[top]
000
FXHW60 PHFO 090139
AFDHFO
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
400 PM HST SUN NOV 8 2009
.SYNOPSIS...
MODERATE TRADES WILL CONTINUE FOR ANOTHER COUPLE DAYS...AS HIGH
PRESSURE REMAINS NORTH OF THE AREA. SCATTERED SHOWERS WILL FAVOR
WINDWARD AND MAUKA AREAS...WITH FEWER SHOWERS REACHING LEEWARD
AREAS. THE SECOND HALF OF THE WEEK LOOKS TO BE WET...WITH AN UPPER
LEVEL LOW DEVELOPING OVER THE ISLANDS.
&&
.DISCUSSION...
A SURFACE HIGH TO THE NORTH WILL BRING MODERATE TRADE WINDS TO THE
ISLANDS FOR THE NEXT COUPLE OF DAYS. SHOWERS WILL ASSUME THE USUAL
DISTRIBUTION DICTATED BY THE TRADE FLOW...FAVORING WINDWARD AND
MAUKA SECTIONS. THE TRADES WILL IN FACT LAST THROUGH NEXT WEEKEND
BUT MAY BE CONSIDERABLY WETTER AS EXPLAINED BELOW.
THE PROBLEM AT HAND INVOLVES AN UPPER LEVEL LOW FORECAST TO DROP
DOWN FROM THE NORTH AND SETTLE OVER THE ISLANDS ON WEDNESDAY AND
THURSDAY. MODELS AGREE THAT THE LOW WILL IN FACT HAPPEN...BUT
SLIGHTLY DISAGREE AS TO WHERE IT WILL END UP AND HOW UNSTABLE THE
AIRMASS WILL GET. THE CONCERN IS THAT THUNDERSTORMS AND HEAVY
RAINFALL ARE POSSIBLE. WILL WAIT ON PUTTING THUNDER IN THE FORECAST
UNTIL THE MODELS ARE IN BETTER AGREEMENT. THE FORECAST DOES HOWEVER
INDICATE THE POSSIBILITY OF LOCALLY HEAVY RAINFALL. A HYDROLOGIC
OUTLOOK HAS BEEN ISSUED...ADVISING THAT THERE IS A POTENTIAL OF
HEAVY RAINFALL AND FLASH FLOODING ON WEDNESDAY AND THURSDAY.
THE LOW MAY LINGER IN THE AREA INTO THE WEEKEND...WHICH COULD KEEP
THE AIRMASS OVER THE ISLANDS UNSTABLE. THE PLACEMENT AND STRENGTH OF
THE LOW DURING THIS TIME WILL DETERMINE WHETHER THE LOCALLY HEAVY
RAIN WILL PERSIST BEYOND THURSDAY.
ALSO OF INTEREST IS THAT THE MODELS PUT THE FREEZING LEVEL BELOW THE
BIG ISLAND SUMMITS ON WEDNESDAY AND THURSDAY. SHOULD THE CONVECTION
BE UNCAPPED BY A SUBSIDENCE INVERSION...THERE IS A CHANCE THAT SNOW
WILL FALL ON THE SUMMITS. WILL ALSO WAIT ON PUTTING SNOW IN THE
FORECAST UNTIL WE CAN NAIL DOWN THE SPECIFICS.
&&
.MARINE...
SURF WILL REMAIN BELOW ADVISORY LEVELS INTO WEDNESDAY. A NORTHEAST
SWELL WILL LIKELY RESULT IN ADVISORY LEVEL SURF ALONG EAST FACING
SHORES LATE WEDNESDAY THROUGH FRIDAY.
&&
.HFO WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
CRAIG
[top]
000
ATHW40 PHFO 090030
SIMHI
HAWAIIAN ISLANDS SATELLITE INTERPRETATION MESSAGE
NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI
0030 UTC MON NOV 9 2009
BASED ON DATA THROUGH 0000 UTC NOVEMBER 9 2009
WATER VAPOR IMAGERY SHOWS AN UPPER LEVEL LOW CENTERED
750 MILES WEST OF KAUAI HAS MOVED SLOWLY EAST OVER THE PAST 6 HOURS.
THUNDERSTORM ACTIVITY HAS LESSENED OVER THE PAST 6 HOURS BUT A FEW
ARE STILL FORMING WITHIN A 100 MILE RADIUS OF THE CENTER WITH CB
CLOUD TOPS REACHING 34 THOUSAND FEET. MID AND UPPER LAYERED CLOUDS
EXTEND FAR TO THE EAST AND NORTH OF THE LOW/S CENTER COVERING SKIES
FROM 150W TO 168W AND 12N TO 30N.
NEAR THE SURFACE...FROM 20N TO 30N...SCATTERED TO BROKEN LOW CLOUDS
ARE MOVING WEST AT 10 TO 20 MPH. FROM 10N TO 20N...LOW CLOUDS ARE
MOVING 15 TO 25 MPH TOWARD THE WEST. THE LEADING EDGE OF AN AREA OF
SHOWERY LOW CLOUDS WITH EMBEDDED TOWERING CUMULUS IS LOCATED 100
MILES EAST-SOUTHEAST OF THE BIG ISLAND AND IS MOVING 20 MPH TOWARD
THE WEST-NORTHWEST. THIS AREA SPANS 200 MILES ACROSS.
ANOTHER AREA OF SHOWERY LOW CLOUDS IS LOCATED 450 MILES
EAST-SOUTHEAST OF THE BIG ISLAND. THE LEADING EDGE OF THIS AREA RUNS
FROM 14N 150W TO 23N 148W WITH A WIDTH OF 225 MILES. THIS AREA
CONTAINS EMBEDDED SHOWERS AND IS MOVING 20 MPH TOWARD THE
WEST-NORTHWEST.
OVER THE ISLANDS...SKIES ARE PARTIALLY OBSCURED BY THE HIGH CIRRUS
EMANATING FROM THE UPPER LOW TO THE WEST. HOWEVER...BROKEN...LOW
CLOUDS CAN BE DISCERNED ALONG THE WINDWARD SLOPES FROM OAHU TO THE
BIG ISLAND. KAUAI IS FIRMLY ENTRENCHED UNDER OVERCAST HIGH CLOUDS.
LEEWARD BIG ISLAND AND LEEWARD HALEAKALA ARE MOSTLY CLOUDY WHILE
MOST OTHER LEEWARD LOCATIONS ARE MOSTLY CLEAR.
$$
MORRISON
000
FXHW60 PHFO 082008
AFDHFO
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
1000 AM HST SUN NOV 8 2009
.SYNOPSIS...
MODERATE TRADES WILL CONTINUE FOR ANOTHER COUPLE DAYS...AS HIGH
PRESSURE REMAINS NORTH OF THE AREA. SCATTERED SHOWERS WILL FAVOR
WINDWARD AND MAUKA AREAS...WITH FEWER SHOWERS REACHING LEEWARD
AREAS. THE SECOND HALF OF THE WEEK LOOKS TO BE WET WITH AN UPPER
LEVEL LOW DEVELOPING OVER THE ISLANDS.
&&
.DISCUSSION...
A SURFACE HIGH NORTH OF HERE WILL BRING MODERATE TRADE WINDS TO THE
ISLANDS OVER THE NEXT COUPLE OF DAYS. SHOWERS WILL ASSUME THE USUAL
DISTRIBUTION DICTATED BY THE TRADE FLOW...FAVORING WINDWARD AND
MAUKA SECTIONS. THE TRADES WILL IN FACT LAST THROUGH NEXT WEEKEND
BUT MAY BE CONSIDERABLY WETTER AS EXPLAINED BELOW.
THE PROBLEM AT HAND INVOLVES AN UPPER LEVEL LOW FORECAST TO DROP
DOWN FROM THE NORTH AND SETTLE OVER THE ISLANDS ON WEDNESDAY AND
THURSDAY. ALL OF THE VARIOUS MODELS AGREE THAT THE LOW WILL IN FACT
HAPPEN...BUT SLIGHTLY DISAGREE AS TO WHERE IT WILL END UP AND HOW
UNSTABLE THE AIRMASS WILL GET. THE CONCERN IS THAT OF HEAVY
RAINFALL...AND THE POSSIBILITY OF THUNDERSTORMS. AM STILL HESITANT
IN PUTTING THUNDER IN THE FORECAST...BUT THE GRIDS DO REFLECT A
CHANCE FOR LOCALLY HEAVY RAINFALL. A HYDROLOGIC OUTLOOK HAS BEEN
ISSUED...ADVISING THAT THERE IS A POTENTIAL OF HEAVY RAINFALL AND
FLASH FLOODING ON WEDNESDAY AND THURSDAY.
THE LOW MAY LINGER IN THE AREA INTO THE WEEKEND...WHICH COULD KEEP
THE AIRMASS OVER THE ISLANDS UNSTABLE. THE PLACEMENT AND STRENGTH OF
THE LOW DURING THE LATTER PART OF THE WEEK WILL DETERMINE WHETHER
THE LOCALLY HEAVY RAIN WILL PERSIST INTO THE WEEKEND.
TAKING A CLOSER LOOK AT THE UPPER LEVELS REVEALS TEMPERATURES
HOVERING AROUND FREEZING AT THE BIG ISLAND SUMMITS ON WEDNESDAY AND
THURSDAY. WILL HAVE TO WATCH THE SUMMIT AREAS AS FUTURE MODEL RUNS
COME IN TO NAIL DOWN THE SPECIFICS FOR THOSE LOCALES.
&&
.MARINE...
A SMALL CRAFT ADVISORY REMAINS IN EFFECT THROUGH TODAY FOR THE
WINDIER AREAS AROUND MAUI AND THE BIG ISLAND. SURF WILL REMAIN BELOW
ADVISORY LEVELS THROUGH WEDNESDAY...THEN A NORTHEAST SWELL MAY
RESULT IN ADVISORY LEVEL SURF ALONG EAST FACING SHORES.
&&
.HFO WATCHES/WARNINGS/ADVISORIES...
SMALL CRAFT ADVISORY UNTIL 6 PM HST SUNDAY FOR MAALAEA BAY-PAILOLO
CHANNEL-ALENUIHAHA CHANNEL-BIG ISLAND SOUTHEAST WATERS.
&&
$$
CRAIG
000
ATHW40 PHFO 081830
SIMHI
HAWAIIAN ISLANDS SATELLITE INTERPRETATION MESSAGE
NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI
1830 UTC SUN NOV 08 2009
BASED ON DATA THROUGH 1800 UTC NOVEMBER 08 2009
WATER VAPOR IMAGERY DEPICTS A STATIONARY UPPER LEVEL LOW CENTERED
800 MILES WEST OF KAUAI THIS MORNING. ISOLATED THUNDERSTORMS ARE
FORMING WITHIN A 100 MILE RADIUS OF THE CENTER WITH CB CLOUD TOPS
REACHING 35 THOUSAND FEET. MID AND UPPER LAYERED CLOUDS EXTEND FAR
TO THE EAST AND NORTH OF THE LOW/S CENTER COVERING SKIES FROM 155W
TO 168W AND 12N TO 30N. HIGH CIRRUS FORMED BY THIS SYSTEM IS ALSO
BEING CARRIED FAR EAST BY THE JET STREAM AND COVERS SKIES FROM 25N
TO 30N FROM 140W TO 155W.
NEAR THE SURFACE...FROM 20N TO 30N...SCATTERED TO BROKEN LOW CLOUDS
ARE MOVING WEST AT 10 TO 20 MPH. FROM 10N TO 20N...LOW CLOUDS ARE
MOVING 15 TO 25 MPH TOWARD THE WEST. THE LEADING EDGE OF AN AREA OF
SHOWERY LOW CLOUDS WITH EMBEDDED TOWERING CUMULUS IS LOCATED 170
MILES EAST-SOUTHEAST OF THE BIG ISLAND AND IS MOVING 20 MPH TOWARD
THE WEST-NORTHWEST. THIS AREA SPANS 250 MILES ACROSS.
ANOTHER AREA OF SHOWERY LOW CLOUDS IS LOCATED 500 MILES
EAST-SOUTHEAST OF THE BIG ISLAND. THE LEADING EDGE OF THIS AREA RUNS
FROM 12N 148W TO 21N 146W WITH A WIDTH OF 175 MILES. THIS AREA
CONTAINS ISOLATED TOWERING CUMULUS AND IS MOVING 20 MPH TOWARD THE
WEST-NORTHWEST.
OVER THE ISLANDS...SKIES ARE PARTIALLY OBSCURED BY THE HIGH CIRRUS
EMANATING FROM THE UPPER LOW TO THE WEST. HOWEVER...BROKEN...LOW
CLOUDS CAN BE DISCERNED ALONG THE WINDWARD SLOPES OF THE SMALLER
ISLANDS AS WELL AS THE LOWER WINDWARD SLOPES OF THE BIG ISLAND.
LEEWARD LOCATIONS ARE MOSTLY CLEAR.
$$
MORRISON
000
FXHW60 PHFO 081330
AFDHFO
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
330 AM HST SUN NOV 8 2009
.SYNOPSIS...
MODERATE TRADES WILL CONTINUE FOR ANOTHER COUPLE DAYS AS HIGH
PRESSURE REMAINS NORTH OF THE AREA. LOW LEVEL MOISTURE WILL CONTINUE
TO BRING WET TRADES TO MAINLY WINDWARD AND MAUKA AREAS...BUT THE
MODERATE TRADES WILL OCCASIONALLY BLOW THE SHOWERS TO LEEWARD AREAS.
THE SECOND HALF OF THE WEEK LOOKS TO BE WET WITH AN UPPER LEVEL LOW
DEVELOPING OVER THE ISLANDS.
&&
.DISCUSSION...
MODELS ARE STILL IN GOOD AGREEMENT WITH THE HIGH CONTINUING TO BRING
TRADES TO THE ISLANDS FOR THE NEXT COUPLE OF DAYS. HAVEN/T MADE ANY
MAJOR CHANGES TO THE FORECAST FOR THE SHORT TERM. LOOK FOR THE WET
TRADE SHOWERS TO CONTINUE AND OCCASIONALLY MAKE IT TO LEE AREAS.
THE BIG FORECAST CHALLENGE REMAINS THE UPPER LEVEL TROUGH THAT THE
MODELS CONTINUE TO BRING OVER THE ISLANDS AT THE MID WEEK. THE ECMWF
DID BACK OFF A LITTLE BIT WITH THE LATEST RUN...WHICH JUST BRINGS IT
MORE IN LINE WITH THE GFS DEPICTION. HAVE GONE AHEAD AND ADJUSTED
THE GRIDS TOWARDS THE GFS WITH REGARDS TO WINDS AND POPS.
THE BIGGEST CONCERN IS THAT OF HEAVY RAINFALL...AND EVEN POSSIBLE
THUNDERSTORMS WITH THIS SYSTEM. WAS HESITANT TO PUT THUNDER IN QUITE
YET...BUT HAVE ADDED THE CHANCE FOR LOCALLY HEAVY RAINFALL FOR
WEDNESDAY AND THURSDAY. THE MODELS ARE SLOW TO GET RID OF THE LOW
ONCE ITS BROUGHT INTO THE AREA AT MID WEEK. THE LOW LINGERS TO THE
NORTHWEST OF THE ISLANDS AS WE HEAD INTO THE WEEKEND...WHICH WILL
KEEP THE AIRMASS OVER THE ISLANDS UNSTABLE. DEPENDING ON THE
PLACEMENT AND STRENGTH OF THE LOW DURING THE LATTER PART OF THE WEEK
WILL FACTOR INTO WHETHER OR NOT THE CHANCE FOR LOCALLY HEAVY RAIN
WILL PERSIST INTO THE WEEKEND.
GIVEN THE CHANCE FOR HEAVY RAINFALL...AND THAT BACK TO BACK RUNS OF
THE MODELS ARE IN AGREEMENT...HAVE DECIDED TO ISSUE A HYDROLOGIC
OUTLOOK FOR LATER IN THE WEEK.
TAKING A CLOSER LOOK AT THE UPPER LEVELS REVEALS TEMPERATURES
HOVERING AROUND FREEZING AT THE BIG ISLAND SUMMITS ON WEDNESDAY AND
THURSDAY. WILL HAVE TO WATCH THE SUMMIT AREAS AS FUTURE MODEL RUNS
COME IN TO NAIL DOWN THE SPECIFICS FOR THOSE LOCALES.
&&
.MARINE...
WINDS REMAIN ABOVE SMALL CRAFT ADVISORY LEVELS FOR THE WINDIER AREAS
AROUND MAUI AND THE BIG ISLAND. THE SMALL CRAFT ADVISORY WILL STAY
UP FOR THOSE AREAS THROUGH TODAY. SURF WILL REMAIN BELOW ADVISORY
LEVELS THROUGH WEDNESDAY...THEN A NORTHEAST SWELL MAY RESULT IN
ADVISORY LEVEL SURF ALONG EAST FACING SHORES.
&&
.HFO WATCHES/WARNINGS/ADVISORIES...
SMALL CRAFT ADVISORY UNTIL 6 PM HST SUNDAY FOR MAALAEA BAY-PAILOLO
CHANNEL-ALENUIHAHA CHANNEL-BIG ISLAND SOUTHEAST WATERS.
&&
$$
000
ATHW40 PHFO 081235
SIMHI
HAWAIIAN ISLANDS SATELLITE INTERPRETATION MESSAGE
NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI
1230 UTC SUN NOV 08 2009
BASED ON DATA THROUGH 1200 UTC NOVEMBER 08 2009
SURFACE HIGH PRESSURE FAR NORTH OF THE FIFTIETH STATE CONTINUED TO
MAINTAIN MODERATE TO LOCALLY FRESH LOW-LEVEL TRADE WIND FLOW ACROSS
THE ISLAND CHAIN EARLY THIS MORNING. THE TRADES WERE CARRYING BROKEN
LOW CLOUDS WITH EMBEDDED SCATTERED SHOWERS ACROSS MOST OF THE
WINDWARD HAWAIIAN COASTAL WATERS. THE INDIVIDUAL LOW CLOUD ELEMENTS
OVER THE WINDWARD COASTAL WATERS WERE GENERALLY MOVING WESTWARD AT
ABOUT 20 MPH. THESE LOW CLOUDS AND SHOWERS EXTENDED UPWIND OF THE
ISLAND CHAIN FOR MORE THAN 300 MILES. NARROW PLUMES OF SCATTERED TO
BROKEN LOW CLOUDS AND ISOLATED SHOWERS WERE ALSO EVIDENT LEEWARD OF
SOME OF THE ISLANDS. IN ADDITION TO THE LOW CLOUDS...BROKEN CIRRUS
CLOUDS WERE ALSO TRAVELLING TOWARD THE EAST AND EAST NORTHEAST HIGH
ABOVE THE ISLAND CHAIN.
AS OF 200 AM HST SUNDAY...THE HIGH CLOUDS WERE MAKING IT DIFFICULT
TO DETERMINE THE COVERAGE OF LOW CLOUDS ON MOST OF THE MAIN HAWAIIAN
ISLANDS. BASED ON BREAKS IN THE CIRRUS COVER...RADAR REFLECTIVITY
DATA AND SURFACE OBSERVATIONS...THE LOW CLOUD COVER WAS DETERMINED
ON SOME OF THE ISLANDS. FOR EXAMPLE...MOST OF THE HIGHER TERRAIN...
THE WINDWARD FACING SLOPES AND NORTHEASTERN BEACHES ON KAUAI AND
OAHU WERE COVERED BY BROKEN TO OVERCAST LOW CLOUDS AND SHOWERS.
THERE APPEARED TO BE MAINLY SCATTERED LOW CLOUDS ACROSS THE
REMAINDER OF THOSE ISLANDS. BROKEN LOW CLOUDS AND SCATTERED SHOWERS
APPEARED TO BE OVER THE EASTERN HALF OF MOLOKAI. BROKEN TO LOCALLY
OVERCAST LOW CLOUDS WERE OVER MOST OF THE NORTHEASTERN AND
SOUTHEASTERN COASTAL AREAS OF THE BIG ISLAND. THERE WERE SCATTERED
TO BROKEN LOW CLOUDS ABOVE PARTS OF THE CENTRAL AND SOUTHERN LEEWARD
COASTLINE ON THE BIG ISLAND.
ACCORDING TO LOOPS OF WATER VAPOR IMAGERY AND SATELLITE DERIVED
UPPER LEVEL WINDS...AN UPPER TROPOSPHERIC LOW WAS CENTERED NEAR 25N
172W...OR ABOUT 820 MILES WEST NORTHWEST OF LIHUE AND 460 MILES
SOUTHEAST OF MIDWAY ATOLL. THIS FEATURE HAS DRIFTED SLOWLY TOWARD
THE EAST NORTHEAST DURING THE PAST 6 HOURS. SCATTERED TO BROKEN
LAYERED CLOUDS WITH EMBEDDED ISOLATED THUNDERSTORMS ASSOCIATED WITH
THIS UPPER LEVEL LOW WERE WITHIN 150 TO 200 MILES ON EITHER SIDE OF
A LINE FROM 20N 173.5W TO 30N 165W. ELSEWHERE...AN ANTICYCLONE ALOFT
CENTERED NEAR 07.5N 152W...OR ABOUT 875 MILES SOUTH SOUTHEAST OF
HILO...HAS BEEN DRIFTING SLOWLY EAST DURING THE PAST 6 HOURS. THE
UPPER TROPOSPHERIC RIDGE ASSOCIATED WITH THIS UPPER LEVEL HIGH
EXTENDED NORTH NORTHWESTWARD OVER THE HAWAIIAN ISLANDS. THIS WAS
RESULTING IN FLOW ALOFT FROM THE WEST OR WEST SOUTHWEST ACROSS THE
ALOHA STATE WITH WIND SPEEDS OF 30 TO 50 MPH. THESE UPPER LEVEL
WINDS WERE CARRYING THE BROKEN CIRRUS OVER THE ISLANDS.
IN THE DEEP TROPICS FAR SOUTH OF THE HAWAIIAN ISLANDS...THE
INTERTROPICAL CONVERGENCE ZONE...OR ITCZ...EXTENDED FROM NEAR 08.5N
140W TO 07N 160W TO 04N 180W. SCATTERED TOWERING CUMULUS CLOUDS AND
ISOLATED THUNDERSTORMS WERE WITHIN 200 MILES ON EITHER SIDE OF THE
ITCZ. THE HIGHEST TOPS OF THESE CUMULONIMBUS CLOUDS EXTENDED UP TO
NEAR 50 THOUSAND FEET.
$$
HOUSTON
000
FXHW60 PHFO 080631
AFDHFO
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
830 PM HST SAT NOV 7 2009
.SYNOPSIS...
HIGH PRESSURE WILL REMAIN NORTH OF THE AREA OVER THE NEXT FEW
DAYS...BRINGING MODERATE TRADE WINDS TO THE ISLANDS. SHOWERS WILL
FAVOR THE TYPICAL WINDWARD AND MAUKA AREAS...HOWEVER SOME OF THE
SHOWERS WILL BE BLOWN OVER TO LEEWARD AREAS DUE TO THE MODERATE
TRADES. AN UPPER LEVEL TROUGH MID WEEK WILL BRING ADDITIONAL RAIN TO
THE REGION FOR THE SECOND HALF OF THE WEEK.
&&
.DISCUSSION...
THE MODELS ARE IN GOOD AGREEMENT WITH THE HIGH NORTH OF THE ISLANDS
KEEPING MODERATE TRADES IN THE AREA OVER THE NEXT COUPLE OF DAYS.
THERE HAS BEEN MORE MOISTURE UPSTREAM OF THE ISLANDS THAT IN RECENT
WEEKS...SO WE HAVE BEEN SEEING A MORE WET TRADE PATTERN. THE SHOWERS
WILL CONTINUE TO FAVOR WINDWARD AND MAUKA AREAS AS WE HEAD INTO THE
NEW WORK WEEK. WITH MODERATE TRADES...SOME OF THE SHOWERS ARE MAKING
IT TO THE LEEWARD AREAS.
A WEAK UPPER LEVEL TROUGH PASSES OVER THE ISLANDS LATE SUNDAY AND
INTO MONDAY...AND THIS WILL CONTINUE TO BRING THE WET TRADES TO THE
ISLANDS...BUT NOT EXPECTING MUCH ELSE WITH THAT SYSTEM.
THE NEXT BIG SYSTEM IS LOOKING TO APPROACH THE ISLANDS WEDNESDAY
NIGHT AS A MUCH STRONGER UPPER LEVEL TROUGH APPROACHES FROM THE
NORTH. THE NOGAPS...ECMWF AND GFS ALL AGREEMENT ON THE GENERAL
HANDLING OF THIS SYSTEM WITH AN UPPER LEVEL CUT OFF LOW DEVELOPING
OVER THE ISLANDS WEDNESDAY NIGHT. THE NOGAPS IS THE WARMEST IN THE
UPPER LEVELS BY JUST A COUPLE DEGREES. WHILE THE SYSTEM DEVELOPS
OVER THE ISLANDS RELATIVELY QUICKLY...THE MODELS ARE SLOW TO GET RID
OF THE SYSTEM ALTOGETHER...WHICH COULD SPELL AN EXTENDED PERIOD OF
WET WEATHER FOR THE ISLANDS TO END THE WEEK.
WHILE NOT ANTICIPATING AN UPDATE TO THE FORECAST PACKAGE RIGHT
NOW...WILL BE MODIFYING THE GRIDS OVERNIGHT FOR THE PERIOD WEDNESDAY
ONWARDS TO INCREASE THE CHANCE OF RAIN ACROSS THE ISLANDS. THERE IS
THE QUESTION OF HEAVY RAIN AND THUNDER WITH THIS EVENT. WILL LIKELY
HOLD OFF ON PUTTING THE CHANCE FOR THUNDER IN THE GRIDS FOR RIGHT
AWAY...BUT WILL MAKE THE DECISION WHEN THE NEXT MODEL RUNS COME IN.
IF THE TREND CONTINUES IT WILL BE HARD NOT TO PUT THAT MENTION IN
FOR THE 4 AM PACKAGE. WILL ALSO PROBABLY NEED TO TWEAK THE WINDS FOR
THE LATER PORTION OF THE FORECAST PERIOD AS THE UPPER TROUGH WILL
DISRUPT THE CURRENTLY FORECAST TRADE WIND PATTERN.
&&
.MARINE...
THE SMALL CRAFT ADVISORIES ARE FOR LOCALLY STRONG TRADE WINDS IN THE
WINDIER AREAS AROUND MAUI AND THE BIG ISLAND. SURF WILL REMAIN BELOW
ADVISORY LEVELS THROUGH WEDNESDAY...THEN A NORTHEAST SWELL MAY
RESULT IN ADVISORY LEVEL SURF ALONG EAST FACING SHORES.
&&
.HFO WATCHES/WARNINGS/ADVISORIES...
SMALL CRAFT ADVISORY UNTIL 6 PM HST SUNDAY FOR MAALAEA BAY-PAILOLO
CHANNEL-ALENUIHAHA CHANNEL-BIG ISLAND SOUTHEAST WATERS.
&&
$$
000
ATHW40 PHFO 080528
SIMHI
HAWAIIAN ISLANDS SATELLITE INTERPRETATION MESSAGE
NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI
0530 UTC SUN NOV 08 2009
BASED ON DATA THROUGH 0500 UTC NOVEMBER 08 2009
A SURFACE RIDGE LOCATED FAR NORTH OF THE MAIN HAWAIIAN ISLANDS WAS
MAINTAINING MODERATE TO LOCALLY FRESH LOW-LEVEL TRADE WIND FLOW
ACROSS THE ALOHA STATE EARLY THIS EVENING. THE TRADES WERE CARRYING
SCATTERED TO BROKEN LOW CLOUDS WITH EMBEDDED SCATTERED SHOWERS
ACROSS MOST OF THE WINDWARD HAWAIIAN COASTAL WATERS. THESE LOW
CLOUDS AND SHOWERS EXTENDED UPWIND OF THE ISLANDS CHAIN FOR MORE
THAN 250 MILES. NARROW PLUMES OF SCATTERED TO BROKEN LOW CLOUDS AND
ISOLATED SHOWERS WERE ALSO EVIDENT LEEWARD OF SOME OF THE ISLANDS.
IN ADDITION TO THE LOW CLOUDS...SCATTERED TO LOCALLY BROKEN CIRRUS
CLOUDS WERE ALSO TRAVELLING RAPIDLY EASTWARD HIGH ABOVE THE ISLAND
CHAIN.
THE INDIVIDUAL LOW CLOUD ELEMENTS OVER THE WINDWARD COASTAL WATERS
WERE GENERALLY MOVING WESTWARD AT 20 TO 25 MPH. THE HIGHEST TOPS OF
THE LOW CLOUDS WERE ESTIMATED TO BE ABOUT 11 THOUSAND FEET OVER THE
WATERS ADJACENT TO THE MAIN HAWAIIAN ISLANDS.
AS OF 700 PM HST SATURDAY...BROKEN TO LOCALLY OVERCAST LOW CLOUDS
COVERED MOST OF THE EASTERN HALF OF KAUAI...WHILE SCATTERED LOW
CLOUDS WERE ELSEWHERE ON THAT ISLAND. BROKEN TO LOCALLY OVERCAST LOW
CLOUDS WERE ALONG THE KOOLAU RANGE AND WINDWARD SHORELINE OF OAHU.
THERE WERE SCATTERED TO BROKEN LOW CLOUDS ELSEWHERE ACROSS OAHU.
SCATTERED TO BROKEN LOW CLOUDS WERE OVER THE EASTERN ONE-THIRD OF
MOLOKAI AND CENTRAL LANAI. THERE WERE MAINLY SCATTERED LOW CLOUD
ACROSS THE REMAINDER OF MOLOKAI AND LANAI. ON MAUI...BROKEN LOW
CLOUDS WERE DETECTED OVER THE WESTERN MOUNTAINS...THE SOUTH CENTRAL
VALLEY AND THE LOWER LEEWARD SLOPES OF MOUNT HALEAKALA. THERE WERE
MAINLY SCATTERED LOW CLOUDS ELSEWHERE ON THAT ISLAND. BROKEN TO
LOCALLY OVERCAST LOW CLOUDS WERE ACROSS MOST OF THE LOWER ELEVATIONS
OF THE SOUTHWESTERN AND SOUTHERN BIG ISLAND. THERE WERE SCATTERED TO
BROKEN LOW CLOUDS OVER MOST OF THE NORTHEASTERN AND SOUTHEASTERN BIG
ISLAND.
ACCORDING TO LOOPS OF WATER VAPOR IMAGERY AND SATELLITE DERIVED
UPPER LEVEL WINDS...AN UPPER TROPOSPHERIC LOW WAS CENTERED NEAR 25N
173W...OR ABOUT 890 MILES WEST NORTHWEST OF LIHUE AND 410 MILES
SOUTHEAST OF MIDWAY ATOLL. THIS FEATURE HAS DRIFTED SLOWLY TOWARD
THE NORTH NORTHEAST DURING THE PAST 6 HOURS. BROKEN TO OVERCAST
LAYERED CLOUDS WITH EMBEDDED ISOLATED THUNDERSTORMS ASSOCIATED WITH
THIS UPPER LEVEL LOW WERE WITHIN 325 MILES ON EITHER SIDE OF A LINE
FROM 22N 169W TO 31.5N 167.5W. ELSEWHERE...A NEARLY STATIONARY
ANTICYCLONE ALOFT WAS CENTERED NEAR 08N 153W...OR ABOUT 850 MILES
SOUTH OF HILO. THE UPPER TROPOSPHERIC RIDGE ASSOCIATED WITH THIS
UPPER LEVEL HIGH EXTENDED NORTHWARD OVER THE HAWAIIAN ISLANDS. THIS
WAS RESULTING IN WESTERLY FLOW ALOFT ACROSS THE ALOHA STATE WITH
WIND SPEEDS OF 30 TO 40 MPH. THESE UPPER LEVEL WINDS WERE CARRYING
THE PATCHES OF CIRRUS OVER THE ISLANDS.
IN THE DEEP TROPICS FAR SOUTH OF THE HAWAIIAN ISLANDS...THE
INTERTROPICAL CONVERGENCE ZONE...OR ITCZ...EXTENDED FROM NEAR 08N
140W TO 06.5N 160W TO 03N 180W. SCATTERED TOWERING CUMULUS CLOUDS
AND ISOLATED THUNDERSTORMS WERE WITHIN 240 MILES ON EITHER SIDE OF
THE ITCZ. THE HIGHEST TOPS OF THESE CUMULONIMBUS CLOUDS EXTENDED UP
TO NEAR 49 THOUSAND FEET.
$$
HOUSTON
000
FXHW60 PHFO 080133
AFDHFO
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
400 PM HST SAT NOV 7 2009
.SYNOPSIS...
HIGH PRESSURE TO THE NORTH WILL BRING MODERATE TRADE WINDS TO THE
ISLANDS INTO NEXT WEEK. TRADE SHOWERS WILL FAVOR WINDWARD AND MAUKA
SECTIONS...BUT SOME WILL BE BLOWN OVER TO LEEWARD AREAS.
&&
.DISCUSSION...
PRESSURE FALLS ON THE ORDER OF 2 MILLIBARS OVER THE LAST 24 HOURS
INDICATE THAT THE SURFACE HIGH TO THE NORTH HAS WEAKENED...WHICH
EXPLAINS THE SLIGHTLY LIGHTER TRADE WINDS WE ARE SEEING AROUND THE
ISLANDS. PROGS SAY THAT THE HIGH SHOULD REMAIN STRONG ENOUGH TO
MAINTAIN THE TRADES AT ABOUT THE PRESENT MODERATE VELOCITIES THROUGH
NEXT WEEK.
MODELS ALSO PREDICT THAT AN UPPER LEVEL LOW WEST NORTHWEST OF KAUAI
WILL WEAKEN INTO A TROUGH WHILST APPROACHING KAUAI SUNDAY NIGHT. THE
TROUGH WILL BRING SOME INSTABILITY AND PERHAPS AN INCREASE THE
SHOWER ACTIVITY TO THE ISLANDS SUNDAY NIGHT AND MONDAY. THE TROUGH
WILL LIFT OUT TO THE NORTHEAST AND THE CHANCE OF SHOWERS WILL
DECREASE MONDAY NIGHT.
HEADING INTO THE MIDDLE OF THE WEEK...MODELS SHOW A STRONGER UPPER
LEVEL TROUGH MOVING OVER THE ISLANDS FROM THE NORTH. AN UPPER LEVEL
LOW IS FORECAST TO DEVELOP IN THE TROUGH OVER THE ISLANDS WEDNESDAY
AND LAST INTO NEXT WEEKEND. THE UPPER LOW MAY RESULT IN SOME MORE
WET TRADE WINDS...WHICH IS HOPEFULLY REFLECTED IN THE FORECAST FROM
WEDNESDAY ONWARD.
&&
.MARINE...
THE SMALL CRAFT ADVISORIES ARE FOR LOCALLY STRONG TRADE WINDS IN THE
WINDIER AREAS AROUND MAUI AND THE BIG ISLAND. SURF WILL REMAIN BELOW
ADVISORY LEVELS THROUGH WEDNESDAY...THEN A NORTHEAST SWELL MAY
RESULT IN ADVISORY LEVEL SURF ALONG EAST FACING SHORES.
&&
.HFO WATCHES/WARNINGS/ADVISORIES...
SMALL CRAFT ADVISORY UNTIL 6 PM HST SUNDAY FOR MAALAEA BAY-PAILOLO
CHANNEL-ALENUIHAHA CHANNEL-BIG ISLAND SOUTHEAST WATERS.
&&
$$
CRAIG
000
ATHW40 PHFO 080037
SIMHI
HAWAIIAN ISLANDS SATELLITE INTERPRETATION MESSAGE
NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI
0030 UTC SUN NOV 8 2009
BASED ON DATA THROUGH 0000 UTC NOVEMBER 8 2009
SHOWERY CUMULUS /CU/ CLOUDS OVER WATERS ADJACENT TO THE ISLANDS HAVE
DECREASED IN COVERAGE SINCE THIS MORNING...BUT WINDWARD SLOPES OF
ALL ISLANDS...EXCEPT THE BIG ISLAND...ARE UNDER BROKEN TO OVERCAST
CU THIS AFTERNOON. MEANWHILE...SCATTERED TO BROKEN CIRRUS ELEMENTS
CONTINUE TO MOVE OVER THE ISLANDS FROM THE WEST AND SOUTHWEST...BUT
ARE THIN ENOUGH TO NOT SIGNIFICANTLY DIMINISH THE INCOMING
SUNSHINE.
SHOWERY OPEN-CELLED CU ARE STILL EVIDENT OVER WATERS EAST OF THE
ISLANDS...BUT ARE LESS EXTENSIVE THAN THEY WERE THIS MORNING. THESE
LOW CLOUDS ARE MOVING TOWARD THE WEST AT SPEEDS BETWEEN 23 AND 27
MPH. THE WINDWARD COASTS AND SLOPES OF THE ISLANDS FROM KAUAI TO
MOLOKAI ARE COVERED IN BROKEN TO OVERCAST SHOWERY CU...WHILE
SCATTERED TO BROKEN LOW CLOUD COVER EXTEND TO THE LEEWARD SIDES OF
BOTH KAUAI AND OAHU. LEEWARD MOLOKAI HAS A NARROW RIBBON OF BROKEN
LOW CLOUDS LOCATED JUST SOUTH OF THE ISLAND...BUT MOST OF THE
LEEWARD SIDE IS FREE OF LOW CLOUDS. BROKEN LOW CLOUDS ARE LOCATED
OVER THE SOUTHWEST SIDE OF HALEAKALA ON MAUI...AND ARE MAKING FOR
CLOUDY SKIES OVER WAILEA AND MAKENA. THE WINDWARD SIDE OF THE BIG
ISLAND HAS SCATTERED LOW CLOUDS ON THE UPPER PORTIONS OF THE LOWER
SLOPES...BUT HILO TOWN AND VICINITY IS RECEIVING LOTS OF SUN. THE
LEEWARD SIDE OF THE ISLAND...AS WELL AS THE WINDWARD KOHALA AND THE
KAU DISTRICTS...ARE UNDER BROKEN TO OVERCAST CU AND STRATOCUMULUS.
HIGH CLOUDS NEAR AND OVER THE ISLANDS ARE DEVELOPING IN RESPONSE TO
AN EASTWARD-DRIFTING LOW ALOFT THAT IS ABOUT 900 MILES WEST OF
KAUAI NEAR 24N 174W...WITH BROKEN TO OVERCAST MID- AND HIGH-LEVEL
CLOUDS...AND ISOLATED EMBEDDED THUNDERSTORMS...COVERING A LARGE AREA
BOTH NORTH AND WEST OF THE ISLANDS. AN ANTICYCLONE ALOFT IS CENTERED
SOUTH OF THE ISLANDS...AND IT/S ASSOCIATED RIDGE EXTENDING NORTHEAST
OVER THE BIG ISLAND IS RESULTING IN SOUTHWEST TO WEST FLOW ALOFT...
WHICH IS CARRYING SCATTERED TO BROKEN CIRRUS ELEMENTS OVER THE
ISLANDS.
$$
BIRCHARD
000
FXHW60 PHFO 072000
AFDHFO
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
1000 AM HST SAT NOV 7 2009
.SYNOPSIS...
HIGH PRESSURE TO THE NORTH WILL BRING MODERATE TRADE WINDS TO THE
ISLANDS INTO NEXT WEEK. TRADE SHOWERS WILL FAVOR WINDWARD AND MAUKA
SECTIONS...BUT SOME WILL BE BLOWN OVER TO LEEWARD AREAS.
&&
.DISCUSSION...
PRESSURE FALLS OF 1 TO 2 MILLIBARS OVER THE LAST 24 HOURS INDICATE
THAT THE SURFACE HIGH TO THE NORTH HAS WEAKENED SLIGHTLY...WHICH
EXPLAINS THE SLIGHTLY LIGHTER TRADE WINDS WE ARE SEEING AROUND THE
ISLANDS. PROGS SAY THAT THE HIGH SHOULD MAINTAIN THE TRADES AT ABOUT
THE PRESENT VELOCITIES AT LEAST THROUGH THE FIRST HALF OF NEXT WEEK.
MODELS ALSO PREDICT THAT AN UPPER LEVEL LOW WILL LINGER WEST
NORTHWEST OF KAUAI...WITH SOUTHWESTERLY FLOW ALOFT CARRYING PATCHY
HIGH CLOUDS UP OVER THE STATE FROM TIME TO TIME. THE LOW IS FORECAST
TO WEAKEN INTO AN UPPER LEVEL TROUGH THAT WILL APPROACH KAUAI SUNDAY
NIGHT. THE TROUGH WILL BRING SOME UNSTABLE AIR TO THE ISLANDS...
WHICH MAY INCREASE THE SHOWER ACTIVITY.
HEADING INTO THE MIDDLE OF THE WEEK...MODELS SHOW A STRONGER UPPER
LEVEL TROUGH MOVING OVER THE ISLANDS FROM THE NORTH. AN UPPER LEVEL
LOW MAY DEVELOP IN THE TROUGH OVER THE ISLANDS WEDNESDAY AFTERNOON
AND NIGHT. THE UPPER LOW AND TROUGH MAY RESULT IN WET TRADE WINDS
WHICH IS REFLECTED IN THE WET FORECAST FROM WEDNESDAY ONWARD.
&&
.MARINE...
THE SMALL CRAFT ADVISORIES HAVE BEEN ADJUSTED TO BETTER REFLECT THE
EXPECTED WIND SPEEDS AND COMBINED SEAS. THE ADVISORIES ARE NOW IN
EFFECT FOR ONLY THE WINDIER AREAS AROUND MAUI AND THE BIG ISLAND.
IN SPITE OF THE NORTH NORTHWEST SWELL...SURF WILL REMAIN BELOW
ADVISORY LEVELS THROUGH WEDNESDAY.
&&
.HFO WATCHES/WARNINGS/ADVISORIES...
SMALL CRAFT ADVISORY UNTIL 6 PM HST SUNDAY FOR MAALAEA BAY-PAILOLO
CHANNEL-ALENUIHAHA CHANNEL-BIG ISLAND SOUTHEAST WATERS.
&&
$$
CRAIG
000
FXHW60 PHFO 071347
AFDHFO
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
400 AM HST SAT NOV 7 2009
.SYNOPSIS...
HIGH PRESSURE TO THE NORTH OF THE ISLANDS WILL CONTINUE TO BRING
MODERATE TRADE WINDS TO THE AREA INTO NEXT WEEK. MOISTURE UPSTREAM
OF THE ISLANDS WILL BRING WET TRADE SHOWERS TO THE ISLANDS OVER THE
WEEKEND...AND THE MODERATE TRADES WILL HELP TO BRING SOME OF THESE
SHOWERS TO LEEWARD AREAS. HIGH CLOUDS WILL PERSIST THROUGH THE
WEEKEND.
&&
.DISCUSSION...
NO BIG CHANGES IN THE FORECAST FOR THIS MORNING. THE HIGH PRESSURE
NORTH OF THE ISLANDS WILL CONTINUE TO BRING MODERATE TRADES TO THE
AREA TODAY. THE MODELS REMAIN IN GOOD AGREEMENT WITH THIS FEATURE.
OVERNIGHT WE SAW A BAND OF LOW LEVEL MOISTURE MOVE OVER THE WINDWARD
SIDES OF THE ISLANDS...BEING CARRIED IN ON THE TRADE WINDS. SEVERAL
GAGES ON KAUAI AND OAHU REPORTED RAINFALL AROUND A QUARTER OF AN
INCH. THE MOST RAIN BETWEEN 8PM AND 2AM WAS REPORTED AT MANOA LYON
ARBORETUM ON OAHU WHICH REPORT 0.41 INCHES. PORTIONS OF THE BAND ARE
STILL OFFSHORE...SO ANTICIPATE MORE RAINFALL IN THE PRE-DAWN HOURS.
UPPER LEVEL CLOUDS CONTINUE TO STREAM OVER THE ISLANDS FROM THE WEST
DUE TO A UPPER LEVEL LOW WEST NORTHWEST OF THE ISLANDS. THE MODELS
ARE IN GOOD AGREEMENT WITH THIS UPPER LOW STAYING TO THE WEST
THROUGH THE WEEKEND...SO EXPECT THE HIGH CLOUDS TO COME AND GO
THROUGHOUT. OVER THE WEEKEND THE MODELS SHOW THE LOW WEAKENING INTO
AN UPPER LEVEL TROUGH THAT WILL APPROACH KAUAI SUNDAY NIGHT. THE
TROUGH WILL BRING SOME UNSTABLE AIR TO THE ISLANDS...WHICH WILL
LIKELY INCREASE THE SHOWER ACTIVITY OVER THE AREA.
HEADING INTO THE MIDDLE OF THE WEEK...THE MODELS SHOW A STRONGER
UPPER LEVEL TROUGH MOVING OVER THE ISLANDS FROM THE NORTH. THE
LATEST RUNS OF THE MODELS HAVE A BIT MORE AGREEMENT WITH THE
PLACEMENT OF AN UPPER LEVEL LOW THAT WOULD DEVELOP OVER THE ISLANDS.
THE ECMWF...GFS AND NOGAPS NOW ALL HAVE THE LOW FORMING OVER THE
ISLANDS WEDNESDAY AFTERNOON AND OVERNIGHT. THERE REMAINS SOME
DISCREPANCY OVER THE STRENGTH OF THE UPPER LOW...WITH THE NOGAPS
BEING THE STRONGEST...WHILE THE ECMWF AND GFS ARE MORE IN LINE WITH
EACH OTHER. HAVE LEFT THE GRIDS IN THE LONG TERM WITH THE WET TRADE
PATTERN WHILE AWAITING ANOTHER RUN OR TWO OF THE MODELS TO SEE IF
THIS TREND CONTINUES.
&&
.MARINE...
A SMALL CRAFT ADVISORY CONTINUES FOR COASTAL AREAS AROUND KAUAI
DUE TO COMBINED SEAS...AND AROUND THE WINDIER AREAS NEAR THE BIG
ISLAND AND MAUI FOR WINDS. DESPITE A NEW NORTH NORTHWEST
SWELL...SURF IS EXPECTED TO REMAIN BELOW ADVISORY LEVELS FOR THE
REST OF THE WEEKEND.
&&
.HFO WATCHES/WARNINGS/ADVISORIES...
SMALL CRAFT ADVISORY UNTIL NOON HST SATURDAY FOR KAUAI WINDWARD
WATERS-KAUAI LEEWARD WATERS-OAHU WINDWARD WATERS-KAIWI CHANNEL-
MAUI COUNTY WINDWARD WATERS-BIG ISLAND LEEWARD WATERS.
SMALL CRAFT ADVISORY UNTIL 6 AM HST SUNDAY FOR KAUAI NORTHWEST
WATERS-KAUAI CHANNEL-MAALAEA BAY-PAILOLO CHANNEL-ALENUIHAHA
CHANNEL-BIG ISLAND SOUTHEAST WATERS.
&&
$$
000
FXHW60 PHFO 070637
AFDHFO
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
830 PM HST FRI NOV 6 2009
.SYNOPSIS...
HIGH PRESSURE TO THE NORTH WILL KEEP TRADE WINDS BLOWING INTO NEXT
WEEK. A SHOWER BAND WILL SAG SOUTH OVER THE ISLANDS TONIGHT AND
PROVIDE AN UPTICK IN WINDWARD SHOWERS OVER THE WEEKEND. HIGH
CLOUDS WILL COVER HAWAIIAN SKIES OVER MUCH OF THE WEEKEND AND
EARLY NEXT WEEK. TRADE SHOWERS WILL INCREASE LATE IN THE WEEKEND
AND CONTINUE THROUGH THE WORK-WEEK AS THE UPPER ATMOSPHERE BECOMES
UNSTABLE.
&&
.DISCUSSION...
NO BIG SURPRISES IN THE SHORT TERM FORECAST TONIGHT. WATCHING THE
BAND OF LOW CLOUDS UPSTREAM OF THE ISLANDS MOVE IN...BUT FEEL THE
GRIDS PROPERLY REFLECT THIS FEATURE AT THIS TIME.
PREVIOUS DISCUSSION FOLLOWS.
&&
.PREV DISCUSSION...
ISSUED AT 345 PM
RAINFALL TODAY HAS BEEN MINIMAL WITH ONLY A FEW HUNDREDTHS
FALLING OVER WINDWARD AND MAUKA LOCATIONS. A CLOUD BAND ABOUT 50
MILES NORTH OF THE ISLANDS WILL CONTINUE MOVING SOUTH SLOWLY AND
SPREAD OVER WINDWARD ISLAND LOCATIONS TONIGHT. RIDGING ALOFT WILL
KEEP THE ATMOSPHERE RATHER STABLE...AND ONLY LIGHT TO MODERATE
SHOWERS ARE EXPECTED OVER WINDWARD AREAS.
AT THE SURFACE...MODERATE TO FRESH TRADE WINDS ARE EXPECTED TO
CONTINUE NEXT WEEK AS HIGH PRESSURE REMAINS FAR NORTH OF THE
STATE WITH THE RIDGE REMAINING BETWEEN 30N AND 35N.
MID AND UPPER LEVEL CLOUD COVER WILL INCREASE FROM WEST TO EAST
BEGINNING SATURDAY AS CLOUDS FORMED BY A TROUGH 750 MILES WEST OF
KAUAI ARE ADVECTED OVER THE STATE. RIDGING ALOFT LOCATED SOUTHEAST
OF THE STATE AND THE UPPER TROUGH TO THE WEST WILL CREATE A
CONVEYOR BELT EFFECT...ALLOWING MID AND UPPER CLOUDS TO STREAM OVER
THE ALOHA STATE. THE TROUGH ALOFT IS EXPECTED TO PUSH EAST OVER
THE NEXT FEW DAYS REACHING KAUAI SUNDAY NIGHT. MODELS SHOW THE
TROUGH WILL BRING SOME INSTABILITY TO THE ATMOSPHERE SUNDAY NIGHT
THROUGH TUESDAY...ALLOWING FOR AN INCREASE IN COVERAGE AND
INTENSITY OF THE TRADE SHOWERS. AS THE UPPER TROUGH MOVES
EAST...THE ENHANCED UPPER CLOUD COVER WILL MOVE EAST OF THE STATE
TUESDAY.
THE GLOBAL COMPUTER MODELS CONTINUE TO SHOW A STRONGER UPPER TROUGH
DIGGING TOWARD THE ISLANDS FROM THE NORTH WEDNESDAY AND THURSDAY.
THE MODELS HAVE BEEN INCONSISTENT IN THEIR FORECASTS FOR THIS
SYSTEM...AND SOME DIFFERENCES REMAIN IN THE LATEST RUNS OF THE GFS
AND ECMWF. BOTH CONTINUE TO SHOW TRADE WINDS PERSISTING THROUGH THE
PERIOD AS THE TROUGH ALOFT APPROACHES FROM THE NORTH DURING THE
SECOND HALF OF THE WEEK. THE DIFFERENCES COME IN THE LOCATION OF
THE UPPER TROUGH WEDNESDAY THROUGH FRIDAY. THE GFS KEEPS THE
TROUGH CLOSE ENOUGH TO THE STATE TO PROVIDE ATMOSPHERIC
INSTABILITY...WHILE THE ECMWF KEEPS THE TROUGH FAR ENOUGH EAST TO
KEEP THE STATE UNDER A MORE STABLE ATMOSPHERE. THE FORECAST FOR
THE SECOND HALF OF NEXT WEEK CALLS FOR WET TRADES...WHICH IS A LEAN
TOWARD THE GFS SOLUTION. CONFIDENCE IN THIS LONG TERM FORECAST
REMAINS LOW WITH SMALL PERTURBATIONS IN THE MODELS CONTINUING TO
CAUSE LARGE CHANGES IN THE FORECAST SOLUTION.
&&
.MARINE...
A SMALL CRAFT ADVISORY CONTINUES FOR COASTAL AREAS AROUND KAUAI
DUE TO COMBINED SEAS...AND AROUND THE WINDIER AREAS NEAR THE BIG
ISLAND AND MAUI FOR WINDS. THE CURRENT NORTH NORTHWEST SWELL WILL
SLOWLY DIMINISH. THIS SWELL WILL BE REINFORCED BY A NEW NORTH
NORTHWEST SWELL ARRIVING TONIGHT...BUT SURF WILL REMAIN BELOW THE
ADVISORY THRESHOLD.
&&
.HFO WATCHES/WARNINGS/ADVISORIES...
SMALL CRAFT ADVISORY UNTIL NOON HST SATURDAY FOR KAUAI WINDWARD
WATERS-KAUAI LEEWARD WATERS-OAHU WINDWARD WATERS-KAIWI CHANNEL-
MAUI COUNTY WINDWARD WATERS-BIG ISLAND LEEWARD WATERS.
SMALL CRAFT ADVISORY UNTIL 6 AM HST SUNDAY FOR KAUAI NORTHWEST
WATERS-KAUAI CHANNEL-MAALAEA BAY-PAILOLO CHANNEL-ALENUIHAHA
CHANNEL-BIG ISLAND SOUTHEAST WATERS.
&&
$$
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