Wind Advisory 9, NWS Honolulu, HI

576 
WWHW70 PHFO 130123
NPWHFO

URGENT - WEATHER MESSAGE
NATIONAL WEATHER SERVICE HONOLULU HI
323 PM HST TUE FEB 12 2013

HIZ028-130230-
/O.CAN.PHFO.WI.Y.0009.000000T0000Z-130213T0400Z/
BIG ISLAND SUMMITS-
INCLUDING THE CITY OF...MAUNA LOA AND MAUNA KEA ABOVE 8000 FEET
323 PM HST TUE FEB 12 2013

...WIND ADVISORY IS CANCELLED...

REPORTS FROM MAUNA KEA SHOW WINDS HAVE DROPPED BELOW THE ADVISORY
THRESHOLD.

$$
DONALDSON

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
330 AM HST TUE FEB 12 2013

.SYNOPSIS...
TRADE WIND WEATHER WILL CONTINUE THROUGH THE WEEK...WITH PASSING
SHOWERS AND GUSTY PERIODS. THE BEST CHANCES OF RAIN WILL REMAIN OVER
WINDWARD AREAS...BUT SHOWERS WILL REACH LEEWARD AREAS AT TIMES. A
MODEST DRYING TREND WILL BECOME ESTABLISHED TOMORROW THROUGH
THURSDAY... FOLLOWED BY A CHANCE FOR ENHANCED SHOWERS DURING THE
WEEKEND.

&&

.DISCUSSION...
AN ACTIVE TRADE WIND WEATHER PATTERN CONTINUES TODAY WITH RAINFALL
FAVORING WINDWARD AD MAUKA AREAS. SHOWERS ARE BEING SUPPORTED BY A
LARGE AREA OF ENHANCED LOW LVL MOISTURE UPSTREAM OF THE ISLANDS.
PWATS CAME OUT UNDER ONE INCH IN THE 12Z HILO AND LIHUE
SOUNDINGS...BUT MIMIC AND MODEL ANALYSES SUGGEST THAT THE MOISTURE
EMBEDDED IN THE TRADES SHOULD BE ENOUGH TO SUPPORT CONTINUING
PASSING SHOWERS ACROSS THE ISLANDS WITH HIGHER ACCUMULATIONS OVER
THE MOUNTAIN RANGES. SOME OF THE LARGER SHOWERS WILL REACH LEEWARD
AREAS AT TIMES.

A DRIER AND SOMEWHAT MORE STABLE AIR MASS ALOFT IS SLOWLY FILTERING
INTO THE AREA IN THE WAKE OF A DEPARTING UPPER LVL TROUGH LOCATED S
OF THE AREA. THIS WILL HELP IN BRINGING A MODEST DECREASE IN SHOWERS
FOR THE MIDDLE OF THE WEEK. MODEL CONSENSUS SHOW A PREVAILING STRONG
HIGH PRESSURE SYSTEM CENTERED FAR N OF THE STATE KEEPING ROBUST AND
GUSTY TRADE WINDS ACROSS THE ISLAND CHAIN THROUGH THE REST OF THE
WEEK. HOWEVER...A MID/UPPER LVL LOW FAR NE OF THE MAIN HAWAIIAN
ISLANDS IS SLOWLY MIGRATING S AND WEAKENING THE PRESSURE GRADIENTS
ACROSS THE AREA BY MID WEEK. THIS WILL LEAD TO A SLIGHT DECREASE IN
WIND SPEEDS ON THU. THEN THE TRADES INCREASE AGAIN BY FRI AS THE LOW
BREAKS DOWN AND QUICKLY DEPARTS EASTWARD. REINFORCING HIGH PRESSURE
MOVES INTO THE NORTH CPAC...WITH GUSTY PERIODS AND INCREASING TRADE
WIND SHOWERS ACROSS THE ISLANDS DURING THE WEEKEND.

&&

.AVIATION...
AIRMET SIERRA CONTINUES FOR MOUNTAIN OBSCURATION ABOVE 2.5KFT ALONG
WINDWARD FACING SLOPES OF MOST ISLANDS DUE TO A PERSISTENT BAND OF
LOW CLOUDS WITH SHRA THIS MORNING. BASED ON THE LATEST SATELLITE
IMAGERY AND RADAR REFLECTIVITY DATA...THESE LOW CLOUDS AND SHOWERS
WILL LIKELY CONTINUE AT LEAST THROUGH MID-MORNING. CONDITIONS MAY
IMPROVE LATER THIS MORNING AS THE COVERAGE OF LOW CLOUDS AND SHOWERS
DIMINISHES DUE TO DAYTIME HEATING AND INCREASED MIXING.

AIRMET TANGO ALSO CONTINUES FOR TEMPO MODERATE LOW-LEVEL MECHANICAL
TURBULENCE IN THE AIR SPACE BELOW 8KFT LEEWARD OF THE MOUNTAINS ON
ALL ISLANDS DUE TO THE BREEZY LOW-LEVEL TRADE WIND FLOW. THESE
TURBULENT CONDITIONS WILL LIKELY PERSIST THROUGH TONIGHT.

&&

.MARINE...
A SMALL CRAFT ADVISORY /SCA/ REMAINS IN EFFECT FOR THE TYPICALLY
WINDY WATERS AROUND MAUI AND THE BIG ISLAND UNTIL WEDNESDAY EVENING.
CONDITIONS WILL BE BORDERLINE BY WEDNESDAY NIGHT. ANOTHER SURGE IN
WINDS MAY BRING SCA CRITERIA AGAIN BY FRI.

A SERIES OF NORTHWEST SWELLS ARE EXPECTED THIS WEEK. MAINLY MODERATE
SWELLS ARE EXPECTED THROUGH SATURDAY WITH ADVISORY LEVEL SURF
EXPECTED ON SUNDAY.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 6 PM HST THIS EVENING FOR THE BIG ISLAND
SUMMITS.

SMALL CRAFT ADVISORY UNTIL 6 PM HST WEDNESDAY FOR THE PAILOLO AND
ALENUIHAHA CHANNELS...MAALAEA BAY AND WATERS SOUTH OF THE BIG ISLAND.

&&

DISCUSSION/MARINE...REYNES
AVIATION...HOUSTON