Area Forecast Discussion
Issued by NWS Honolulu, HI

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FXHW60 PHFO 190645
AFDHFO

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
830 PM HST THU SEP 18 2014

.SYNOPSIS...
LIGHT WINDS THROUGH THE WEEKEND WILL ALLOW LOCAL LAND AND SEA
BREEZES TO FORM. EXPECT INCREASED CLOUDS AND SHOWERS ACROSS MAUKA
AREAS EACH AFTERNOON AND EVENING...FOLLOWED BY CLEARING AT NIGHT.
HOT AND MUGGY CONDITIONS WILL CONTINUE UNTIL THE RETURN OF MODERATE
TRADE WINDS EARLY NEXT WEEK. INCREASING MOISTURE SOUTH OF THE
ISLANDS MAY BRING AN UPTICK IN RAINFALL FOR THE BIG ISLAND OVER THE
WEEKEND.

&&

.DISCUSSION...
A WEAK RIDGE OF HIGH PRESSURE EXTENDS FROM A 1020 MB HIGH NEAR
36N141W THROUGH 30N160W AND 30N180W...600 MILES OR SO NORTH OF THE
MAIN HAWAIIAN ISLANDS. A FRONT DIGGING INTO THE NORTHERN FLANK OF
THIS RIDGE BETWEEN 150W AND 170W WILL GRADUALLY APPROACH THE
ISLANDS...PUTTING A BIG DENT IN THE RIDGE AND KEEPING LOCAL TRADE
WINDS LIGHT AT LEAST THROUGH THE WEEKEND.

SATELLITE LOOP SHOWED SLUGGISH 10 MPH EAST TO WEST FLOW ACROSS LOCAL
WATERS...AND BROKEN TO OVERCAST CLOUDS ACROSS MAUKA AREAS OF THE
ISLANDS THIS AFTERNOON SHOWED THAT THIS LIGHT FLOW IS NOT STRONG
ENOUGH TO PREVENT THE DEVELOPMENT OF AFTERNOON SEA BREEZES. CLOUD
COVER AND SHOWERS WILL TAPER OFF AS THE EVENING WEARS ON AND COOLING
SETS IN. WE EXPECT THIS PATTERN TO REPEAT EACH DAY THROUGH THE
WEEKEND...WITH CLOUDS AND SHOWERS INCREASING EACH AFTERNOON AND
EVENING...FOLLOWED BY CLEARING LATE AT NIGHT.

MODELS SHOW THE FRONT WILL PUSH TO THE EAST SUNDAY...ALLOWING THE
RIDGE TO STRENGTHEN TO OUR NORTH. WE EXPECT LIGHT TRADES WILL RETURN
TO THE EASTERN HALF OF THE STATE SUNDAY. HOWEVER...MOST LEEWARD
AREAS WILL STILL EXPERIENCE SEA BREEZES AS THE TRADES FILTER IN.
RELIEF FROM THE CURRENT HOT AND MUGGY CONDITIONS SHOULD COME MONDAY
AS THE RIDGE CONTINUES TO STRENGTHEN AND MODERATE TRADE WINDS BUILD
IN.

RAINFALL AND HUMIDITY MAY PICK UP OVER WINDWARD AND SOUTHEAST
SECTIONS OF THE BIG ISLAND FRIDAY NIGHT THROUGH SUNDAY AS AN AREA
OF TROPICAL MOISTURE SKIRTS BY TO THE SOUTH.

&&

.AVIATION...
THE CLEARING TREND SHOULD CONTINUE OVERNIGHT FOR LEEWARD COASTS
WHILE MOSTLY CLOUDY SKIES AND ISOLATED SHOWERS WILL PERSIST ALONG
WINDWARD SLOPES. PREVAILING VFR EXPECTED ALL AREAS. ISOL MVFR CIGS
LIKELY IN PASSING SHOWERS...MAINLY WINDWARD BIG ISLAND.

SEA BREEZES AND INLAND SHOWERS ARE EXPECTED TO REDEVELOP FRIDAY
AFTERNOON ALL ISLANDS.

&&

.MARINE...
SMALL SOUTHERLY SWELLS WILL CONTINUE THROUGH THE PERIOD. A SHORT-
PERIOD 2-FOOT NORTHWEST SWELL WILL LAST THROUGH THE WEEKEND.
ANOTHER SMALL NW SWELL IS DUE WEDNESDAY.

WINDS WILL REMAIN LIGHT THROUGH THE WEEKEND WITH TRADE WINDS
PICKING UP NEXT WEEK.


&&

.HFO WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$

PUBLIC/MARINE...POWELL
AVIATION...BEDAL








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