Drought in Hawaii, June 11 to 30, 2013

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
400 AM HST TUE JUN 11 2013

.SYNOPSIS...
BREEZY TRADE WINDS WILL CONTINUE AT LEAST THROUGH THE WEEKEND...
THOUGH SPEEDS ARE EXPECTED TO PEAK ON THURSDAY AND FRIDAY. MOST LOW
CLOUDS AND SHOWERS WILL BE LIMITED TO LEE SLOPES OF THE BIG ISLAND
EACH AFTERNOON...AND WINDWARD SLOPES ALL DAY. WHERE IT DOES FALL...
RAINFALL SHOULD BE LIGHT. HIGH CLOUDS WILL HIDE MUCH OF THE SKY INTO
FRIDAY.

&&

.DISCUSSION...
SURFACE OBSERVATIONS AROUND THE MAIN HAWAIIAN ISLANDS REPORTED LIGHT
TO MODERATE TRADE WINDS BLOWING...WHILE PRESSURE TRENDS SUGGESTED A
SLIGHT INCREASE IN WIND SPEED THROUGH THE SHORT RUN. HOWEVER...
SOUNDING DATA REPORTED UNIMPRESSIVE AMOUNTS OF MOMENTUM THROUGH THE
DEPTH OF THE MARINE LAYER.

BOTH SOUNDINGS AND SATELLITE ESTIMATES MEASURED SLIGHTLY MORE WATER
VAPOR IN THE LOCAL AIR MASS THAN IS TYPICAL FOR THE SEASON...BUT THE
SATELLITE DATA SHOWED A SOMEWHAT DRIER AIR MASS UPWIND. IN
PRACTICE...MOST PRECIPITATION ACROSS THE STATE WILL BE DRIVEN BY
OROGRAPHIC FORCING THROUGH ESSENTIALLY THE WHOLE FORECAST PERIOD...
SO THE TYPICAL WINDWARD SHOWERS WILL PREVAIL...THOUGH AFTERNOON
CUMULUS BUILDUPS ALSO WILL RECUR OVER LEE SLOPES OF THE BIG ISLAND.
ACCUMULATION SHOULD REMAIN LIGHT THROUGHOUT.

ALOFT...STRONG RIDGING PREVAILED OVER AND EAST OF THE ISLANDS.
GUIDANCE AGREES QUITE CLOSELY THAT THIS RIDGE WILL SHIFT WEST
THROUGH THE WEEK...GRADUALLY PASSING OVERHEAD AND EXERTING A
STABILIZING INFLUENCE ON LOCAL WEATHER. AS SUBSIDENCE INCREASES
CORRESPONDINGLY AT THE SURFACE TO THE NORTHEAST...THE SURFACE HIGH
WILL TIGHTEN THE PRESSURE GRADIENT ACROSS THE STATE SLIGHTLY...
BOOSTING TRADE WIND SPEEDS FROM LATE WEDNESDAY INTO FRIDAY. IF THIS
FORECAST VERIFIES...THEN A WIND ADVISORY POSSIBLY MAY BE NEEDED FOR
SOME AREAS. ONCE THE RIDGE ALOFT PASSES FAR ENOUGH WEST...CONDITIONS
AT THE SURFACE WILL RETURN CLOSER TO THEIR CURRENT STATE. RECENT
SOLUTIONS PREDICT THIS REVERSION TO OCCUR AROUND SATURDAY.

HIGH CLOUDS SKIRTING THE WEST EDGE OF THE RIDGE ALOFT ARE EXPECTED
TO REMAIN SIGNIFICANT THROUGH ABOUT FRIDAY. THEIR MAIN EFFECT WILL
BE TO REDUCE DIURNAL HEATING AND COOLING SOMEWHAT...BUT THEY ALSO
WILL BE QUITE NOTICEABLE.

&&

.MARINE...
A SMALL CRAFT ADVISORY /SCA/ CONTINUES THROUGH FRIDAY FOR TYPICALLY
WINDY WATERS AROUND THE BIG ISLAND AND MAUI. THE ADVISORY LIKELY
WILL EXPAND TO OTHER AREAS AS WIND SPEEDS PEAK AROUND MID-WEEK.

NO SIGNIFICANT SWELLS ARE EXPECTED. SMALL LONG-PERIOD SWELLS FROM
THE SOUTHERN HEMISPHERE WILL BRING SEASONABLY SMALL SURF TO
SOUTH-FACING SHORES THROUGH THE WEEK...AND TRADE WINDS WILL PUSH
SHORT-PERIOD WIND SWELLS TOWARD EAST-FACING SHORES. THERE IS A SMALL
CHANCE THAT THIS WIND SWELL MAY PRODUCE SURF ABOVE THE THRESHOLD FOR
A HIGH SURF ADVISORY ON THURSDAY OR FRIDAY.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
SMALL CRAFT ADVISORY UNTIL 6 PM HST FRIDAY FOR MAALAEA BAY-
PAILOLO CHANNEL-ALENUIHAHA CHANNEL-BIG ISLAND LEEWARD WATERS-BIG
ISLAND SOUTHEAST WATERS.

&&

RYSHKO