Wildfire in Hawaii, August 14 to 15, 2015

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
1000 AM HST FRI AUG 14 2015

.SYNOPSIS...
LOCALLY HEAVY SHOWERS AND POSSIBLE THUNDERSTORMS ARE POSSIBLE OVER
THE BIG ISLAND TODAY AS MOISTURE ASSOCIATED WITH FORMER TROPICAL
CYCLONE HILDA MOVES ACROSS THE AREA. OTHERWISE PASSING SHOWERS OVER
WINDWARD AND MAUKA AREAS CAN BE EXPECTED. TRADE WINDS WILL REMAIN AT
MODERATE LEVELS THROUGH SATURDAY. WINDS WILL BECOME LIGHTER EARLY
NEXT WEEK AS A TROUGH OF LOW PRESSURE MOVES ACROSS THE AREA.
MOISTURE ASSOCIATED WITH THE TROUGH MAY ALSO CAUSE AN INCREASE IN
SHOWER ACTIVITY OVER SOME AREAS.

&&

.DISCUSSION...
MOISTURE ASSOCIATED WITH FORMER TROPICAL CYCLONE HILDA LINGERS
ACROSS THE AREA. THIS MOISTURE MAY FUEL SOME LOCALLY HEAVY SHOWERS
AND POSSIBLE THUNDERSTORMS OVER THE BIG ISLAND TODAY WHERE A FLASH
FLOOD WATCH REMAINS IN EFFECT. PASSING SHOWERS CAN ALSO BE EXPECTED
OVER WINDWARD AND MAUKA AREAS OVER THE SMALLER ISLANDS AS WELL.

HIGH PRESSURE IS STRENGTHENING FAR TO THE NORTH NORTHEAST OF THE
STATE AND THE REMNANT LOW OF HILDA IS PASSING BY SEVERAL HUNDRED
MILES SOUTH OF THE STATE. THE GRADIENT BETWEEN THE TWO WILL ALLOW
FOR GENERALLY MODERATE TRADE WINDS TODAY THROUGH SATURDAY.

A WEAK TROUGH OF LOW PRESSURE IS SEEN ON SATELLITE IMAGERY SEVERAL
HUNDRED MILES TO THE EAST OF THE STATE. IT IS FORECAST TO CONTINUE
MOVING WESTWARD SOUTH THE HIGH. AS THE TROUGH NEARS THE ISLANDS IT
WILL DISRUPT THE GRADIENT SOUTH OF THE HIGH RESULTING IN LIGHTER
WINDS. LOCAL LAND AND SEA BREEZES WILL BEGIN TO DOMINATE EARLY NEXT
WEEK.

SLIGHTLY DRIER WEATHER IS EXPECTED OVER THE WEEKEND AS THE MOISTURE
FROM HILDA MOVES AWAY FROM THE AREA. BY EARLY NEXT WEEK MOISTURE
ASSOCIATED WITH THE TROUGH ALONG WITH AN UPPER LEVEL LOW
STRENGTHENING AND MOVING CLOSER TO THE STATE WILL LIKELY CAUSE AN
INCREASE IN SHOWER ACTIVITY ACROSS THE AREA. LOCALLY HEAVY RAINFALL
IS A POSSIBILITY BUT ITS STILL A BIT EARLY TO PINPOINT THE DETAILS
AS MUCH WILL DEPEND ON THE LOCATION OF THE UPPER TROUGH AND WHERE
LOW LEVEL MOISTURE IS ENHANCED BY TERRAIN EFFECTS AND DAYTIME
HEATING EFFECTS. HUMIDITY LEVELS WILL ALSO REMAIN ON THE HIGH SIDE
DUE TO WARM TEMPERATURES AND HIGH DEW POINTS.

&&

.AVIATION...
HIGH PRESSURE N OF THE STATE AND THE REMNANTS OF HILDA TO THE S WILL
KEEP A WET TRADE WIND FLOW IN PLACE THROUGH TONIGHT. CLOUDS AND
SHOWERS WILL FAVOR WINDWARD AND MAUKA AREAS...ESPECIALLY ACROSS
ACROSS MAUI AND THE BIG ISLAND WHERE THE MOISTURE DEPTH WILL BE THE
GREATEST. ADDITIONALLY...ISOLATED THUNDERSTORMS WILL BE POSSIBLE
OVER THE BIG ISLAND...PARTICULARLY OVER THE MTN SLOPES.

AIRMET SIERRA IS IN EFFECT FOR MTN OBSC ACROSS PORTIONS OF THE BIG
ISLAND MAUI MOLOKAI AND OAHU. CONDITIONS ARE EXPECTED TO IMPROVE BY
LATE MORNING/EARLY AFTERNOON IN MOST AREAS...BUT WILL LIKELY LINGER
FOR MUCH OF THE DAY OVER WINDWARD SECTIONS OF THE BIG ISLAND.

&&

.MARINE...
THE SMALL CRAFT ADVISORY HAS BEEN EXTENDED THROUGH THE DAY SATURDAY
OVER THE TYPICALLY WINDY WATERS AROUND MAUI COUNTY AND THE BIG
ISLAND AS HIGH PRESSURE STRENGTHENS FAR TO OUR NORTH. THE PRESSURE
GRADIENT IS EXPECTED TO WEAKEN BEGINNING SATURDAY NIGHT AS A WEAK
TROUGH OF LOW PRESSURE BEGINS TO DISRUPT THE TRADES. WINDS ARE
EXPECTED TO REMAIN ON THE LIGHTER SIDE INTO THE MIDDLE OF NEXT WEEK.

NO SIGNIFICANT SWELLS ARE EXPECTED THROUGH THE WEEKEND AND ON
THROUGH THE MIDDLE OF NEXT WEEK WITH SURF HEIGHTS REMAINING WELL
BELOW
ADVISORY LEVELS.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH THROUGH LATE TONIGHT FOR BIG ISLAND.

SMALL CRAFT ADVISORY UNTIL 6 PM HST SATURDAY FOR MAALAEA BAY-
PAILOLO CHANNEL-ALENUIHAHA CHANNEL-BIG ISLAND LEEWARD WATERS-BIG
ISLAND SOUTHEAST WATERS.

&&

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