Wildfire in Hawaii, March 17 to 22, 2016

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
1000 AM HST THU MAR 17 2016

.SYNOPSIS...
A HIGH FAR NORTHWEST OF THE AREA WILL MOVE EAST THROUGH EARLY
NEXT WEEK. THE HIGH WILL PRODUCE LOCALLY BREEZY TRADE WINDS
THROUGH THE WEEKEND. THE TRADES WILL PUSH CLOUDS AND SOME SHOWERS
OVER WINDWARD AREAS...BUT THE ATMOSPHERE WILL BE STABLE...SO
RAINFALL AMOUNTS WILL BE LIGHT. WINDS WILL WEAKEN AND SHIFT OUT
OF THE SOUTH NEXT WEEK AS A FRONT APPROACHES FROM THE NORTHWEST.
SHOWER ACTIVITY WILL INCREASE AS THE ATMOSPHERE BECOME MORE MOIST
AND UNSTABLE.

&&

.DISCUSSION...
SURFACE ANALYSES SHOW A 1028 HIGH CENTERED ABOUT 1000 MILES
NORTHWEST OF OAHU NEAR 30N172W AND A 1030 MB HIGH ABOUT 1900
MILES NORTHWEST OF OAHU NEAR 38N177W. THE PRESSURE GRADIENT
SOUTHEAST OF THESE HIGHS IS BEING TIGHTENED A BIT BY A TROUGH
SOUTHEAST OF THE ISLANDS...THE REMNANT OF AN OLD FRONT. THE
PRESSURE GRADIENT WILL REMAIN TIGHT ENOUGH TO PRODUCE BREEZY
TRADE WINDS THROUGH THE WEEKEND. THE ATMOSPHERE OVER THE ISLANDS
IS QUITE STABLE WITH THE 200 AM BALLOON SOUNDINGS SHOWING A
STRONG TEMPERATURE INVERSION NEAR 5000 FT AT LIHUE AND AN
INVERSION NEAR 7000 FT AT HILO. THE TRADE WINDS WILL PUSH LOW
CLOUDS OVER WINDWARD AREAS BUT THE ATMOSPHERE WILL BE TOO
STABLE FOR THESE CLOUDS TO PRODUCE MUCH RAIN.

THE GLOBAL MODELS ARE IN GOOD AGREEMENT SHOWING THE SURFACE
HIGH MOVING OFF TO THE NORTHEAST OF THE AREA EARLY NEXT WEEK
AND A FRONT APPROACHING FROM THE NORTHWEST. THE SUBTROPICAL
RIDGE WILL MOVE SOUTH OVER THE ISLANDS AS THE FRONT APPROACHES.
WINDS WILL WEAKEN AND VEER OUT OF THE SOUTHEAST MONDAY. THE
MODELS START TO DIVERGE BY THE MIDDLE OF NEXT WEEK AND IT IS
NOT YET CLEAR WHETHER THE FRONT WILL REACH THE ISLANDS. IN ANY
CASE...THE ATMOSPHERE WILL BECOME MORE MOIST AND UNSTABLE SO
SHOWERS MAY BECOME MORE ACTIVE.

&&

.AVIATION...
STRONG NE LOW LEVEL WINDS WILL PUSH CLOUDS OVER THE NE SECTIONS OF
THE ISLANDS...BUT THE CLOUD BASES ARE HIGH ENOUGH SO THAT VFR COND
WILL PREVAIL.

THE STRONG LOW LEVEL WINDS WILL ALSO PRODUCE MOD TURB SW THRU SW OF
THE MTN OF ALL ISLANDS BLW 060. AIRMET TANGO WILL LIKELY REMAIN UP
THROUGH TODAY FOR THIS LOW LEVEL TURB. ALSO...A JET STREAM WILL
PRODUCE MOD TURB ALOFT. AIRMET TANGO FOR THE TURB ALOFT WILL BE
IN EFFECT THRU AT LEAST 2200 UTC.

&&

.MARINE...
BUOY OBSERVATIONS LATE LAST NIGHT SHOWED A RAPID RISE IN THE NORTH
NORTHWEST SWELL. WE HAVE ISSUED A HIGH SURF ADVISORY FOR NORTH
FACING SHORES AND A MARINE WEATHER STATEMENT FOR NORTH FACING
HARBORS BECAUSE OF THE LARGE SWELL. THE BUOYS ARE RUNNING HIGHER
THAN THE WAVE WATCH MODEL HAS BEEN FORECASTING. THE NORTH NORTHWEST
SWELL WILL CONTINUE THROUGH THE WEEKEND...AND A NEW NORTHWEST
SWELL IS EXPECTED TO ARRIVE SATURDAY. IF THE SWELL CONTINUES TO
RISE...THE HIGH SURF ADVISORY MAY NEED TO BE REPLACED WITH A HIGH
SURF WARNING. OTHERWISE...THE HIGH SURF ADVISORY IS LIKELY TO
CONTINUE THROUGH THE WEEKEND.

THE PRESSURE GRADIENT OVER THE AREA REMAINS TIGHT ENOUGH TO PRODUCE
STRONG NORTHEAST TRADE WINDS OVER THE AREA. A SMALL CRAFT
ADVISORY...SCA...IS IN EFFECT FOR ALL COASTAL WATERS DUE TO THE
STRONG TRADE WINDS ALONG WITH THE LARGE NORTH NORTHWEST SWELL. THE
SCA IS LIKELY TO REMAIN UP FOR MOST AREAS THROUGH THE WEEKEND.

THE WINDS WILL WEAKEN AND VEER OUT OF THE SOUTHEAST MONDAY AS A
SURFACE RIDGE SHIFTS SOUTH NEAR THE ISLANDS.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
HIGH SURF ADVISORY FOR NORTH FACING SHORES OF ALL ISLANDS EXCEPT
LANAI AND KAHOOLAWE THROUGH 600 PM FRIDAY.

WIND ADVISORY UNTIL 600 PM THIS EVENING FOR LANAI...KAHOOLAWE
AND THE SOUTH AND KOHALA AREAS OF THE BIG ISLAND.

SMALL CRAFT ADVISORY UNTIL 600 PM FRIDAY FOR ALL HAWAIIAN
WATERS

&&

DONALDSON