAUAI LEEWARD-WAIANAE COAST-OAHU NORTH SHORE-OAHU
KOOLAU-MOLOKAI-MAUI WINDWARD WEST-MAUI CENTRAL VALLEY-WINDWARD
HALEAKALA.

HIGH SURF ADVISORY FROM 6 PM THURSDAY TO 6 AM HST SUNDAY FOR
KONA-BIG ISLAND NORTH AND EAST.

&&

PUBLIC/MARINE...DEJESUS
AVIATION...BRAVENDER/BEDAL