Drought in Hawaii, September 1 to 30, 2013

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
830 PM HST SAT AUG 31 2013

.SYNOPSIS...
THE TRADES WILL GRADUALLY STRENGTHEN OVER THE NEXT COUPLE OF DAYS
WITH LOW CLOUDS AND SHOWERS FAVORING WINDWARD AND MAUKA AREAS. SOME
OF THE LARGER SHOWERS WILL REACH LEEWARD LOCATIONS AT TIMES. DRIER
CONDITIONS ARE EXPECTED EARLY NEXT WEEK...THEN THE TRADES EASE AGAIN
BY THE MID WEEK AND ALLOW FOR SEA AND LAND BREEZES TO RETURN.

&&

.DISCUSSION...
A SFC HIGH PRESSURE SYSTEM IS GRADUALLY BUILDING FAR N OF THE MAIN
HAWAIIAN ISLANDS...WITH THE TRADES STEADILY INCREASING ACROSS THE
AREA DURING THE NEXT COUPLE OF DAYS. TRADE SPEEDS WILL REMAIN
MODERATE IN GENERAL...BECOMING LOCALLY FRESH AND GUSTY AT TIMES.
LATEST SOUNDING DATA FROM HILO SHOW A SOLID INVERSION AROUND 8
KFT...WHILE LIHUE DEPICTS A MORE UNSTABLE AIRMASS OVER THE W EDGE OF
THE ISLAND CHAIN. THIS IS DUE TO AN UPPER LVL TROUGH JUST NW OF
KAUAI.

PASSING SHOWERS WILL KEEP STREAMING ACROSS THE ISLANDS TONIGHT WITH
BEST CHANCES OF RAIN OVER WINDWARD AND MAUKA AREAS...WITH A FEW
SHOWERS REACHING LEEWARD LOCATIONS AT TIMES. THE AFOREMENTIONED
UPPER TROUGH IS FORECAST TO DRIFT NW THROUGH THE NEXT COUPLE OF DAYS
AS AN UPPER RIDGE BUILDS IN FROM THE NE. MEANWHILE...A DRIER AIRMASS
UPSTREAM OF THE ISLANDS WILL FILTER INTO THE AREA AND BRING A
GRADUAL DECREASE IN SHOWER ACTIVITY...LEAVING MAINLY BRIEF LIGHT
PASSING SHOWERS ACROSS WINDWARD SHORES EARLY NEXT WEEK.

THE MODERATE TRADES WILL BE RELATIVELY SHORT-LIVED AS PRESSURE
GRADIENTS BEGIN WEAKENING ON TUE DUE TO THE HIGH MOVING E TO A
POSITION FAR NE OF THE ALOHA STATE. BY MID WEEK...MODEL GUIDANCE
SHOW AN AREA OF LOW PRESSURE DEVELOPING FAR NW OF THE ALOHA STATE
WHICH PUSHES THE RIDGE AXIS OF THE HIGH FURTHER S AND CLOSER TO THE
ISLANDS. THE TRADES WILL RESPOND BY WEAKENING...LIKELY BECOMING
LIGHT FOR THE LATER PART OF NEXT WEEK AND ALLOWING FOR LOCAL LAND
AND SEA BREEZES TO DEVELOP. THIS WILL BRING CLOUDS AND A FEW SHOWERS
OVER LEEWARD AND INTERIOR AREAS DURING THE AFTERNOON AND EARLY
EVENING HOURS.

&&

.AVIATION...
THE RECENTLY STRENGTHENED TRADES WILL SWEEP MORE CLOUDS AND SHOWERS
INTO THE ISLANDS THROUGH THE REST OF THE WEEKEND. THUS EXPECT SOME
OCCASIONAL MVFR CEILINGS AND VISIBILITIES MAINLY ALONG THE WINDWARD
SECTIONS. TRADEWIND STRENGTH WILL BE MONITORED FOR THE POSSIBILITY
OF MECHANICAL LOW-LEVEL TURBULENCE FORMING LEE OF THE MOUNTAINS. BUT
WINDS CURRENTLY REMAIN MARGINAL AT MEETING AIRMET CRITERIA AT THIS
TIME.

&&

.MARINE...
A SMALL CRAFT ADVISORY REMAINS IN EFFECT FOR THE THE TYPICALLY WINDY
WATERS AROUND MAUI COUNTY AND THE BIG ISLAND THROUGH MON.

THE STRONGER TRADES WILL ALSO CAUSE A BIT OF AN INCREASE IN SHORT
PERIOD CHOPPY SURF ALONG E FACING SHORES. THERE WILL BE A SERIES
OF SMALL...MAINLY BACKGROUND S SWELLS THROUGHOUT THE FORECAST
PERIOD. THERE MAY ALSO BE A COUPLE OF SMALL PULSES FROM THE N NEXT
WEEK WITH POSSIBLY A SMALL NW SWELL LATER IN THE WEEK.

&&

.FIRE WEATHER...
THE STRENGTHENING TRADE WINDS AND LOW RELATIVE HUMIDITY ACROSS THE
AREA HAS INCREASED THE CHANCES FOR CRITICAL FIRE CONDITIONS. THE
DRIEST AND WINDIEST CONDITIONS ARE EXPECTED AGAIN ON SUN FROM THE
MID MORNING THROUGH LATE AFTERNOON HOURS.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
RED FLAG WARNING UNTIL 6 PM HST SUNDAY FOR NIIHAU-KAUAI LEEWARD-
OAHU SOUTH SHORE-WAIANAE COAST-WAIANAE MOUNTAINS-MOLOKAI LEEWARD-
LANAI-MAUI LEEWARD WEST-LEEWARD HALEAKALA-KONA-SOUTH BIG ISLAND-
KOHALA.

SMALL CRAFT ADVISORY UNTIL 6 PM HST MONDAY FOR MAALAEA BAY-
PAILOLO CHANNEL-ALENUIHAHA CHANNEL-BIG ISLAND LEEWARD WATERS-BIG
ISLAND SOUTHEAST WATERS.

&&

REYNES