Heavy Rain in Hawaii, February 12 to 15, 2014

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE HONOLULU HI
845 PM HST WED FEB 12 2014

.SYNOPSIS...
CLOUDY SKIES ARE ON TAP FOR THE WEEKEND AND INTO EARLY NEXT WEEK
AS A DISTURBANCE TAKES UP SHOP WEST OF KAUAI. IN THE MEAN TIME...
BREEZY TRADES ACCOMPANIED BY SHOWERS WILL SPREAD EASTWARD FROM KAUAI
TO MAUI THROUGH FRIDAY. THE WINDS WILL BE SHIFTING TO SOUTHERLY LATE
IN THE WEEKEND WITH CONTINUED CLOUDY SKIES AS THE DISTURBANCE
REMAINS WEST OF KAUAI. THESE CLOUDS WILL BE DENSE ENOUGH TO PRODUCE
AREAS OF RAIN.

&&

.DISCUSSION...

A STALLED FRONT 100 MILES WEST OF KAUAI THIS EVENING IS PROGGED TO
WEAKEN THERE. BUT AS IT DOES...THE BREEZY NORTHEAST WINDS WILL
SPREAD EASTWARD...ACCOMPANIED BY TRADE WIND SHOWERS WHICH WILL
AFFECT PRIMARILY THE WINDWARD AND MOUNTAIN AREAS. THE TIMELINE CALLS
FOR THIS TRADE WIND WEATHER TO REACH OAHU THURSDAY EVENING...MOLOKAI
EARLY FRIDAY MORNING...AND THE REST OF MAUI COUNTY FRIDAY AFTERNOON.
SLIGHTLY WEAKER TRADES ARE ON TAP TO FILL AROUND THE BIG ISLAND
WATERS SATURDAY MORNING AND WILL NOT SEE MUCH OF THE TRADE SHOWERS.

DUE TO THE STRENGTH OF THE TRADES...THESE SHOWERS WILL BE
FREQUENTING THE LEEWARD COMMUNITIES OF PRIMARILY KAUAI OAHU AND
MOLOKAI.

WIND-WISE...THE CHANGE WILL BE FLUID...BEGINNING WITH NORTHEAST
WINDS...BECOMING EASTERLY SATURDAY...THEN VEERING TO SOUTHERLY
SUNDAY AND MONDAY.

ON FRIDAY NIGHT...A DEEPENING UPPER LEVEL LOW 800 MILES WEST OF
KAUAI WILL BE SENDING DENSE...LAYERED MID AND HIGH LEVEL CLOUDS
ACROSS THE ISLAND CHAIN UNDER A WESTERLY WIND FLOW ALOFT WITH THE
LIKEIHOOD OF RAIN FALLING FROM IT.

THE STRENGTH OF THE SOUTHERLY WINDS IS QUESTIONABLE FOR NOW. IT
COULD GET AS STRONG AS MODERATE TO STRONG. IT DEPENDS HOW CLOSE THE
LOW SETS UP SHOP TO THE ISLANDS. THE LATEST GFS RUN HAS THE UPPER
LOW AFFECTING KAUAI AND OAHU WITH HEAVY RAINS SUNDAY AND MONDAY
BEFORE BACKING OFF TUESDAY. THE ECMWF SUPPORTS THIS ASSESSMENT AS
WELL.  MORE TO COME.

IN THE MEANTIME...SHOWER ACTIVITY ON KAUAI IS CONFINED TO THE
NORTHERN HALF OF THE ISLAND. THE LOW LEVEL MOISTURE IS SHALLOW...
BELOW 10000 FEET AND THE RADAR...LOCATED NEAR PORT ALLEN...IS NOT
SEEING IT ALL THAT WELL. BUT WE EXPECT CONTINUE SHOWER ACTIVITY
THERE FOR THE REST OF THE NIGHT. A FLOOD ADVISORY WAS JUST ISSUED
NORTH OF A LINE FROM BARKING SANDS TO JUST NORTH OFN ANAHOLA. WE
WILL BE MONITORING THIS AREA CLOSELY OVERNIGHT.

&&

.AVIATION...
LITTLE CHANGE ON THE AVIATION FRONT. AIRMET SIERRA FOR MTN
OBSCURATION ABOVE 020 WILL CONTINUE FOR KAUAI THROUGH TONIGHT.
ISOLATED AREAS OF IFR OR LIFR CEILINGS AND VISIBILITIES MAY BE
POSSIBLE AS THE STALLED FRONT WEAKENS SOMEWHAT THROUGH THURSDAY WITH
THE BREEZY TRADES AND SHOWERS SPREADING EASTWARD TO OAHU LATE IN THE
AFTERNOON OR THURSDAY EVENING.

OTHERWISE...LIGHT WINDS CONTINUE ACROSS THE STATE WITH LAND AND SEA
BREEZES DOMINATING THE TERMINALS. VFR CONDITIONS TO PREVAIL FOR THE
REST OF THE STATE.

&&

.MARINE...
THE SMALL CRAFT ADVISORY /SCA/ REMAINS IN EFFECT FOR WATERS AROUND
KAUAI INTO THURSDAY...NOT ONLY DUE TO WINDS BUT SEAS AS WELL.
NORTHEAST WINDS WILL SPREAD EASTWARD TO OAHU THURSDAY AFTERNOON OR
EVENING...BUT THERE REMAINS CONSIDERABLE UNCERTAINTY AS TO THE
STRENGTH OF THESE WINDS. AS A RESULT...THE EXPIRATION TIME OF THE
SCA IS SET FOR 6 PM THURSDAY.

AS NOTED ABOVE...THE WESTERN END OF THE STATE COULD SEE FRESH TO
STRONG SOUTHEAST TO SOUTH WINDS ON SUNDAY AND MONDAY WHICH WOULD
WARRANT AN SCA.

A SERIES OF NORTH-NORTHWEST SWELLS WILL CONTINUE THROUGH THE REST
OF THE WEEK. THE CURRENT MODERATE SWELL IS ON THE DECLINE...WHILE A
LARGER PULSE SHOULD PRODUCE ADVISORY LEVEL SURF ALONG NORTH FACING
SHORES OF MOST ISLANDS ON FRIDAY AND FRIDAY NIGHT. ADDITIONAL PULSES
DUE ON SUNDAY AND EARLY NEXT WEEK WILL PRODUCE NORTH SHORE SURF IN
THE DOUBLE OVERHEAD RANGE.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
SMALL CRAFT ADVISORY THROUGH 6 PM HST THURSDAY FOR WATERS AROUND
KAUAI.

&&

LAU