Saturday, August 02, 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 011948
AFDHFO

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
948 AM HST FRI AUG 1 2014

.SYNOPSIS...
HIGH PRESSURE FAR NORTH OF THE STATE WILL KEEP TRADE WINDS BLOWING
INTO NEXT WEEK. ENHANCED MOISTURE MOVING FROM EAST TO WEST ACROSS
THE ISLANDS TODAY THROUGH SATURDAY WILL RESULT IN AN INCREASE IN
SHOWERS WITH LOCALLY HEAVY RAINFALL POSSIBLE. DRIER AND MORE
STABLE WEATHER IS EXPECTED FROM SUNDAY THROUGH THE MIDDLE OF NEXT
WEEK. ANOTHER BOUT OF WET WEATHER IS POSSIBLE LATE NEXT WEEK.

&&

.DISCUSSION...
CURRENT FRESH TRADE WINDS ARE PROPELLING CLOUDS AND LIMITED
SHOWERS INTO THE WINDWARD SLOPES OF THE SMALLER ISLANDS. THE
WINDWARD BIG ISLAND HAS INCREASING LOW LEVEL MOISTURE ENTERING THE
AREA FROM THE EAST AS THE REMNANT MOISTURE OF TROPICAL DEPRESSION
GENEVIEVE PASSES THROUGH THE AREA. LAYERED LOW AND MID LEVEL
CLOUDS ARE NOTED JUST UPSTREAM OF THE BIG ISLAND AND THIS ENHANCED
MOISTURE WILL CONTINUALLY MOVE ACROSS THE ORCHID ISLE TODAY AND
TONIGHT...BRINGING LOW CLOUDS AND SHOWERS. THESE CLOUDS AND
SHOWERS WILL MOVE INTO WINDWARD MAUI LATER THIS MORNING... AND THE
REST OF THE STATE THIS EVENING AND TONIGHT. EXPECT INCREASING
MUGGINESS AS THIS MOISTURE MOVES ACROSS THE STATE.

SHOWERS WILL INCREASE AS THE MOISTURE MOVES THROUGH THE STATE WITH MORE
STEADY RAINS OVER WINDWARD AREAS WITH THE CHANCE OF LOCALLY HEAVY
SHOWERS. THE SATELLITE MIMIC TOTAL PRECIPITABLE WATER ESTIMATE
SHOWS A SLUG OF 2 INCHES PLUS PRECIPITABLE WATER ENTERING THE BIG
ISLAND COASTAL WATERS THIS MORNING AND WILL REACH THE BIG ISLAND
THIS AFTERNOON. THIS AMOUNT OF PW WILL INCREASE SHOWER COVERAGE
AND INTENSITY THIS AFTERNOON AND TONIGHT FOR THE WINDWARD BIG
ISLAND. WITH ONLY A WEAK UPPER TROUGH LIFTING OUT TO OUR WEST AND
NORTH DURING THIS TIME...IT APPEARS THAT THIS WILL PROBABLY BE
MORE OF AN OROGRAPHICALLY DRIVEN EVENT WITH LOCALLY HEAVY RAINS
MOST LIKELY OVER THE WINDWARD SLOPES. EXPECTED TOTAL RAINFALL
AMOUNTS THROUGH SATURDAY...WINDWARD AREAS OF THE BIG ISLAND 1-3
INCHES WITH POCKETS OF HIGHER AMOUNTS. WINDWARD AND MAUKA AREAS OF
THE SMALLER ISLANDS AROUND A HALF AN INCH TO POSSIBLY AS MUCH AS 2
INCHES. LEEWARD AREAS WILL RECEIVE GENERALLY LESS THAN HALF AN
INCH.

SUNDAY THINGS WILL DRY OUT AND HUMIDITY WILL DECREASE AS DRIER AIR
MOVES IN FROM THE EAST... AND RIDGING SETS UP ALOFT KEEPING SHOWERS
TO A MINIMUM. A STABLE TRADE WIND PATTERN IS EXPECTED THROUGH MID-
WEEK WITH THE RIDGE REMAINING IN PLACE AND HIGH PRESSURE ANCHORED
TO THE NORTH.

LATE NEXT WEEK STARTING THURSDAY... GLOBAL MODELS HAVE BEEN
CONSISTENTLY ADVECTING TROPICAL MOISTURE OVER THE STATE FROM THE
EAST... BRINGING MUGGY CONDITIONS AND INCREASING RAIN TO
THE ISLANDS. THIS MOISTURE IN THE MODEL FIELD COMES FROM WHAT IS NOW
TROPICAL STORM ISELLE. HOWEVER AT 6-7 DAYS OUT...THIS FORECAST IS
HIGHLY UNCERTAIN AND THE OFFICIAL FORECAST FOR THE EXTENDED PERIOD
HAS ONLY BEEN NUDGED TOWARD A WETTER FORECAST. STAY TUNED FOR
UPDATES AS THIS TIME PERIOD APPROACHES.

&&

.AVIATION...
AN AREA OF INCREASED MOISTURE SPREADING WEST ACROSS THE ISLANDS WILL
PROMPT US TO KEEP AIRMET SIERRA UP THROUGH THE DAY FOR MOUNTAIN
OBSCURATION. AIRMET TANGO FOR MODERATE TURBULENCE IMMEDIATELY LEE OF
THE ISLANDS WILL REMAIN IN EFFECT AS WELL...THANKS TO LOCALLY STRONG
TRADE WINDS. WINDWARD TERMINALS MAY SEE OCCASIONAL MVFR CONDITIONS
TODAY...BUT VFR CONTINUES TO DOMINATE.

&&

.MARINE...
FRESH TRADE WINDS WILL CONTINUE AND A SMALL CRAFT ADVISORY REMAINS
FOR THE WINDIER AREAS AROUND THE BIG ISLAND AND MAUI.

MODERATE SSW SWELL WILL INCREASE SLIGHTLY THIS AFTERNOON... AND
THEN REINFORCING SOUTH SWELL SHOULD INCREASE SURF FURTHER
SATURDAY... APPROACHING ADVISORY LEVELS ON SOUTH FACING SHORES.
THIS SURF EVENT SHOULD PEAK SATURDAY THEN SLOWLY DECREASE SUNDAY
THROUGH MONDAY. SURF WILL SEE A SLIGHT BUMP ON WEST FACING SHORES
AS WELL DUE TO THE SSW DIRECTION. OTHERWISE...PREVAILING TRADE
WINDS WILL CONTINUE TO PRODUCE SHORT PERIOD SWELL AND CHOPPY NEAR
AVERAGE SURF ALONG EAST FACING SHORES THROUGH THE NEXT SEVERAL
DAYS.

&&

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


&&

$$

MORRISON...DISCUSSION AND MARINE
POWELL...AVIATION



The Weather Prediction Center

College Park, MD

Hawaii Extended Forecast Discussion




Hawaii Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
808 AM EDT Fri Aug 01 2014

Valid 00Z Sat Aug 02 2014 - 00Z Sat Aug 09 2014

The August 1/00Z ECENS and GEFS means and their deterministic runs
maintained decent continuity through 6/12Z (mid-point_day 5)
across a large portion of the northern hemispheric Pacific Ocean.

An active tropical pattern and series of systems off the east
Asian coast between the Marianas and Japan are creating large
spreads in the guidance beyond day 6. The key feature in the
northern Pacific is the mid-level and upper-level long wave trough
invof 155W and it's quasi-stationary positioning along 150W
throughout much of this medium range period--as energy and
moisture off the Japan reloads the trough.

For the Subtropics, the long wave trough extends sufficiently
southward into the Subtropics to produce an appreciable weakness
in the Subtropical Ridge axis invof 25N. In turn, this weakness
appears to directly impact the Islands with more influence from
the Tropics--and an enhancement of the trade wind flow regime.

The 31/00Z GFS/ECMWF deterministic runs initialized 'Iselle' with
the 00Z cycle producing an additionally slower west-northwestward
track west of 140W between 16N (ECMWF solution) and 19N (GFS
solution) for days 6-7.

fyi...looked like the 31/00Z Canadian had a bad run across the
Tropics.

After 6/12z, recommend an equally-weighted blend of the 1/00Z
ECENS, GEFS AND NAEFS means to handle the large spread across the
southern Bering Sea, Gulf of Alaska and with the track of 'Iselle'.

For additional information, please consult/refer to the latest
updates and bulletins from the Central Pacific Hurricane Center
and National Hurricane Center.

Vojtesak





Last Updated: 808 AM EDT Fri Aug 01 2014




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

Login Form