High Surf in Hawaii, February 14 to 16, 2015

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
330 AM HST SAT FEB 14 2015

.SYNOPSIS...
A COLD FRONT WILL CONTINUE TO MOVE DOWN THE ISLAND CHAIN
TODAY...BRINGING STRONG AND GUSTY SOUTHWEST WINDS ESPECIALLY TO
THE NORTH AND EAST OF THE MOUNTAINS. LOCALLY DAMAGING WIND GUSTS ARE
POSSIBLE ON KAUAI AND OAHU AT TIMES...FOR WHICH A HIGH WIND WARNING
REMAINS IN EFFECT ALONG WITH A WIND ADVISORY ELSEWHERE ACROSS THE
STATE. THE FRONT WILL GENERATE SHOWERS OVER KAUAI AND OAHU THROUGH
THE EARLY MORNING HOURS...AND SPREADING INTO MAUI COUNTY DURING THE
LATE MORNING HOURS AND INTO THIS AFTERNOON. THERE IS ALSO POTENTIAL
FOR LOCALIZED HEAVY RAIN AND A SLIGHT CHANCE OF THUNDERSTORMS. THE
FRONT IS EXPECTED TO WEAKEN BY THE TIME IT REACHES THE BIG ISLAND
TONIGHT...WITH WINDS DECREASING SIGNIFICANTLY AND TURNING TO A MORE
NORTHERLY FLOW IN THE WAKE OF THE FRONT. COOLER AND DRIER CONDITIONS
WILL ESTABLISH ACROSS THE ISLANDS ON SUNDAY AND INTO EARLY NEXT
WEEK.

&&

.DISCUSSION...
A COLD FRONT WILL MOVE DOWN THE ISLAND CHAIN TODAY BRINGING STRONG
AND GUSTY SW WINDS...WIDESPREAD SHOWERS AND POTENTIAL FOR LOCALLY
HEAVY RAINFALL. AREAS OVER HIGHER ELEVATIONS AND TO THE NORTH AND
EAST OF MOUNTAINS ARE EXPERIENCING THE STRONGEST WIND GUSTS. WIND
OBSERVATIONS FROM SEVERAL LOCATIONS ON OAHU WERE SHOWING GUSTS IN
THE 40 TO 60 MPH RANGE DURING THE OVERNIGHT HOURS...INCLUDING
SCHOFIELD BARRACKS AND KAWAILOA. THE STRONG SW WIND GUSTS WILL REACH
WARNING LEVELS AT TIMES OVER PORTIONS OF KAUAI AND OAHU WHERE
DAMAGING DOWNSLOPE WINDS ARE KNOWN TO OCCUR...ESPECIALLY
WINDWARD LOCATIONS.

AS THE FRONT PUSHES FURTHER DOWN THE ISLAND CHAIN...WINDS WILL
EVENTUALLY BE AROUND ADVISORY LEVELS AT TIMES OVER MOST AREAS OF THE
STATE THROUGHOUT THE DAY...THUS THE WIND ADVISORY HAS BEEN EXPANDED
TO INCLUDE BASICALLY ALL AREAS OF THE ISLANDS THAT ARE NOT UNDER A
HIGH WIND WARNING. THE ADVISORY...AS IS THE WARNING...WILL EXPIRE AT
6 PM HST THIS EVENING WHEN WINDS ARE EXPECTED TO DIMINISH.

AT 3 AM HST...LATEST INFRARED SATELLITE IMAGERY AND DOPPLER WEATHER
RADAR DATA SHOWED A PRE-FRONTAL BAND MOVING INTO THE W PORTIONS OF
KAUAI COUNTY...WITH SHOWERS INCREASING OVER INTERIOR KAUAI AND SW
WINDS OVER LIHUE AIRPORT GUSTING AROUND 45 KT. THIS SEEMS TO BE IN
AGREEMENT WITH THE OVERALL TIMING OF THIS FROPA FROM THE LATEST
GLOBAL MODEL RUNS WHICH MOVE THE BULK OF THE ASSOCIATED WEATHER
OVER KAUAI COUNTY AND OAHU THROUGH THE MORNING HOURS...REACHING
MAUI COUNTY LATER THIS MORNING AND INTO THE AFTERNOON HOURS...AND
GRADUALLY WEAKENING AS IT MOVES INTO THE BIG ISLAND AREA THIS
EVENING. EXPECT POTENTIAL FOR LOCALIZED HEAVY RAIN...ESPECIALLY OVER
MOUNTAIN AREAS TODAY. AND ALTHOUGH THE BEST DYNAMIC SUPPORT SEEMS TO
REMAIN FURTHER N OF THE ISLANDS...THERE IS A SLIGHT CHANCE OF
THUNDERSTORMS WITH THE LEADING EDGE OF THE FRONT...WHICH SHOULD
WEAKEN QUICKLY TONIGHT WITH WINDS AND SHOWERS GRADUALLY DIMINISHING
THROUGH EARLY SUN.

WEAK HIGH PRESSURE WILL MOVE JUST TO THE N OF THE ISLANDS ON SUN IN
THE WAKE OF THE FROPA WITH SFC WINDS BECOMING LIGHTER AND VEERING TO
THE N/NE. A DRIER AND MORE STABLE AIRMASS WILL FILTER INTO THE AREA
WITH LOW CHANCES OF RAIN AND COOLER CONDITIONS EXPECTED ACROSS THE
ALOHA STATE. A SFC RIDGE IS EXPECTED TO ESTABLISH OVER THE ISLAND
CHAIN AND BRING MAINLY LIGHT AND VARIABLE WINDS...ALONG WITH BENIGN
WEATHER CONDITIONS FOR THE FIRST HALF OF NEXT WEEK.

&&

.AVIATION...
STRONG AND GUSTY LOW-LEVEL SOUTH TO SOUTHWEST WINDS AHEAD OF A
VIGOROUS COLD FRONT LOCATED NEAR KAUAI WILL CONTINUE INTO THIS
AFTERNOON. PREFRONTAL BANDS OF CLOUDS/SHRA EAST OF THE FRONT...WITH
+SHRA ALONG THE FRONT...DUE TO THE MOIST LOW-LEVEL FLOW...LOW-LEVEL
AND TERRAIN INDUCED CONVERGENCE...AND ATMOSPHERIC INSTABILITY WILL
ALSO LIKELY RESULT IN PERIODS OF MVFR CIGS/VSBYS AT MANY OF THE TAF
SITES TODAY. CONDITIONS HAVE DETERIORATED AT PHLI WITH PREVAILING
MVFR CIGS AND SCATTERED TO NUMEROUS SHRA AS THE FRONT CROSSES KAUAI.
THESE CONDITIONS ARE FORECAST TO THEN SPREAD DOWN TO OAHU AFTER
14/1600Z...THE ISLANDS OF MOLOKAI AND LANAI AFTER 14/1800Z...AND
MAUI LATER THIS MORNING. THE STRONG GUSTY SOUTH TO SOUTHWEST WINDS
WILL ALSO IMPACT THE TERMINALS AHEAD OF THE FRONT TODAY...WITH THE
WINDS EVENTUALLY SHIFTING TO THE WEST AFTER THE FRONT PASSES. THESE
WEST WINDS WILL BECOME SOMEWHAT LIGHTER WITHIN A FEW HOURS AFTER THE
FRONT PASSES.

AIRMET SIERRA REMAINS IN EFFECT FOR MTN OBSC ABOVE 2500 FEET ON THE
ISLANDS OF KAUAI...OAHU...MOLOKAI...LANAI AND MAUI. AIRMET TANGO IS
ALSO IN EFFECT FOR TEMPO MOD TURB BELOW 14 KFT OVER THE MOUNTAINS...
AND THE NORTH THROUGH EAST FACING SECTIONS OF ALL ISLANDS.

&&

.MARINE...
A LARGE BUT RATHER BRIEF NW SWELL IS EXPECTED TO ARRIVE ON SUNDAY
THEN DIMINISH RAPIDLY ON MONDAY. ALSO...A WIDE RANGE OF WAVE PERIODS
WILL CREATE A RATHER SLOPPY SWELL IN ADDITION TO THE INCREASING NW
SWELL DUE TO A LOW MOVING CLOSE TO THE ISLANDS. THUS...A HIGH SURF
ADVISORY REMAINS IN EFFECT FOR S FACING SHORES OF MOST ISLANDS AND
THE W FACING SHORES OF THE BIG ISLAND WITH LOCALLY GENERATED SW
WINDSWELL PUSHING SURF HEIGHTS TO AROUND 8 FT.

A FRONTAL PASSAGE IS KEEPING GALE WARNING CONDITIONS OVER WATERS
AROUND KAUAI AND OAHU AS STRONG SOUTHWEST WINDS WILL CONTINUE TODAY.
IN ADDITION...SOME AREAS OF THE WINDWARD MAUI WATERS AND OVER THE
PAILOLO CHANNEL MAY ALSO REACH GALE WARNING LEVELS AT TIMES
TODAY...WHICH HAVE ALSO BEEN INCLUDED IN THE GALE WARNING. A SMALL
CRAFT ADVISORY /SCA/ IS IN EFFECT FOR THE REST OF THE COASTAL
WATERS. WINDS WILL DECREASE AND VEER TO THE NORTH AND NORTHEAST
BEHIND THE FRONT...BUT INCREASING SEAS DUE TO THE AFOREMENTIONED
NORTHWEST SWELL WILL LIKELY REQUIRE EXTENDING THE SCA THROUGH SUNDAY
FOR WATERS EXPOSED TO THE LARGE AND ROUGH SWELL.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
HIGH SURF ADVISORY UNTIL 6 AM HST SUNDAY FOR NIIHAU-KAUAI
WINDWARD-KAUAI LEEWARD-OAHU SOUTH SHORE-WAIANAE COAST-MOLOKAI
LEEWARD-LANAI MAKAI-KAHOOLAWE-MAUI LEEWARD WEST-MAUI CENTRAL
VALLEY-LEEWARD HALEAKALA-KONA-SOUTH BIG ISLAND.

WIND ADVISORY UNTIL 6 PM HST THIS EVENING FOR NIIHAU-KAUAI
LEEWARD-OAHU SOUTH SHORE-WAIANAE COAST-MOLOKAI-LANAI-KAHOOLAWE-
MAUI-KONA-SOUTH BIG ISLAND-BIG ISLAND NORTH AND EAST-KOHALA-BIG
ISLAND INTERIOR.

HIGH WIND WARNING UNTIL 6 PM HST THIS EVENING FOR KAUAI WINDWARD-
KAUAI MOUNTAINS-OAHU NORTH SHORE-OAHU KOOLAU-OLOMANA-CENTRAL
OAHU-WAIANAE MOUNTAINS.

HIGH WIND WARNING UNTIL 6 AM HST SUNDAY FOR BIG ISLAND SUMMITS.

SMALL CRAFT ADVISORY UNTIL 6 PM HST THIS EVENING FOR MAUI COUNTY
LEEWARD WATERS-MAALAEA BAY-ALENUIHAHA CHANNEL-BIG ISLAND
WINDWARD WATERS-BIG ISLAND LEEWARD WATERS-BIG ISLAND SOUTHEAST
WATERS.

GALE WARNING UNTIL 6 PM HST THIS EVENING FOR KAUAI NORTHWEST
WATERS-KAUAI WINDWARD WATERS-KAUAI LEEWARD WATERS-KAUAI CHANNEL-
OAHU WINDWARD WATERS-OAHU LEEWARD WATERS-KAIWI CHANNEL-MAUI
COUNTY WINDWARD WATERS-PAILOLO CHANNEL.

&&

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