High Surf in Hawaii, February 14, 2014

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
400 AM HST FRI FEB 14 2014

.SYNOPSIS...
CLOUDS...SHOWERS...AND GUSTY NORTHEAST WINDS WILL CONTINUE OVER THE
NORTHWEST END OF THE STATE...BUT DRY EASTERLY FLOW WILL PREVAIL
ELSEWHERE. BY LATE IN THE WEEKEND...INCREASING SOUTHEASTERLY WINDS
WILL ENHANCE TRADE-WIND SHOWERS FURTHER ACROSS THE WEST HALF OF THE
STATE. A KONA LOW WILL FORM SEVERAL HUNDRED MILES WEST OF THE
ISLANDS DURING THE WEEKEND...BRINGING SOUTHERLY WINDS AND THE
POTENTIAL FOR HEAVY SHOWERS FROM LATE SUNDAY INTO TUESDAY ACROSS
MUCH OF THE STATE.

&&

.DISCUSSION...
A WEAKENING FRONTAL CLOUD BAND LANGUISHED OVER THE MAIN HAWAIIAN
ISLANDS. ALTHOUGH THE AIR MASS CERTAINLY WAS MOIST THROUGH MOST OF
THE ATMOSPHERE OVER KAUAI...AND AT HIGH LEVELS OVER THE BIG
ISLAND...DRIER AIR PREVAILED AT MID-LEVELS OVER THE SOUTHEAST HALF
OF THE STATE. RAINFALL PICKED UP SOMEWHAT OVERNIGHT...ALMOST
ENTIRELY OVER KAUAI COUNTY AND OAHU. ALTHOUGH THE MAJORITY OF THIS
PRECIPITATION COULD BE DESCRIBED AS STRATUS RAIN...EMBEDDED
CONVECTIVE SHOWERS ALSO WERE SIGNIFICANT...ESPECIALLY OVER OAHU.
STRONG DEEP CONVECTION WAS ABSENT...HOWEVER.

ALOFT...A FAIRLY SHARP TROUGH WAS PRESENT TO THE WEST OF THE
STATE...BUT BECAUSE OF ITS ORIENTATION TOWARD THE WEST...FOR NOW
LITTLE OF ITS ENERGY REACHED THE ISLANDS. GUIDANCE AGREED IN
PREDICTING THIS FEATURE TO PRODUCE SOME DRAMATIC EFFECTS OVER THE
NEXT WEEK. FIRST...THE TROUGH WILL CUT OFF AND DEEPEN IN PLACE FROM
TODAY INTO SATURDAY. WITH THE RESULTING ENCOURAGEMENT FROM ALOFT...A
SURFACE REFLECTION WILL DEEPEN TO THE WEST OF THE STATE. SOUTHERLY
WINDS WILL INCREASE FROM SUNDAY INTO MONDAY...FLOWING INTO THE
SURFACE LOW...BRINGING WITH THEM ADDITIONAL MOISTURE. MODELS ALMOST
UNIVERSALLY PREDICTED PRECIPITABLE WATER CONVERGING IN EXCESS OF TWO
INCHES THROUGHOUT...AND PROBABLY SUCH FIGURES REPRESENTED AN
UNDERESTIMATE FOR MANY AREAS.

THUS...WIDESPREAD RAIN IS LIKELY FROM SUNDAY OR SUNDAY NIGHT INTO
TUESDAY. SOME OF THIS RAIN INDEED MAY BE HEAVY...THOUGH WITH THE
MID-LEVEL COLD POOL LIKELY REMAINING WEST OF THE STATE...DEEP
CONVECTION IS UNLIKELY TO BE THE MAIN CONCERN. ON THE OTHER HAND...
STEADY RAIN MAY CONTINUE AT HIGH LEVELS FOR EXTENDED PERIODS OF
TIME...ESPECIALLY OVER HIGHER TERRAIN EXPOSED TO THE PREVAILING
FLOW. IT WAS TOO EARLY TO ISSUE A FLOOD WATCH...BUT IF CURRENT
TRENDS CONTINUE...THEN THIS PRODUCT MAY BE NEEDED.

FROM MONDAY NIGHT INTO MIDWEEK...GUIDANCE PREDICTED THE MID-LEVEL
LOW TO WEAKEN AND MOVE OFF TOWARD THE NORTHEAST SLOWLY. ALTHOUGH
BOTH WINDS AND RAIN SHOULD DIMINISH AS SUPPORT FROM ALOFT WEAKENS...
NO CLEAR BREAK IN THE WEATHER IS LIKELY. INSTEAD...CONDITIONS WILL
DRY AND SKIES WILL CLEAR SLOWLY INTO LATE NEXT WEEK. TRADE WINDS ARE
UNLIKELY TO RETURN EVEN AS LATE AS NEXT FRIDAY...LEAVING PREVAILING
WINDS LIGHT AND GENERALLY SOUTHERLY.

&&

.MARINE...
A SMALL CRAFT ADVISORY /SCA/ REMAINED IN EFFECT FOR ALL WATERS WEST
OF THE BIG ISLAND THROUGH TONIGHT FOR A COMBINATION OF WIND SPEED
AND HIGH SEAS ASSOCIATED WITH LARGE SWELL. WINDS WILL DIMINISH
SLIGHTLY BY SATURDAY NIGHT...AND THEN INCREASE FROM THE SOUTH
STARTING SUNDAY.

A HIGH SURF ADVISORY REMAINS IN EFFECT FOR MOST NORTH-FACING SHORES
THROUGH TONIGHT. ADDITIONAL PULSES OF NORTH-NORTHWEST SWELL DUE ON
SUNDAY AND THROUGH NEXT WEEK WILL PRODUCE NORTH SHORE SURF IN THE
DOUBLE OVERHEAD RANGE AT TIMES.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
HIGH SURF ADVISORY UNTIL 6 AM HST SATURDAY FOR NIIHAU-KAUAI
WINDWARD-KAUAI LEEWARD-OAHU NORTH SHORE-OAHU KOOLAU-OLOMANA-
MOLOKAI-MAUI WINDWARD WEST-MAUI CENTRAL VALLEY-WINDWARD
HALEAKALA-BIG ISLAND NORTH AND EAST.

SMALL CRAFT ADVISORY UNTIL 6 AM HST SATURDAY FOR KAUAI NORTHWEST
WATERS-KAUAI WINDWARD WATERS-KAUAI LEEWARD WATERS-KAUAI CHANNEL-
OAHU WINDWARD WATERS-OAHU LEEWARD WATERS-KAIWI CHANNEL-MAUI
COUNTY WINDWARD WATERS-MAUI COUNTY LEEWARD WATERS-ALENUIHAHA
CHANNEL.

&&

RYSHKO