Area Forecast Discussion
Issued by NWS Honolulu, HI

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
000
FXHW60 PHFO 291456 CCA
AFDHFO

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
330 AM HST SAT AUG 29 2015

CORRECTED SYNOPSIS

.SYNOPSIS...
VERY WARM AND HUMID CONDITIONS WILL CONTINUE DESPITE THE RETURN OF
THE TRADES THIS WEEKEND. THE TRADES ARE EXPECTED TO STRENGTHEN TO
LOCALLY STRONG BY SUNDAY NIGHT...BY WHICH TIME TROPICAL STORM
CONDITIONS COMES INTO PLAY. THE SPOTTY SHOWERS TODAY WILL BE
FOLLOWED BY AN UPTICK IN TRADE SHOWERS SUNDAY.

THE REST OF THE FORECAST HINGES ON THE TRACK OF HURRICANE IGNACIO
WITH THE FORECAST OF UNCERTAINTY INCREASING SIGNIFICANTLY ON MONDAY
AND TUESDAY.

&&

.DISCUSSION...
WE WELCOME BACK THE RETURN OF THE TRADES AND A SLIGHTLY MORE STABLE
AND DRIER AIR MASS. BELIEVE ONLY OAHU AND KAUAI HAD A FEW MINOR
CONVECTIVE SHOWERS OVER ON THE INTERIOR AND OR LEEWARD PARTS OF THE
ISLANDS YESTERDAY. SHOWERS WERE HARD TO FIND ACROSS MAUI COUNTY AND
THE BIG ISLAND YESTERDAY.

A MORE BEARABLE AIR MASS THIS EARLY SATURDAY MORNING WITH DEW POINTS
UP TO 6 DEGREES LESS COMPARED TO 24 HOURS AGO. THE LATEST DEW POINT
READINGS STATEWIDE RANGED FROM A 67 AT KONA TO A 74 AT LIHUE. THIS
TRANSLATES TO LOWER RH...UP TO 20 PERCENT LESS COMPARED TO 24 HOURS
AGO. IT LOOKS LIKE THAT BUBBLE OF LOWER PRECIPITABLE WATER OF 1.4 TO
1.7 IN...NOTED IN THE PREVIOUS DISCUSSION...IS ABOUT GONE. SO THE
ISLANDS WILL LIKELY STAY ABOUT 1.8 TO 2.2 RANGE AREA WIDE THROUGH
TODAY. A JUCIER AIR MASS WELL ABOVE 2 INCHES SHOULD BE SPREADING
ACROSS THE AREA TONIGHT INTO SUNDAY AS HURRICANE IGNACIO APPROACHES
THE ISLANDS FROM THE EAST AND SOUTHEAST.

SATELLITE AND RADAR SHOWS A GROUP OF SCATTERED SHOWERS UPWIND OF
KAUAI. SO IT APPEARS WINDWARD KAUAI HAVE A FEW PASSING SHOWERS THIS
MORNING. IT IS RATHER DRY ELSEWHERE WITH ISOLATED SHOWERS AT BEST
FOR AT LEAST THIS MORNING.

THE FORECAST FROM SUNDAY NIGHT ON...HINGES ON THE TRACK OF IGNACIO
WITH THE FORECAST OF UNCERTAINTY INCREASING SIGNIFICANTLY ON MONDAY
AND TUESDAY. PLEASE SEE THE LATEST DISCUSSION ISSUED BY THE CENTRAL
PACIFIC HURRICANE CENTER FOR SPECIFICS RELATED TO THE TRACK AND
INTENSITY...ISSUED UNDER AWIPS HEADER TCDCP3 AND WMO HEADER WTPA43
PHFO.

GIVEN THE LATEST TRACK OF IGNACIO...THE WINDS SHOULD START
DIMINISHING AROUND THE ISLANDS AS EARLY AS LATE TUESDAY NIGHT...AND
THE WINDS EASING TO A WARM AND MUGGY SOUTH DIRECTION BY THURSDAY.
UNDER THIS WIND FLOW...NOT ONLY WILL IT BE MUGGY BUT COULD ALSO BE
VOGGY AND ALSO SHOWERY. VOG...HAZE IS QUESTIONABLE AT THIS TIME.
THE HAZE WAS NOT MUCH OF AN ISSUE A FEW DAYS AGO WHILE THE SMALLER
ISLANDS WERE UNDER A LIGHT SOUTHERLY FLOW.

THE CONE OF UNCERTAINTY...WHICH IS THE POTENTIAL TRACK GIVEN
HISTORIC TRACK ERROR...INCLUDES THE ENTIRE STATE. IF IGNACIO SHIFTS
TO THE RIGHT...WE COULD SEE LIGHT WINDS...MORE HUMID
CONDITIONS...AND LOCALIZED HEAVY RAIN. ON A MORE LEFTWARD TRACK
CLOSER TO THE ISLANDS...WE COULD SEE STRONGER/DAMAGING WINDS AND
MORE WIDESPREAD HEAVY RAIN/FLOODING. EVERYONE SHOULD CONTINUE TO
MONITOR THE PROGRESS OF IGNACIO DURING THE NEXT SEVERAL DAYS.

&&

.AVIATION...
GENTLE TRADES WILL PREVAIL ACROSS THE STATE TODAY AND TONIGHT.
ISOLATED MVFR CIGS WILL ALSO BE POSSIBLE ACROSS WINDWARD AREAS
MAINLY DURING THE MORNING...AND ACROSS INTERIOR/LEEWARD AREAS
ALONG LOCALIZED SEABREEZES DURING THE AFTERNOON. VFR CONDITIONS
SHOULD PREVAIL AT THE TERMINALS...WITH THE EXCEPTION OF PHNY WHERE
MVFR CIGS WILL LIKELY DEVELOP BY LATE MORNING AND CONTINUE THROUGH
MID TO LATE AFTERNOON. NO AIRMETS ARE CURRENTLY IN EFFECT...AND
NONE ARE ANTICIPATED THROUGH THE DAY.

&&

.MARINE...
THE TRADE WINDS ARE EXPECTED TO STRENGTHEN INTO SUNDAY...REACHING
SMALL CRAFT ADVISORY CRITERIA FOR THE MORE SENSITIVE AREAS SUCH AS
THE ALENUIHAHA CHANNEL. OF COURSE TROPICAL STORM FORCE CONDITIONS
WILL COME INTO PLAY AS HURRICANE IGNACIO APPROACHES THE ISLANDS.
ALL MARINERS SHOULD MONITOR THE PROGRESS OF HURRICANE IGNACIO DURING
THE NEXT SEVERAL DAYS.

SWELL-WISE...THE HANALEI BUOY IS SENSING A LONGER PERIOD WNW SWELL
OF 17 SECONDS AT 3.6 FT IN THE PAST COUPLE OF HOURS...WHILE WAIMEA
BUOY LOWERED A BIT TO 3 FT WITH A PERIOD 15 SEC IN THE PAST FEW
HOURS. THE BARBERS POINT BUOY HAS PEAKED AND LOWERED SLIGHTLY
HOLDING AT 3.6 FT AT 14 SECONDS. ALL SAID...THE HIGH SURF ADVISORY
FOR THE WEST SHORES OF THE BIG ISLAND LOOKS GOOD. WE WILL CONTINUE
TO TRACKS THESE BUOYS TO SEE IF THERE IS A DOWNWARD TREND. SHOULD
THERE BE ONE...WE CAN LET THE ADVISORY EXPIRE AT 6 PM HST THIS
AFTERNOON. IF THERE IS AN REINFORCING SWELL...WE MAY NEED TO EXTEND
THE ADVISORY.

THE HIGH SURF ADVISORY FOR THE EAST FACING SHORE COMES INTO PLAY IN
SHORTLY IN ANTICIPATION OF THE ARRIVAL OF THE EAST SWELL GENERATED
BY HURRICANE IGNACIO A FEW DAYS AGO. THE ADVISORY MAY BE EXTENDED TO
THE EAST FACING SHORES OF MAUI TONIGHT. TIMING FOR THE OTHER ISLANDS
WILL BE DELAYED DUE TO SHADOWING/BLOCKING FROM THE BIG ISLAND AND
MAUI. WARNING LEVEL SURF IS LIKELY FOR THE BIG ISLAND IN THE DAYS
AHEAD. THE SURF FORECAST THEREAFTER REST ON THE TRACK AND STRENGTH
OF IGNACIO.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
HIGH SURF ADVISORY UNTIL 6 PM HST TODAY FOR WEST FACING SHORES OF
THE BIG ISLAND.

HIGH SURF ADVISORY TO 6 PM HST SUNDAY FOR EAST FACING SHORES OF THE
BIG ISLAND.

&&

$$

LAU










USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.