Area Forecast Discussion
Issued by NWS Honolulu, HI

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FXHW60 PHFO 251431 AAA
AFDHFO

AREA FORECAST DISCUSSION...UPDATED...
NATIONAL WEATHER SERVICE HONOLULU HI
420 AM HST SAT APR 25 2015

.UPDATE...
FORECAST UPDATED FOR EAST FACING BIG ISLAND...CALLING FOR A WETTER
SATURDAY AFTERNOON. SATELLITE IMAGERY SHOWS A PATCH OF SHOWER
BEARING CLOUDS OFF THE EASTERN COAST OF THE BIG ISLAND. THE PATCH
SHOULD BE MOVING ASHORE LATER TODAY.

&&

.SYNOPSIS...
A FRONT APPROACHING FROM THE WEST IS FORECAST BRING SHOWERY WEATHER
TO THE SMALLER ISLANDS OVER THE WEEKEND. THE FRONT WILL FIRST REACH
KAUAI EARLY THIS EVENING...FOLLOWED BY OAHU EARLY SUNDAY MORNING.
THE FRONT WILL THEN STALL AND DISSIPATE OVER MAUI COUNTY BETWEEN
SUNDAY EVENING AND MONDAY. A STRONG HIGH FOLLOWING THE FRONT
WILL SETTLE NORTH OF KAUAI MONDAY AND BRING IN SOME BREEZY TRADES
TO THE ISLANDS LASTING THROUGH AT LEAST WEDNESDAY. THE BIG ISLAND
WILL BE MOSTLY DRY THROUGH THE WEEKEND. A MORE TYPICAL TRADE WIND
SHOWER PATTERN WILL RETURN TO THE ISLANDS AFTER MONDAY WITH THE
SHOWERS FAVORING THE WINDWARD AND MOUNTAIN AREAS...ESPECIALLY NIGHTS
AND MORNINGS.

&&

.DISCUSSION...

RELIEF IS IN SIGHT FROM THE WARM AND MUGGY WEATHER WITH COOLING
TRADES JUST A DAY OR SO AWAY.

THE FRONT THAT IS EXPECTED TO AFFECT THE ISLANDS OVER THE WEEKEND
IS 80 MILES WEST OF KAUAI/S NA PALI COAST AT 3 AM HST. THE FRONT IS
INCHING ITS WAY EASTWARD AT 5 TO 10 MPH. RADAR SHOWS A RAIN BAND
RUNNING AHEAD OF THE FRONT NEARING NIIHAU. THE MODELS ARE IN PRETTY
GOOD AGREEMENT WITH THE TIMING OF THE FRONT...AS NOTED IN THE
SYNOPTIC SECTION. DESPITE THE LACK OF UPPER LEVEL SUPPORT...THE
FRONT WILL STILL BE CARRYING A PUNCH WITH THE GFS SHOWING MOISTURE
UP TO 18 THOUSAND FEET. THIS IS GOOD ENOUGH FOR SOME LOCALLY HEAVY
DOWNPOURS FOR KAUAI AND OAHU. THE FRONT IS EXPECTED TO WEAKEN AS IT
SETTLES OVER MAUI COUNTY...THUS THE LOCALLY HEAVY SHOWERS IS LEFT
OUT OF THE FORECAST FOR THEM. SUNDAY APPEARS TO BE SHAPING UP TO BE
A DAMP ONE FOR KAUAI AND OAHU SO FAR. MONDAY ALSO APPEARS TO BE WET
AS WELL FOR THE SMALLER ISLANDS AS THE FRONT FALLS APART.

A BROAD SURFACE HIGH OF 1036 MB IS FORECAST TO ENTER THE FORECAST
PICTURE SUNDAY NIGHT WHERE IT MOVES INTO POSITION NORTH OF KAUAI AND
START SUPPLYING THE ISLANDS WITH BREEZY TRADES THAT WILL LAST
THROUGH AT LEAST WEDNESDAY. HAVING SAID THIS...MONDAY COULD NOT ONLY
BE SHOWERY BUT WINDY AS WELL. BUT AFTER MONDAY...WE ANTICIPATE A
MORE TYPICAL TRADE SHOWER PATTERN WITH SHOWERS FAVORING THE WINDWARD
AND MOUNTAIN AREAS...ESPECIALLY NIGHTS AND MORNINGS. A FEW STRAY
SHOWERS WILL ENTER THE LEEWARD ZONE OF THE SMALLER ISLANDS BUT WILL
BE RELATIVELY DRY. LEEWARD BIG ISLAND WILL LIKELY HAVE DAILY
ISOLATED TO SCATTERED AFTERNOON AND EVENING SHOWERS.

IN THE MEAN TIME A FEW SHOWERS HAVE FORMED SOUTH OF OAHU AND IS
THREATENING NO ONLY OAHU BUT WESTERNMOST MOLOKAI AS WE APPROACH
SUNRISE. MOST OF THESE SHOWERS WILL LIKELY DISSIPATE OR MOVE NORTH
OF THESE ISLANDS BY LATE MORNING. BUT MORE SHOWERS ARE ON TAP FOR
OAHU THIS AFTERNOON AS A CONVERGENT SOUTHERLY WIND FLOW SETTLES OVER
THE ISLAND. ISOLATED SHOWERS MAY ALSO DEVELOP ACROSS MAUI COUNTY
THIS AFTERNOON AND EVENING.

&&

.AVIATION...
MVFR CONDITIONS DUE TO LOW CLOUDS AND SHOWERS WILL BECOME
INCREASINGLY LIKELY ACROSS KAUAI TODAY...AS A FRONT APPROACHES
THE AREA FROM THE WEST. NO AIRMETS ARE IN EFFECT ACROSS THE STATE
AT THIS TIME...BUT AIRMET SIERRA FOR MOUNTAIN OBSCURATION WILL
PROBABLY BE NEEDED AT SOME POINT LATER TODAY OVER KAUAI. FURTHER
EAST...SCATTERED SHOWERS WELL AHEAD OF THE FRONT WILL AFFECT PARTS
OF OAHU AT TIMES...AND AIRMET SIERRA FOR MOUNTAIN OBSCURATION CANNOT
BE RULED OUT THERE AS WELL.

MAINLY VFR CONDITIONS WILL PREVAIL TODAY ACROSS MAUI COUNTY AND THE
BIG ISLAND...WITH JUST ISOLATED TO WIDELY SCATTERED SHOWERS EXPECTED.


&&

.MARINE...

SURF ALONG EAST AND SOUTH FACING SHORES WILL CONTINUE TO SUBSIDE
THROUGH THE WEEKEND. A LARGER NORTH NORTHWEST SWELL IS SET TO ARRIVE
SUNDAY. IT WILL BUILD AND SHIFT FROM THE NORTH MONDAY NIGHT. THIS
SWELL WILL LIKELY PRODUCE SURF ABOVE THE ADVISORY THRESHOLD ALONG
NORTH FACING SHORES BY MONDAY MORNING...AND COULD PRODUCE
ADVISORY-LEVEL SURF ALONG EAST FACING SHORES TUESDAY AS THE SWELL
DIRECTION SHIFTS OUT OF THE NORTH NORTHEAST.

A SMALL CRAFT ADVISORY /SCA/ REMAINS IN PLACE FOR THE WINDWARD BIG
ISLAND WATERS DUE TO THE SOUTHEAST WINDS ACCELERATING ALONG THE
HAMAKUA COAST. THE ASCAT PASS DURING THE EVENING SHOWED 25
KNOT...SCA LEVEL WINDS...OVER THE WINDWARD WATERS OF MAUI COUNTY AND
WATERS OFF LEEWARD THE BIG ISLAND. THUS THE SCA HAS BEEN EXPAND TO
COVER THESE WATERS. THE SCA FOR ALL THESE WATERS WILL EXPIRE AT 6
PM HST THIS AFTERNOON.

STRONG NORTHEAST WINDS WILL SPREAD DOWN THE ISLAND CHAIN FROM KAUAI
TO THE BIG ISLAND FROM SUNDAY NIGHT THROUGH MONDAY NIGHT. A SCA IS
LIKELY FOR THE WATERS SURROUNDING THE SMALLER ISLANDS INCLUDING THE
ALENUIHAHA CHANNEL.


&&

.HFO WATCHES/WARNINGS/ADVISORIES...
SMALL CRAFT ADVISORY UNTIL 600 PM TODAY FOR THE WINDWARD WATERS OF
MAUI COUNTY AND THE BIG ISLAND...AND WATERS OFF LEEWARD BIG ISLAND.


&&

$$
PUBLIC/MARINE...LAU
AVIATION...JACOBSON












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