Wind Advisory 1, NWS Honolulu, HI

229 
WWHW70 PHFO 180153
NPWHFO

URGENT - WEATHER MESSAGE
NATIONAL WEATHER SERVICE HONOLULU HI
353 PM HST TUE JAN 17 2012

HIZ002-004-007>012-017-019-020-180300-
/O.CAN.PHFO.WI.Y.0001.000000T0000Z-120118T0400Z/
KAUAI WINDWARD-KAUAI MOUNTAINS-OAHU NORTH SHORE-OAHU KOOLAU-
OLOMANA-CENTRAL OAHU-WAIANAE MOUNTAINS-MOLOKAI WINDWARD-
MAUI WINDWARD WEST-MAUI CENTRAL VALLEY-WINDWARD HALEAKALA-
INCLUDING THE CITIES OF...LIHUE...PRINCEVILLE...POIPU...
KOKEE STATE PARK...HALEIWA...WAIALUA...KAHUKU...PUNALUU...LAIE...
KAILUA...KANEOHE...WAIMANALO...MILILANI...WAHIAWA...PEARL CITY...
MAKAKILO...KALAUPAPA...WAILUKU...KAHULUI...HANA...MAKAWAO
353 PM HST TUE JAN 17 2012

...WIND ADVISORY IS CANCELLED...

THE NATIONAL WEATHER SERVICE IN HONOLULU HAS CANCELLED THE WIND
ADVISORY. 

WINDS HAVE DROPPED BELOW ADVISORY LEVELS.

$$

DEJESUS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
1000 AM HST TUE JAN 17 2012

.SYNOPSIS...
HAZY CONDITIONS WILL PREVAIL ACROSS THE STATE...WITH THICKENING
CLOUDS FROM WEST TO EAST. SOUTHERLY WINDS WILL FOCUS SHOWERS ACROSS
THE NORMALLY DRY LEEWARD AREAS. LOCALLY HEAVY RAINFALL IS POSSIBLE
FROM OAHU WESTWARD. AS A STALLED FRONT NORTHWEST OF KAUAI WEAKENS
AND MOVES NORTH...MORE TYPICAL TRADE WIND WEATHER WILL RETURN BY
THURSDAY AND FRIDAY. EARLY NEXT WEEK...WINDS WILL TURN SOUTHEASTERLY
AGAIN AHEAD OF ANOTHER FRONT.

&&

.DISCUSSION...
WATER VAPOR IMAGERY SHOWS AN UPPER LEVEL TROUGH NORTHWEST OF
KAUAI...PART OF A LARGER LOW PRESSURE SYSTEM OVER THE NORTH PACIFIC.
A MID-LEVEL HIGH IS LOCATED JUST SOUTH OF THE BIG ISLAND. AT THE
SURFACE...A FRONT IS LOCATED ABOUT 200 MILES NORTHWEST OF
KAUAI...WITH A RIDGE EXTENDING ACROSS THE BIG ISLAND. THE 12Z
SOUNDING FROM LIHUE SHOWS MID-LEVEL TEMPERATURES HAVE COOLED BY UP
TO 5C OVER THE PAST 24 HOURS...BUT A WEAK INVERSION REMAINS IN PLACE
JUST OVER 10KFT. HOWEVER...THE PROFILE IS UNSTABLE WITH NEARLY 1400
J/KG CAPE AND LITTLE CIN BASED ON AN UNMODIFIED MIXED-LAYER PARCEL.

SATELLITE IMAGERY SHOWS TWO MAIN LINES OF CONVECTION. ONE LINE IS
FOCUSED ALONG THE FRONT NORTHWEST OF KAUAI. ADDITIONAL THUNDERSTORMS
ARE LOCATED ALONG A CONVERGENCE LINE EAST OF THE MAIN FRONT...
LOCATED OVER AND JUST WEST OF KAUAI. CLOUDS TOPS WITH THE
CONVERGENCE LINE ARE COLDER...INDICATING THE CONVECTION IS STRONGER.
THE VAD WIND PROFILE FROM THE SOUTH KAUAI RADAR SHOWED UP TO 50
KNOTS OF WIND AT LOW-MID LEVELS...WHICH CONTRIBUTES TO THE 30-35
KNOTS OF 0-6KM BULK SHEAR INDICATED BY THE 12Z GFS. THE GREATEST
POTENTIAL FOR THUNDERSTORMS WILL BE THIS MORNING...BUT WITH THE
FRONT STALLING NORTHWEST OF KAUAI AND THE AIRMASS ONLY SLOWLY
STABILIZING...THERE WILL REMAIN A CHANCE OF THUNDER THROUGH THE
DAY. HEAVY RAIN IS ALSO POSSIBLE ACROSS OAHU...BUT HIGHEST QPF IS
EXPECTED ACROSS KAUAI. EARLIER CONVECTION BROUGHT 1-2 INCHES OF RAIN
TO KAUAI EARLY THIS MORNING...AND SIMILAR RAINFALL RATES ARE
POSSIBLE WITH SUBSEQUENT CONVECTION.

SHOWERS ACROSS THE EASTERN HALF OF THE STATE DIMINISHED OVERNIGHT...
AND CURRENT RADAR IMAGERY IS RATHER QUIET EAST OF OAHU. THIS IS
LIKELY DUE TO COMPENSATING SUBSIDENCE EAST OF THE STRONG CONVECTION.
IN FACT THE BIG ISLAND IS MOSTLY FREE OF LOW CLOUDS. LOW CLOUDS WILL
FILL IN WITH INSOLATION THIS MORNING...AND WE SHOULD STILL SEE
SCATTERED SHOWERS TODAY. WITH THE SOUTHERLY AHEAD OF THE FRONT...
THESE SHOWERS WILL BE FOCUSED PRIMARILY ACROSS THE NORMALLY DRY
LEEWARD SECTIONS OF THE ISLANDS.

SOUTHERLY WINDS WILL REMAIN STRONG AND GUSTY AHEAD OF THE FRONT.
BOTH THE MOLOKAI AND KAUAI VAD WIND PROFILES SHOW UP TO 30 KNOTS OF
WIND AT THE LOWEST LEVEL. THIS GRADIENT WIND IS ENHANCED BY THE
CONVECTION AND THE CONVERGENCE BAND NEAR KAUAI. 12Z GUIDANCE
INDICATES THAT WINDS WILL DIMINISH SIGNIFICANTLY THIS
AFTERNOON...BUT THIS LOOKS TOO FAST GIVEN THE STRENGTH OF THE
GRADIENT AND PERSISTENCE OF THE CONVECTION. HAVE UPDATED TO MAKE
SURE GUSTS TO 40 MPH WERE MENTIONED IN THE DOWNSLOPE ZONES OF THE
SMALLER ISLANDS.

TONIGHT AND WEDNESDAY...THE FRONT NORTHWEST OF KAUAI WILL WEAKEN
AND START TO LIFT NORTHWARD AS THE UPPER LEVEL SUPPORT MOVES AWAY TO
THE NORTHEAST. THE RIDGE NEAR THE BIG ISLAND WILL BEGIN TO SHIFT
NORTHWARD ACROSS THE SMALLER ISLANDS. WINDS WILL WEAKEN AS THE
GRADIENT DROPS OFF UNDER THE RIDGE. EVEN THOUGH THE FRONT WEAKENS
AND STARTS TO MOVE NORTHWARD...LOW-LEVEL MOISTURE WILL LINGER INTO
WEDNESDAY...MAINLY ACROSS THE WESTERN HALF OF THE STATE. WITH THE
SOUTHEASTERLY FLOW...SHOWERS WILL REMAIN FOCUSED ACROSS THE NORMALLY
DRY SOUTHERLY SECTIONS.

THE SURFACE RIDGE LIFTS FARTHER NORTHWARD ON THURSDAY AND
FRIDAY...BRINGING A RETURN TO A MORE TYPICAL TRADE WIND FLOW BY THE
END OF THE WEEK. THURSDAY LOOKS TO BE MORE OF A TRANSITION
DAY...WITH SCATTERED SHOWERS IN THE MORNING BECOMING MORE FOCUSED
ACROSS WINDWARD SECTIONS. THE RIDGE WILL MOVE TO THE NORTHERN
OFFSHORE WATERS...WHERE IT WILL REMAIN THROUGH THE WEEKEND. EARLY
NEXT WEEK...THE APPROACH OF ANOTHER FRONT WILL SHIFT THE RIDGE
SOUTHWARD ACROSS THE STATE...BRINGING ANOTHER ROUND OF SOUTHEASTERLY
FLOW.

&&

.MARINE...
HAVE EXPANDED THE SMALL CRAFT ADVISORY TO INCLUDE THE KAUAI CHANNEL
AND WINDWARD OAHU WATERS. THE STRONGER GRADIENT WILL LEAD TO 25
KNOTS OF SUSTAINED WINDS NEAR KAUAI. HOWEVER...THE COMBINATION OF
WIND WAVES AND A LARGE WESTERLY SWELL WILL LEAD TO HAZARDOUS SEAS
GREATER THAN 10 FEET. IN ADDITION...THUNDERSTORMS WILL ALSO BE
PRESENT OVER THE NORTHWEST COASTAL WATERS. THUNDERSTORMS WILL BE
MOST LIKELY NEAR AND TO THE WEST OF KAUAI...BUT ARE ALSO POSSIBLE
ACROSS THE KAUAI CHANNEL AND INTO THE OAHU WINDWARD WATERS. THE WEST
SWELL MENTIONED ABOVE WILL PRODUCE HIGH SURF CONDITIONS ON WEST
FACING SHORES OF KAUAI AND NIIHAU. THIS SWELL IS EXPECTED TO
DIMINISH THIS EVENING.

&&

.AVIATION...
SIGMET WHISKEY IS IN EFFECT FOR EMBEDDED THUNDERSTORMS ALONG A
CONVERGENCE BAND ACROSS KAUAI. EXPECT MOUNTAIN OBSCURATIONS...IFR
CONDITIONS...ICING AND SEVERE TURBULENCE WITHIN THE THUNDERSTORMS.
THIS BAND WILL WEAKEN LATER TODAY AND STALL OUT TONIGHT AROUND THE
KAUAI CHANNEL AND OAHU. OTHER THAN THE SIGMET AREA...MODERATE TO
ISOLATED SEVERE TURBULENCE WILL BE ASSOCIATED WITH DOWNSLOPE WINDS
ON THE NORTHERN SLOPES OF OAHU AND MOLOKAI. VFR CONDITIONS SHOULD
PREVAIL THROUGH THE REST OF THE MAIN HAWAIIAN ISLANDS TODAY WITH
OCCASIONAL MVFR CIGS WITH SHOWERS. CONDITIONS ARE EXPECTED TO
IMPROVE THROUGH THE OVERNIGHT INTO WEDNESDAY MORNING FOR THE WESTERN
HALF OF THE STATE.

.HFO WATCHES/WARNINGS/ADVISORIES...
HIGH SURF ADVISORY UNTIL 6 PM HST THIS EVENING FOR NIIHAU-KAUAI
WINDWARD-KAUAI LEEWARD.

SMALL CRAFT ADVISORY UNTIL 6 PM HST THIS EVENING FOR KAUAI
NORTHWEST WATERS-KAUAI WINDWARD WATERS-KAUAI LEEWARD WATERS-
KAUAI CHANNEL-OAHU WINDWARD WATERS.

&&

DISCUSSION/MARINE...BRAVENDER
AVIATION...FOSTER

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE HONOLULU HI
735 AM HST TUE JAN 17 2012

HIZ001>004-180200-
NIIHAU-KAUAI WINDWARD-KAUAI LEEWARD-KAUAI MOUNTAINS-
735 AM HST TUE JAN 17 2012

...STRONG THUNDERSTORMS WITH GUSTY WINDS FOR KAUAI AND NIIHAU THROUGH
TODAY...

ISOLATED THUNDERSTORMS WITH LOCALLY STRONG WIND GUSTS OVER 40 MPH
ARE EXPECTED THROUGH TODAY. IN ADDITION TO THE GUSTY
WINDS...DANGEROUS CLOUD TO GROUND LIGHTNING AND BRIEF HEAVY
RAINFALL ARE EXPECTED AS THE FAST MOVING STORMS PASS BY.

BRENCHLEY