Wednesday, July 30, 2014 596-SURF , 596-WAVE , 922-BONG , 638-RUSH , 572-SURF(MAUI) , 241-SURF (KAUAI) , 324-RUSH (BIG ISLAND)
   
Text Size
Login
off 2/20/14; off 3/27. on 4/4. on 7/20/14
Banner
Banner

000
FXHW60 PHFO 300121
AFDHFO

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
330 PM HST TUE JUL 29 2014

.SYNOPSIS...
HIGH PRESSURE FAR NORTH OF THE STATE WILL PROVIDE FOR TRADE WINDS
FOR THE REST OF THE WEEK AND ON INTO THE WEEKEND. SPARSE CLOUDS AND
ONLY A FEW BRIEF WINDWARD AND MAUKA SHOWERS CAN BE EXPECTED INTO
EARLY THURSDAY. AN INCREASE IN SHOWERS IS EXPECTED FROM EAST TO
WEST ACROSS THE STATE THURSDAY NIGHT THROUGH THE WEEKEND.

&&

.DISCUSSION...
DRY AND STABLE TRADE WIND WEATHER WILL CONTINUE THROUGH THE NEXT 36
HOURS ACROSS THE ALOHA STATE. THE TRADES ARE BEING FED BY THE
PRESSURE GRADIENT BETWEEN A 1023 MB HIGH FAR TO THE NORTHEAST AND A
PERSISTENT AREAS OF LOW PRESSURE TO OUR SOUTH...AND THIS PATTERN
LOOKS TO CONTINUE THROUGH THURSDAY. THE STABLE AND SOMEWHAT DRY
AIRMASS EXTENDS UPSTREAM FOR SEVERAL HUNDRED MILES...THUS KEEPING
QUIET WEATHER ACROSS OUR AREA...AND DEEP TROPICAL MOISTURE AT BAY TO
OUR SOUTH.

THE GENERAL WEATHER PATTERN WILL SHIFT EVER SO SLIGHTLY BY LATER
THURSDAY AND FRIDAY AS THE HIGH MOVES JUST ENOUGH TO BRING THE
TRADES TO A MORE EASTERLY TO EAST SOUTHEASTERLY DIRECTION. THIS
WILL BE JUST ENOUGH TO ADVECT SOME OF THE POOL OF TROPICAL MOISTURE
TO OUR EAST SOUTHEAST OVER THE MAIN HAWAIIAN ISLANDS...BEGINNING
WITH THE BIG ISLAND THURSDAY NIGHT. MODEL GUIDANCE HAS BEEN
HINTING THAT THERE WILL BE ENOUGH MOISTURE AND MODEST INSTABILITY
WILL EXIST FOR THE THREAT OF LOCALLY HEAVY RAINFALL...MAINLY OVER
WINDWARD AREAS...AS THE TRADE WIND SHOWERS BECOME ENHANCED BY THIS
MOIST AND MORE UNSTABLE AIRMASS. AT THIS TIME THUNDERSTORMS ARE NOT
ANTICIPATED IN THE FORECAST...AS THE STABILITY PROFILE REMAINS UPPER
LEVELS REMAIN MORE STABLE THAN RECENT MOISTURE SURGES ACROSS THE
STATE.

MODEL GUIDANCE IN GOOD AGREEMENT WITH RESPECT TO THE MOIST AIRMASS
SPREADING ACROSS THE SMALLER ISLANDS FROM EAST TO WEST ON FRIDAY
AND SATURDAY. BRINGING AN INCREASE IN HUMIDITY...CLOUD COVER AND
THE THREAT FOR LOCALLY HEAVY RAINFALL STATEWIDE INTO THE FIRST HALF
OF THE WEEKEND.

ONCE THE MOISTURE MOVES THROUGH AND WEST OF THE AREA BY SUNDAY AND
INTO MONDAY...A DRIER WEATHER PATTERN WILL ONCE AGAIN TAKE OVER WITH
CLOUDS AND PASSING LIGHT SHOWERS AFFECTING MAINLY WINDWARD AND MAUKA
AREAS. MODERATE TRADE WINDS WILL CONTINUE INTO EARLY NEXT WEEK AS
HIGH PRESSURE REMAINS TO OUR NORTH.

&&

.AVIATION...
VFR WILL PREDOMINATE OVER THE ISLAND CHAIN THIS EVENING AND
TONIGHT...WITH ONLY ISOLATED AREAS OF MVFR IN WINDWARD AND MAUKA
AREAS FROM PASSING LOW CLOUDS AND ANY ACCOMPANYING SHOWERS.

THERE ARE MODERATE TO LOCALLY STRONG TRADE WINDS JUST DOWNWIND FROM
THE MOUNTAINS...THUS AN AIRMET FOR TEMPO MODERATE TURBULENCE REMAINS
IN EFFECT.

&&

.MARINE...
A SMALL CRAFT ADVISORY CONTINUES FOR THE TYPICALLY WINDIER WATERS
AROUND MAUI COUNTY AND THE BIG ISLAND. THESE CONDITIONS ARE EXPECTED
TO CONTINUE THROUGH AT LEAST THE REST OF THE WEEK.

A SERIES OF SMALL SOUTHERLY SWELLS ARE EXPECTED FOR THE NEXT FEW
DAYS WITH A LARGER SOUTH SWELL EXPECTED OVER THE WEEKEND. TRADE
WINDS WILL CONTINUE TO PRODUCE SHORT PERIOD CHOPPY SURF ALONG EAST
FACING SHORES.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
SMALL CRAFT ADVISORY UNTIL 6 PM HST FRIDAY FOR MAALAEA BAY-
PAILOLO CHANNEL-ALENUIHAHA CHANNEL-BIG ISLAND LEEWARD WATERS-BIG
ISLAND SOUTHEAST WATERS.

&&

$$

SYNOPSIS/DISCUSSION/MARINE...BRENCHLEY
AVIATION...KINEL



The Weather Prediction Center

College Park, MD

Hawaii Extended Forecast Discussion




Hawaii Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
824 AM EDT Tue Jul 29 2014

Valid 00Z Wed Jul 30 2014 - 00Z Wed Aug 06 2014

Mid-latitude stagnation--in the Pacific flow pattern--offers some
degree of ensemble agreement for upper-level troughing along 150W
longitude.

The 29/00Z ECENS/GEFS for a slow northeastward migration of a
closed h5-to-sfc low through the central gulf of Alaska and
maintain a surface ridge to the northeast of the Hawai'ian Islands
into day 6 (4/00Z).  

This allows remnants of 'Genevieve' to pass south of the islands
and maintain a general track along 20N latitude through the
upcoming weekend.

Unfortunately, the deterministic GFS/ECMWF agree that it will be
an active period in the tropical east Pacific with additional
tropical disturbances progged to develop invof 15N 125W (an
origination region/point) around day 3 (Friday)...and follow a
track that is a tad north and west of where 'Genevieve' is progged
to move through time.

Can see merit in blending pieces of the GFS/ECMWF deterministic
with their means to handle the next 7 days.

Please monitor/consult more detailed information from the Central
Pacific Hurricane Center and National Hurricane Center concerning
tropical weather developments.

Vojtesak





Last Updated: 824 AM EDT Tue Jul 29 2014




Banner
Banner
Banner
Banner
Banner
Banner
Banner
Banner
Banner
Banner
Banner
Banner
Banner
Banner
Banner
Banner

Login Form