Small Craft Advisory 63, NWS Honolulu, HI

AREA FORECAST DISCUSSION...UPDATE
NATIONAL WEATHER SERVICE HONOLULU HI
330 AM HST SUN FEB 3 2013

.SYNOPSIS...
THE PREVAILING DRY AND STABLE CONDITIONS CONTINUE TODAY. THE TRADES
REMAIN STEADY THROUGH THE EVENING HOURS...THEN GRADUALLY INCREASING
THROUGH THE FIRST HALF OF THE WEEK AS HIGH PRESSURE NORTH OF THE
ISLANDS INTENSIFIES. LIMITED SHOWER ACTIVITY WILL REMAIN FOCUSED
OVER WINDWARD AND MAUKA AREAS. TRADE SHOWERS ARE EXPECTED TO
INCREASE FOR THE LATTER HALF OF THE WORK WEEK.

&&

.DISCUSSION...
THE BENIGN WEATHER CONTINUES TODAY WITH A RELATIVELY DRY AIRMASS
REMAINING IN PLACE ACROSS THE MAIN HAWAIIAN ISLANDS. 12Z SOUNDINGS
FROM HILO AND LIHUE SHOW LITTLE CHANGES IN INVERSION
STRUCTURE...LOCATED AROUND 4K FT. THIS WILL KEEP VERTICAL CLOUD
DEVELOPMENT FAIRLY SUPPRESSED...WITH MAINLY SHALLOW STRATOCU
FORMING OVER THE WINDWARD WATERS AND UPSTREAM. SOME OF THE
STRATOCU LAYERS HAVE BEEN REACHING WINDWARD COASTS THROUGHOUT THE
NIGHT HOURS...BUT SHOULD DISSIPATE BY NOON TODAY.

LATEST MODEL GUIDANCE REMAINS ON TRACK REGARDING THE EVOLUTION OF
THE HIGH PRESSURE FAR N OF THE ISLANDS...WHICH INTENSIFIES TODAY
WITH TRADES STRENGTHENING DURING THE NEXT COUPLE OF DAYS. A SECOND
REINFORCING HIGH PRESSURE SYSTEM MOVES INTO THE CENTRAL PACIFIC.
BY MID WEEK...A WEAK MESO LOW DEVELOPS FAR E OF THE BIG ISLAND
WHICH WILL COMBINE WITH THE DOMINANT HIGH PRESSURE N OF THE AREA TO
BRING TIGHTER PRESSURE GRADIENTS ACROSS THE ALOHA STATE. THIS IN
TURN WILL RESULT IN STRONGER TRADES.

CONSENSUS BETWEEN MODELS REMAINS FAIRLY GOOD IN TERMS OF SHOWING AN
APPROACHING FRONTAL BOUNDARY BY LATE TUE...WHICH SEEMS TO QUICKLY
WEAKEN OR EVEN DISSIPATE BEFORE REACHING THE MAIN HAWAIIAN ISLANDS.
AS THE FRONT BREAKS DOWN...IT WILL BRING AN OVERALL INCREASE IN
ATMOSPHERIC MOISTURE ACROSS THE AREA BY MID WEEK.

MODEL GUIDANCE IS ALSO DEVELOPING A MID/UPPER LVL TROUGH BY MID
WEEK WITH TEMPERATURES ALOFT COOLING DOWN SIGNIFICANTLY...AND
INCREASING ATMOSPHERIC INSTABILITY OVER THE AREA. WITH THIS SYNOPTIC
SETUP IN PLACE...SEVERAL INGREDIENTS WILL BE IN PLACE FOR MORE
SHOWERS TO DEVELOP DURING THE LATER PART OF THE WORK WEEK AS
MOISTURE FROM THE DISSIPATING FRONT IS ADVECTED INTO THE ISLANDS BY
THE INCREASING TRADES AND COMBINES WITH THE ENHANCED INSTABILITY.
ALSO...THERE WILL BE POTENTIAL FOR SOME PERIODS OF WINTER WEATHER
OVER THE BIG ISLAND SUMMITS...MAINLY A MIX OF RAIN AND SNOW. THE
FORECAST REMAINS WITH NO MENTION OF THUNDERSTORM ACTIVITY FOR THE
AFOREMENTIONED PERIOD OF INCREASING INSTABILITY. BUT THE SITUATION
WILL BE CLOSELY MONITORED AS NEW MODEL GUIDANCE BECOMES AVAILABLE IN
CASE INCLUSION OF THUNDERSTORMS FOR THE LATER PART OF THE WEEK
BECOMES NECESSARY.

&&

.AVIATION...
VFR CONDITIONS PREVAIL AT ALL TAF SITES THROUGHOUT THE FORECAST
PERIOD.

&&

.MARINE...
SURF ALONG NORTH AND WEST SHORES WILL REMAIN MODERATE THROUGH MID
WEEK...BELOW ADVISORY LEVELS. A LARGER NORTHWEST SWELL WILL BRING
ADVISORY LEVEL SURF FRIDAY...AND INTO NEXT WEEKEND.

THE SMALL CRAFT ADVISORY /SCA/ IS UP FOR THE WINDIER AREAS AROUND
MAUI AND THE BIG ISLAND. SUNDAY NIGHT WINDS ARE EXPECTED TO
INCREASE OUT OF THE NORTHEAST...LIKELY PROVOKING ADDITIONAL ZONES
TO BE ADDED INTO THE SCA.

&&

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

&&

DISCUSSION AND MARINE...REYNES
AVIATION...LUTU-MCMOORE