Area Forecast Discussion
Issued by NWS Honolulu, HI

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FXHW60 PHFO 280631
AFDHFO

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
830 PM HST THU NOV 27 2014

.SYNOPSIS...
SURFACE HIGH PRESSURE FAR NORTH OF THE ISLANDS WILL MAINTAIN STRONG
AND GUSTY TRADE WINDS ACROSS THE STATE INTO THIS WEEKEND. LINGERING
LOW-LEVEL MOISTURE WILL CONTINUE TO GENERATE SCATTERED TRADE SHOWERS
ACROSS WINDWARD SECTIONS OF THE BIG ISLAND AND MAUI. ELSEWHERE...
EXPECT A RATHER DRY TRADE WIND PATTERN TO PREVAIL INTO THIS WEEKEND.
THE TRADE WIND SPEEDS ARE FORECAST TO DIMINISH SLIGHTLY EARLY NEXT
WEEK...WITH TRADE SHOWERS REMAINING FOCUSED MAINLY ACROSS WINDWARD
AND MAUKA AREAS.

&&

.DISCUSSION...
THE TIGHT PRESSURE GRADIENT SOUTH OF A NEARLY STATIONARY 1029 MB
SURFACE HIGH NEAR 38N 161W...OR ABOUT 1100 MILES NORTH OF
HONOLULU...IS MAINTAINING STRONG AND GUSTY TRADE WINDS ACROSS THE
MAIN HAWAIIAN ISLAND CHAIN EARLY THIS EVENING. ALOFT...A
MID-TROPOSPHERIC RIDGE OVER THE ISLANDS IS ALSO PRODUCING STABLE
ATMOSPHERIC CONDITIONS ACROSS THE REGION. THIS IS KEEPING THE TRADE
WIND INVERSION HEIGHT RELATIVELY LOW ACROSS THE ISLAND CHAIN. THIS
IS ALSO ALLOWING LOCALLY HIGHER WIND GUSTS IN CHANNELED AREAS IN
THE VICINITY OF HIGHER TERRAIN.

THE DRY AND STABLE ATMOSPHERIC CONDITIONS ALSO ARE LIMITING THE
DEVELOPMENT OF TRADE SHOWERS OVER MOST AREAS OF THE STATE.
ALSO...MOST OF THE LOW CLOUDS APPEAR TO BE STRATOCUMULUS TYPE...
WHICH IS ALSO NORMALLY INDICATIVE OF STABLE CONDITIONS. HOWEVER...
SATELLITE IMAGERY AND RADAR REFLECTIVITY DATA CONTINUE TO SHOW LOW
CLOUDS AND SHOWERS OVER THE WINDWARD SECTIONS OF MAUI AND THE BIG
ISLAND.

THE FORECAST MODELS INDICATE THE TIGHT PRESSURE GRADIENT WILL REMAIN
ACROSS THE STATE FRIDAY AND SATURDAY AS THE SURFACE HIGH SHIFTS
SLOWLY EASTWARD. SPARSE TRADE SHOWER COVERAGE WILL CONTINUE TO
REMAIN FOCUSED MAINLY ALONG WINDWARD AND MAUKA AREAS THROUGH THIS
WEEKEND. THE BEST CHANCE FOR SHOWERS WILL REMAIN ACROSS THE WINDWARD
BIG ISLAND...WITH RAINFALL AMOUNTS EXPECTED TO BE MEAGER ELSEWHERE.

AS THE SURFACE HIGH TO THE NORTH OF THE STATE CONTINUES TO WEAKEN
AND SHIFT EASTWARD...THE PRESSURE GRADIENT WILL CONTINUE TO RELAX.
THIS WILL RESULT IN A CONTINUED GRADUAL WEAKENING OF TRADE WINDS
EARLY NEXT WEEK. AT THE SAME TIME...A MODEST INCREASE IN LOW-LEVEL
MOISTURE MAY OCCUR. THE FORECAST MODELS ALSO INDICATE A VERY WEAK
FRONT OR SHEAR LINE MAY MOVE DOWN THE STATE AROUND NEXT WEDNESDAY.
WITH THE ADDITIONAL MOISTURE ASSOCIATED WITH THIS AREA...TRADE
SHOWERS MAY INCREASE ACROSS WINDWARD AND MAUKA AREAS. AS NOTED IN
THE PREVIOUS DISCUSSION...OVERALL DO NOT EXPECT ANY MAJOR CHANGES TO
THE WEATHER PATTERN THROUGH THE MIDDLE OF NEXT WEEK.

&&

.AVIATION...
FRESH AND GUSTY TRADE WINDS BENEATH A WELL DEFINED INVERSION ALOFT
ARE EXPECTED TO PERSIST THROUGH FRIDAY. WIND SPEEDS IN EXCESS OF 25
KT ARE EXPECTED ALONG NORTHEASTERN EXPOSURES AND OVER MOUNTAIN
RIDGES...WITH SOME LOCAL CHANNELED AREAS POTENTIALLY EXPERIENCING
STRONGER WIND GUSTS. AS A RESULT...AIRMET TANGO REMAINS IN EFFECT
FOR MODERATE LOW-LEVEL TURBULENCE IN THE AIR SPACE LEEWARD OF ALL
MOUNTAINS AT LEAST THROUGH FRIDAY.

BRIEF TRADE WIND SHOWERS ARE EXPECTED TO CONTINUE AFFECTING MAINLY
WINDWARD FACING SLOPES AND TERRAIN ON MAUI AND THE BIG ISLAND
TONIGHT. HOWEVER...ISOLATED MVFR CIGS MAY BECOME MORE NUMEROUS
ACROSS THE NORTHEAST BIG ISLAND COAST LATER THIS EVENING. WILL
MONITOR FOR POSSIBLE DEVELOPING MOUNTAIN OBSCURATION. OTHERWISE...
VFR CONDS ARE EXPECTED TO PREVAIL ACROSS ALL OTHER AREAS THROUGH
FRIDAY AFTERNOON.

&&

.MARINE...
THE CURRENT LARGE NORTH NORTHEAST SWELL CONTINUES TO SLOWLY SUBSIDE
EARLY THIS EVENING. THE MOST RECENT READINGS FROM THE HILO...
PAUWELA...MOKAPU AND WAIMEA BUOYS INDICATE THE SIGNIFICANT WAVE
HEIGHT IS STILL 9 TO 10 FEET WITH A WAVE PERIOD OF AROUND 13
SECONDS. AS A RESULT...THE HIGH SURF ADVISORY REMAINS IN EFFECT FOR
EAST FACING SHORES OF KAUAI...OAHU...MOLOKAI...MAUI AND THE BIG
ISLAND THROUGH FRIDAY. THIS SWELL IS FORECAST TO GRADUALLY SHIFT TO
A MORE NORTHEASTERLY DIRECTION. THIS SWELL COMBINED WITH LOCALLY
GENERATED WIND WAVES WILL KEEP SURF ELEVATED ALONG EAST FACING
SHORES THROUGH THIS WEEKEND.

THE CURRENT NORTH NORTHEAST SWELL MAY ALSO CAUSE MODERATE HARBOR
SURGES WITHIN...AND LARGE BREAKING WAVES NEAR THE ENTRANCES OF NORTH
FACING HARBORS...SUCH AS KAHULUI AND HILO HARBORS...THROUGH FRIDAY.
A MARINE WEATHER STATEMENT HAS BEEN ISSUED TO COVER THIS POTENTIAL
THREAT.

A SMALL CRAFT ADVISORY /SCA/ REMAINS IN EFFECT FOR ALL HAWAIIAN
COASTAL WATERS...EXCEPT THE LEEWARD MAUI COUNTY MARINE ZONE THROUGH
FRIDAY AFTERNOON DUE TO A COMBINATION OF STRONG TRADE WINDS AND
ROUGH SEAS. THE NORTH NORTHEAST SWELL AND LOCAL WIND WAVES WILL
LIKELY KEEP MANY WINDWARD WATERS...AS WELL AS THE TYPICALLY WINDY
WATERS ADJACENT TO THE ISLANDS OF MAUI AND HAWAII COUNTIES...IN THE
SCA FROM FRIDAY NIGHT INTO THIS WEEKEND.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
HIGH SURF ADVISORY UNTIL 6 PM HST FRIDAY FOR EAST FACING SHORES
OF KAUAI...OAHU...MOLOKAI...MAUI AND THE BIG ISLAND.

SMALL CRAFT ADVISORY UNTIL 6 AM HST SATURDAY FOR KAUAI NORTHWEST
WATERS-KAUAI CHANNEL-OAHU LEEWARD WATERS-KAIWI CHANNEL-MAALAEA
BAY-PAILOLO CHANNEL-ALENUIHAHA CHANNEL-BIG ISLAND LEEWARD WATERS-
BIG ISLAND SOUTHEAST WATERS.

SMALL CRAFT ADVISORY UNTIL 6 PM HST FRIDAY FOR KAUAI WINDWARD
WATERS-KAUAI LEEWARD WATERS-OAHU WINDWARD WATERS-MAUI COUNTY
WINDWARD WATERS-BIG ISLAND WINDWARD WATERS.

&&

$$

HOUSTON






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