Small Craft Advisory 55, NWS Honolulu, HI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
332 PM HST MON OCT 26 2015

.SYNOPSIS...
A WEAK FRONT WILL GRADUALLY MOVE DOWN THE ISLAND CHAIN TONIGHT AND
TUESDAY ACCOMPANIED BY SOME PASSING LIGHT SHOWERS MAINLY OVER
WINDWARD AND MAUKA AREAS. HIGH PRESSURE WILL BUILD IN BEHIND THE
FRONT WITH TRADE WINDS RETURNING. CLOUDS AND PASSING SHOWERS WILL
CONTINUE TO FAVOR WINDWARD AND MAUKA AREAS. ANOTHER FRONT WILL
APPROACH THE AREA LATE IN THE WEEK WITH WINDS BECOMING LIGHTER.
THERE MAY BE AND INCREASE IN SHOWER ACTIVITY OUT AHEAD OF THE
FRONT.

&&

.DISCUSSION...
A WEAKENING EAST TO WEST ORIENTED FRONTAL CLOUD BAND HAS RECENTLY
REACHED KAUAI AND IS GRADUALLY APPROACHING OAHU FROM THE NORTH. A
SECOND CLOUD BAND IS SEEN DRAPED ACROSS PORTIONS OF MAUI COUNTY
AND THE BIG ISLAND BUT IT IS GRADUALLY DISSIPATING. THE BANDS OF
CLOUDS ARE RATHER SHALLOW WITH RADAR INDICATING ONLY SCATTERED
LIGHT SHOWERS ASSOCIATED WITH THEM MAINLY OVER NORTH AND NORTHEAST
FACING SLOPES. WINDS WILL BE LIGHT THROUGH TONIGHT DUE TO THE
FRONTS PROXIMITY.

THE FRONT IS FORECAST TO SLOWLY MOVE DOWN THE ISLAND CHAIN
TONIGHT AND TUESDAY AND STALL AND DISSIPATE NEAR THE BIG ISLAND BY
MID WEEK. WITH RIDGING ALOFT AND THE SHALLOWNESS OF THE
FRONT...ONLY LIGHT PASSING SHOWERS ARE EXPECTED DURING ITS PASSAGE
MAINLY OVER WINDWARD AND MAUKA AREAS. WINDWARD BIG ISLAND MAY SEE
A BIT MORE OF A PROLONGED SHOWER PERIOD DEPENDING ON HOW CLOSE THE
FRONT STALLS TO THEM.

HIGH PRESSURE WILL BUILD IN BEHIND THE FRONT AND GRADUALLY MOVE
FROM WEST TO EAST FAR NORTH OF THE STATE. THIS WILL PLACE THE
ISLANDS IN A MODERATE TRADE WIND ENVIRONMENT DURING THE MID WEEK
PERIOD.

LATER IN THE WEEK THE HIGH WILL BE LOCATED FAR NORTHEAST OF THE
AREA WHILE ANOTHER FRONT APPROACHES THE AREA FROM THE NORTHWEST.
THIS WILL CAUSE OUR WINDS TO BECOME LIGHTER AS WE HEAD INTO THE
WEEKEND. THE FRONT IS FORECAST TO STALL NORTH OF THE AREA HOWEVER
MOISTURE MAY GET DRAWN UP FROM THE SOUTHEAST OUT AHEAD OF IT
ALLOWING FOR AN INCREASE IN SHOWER ACTIVITY. ALSO THE AN UPPER
TROUGH WILL MOVE CLOSER TO THE AREA AND WILL LIKELY CAUSE THE
AIRMASS TO BECOME A BIT LESS STABLE.

&&

.AVIATION...
A WEAK COLD FRONT WILL MOVE SOUTHWARD THROUGH KAUAI LATE
THIS AFTERNOON...OAHU AND MAUI COUNTY TONIGHT...AND WILL REACH THE
BIG ISLAND BY DAYBREAK TUESDAY. SOME MVFR CIGS AND/OR VSBYS WILL BE
POSSIBLE IN SHRA AS THE FRONT MOVES THROUGH.
OTHERWISE...PREDOMINANTLY VFR CONDITIONS ARE EXPECTED THROUGH THE
TAF FORECAST PERIOD.

AIRMET SIERRA IS IN EFFECT FOR MOUNTAIN OBSCURATION ACROSS KAUAI.
THE AIRMET WILL LIKELY NEED TO BE EXPANDED ACROSS PORTIONS OF THE
OTHER ISLANDS LATER TONIGHT.

&&

.MARINE...
SWELLS FROM TROPICAL STORM OLAF WILL CONTINUE TO LOWER TONIGHT THROUGH
TUESDAY. THE HIGH SURF ADVISORY FOR THE EAST FACING SHORES ON THE
BIG ISLAND HAS BEEN CANCELLED.

A RATHER LARGE NORTH NORTHWEST SWELL WILL BEGIN TO FILL IN
OVERNIGHT AND TUESDAY MORNING. THIS SWELL IS EXPECTED TO PEAK
LATE TUESDAY AND TUESDAY NIGHT...THEN LOWER GRADUALLY WEDNESDAY
INTO THURSDAY. SURF HEIGHTS ARE EXPECTED TO REACH LOW END WARNING
LEVELS DURING THE PEAK OF THE SWELL. THE NORTHERLY DIRECTION OF
THE SWELL WILL ALSO CAUSE ELEVATED SURF ALONG SOME EAST FACING
SHORES WITH NORTHERLY EXPOSURE.

ANOTHER LARGE NORTHWEST SWELL IS EXPECTED TO GRADUALLY FILL IN
WEDNESDAY NIGHT AND THURSDAY MORNING...PEAK THURSDAY NIGHT AND
FRIDAY...THEN LOWER GRADUALLY SATURDAY INTO SUNDAY. SURF HEIGHTS
WILL LIKELY REACH WARNING LEVELS DURING THE PEAK OF THE SWELL.

THE CURRENT SOUTH SWELL WILL CONTINUE TO LOWER GRADUALLY OVER THE
NEXT COUPLE OF DAYS. OTHERWISE THERE WILL BE A SERIES OF SMALL
SOUTHERLY SWELLS THROUGH THE WEEK AND ON INTO THE WEEKEND.

THE ABOVE MENTIONED NORTH AND NORTHWEST SWELLS COMBINED WITH
LOCALLY GENERATED WINDS WAVES...WILL CAUSE SMALL CRAFT ADVISORY
CONDITIONS AT TIMES OVER EXPOSED COASTAL WATERS.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
HIGH SURF WARNING UNTIL 6 PM HST WEDNESDAY FOR NIIHAU-KAUAI
WINDWARD-KAUAI LEEWARD-WAIANAE COAST-OAHU NORTH SHORE-OAHU
KOOLAU-OLOMANA-MOLOKAI-MAUI WINDWARD WEST-MAUI CENTRAL VALLEY-
WINDWARD HALEAKALA.

SMALL CRAFT ADVISORY UNTIL 6 PM HST WEDNESDAY 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 WINDWARD WATERS.

&&

SYNOPSIS/DISCUSSION/MARINE...BURKE
AVIATION...JELSEMA