Drought in Hawaii, May 1 to 31, 2013

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
835 PM HST TUE APR 30 2013

.SYNOPSIS...
A LIGHT TO MODERATE TRADE WIND REGIME WILL GRADUALLY ESTABLISH FROM
TONIGHT AND INTO EARLY WEDNESDAY...AND WILL PREVAIL THROUGH LATE
THURSDAY. A SURFACE COLD FRONT WILL APPROACH THE ISLANDS FROM THE
NORTHWEST ON FRIDAY BRINGING LIGHT SOUTHERLY WINDS BACK TO THE
AREA DURING WEEKEND. THE LIGHTER WINDS...COMBINED WITH MOISTURE
FROM THE APPROACHING FRONT...WILL ALSO BRING AN INCREASE IN SHOWER
ACTIVITY...PARTICULARLY OVER THE INTERIOR AND MOUNTAIN SECTIONS OF
THE SMALLER ISLANDS.

&&

.DISCUSSION...
LATEST SFC ANALYSIS AND SATELLITE IMAGERY DATA SHOWS A DISSIPATING
COLD FRONT BOUNDARY STALLED AROUND 180 MILES NW OF KAUAI. THE
INFLUENCE OF THIS FRONT ACROSS THE AREA IS DIMINISHING...WITH WINDS
STARTING TO SHIFT BACK TO THE E AND A TRADE WIND WEATHER REGIME
RETURNING BY EARLY WED.

MOST OF THE EARLIER AFTERNOON CONVECTION IS NOW CLEARING
OUT...EXCEPT FOR A FEW SHOWERS STILL BEING OBSERVED IN RADAR DATA
OVER S AND INTERIOR KAUAI...LEEWARD OAHU AND THE SE SLOPES OF THE
BIG ISLAND. HOWEVER...AS THE TRADES GRADUALLY ESTABLISH...IT IS
POSSIBLE FOR SOME LOW CLOUDS AND A FEW SHOWERS TO LINGER OVER
WINDWARD AND MOUNTAIN AREAS OVERNIGHT.

FOR WED THROUGH LATE THU...MODELS ARE IN GOOD AGREEMENT REGARDING
HAVING A RIDGE ACROSS THE AREA GRADUALLY STRENGTHENING...THEN
LIFTING N AS THE AFOREMENTIONED COLD FRONT DISSIPATES. THIS WILL
KEEP THE TRADES IN PLACE THROUGH LATE THU OR EARLY FRI WHEN ANOTHER
COLD FRONT IS EXPECTED TO APPROACH THE MAIN HAWAIIAN ISLANDS FROM
THE NW.

CONSENSUS BETWEEN GLOBAL MODELS REMAINS POOR REGARDING THE FORECAST
SCENARIO FOR THE UPCOMING WEEKEND. AN AMPLIFYING UPPER LVL TROUGH
WILL MOVE ACROSS THE N CPAC AND PUSH A SFC COLD FRONT TOWARDS THE
ISLAND CHAIN. AT THE VERY LEAST...A WEAKENING OF THE TRADES IS
EXPECTED FOR SAT AND SUN WHICH WILL LIKELY LEAD TO A RETURN OF VOG
ACROSS THE SMALLER ISLANDS. HOWEVER...SIGNIFICANT DISCREPANCIES
STILL REMAIN IN TERMS OF HOW FAR E INTO THE ISLAND CHAIN THE FRONT
OR ITS REMNANTS WILL ACTUALLY REACH. THE OVERALL INTENSITY AND
TIMING OF THE POTENTIAL FROPA LOOKS VERY DIFFERENT FOR EACH MODEL
SOLUTION. THEREFORE...WILL REFRAIN FROM INCORPORATING SIGNIFICANT
CHANGES TO THE INHERITED LONG RANGE FORECAST WHICH CALLS FOR
LIGHTER WINDS ACROSS THE ISLANDS AND A CONVECTIVE PATTERN DEVELOPING
EACH AFTERNOON WITH SEA BREEZES THROUGH EARLY NEXT WEEK. THE
FORECAST WILL CERTAINLY BE ADJUSTED AS UPCOMING MODEL GUIDANCE
BECOMES AVAILABLE.

&&

.MARINE...
DESPITE THE BRIEF UPTICK IN WINDS ON WEDNESDAY AND THURSDAY...WINDS
WILL REMAIN BELOW SMALL CRAFT ADVISORY THROUGH THE END OF THE WEEK.
SEAS ARE ALSO EXPECTED TO REMAIN BELOW CRITERIA.

&&

.AVIATION...
VFR CONDITIONS WILL PREVAIL AT ALL TERMINALS WITH THE EXCEPTION OF
ISOL MVFR CEILINGS AND VISIBILITIES FOR PHTO. TRADE WINDS WILL
RETURN OVERNIGHT BRINGING CLOUDS AND LOWERING CEILING TO WINDWARD
SLOPES.

&&

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

DISCUSSION/MARINE...REYNES
AVIATION...MORRISON