Drought in Hawaii, December 1 to 31, 2009

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
845 PM HST MON NOV 30 2009

.SYNOPSIS...
LOCALLY BREEZY NORTHEAST WINDS WILL DELIVER SOME WINDWARD SHOWERS
TONIGHT...BUT WILL WEAKEN ON TUESDAY...WITH WINDS THEN BECOMING
LIGHT AND VARIABLE THROUGH WEDNESDAY. WEATHER WILL BE MOSTLY DRY
FROM TUESDAY THROUGH THURSDAY...WITH ONLY ISOLATED SHOWERS EXPECTED.
AN APPROACHING FRONT WILL BRING SOUTHWEST WINDS ON THURSDAY...WITH
THE FRONT BRINGING CLOUDS AND SHOWERS AS IT MOVES DOWN THE ISLAND
CHAIN ON FRIDAY. THE FRONT WILL WEAKEN NEAR THE ISLANDS ON SATURDAY
AND SUNDAY...WITH ANOTHER FRONT APPROACHING EARLY NEXT WEEK.

&&

.DISCUSSION...
SATELLITE IMAGERY HIGHLIGHTS A FRAGMENTING NE TO SW ORIENTED WEDGE
OF CLOUDS AND SHOWERS OVER OAHU...THAT HAS BEEN KEEPING THE ISLAND
FAIRLY DAMP OVER THE PAST 12 HOURS...ESPECIALLY WINDWARD. BRIEFLY
HEAVY SHOWERS ARE AFFECTING SOUTHEAST OAHU AS OF THIS EVENING. THIS
BAND IS ANALYZED AS THE SW EXTENSION OF A STALLED FRONTAL BOUNDARY
ON THE LATEST SURFACE ANALYSIS...EXTENDING FROM A LOW WELL TO THE
NE. STABLE LOW CLOUDS HAVE INCREASED TO OVERCAST OVER WINDWARD KAUAI
OVER THE PAST COUPLE OF HOURS...IN RESPONSE TO A PASSING GRAVITY
WAVE...WHILE SHOWERY CU ARE SEEN UPWIND OF MAUI COUNTY. WILL BE
UPDATING FORECASTS SHORTLY TO ACCOUNT FOR LATEST TRENDS...BUT MOSTLY
TO INCREASE SKY AND POP OVER WINDWARD KAUAI.

LOW CLOUDS AND SHOWERS NEAR THE ISLANDS ARE MOVING SW...THANKS TO
HIGH PRESSURE TO THE NE AND WEAK TROUGHING E OF THE ISLANDS ALONG
150W. THESE WINDS WILL NOT LAST LONG THOUGH...AS A DYNAMIC WEATHER
PATTERN IS IN THE WORKS. FORECAST MODELS ARE DEPICTING A VERY
SEASONABLE WEATHER PATTERN FOR HAWAII OVER THE NEXT WEEK...
CONSIDERING THAT IS DECEMBER OF AN EL NINO YEAR.

A ZONAL JET STREAM WILL CARRY FAST MOVING LOWS FROM WEST TO EAST
ACROSS THE NORTH PACIFIC OVER THE NEXT 7 TO 10 DAYS...WITH FRONTS
ASSOCIATED WITH THESE LOWS TO APPROACH...AND POSSIBLY MOVE
DOWN...THE ISLAND CHAIN WITH LITTLE SIGNIFICANT SUPPORT ALOFT. FIRST
FRONT IS EXPECTED TO FALL APART N OF KAUAI ON WEDNESDAY...THE SECOND
IS EXPECTED TO MOVE DOWN AT LEAST A PART OF THE ISLAND CHAIN FROM
FRIDAY INTO THE WEEKEND...WITH A THIRD APPROACHING LATE THIS
WEEKEND...AND POSSIBLY ACCOMPANYING A GIANT NW SWELL WHEN IT NEARS
NEXT MONDAY AND TUESDAY. WITH THE FAST FLOW ALOFT...TIMING ON THESE
FEATURES...AND THEIR POSSIBLE IMPACTS ON THE ISLANDS...WILL BE
CHANGING AS MODELS TRY TO KEEP UP WITH THE ATMOSPHERE.

FOR THE DETAILS...HIGH PRESSURE TO THE NE WILL MOVE QUICKLY E AND
DISSIPATE OVER THE NEXT 24 HOURS AS THE AFOREMENTIONED FRONT NEARS.
WINDS WILL TREND DOWN QUICKLY ON TUESDAY...AS THE RIDGE WEAKENS AND
THE FRONT STALLS ALONG 25N...N OF KAUAI. PRESSURE TRENDS ALREADY
SHOW THIS PROCESS IS UNDERWAY...DOWN 1 TO 2 MB OVER THE PAST 24
HOURS. WITH A WEAK GRADIENT DEVELOPING TUESDAY NIGHT THROUGH
WEDNESDAY NIGHT...THE RESULT WILL BE LAND AND SEA BREEZES OVER THE
ISLANDS...WITH AFTERNOON AND EVENING INTERIOR CLOUDS...AND MOSTLY
CLEAR MORNINGS AND NIGHTS. THE AIRMASS WILL BE DRY AND STABLE FOR
MOST OF THE UPCOMING WEEK...WITH LITTLE IN THE WAY OF RAINFALL
EXPECTED...DESPITE THIS EVENING/S SHOWERS.

A NEWLY APPROACHING FRONT WILL BRING A WIND SHIFT TO THE SW ON
THURSDAY...WITH THE FRONT EXPECTED TO MOVE DOWN AT LEAST A PORTION
OF THE ISLAND CHAIN THURSDAY NIGHT AND FRIDAY. WEAK MID-LEVEL
SUPPORT WILL ALLOW A BAND OF CLOUDS AND SHOWERS TO ACCOMPANY THE
FRONT...WITH A BRIEF PERIOD OF N WINDS BEHIND THE FRONT. FOR NOW...
THE FRONT IS FORECAST TO STALL AND WEAKEN OVER MAUI COUNTY AND THE
BIG ISLAND ON FRIDAY NIGHT AS THE SUPPORT ALOFT LIFTS OFF TO THE
NE. LINGERING MOISTURE FROM THE FRONT IS DEPICTED AS BEING SLOW TO
TO CLEAR THE ISLANDS THIS WEEKEND...DESPITE LITTLE TO NO SUPPORT
ALOFT.

WINDS WILL QUICKLY EASE BEHIND FRIDAY/S FRONT AS THE RIDGE SETTLES
OVER THE ISLANDS AGAIN...WITH LIGHT WINDS ON SATURDAY. WINDS WILL
BECOME SW AGAIN ON SUNDAY AS THE THIRD FRONT APPROACHES LATE THIS
WEEKEND. TOO SOON FOR DETAILS ON THIS ONE...BUT WORTH NOTING THAT
LONG TERM WAVE MODEL GUIDANCE HAS 50 FOOT SEAS NEAR THE CORE OF THE
PARENT LOW...AND DEPICTS A BELIEVABLE 25 FOOT NW SWELL BUILDING AT
BUOY 51001 ON SUNDAY AND MONDAY.

&&

.MARINE...
A LONG PERIOD NNW SWELL AND A SHORTER PERIOD NNE SWELL IS RESULTING
IN HIGH SURF ADVISORY CONDITIONS IN A VARIETY OF AREAS. ON KAUAI AND
NIIHAU...WEST...NORTH AND EAST FACING SHORES ARE AFFECTED. ON
OAHU...MOLOKAI AND THE ISLAND OF MAUI...NORTH AND EAST FACING SHORES
ARE AFFECTED. AND ON THE BIG ISLAND...EAST FACING SHORES ARE
AFFECTED. THE TREND WILL BE DOWN ON TUESDAY...BUT MORE SURF IS ON
THE WAY. THE DISCUSSION PORTION OF THE OAHU SURF FORECAST CONTAINS
THE LATEST ON THAT...AND CAN BE LOOSELY APPLIED ELSEWHERE ACROSS THE
STATE.

A SMALL CRAFT ADVISORY IS UP FOR MOST OF THE MARINE ZONES DUE TO
NORTHEAST WINDS OF 20 TO 25 KT AND/OR SEAS OF 10 FEET OR GREATER.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
HIGH SURF ADVISORY THROUGH 600 AM HST TUESDAY FOR WEST...NORTH AND
EAST FACING SHORES OF KAUAI AND NIIHAU...AND FOR NORTH AND EAST
FACING SHORES OF OAHU MOLOKAI AND MAUI...AND FOR EAST FACING SHORES
OF THE BIG ISLAND.

SMALL CRAFT ADVISORY UNTIL 600 AM HST TUESDAY FOR KAUAI NORTHWEST
WATERS-KAUAI WINDWARD WATERS-KAUAI LEEWARD WATERS-KAUAI CHANNEL-OAHU
WINDWARD WATERS-OAHU LEEWARD WATERS-KAIWI CHANNEL-MAUI COUNTY
WINDWARD WATERS-MAALAEA BAY-PAILOLO CHANNEL-ALENUIHAHA CHANNEL-BIG
ISLAND LEEWARD WATERS-BIG ISLAND SOUTHEAST WATERS.

&&

BIRCHARD