Area Forecast Discussion
Issued by NWS Honolulu, HI

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 020635
AFDHFO

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
815 PM HST SAT AUG 1 2015

.SYNOPSIS...
MODERATE TO FRESH TRADES BROUGHT ON BY A PASSING DISTURBANCE SOUTH
OF THE ISLANDS WILL CONTINUE THROUGH SUNDAY BEFORE EASING OFF TO
MODERATE SPEEDS. SHOWERS COMING IN WITH THE TRADES WILL FAVOR
MOSTLY THE WINDWARD AND MOUNTAIN AREAS. THIS TRADE FLOW COULD BE
INTERRUPTED BY THE CIRCULATION OF TROPICAL CYCLONE GUILLERMO AND ITS
ASSOCIATED MOISTURE BETWEEN TUESDAY NIGHT AND THURSDAY.


&&

.DISCUSSION...
THE FORECAST WAS UPDATED FOR STRONG AND GUSTIER TRADES PERTAINING TO
THE TONIGHT AND SUNDAY PERIODS. THIS IS IN LIGHT OF STRONGER TRADES
OCCURRING ON LANAI MOLOKAI AND PARTS OF OAHU...DUE TO THE PASSING OF
REMNANTS EIGHT-E CURRENTLY LOCATED ABOUT 300 MILES SOUTH SOUTHEAST
OF SOUTH POINT BIG ISLAND. RIDGES AND VALLEYS EXPOSED TO THE NORTH
AND NORTHEAST WILL BE MOST SUSCEPTIBLE.

THE LATEST SATELLITE IMAGERY SHOWS THE THE OUTER FRINGE OF
EIGHT-E/S CLOUD MASS AFFECTING PRIMARILY THE BIG ISLAND AND MAUI...
AND GRAZING NE MOLOKAI TIME TO TIME. THE MODELS PRETTY MUCH AGREES
WITH THIS ASSESSMENT WITH THE TENDENCY OF CLEARING MAUI SUNDAY
AFTERNOON BUT KEEPING WINDWARD BIG ISLAND DAMP THROUGH MONDAY NIGHT.
WE SHALL SEE HOW THIS GOES WITH MAUI BUT CONCUR WITH THE FORECAST
FOR THE WINDWARD BIG ISLAND.

SUBSIDENCE FROM THE APPROACHING TROPICAL CYCLONE GUILLERMO MAY OCCUR
ON TUESDAY WHICH MEANS RATHER DRY CONDITION FOR THE ISLANDS.
THE REST OF THE FORECAST PACKAGE WILL BE HIGHLY DEPENDENT ON THE
EVENTUAL TRACK OF GUILLERMO. BASED ON THE LATEST 5 PM HST TRACK...
GUILLERMO IS FORECAST TO BE A TROPICAL STORM AS IT NEARS THE ISLANDS
WITH FURTHER WEAKENING EXPECTED AS IT MOVES WESTWARD. GUILLERMO WILL
BE SPREADING CLOUDS SHOWERS AND WIND STARTING WITH THE BIG ISLAND
TUESDAY NIGHT. RAINY AND SOMEWHAT WINDY WEATHER ARE EXPECTED TO
SPREAD TO THE OTHER ISLANDS THROUGH THURSDAY EVENING. AGAIN...THIS
IS ALL SUBJECT TO CHANGE.

MODELS ARE LOOKING AT A MORE TYPICAL MODERATE TO LOCALLY STRONG
TRADE WIND PATTERN TO RETURN FOR THE WEEKEND.

&&

.AVIATION...
NE TRADE WINDS REMAIN ELEVATED...AND AIRMET TANGO FOR LOW LEVEL
TURB OVER AND IMMEDIATELY S THRU W OF MOUNTAIN RANGES REMAINS
POSTED. WIND SPEEDS SHOULD BEGIN TO SLIGHTLY EASE SUNDAY AFTERNOON
BACK TO MODERATE LEVELS.

ENHANCED MOISTURE FROM THE REMNANTS OF POST TROPICAL DEPRESSION
EIGHT-E OVER THE BIG ISLAND WILL CONTINUE TO PUSH S AND W. N THRU E
SLOPES OF THE BIG ISLAND CAN EXPECT PREVAILING MVFR WITH ISOL IFR
CIGS/VIS INTO SUNDAY. AIRMET SIERRA FOR MOUNTAIN OBSC IS POSTED
ALONG THESE SLOPES. MOST MOISTURE WILL REMAIN E OF THE SMALLER
ISLANDS...HOWEVER THE POTENTIAL FOR INCREASED CLOUDS AND SHOWERS
ALONG N THRU E SLOPES OF MAUI AND MOLOKAI REMAIN INTO TONIGHT.
AIRMET SIERRA IS POSTED THROUGH 10Z FOR N THRU E SLOPES MAUI AND
MOLOKAI...THIS WILL BE AMENDED AS NEEDED. OTHERWISE...EXPECT
PREVAILING VFR.


&&

.MARINE...
THE EXISTING SMALL CRAFT ADVISORY /SCA/ WAS EXPANDED TO INCLUDE THE
KAIWI CHANNEL AND  LEEWARD WATERS OF OAHU. AGAIN...THIS IS ALL DUE
TO THE PASSING OF THE REMNANTS OF ONCE TROPICAL DEPRESSION
EIGHT-E. EIGHT-E IS FORECAST TO CONTINUE WESTWARD AND SHOULD BE OUT
OF RANGE BY SUNDAY NIGHT WHERE THE SCA CAN BE LOWERED. ALSO...THE
SURFACE HIGH SUPPLYING THE ISLANDS WITH THE TRADES IS FORECAST TO
MOVE NORTHEAST...FURTHER AWAY FROM THE ISLANDS.

GUILLERMO IS FORECAST TO REACH OUR OFFSHORE WATERS SOME 270 MILES
EAST SOUTHEAST OF THE BIG ISLAND TUESDAY AFTERNOON AT TROPICAL
STORM STRENGTH AND CONTINUE AT THIS STRENGTH AS IT NEARS THE
ISLANDS. ALTHOUGH THE TRACK AND INTENSITY OF THE TROPICAL CYCLONE
REMAINS UNCERTAIN SO FAR IN THE FUTURE...ADVERSE EFFECTS FOR
HAWAIIAN COASTAL WATERS CANNOT NOT BE RULED OUT.

A HIGH SURF ADVISORY FOR THE EAST FACING SHORES OF MOST ISLANDS IS
SLATED TO GO INTO EFFECT AT NOON SUNDAY FOR A BUILD SWELL FROM THE
EAST GENERATED BY GUILLERMO. WE EXPECT THE SURF TO REACH ADVISORY
LEVEL BY SUNDAY NIGHT. THIS ADVISORY WILL LIKELY STAY IN EFFECT
THROUGH MOST OF THE WEEK WITH GUILLERMO NEARBY. THE ADVISORY CAN BE
RAISE TO WARNING LEVEL DEPENDING OF THE STRENGTH OF GUILLERMO.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
HIGH SURF ADVISORY FROM NOON SUNDAY TO 6 PM HST TUESDAY FOR EAST
FACING SHORES OF KAUAI OAHU MOLOKAI MAUI AND THE BIG ISLAND.

SMALL CRAFT ADVISORY UNTIL 6 PM HST SUNDAY FOR THE KAIWI PAILOLO AND
ALENUIHAHA CHANNELS...LEEWARD WATERS OF OAHU...MAALAEA BAY...AND
WATERS SOUTH OF THE BIG ISLAND.


&&

$$

DISCUSSION/MARINE...LAU
AVIATION...EATON









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