Drought in Hawaii, February 23 to 29, 2016

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
423 AM HST TUE FEB 23 2016

.SYNOPSIS...A VERY LARGE NORTH-NORTHWEST SWELL WILL CONTINUE TO
IMPACT THE ALOHA STATE TODAY. A SURFACE RIDGE IN THE VICINITY OF
THE ISLANDS WILL MAINTAIN LIGHT WINDS THROUGH WEDNESDAY. ANOTHER
FRONT WILL MOVE OVER KAUAI AND OAHU THURSDAY...THEN STALL AND
DISSIPATE AS A NEW SURFACE RIDGE BUILDS NORTHWEST OF THE AREA.
ALSO...ANOTHER VERY LARGE AND LONG PERIOD NORTHWEST SWELL IS
EXPECTED TO AFFECT THE ISLANDS FROM LATE WEDNESDAY THROUGH
THURSDAY. A STRONGER COLD FRONT MAY REACH THE ISLANDS EARLY NEXT
WEEK.

&&

.DISCUSSION...
A NEARLY EAST TO WEST ORIENTED SURFACE RIDGE REMAINS IN THE
VICINITY OF THE ISLANDS EARLY THIS MORNING. AS A RESULT...THE
PRESSURE GRADIENT IS RELAXED OVER THE REGION. THIS IS CAUSING THE
BACKGROUND WINDS TO BE LIGHT OVER THE ISLANDS. LOCAL NIGHTTIME
LAND BREEZES ARE DOMINATING THE FLOW OVER THE INTERIOR SECTIONS OF
MOST ISLANDS. SOME LOW CLOUDS AND LIGHT SHOWERS ARE LINGERING IN
THE VICINITY OF THE ISLANDS.

ALOFT...THE SOUTHERN END OF A BROAD MID TO UPPER LEVEL TROPOSPHERIC
TROUGH IS JUST NORTHEAST OF THE ISLANDS. WINDS ON THE BIG ISLAND
SUMMITS UNEXPECTEDLY INCREASED LATE MONDAY AFTERNOON. HOWEVER...AS
THIS TROUGH ALOFT PUSHED EASTWARD OVERNIGHT...WINDS HAVE DIMINISHED
THERE. AS A RESULT...THE WIND ADVISORY HAS BEEN CANCELLED.

WITH THE RIDGING IN PLACE OVER THE AREA...THE WINDS WILL REMAIN
LIGHT. THEREFORE...EXPECT LOCAL AFTERNOON SEA BREEZES AND
NIGHTTIME LAND BREEZES TO DEVELOP. WEAK RIDGING DEVELOPING ALOFT
SHOULD KEEP THE ATMOSPHERE RELATIVELY STABLE. THIS STABILITY
COMBINED WITH BELOW TO NEAR NORMAL LOW LEVEL MOISTURE VALUES WILL
LIKELY LIMIT RAINFALL AMOUNTS FOR THE NEXT COUPLE OF DAYS. NOTE
THAT LIGHT EAST TO NORTHEAST FLOW SOUTH OF THE RIDGE NEAR THE BIG
ISLAND MAY PRODUCE SOME WINDWARD SHOWERS FOR THE NEXT COUPLE OF
DAYS.

THE FORECAST MODELS CONTINUE TO SHOW A WEAK FRONT APPROACHING THE
MAIN HAWAIIAN ISLANDS WEDNESDAY NIGHT. A BAND OF LOW CLOUDS AND
SHOWERS ALONG THE FRONT WILL LIKELY BRING SOME RAINFALL TO KAUAI
AND OAHU FROM LATE WEDNESDAY NIGHT THROUGH THURSDAY. THERE IS
SOME UNCERTAINTY WHETHER OR NOT THE FRONT WILL STALL AND DISSIPATE
NEAR KAUAI AND OAHU. IF SO...IT MAY NOT AFFECT THE WEATHER OVER
MAUI COUNTY OR THE BIG ISLAND. REGARDLESS OF WHERE THE FRONT ENDS
UP...A SURFACE RIDGE BUILDING NORTHWEST OF THE REGION WILL LIKELY
CAUSE TRADE WINDS TO DEVELOP OVER THE STATE. NOTE THAT WINDS ARE
LIKELY TO STRENGTHEN AGAIN OVER THE BIG ISLAND SUMMITS ON
THURSDAY. IF SO...A WIND ADVISORY MAY BE NEEDED AT THAT TIME.

SURFACE RIDGING NEAR THE ISLANDS WILL LIKELY KEEP WINDS LIGHT AND
MAINTAIN DRY WEATHER FROM FRIDAY THROUGH THE MOST OF THIS WEEKEND.
EARLY NEXT WEEK...THE MODELS CONTINUE TO SHOW A STRONGER COLD
FRONT MOVING DOWN THE ISLAND CHAIN WITH STRONG NORTHWEST TO NORTH
WINDS DEVELOPING OVER THE AREA BEHIND THE FRONT.

&&

.AVIATION...
VFR WILL PREVAIL THROUGH THE DAY...THOUGH LINGERING MOISTURE FROM
AN OLD FRONT MAY BRING ISOL MVFR IN LOWER CEILINGS IN WINDWARD
AREAS OF THE BIG ISLAND THROUGH THE MORNING HOURS. WITH WEAK HIGH
PRESSURE MOVING EAST ACROSS THE AREA...SEA BREEZES WILL DEVELOP
OVER THE ISLAND CHAIN AS THE DAY PROGRESSES.

NO AIRMETS ARE CURRENTLY POSTED.

&&

.MARINE...
THE VERY LARGE NORTH-NORTHWEST SWELL CONTINUES TO SLOWLY DIMINISH
ACROSS THE STATE EARLY THIS AFTERNOON. HOWEVER...THE SIGNIFICANT
WAVE HEIGHT AT THE WAIMEA BAY BUOY CONTINUES AROUND 20 FEET...
WHILE THE HILO BAY BUOY IS AROUND 18 FEET...WITH WAVE PERIODS OF
NEAR 15 SECONDS. AS A RESULT...A HIGH SURF WARNING REMAINS IN
EFFECT FOR NORTH AND WEST FACING SHORES OF NIIHAU...KAUAI...OAHU
AND MOLOKAI...AND NORTH FACING SHORES OF MAUI AND THE BIG ISLAND.
THERE IS ALSO A HIGH SURF ADVISORY ALONG WEST FACING SHORES OF
MAUI AND THE BIG ISLAND...AND FOR EAST FACING SHORES OF OAHU. THE
CURRENT HIGH TIDES ARE RANGE FROM NEAR 1.5 FEET ON OAHU TO AROUND
2 FEET ON KAUAI AND MAUI. SEE THE TIDE TABLES ON THE NOAA WEB SITE
FOR DETAILS ON TIDES LATER TODAY. THIS SWELL WILL SLOWLY DECLINE
FROM LATER TODAY THROUGH TONIGHT.

THE NEXT VERY LARGE AND LONG PERIOD NORTHWEST SWELL IS EXPECTED
TO ARRIVE WEDNESDAY MORNING...AND CONTINUE TO BUILD THROUGH EARLY
THURSDAY. THIS SWELL IS EXPECTED TO PRODUCE SURF WELL ABOVE THE
HIGH SURF WARNING THRESHOLDS ALONG MOST NORTH AND WEST FACING
SHORES OF THE SMALLER ISLANDS. NOTE THAT THIS SWELL IS EXPECTED TO
BE FROM A SLIGHTLY MORE WESTERLY DIRECTION THAN THE CURRENT SWELL.
AS A RESULT...A HIGH SURF ADVISORY MAY ALSO BE NEEDED FOR WEST
FACING SHORES OF THE BIG ISLAND ON THURSDAY.

DUE TO THE ELEVATED SEAS PRODUCED BY THE NORTH-NORTHWEST SWELL...
A SMALL CRAFT ADVISORY REMAINS IN EFFECT THROUGH THIS AFTERNOON
FOR ALL HAWAIIAN WATERS...EXCEPT MAALAEA BAY. THERE IS ALSO A
MARINE WEATHER STATEMENT IN EFFECT FOR HARBOR SURGES DUE TO THE
NORTH-NORTHWEST SWELL. SOME OF THE LEEWARD COASTAL WATERS MAY
DROP BELOW THE SCA CRITERIA BY TONIGHT. HOWEVER...SCA CONDITIONS
WILL RETURN AGAIN WITH THE NEXT NORTHWEST SWELL...SO EXPECT
ELEVATED SEAS THROUGH MOST OF THE CURRENT WORK WEEK. NOTE THAT
WINDS OVER ALL WATERS ARE FORECAST TO BE BELOW THE SCA THRESHOLD
THROUGH WEDNESDAY NIGHT. HOWEVER...TRADE WINDS MAY BE NEAR 25 KT
OVER SOME OF THE TYPICALLY WINDIER WATERS ADJACENT TO THE ISLANDS
OF MAUI COUNTY AND THE BIG ISLAND ON THURSDAY.

&&

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

HIGH SURF WARNING UNTIL 6 PM HST THIS EVENING FOR NORTH AND WEST
FACING SHORES OF NIIHAU KAUAI OAHU AND MOLOKAI...AND NORTH FACING
SHORES OF MAUI AND THE BIG ISLAND.

SMALL CRAFT ADVISORY UNTIL 6 PM HST THIS EVENING FOR ALL
HAWAIIAN WATERS EXCEPT MAALAEA BAY.

&&

DISCUSSION/MARINE...HOUSTON
AVIATION...KINEL