AFDHFO

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
400 AM HST MON JUN 27 2011

.SYNOPSIS...
A SURFACE HIGH TO THE NORTH WILL PRODUCE LOCALLY BREEZY TRADE WINDS
THROUGH TOMORROW MORNING. A LOW ALOFT IS MAKING THE ATMOSPHERE A
BIT UNSTABLE SO SHOWERS WILL BE MORE ACTIVE AND WIDESPREAD TODAY
THROUGH TUESDAY WITH SOME SHOWERS SPREADING LEEWARD OVER THE SMALLER
ISLANDS. THE LOW ALOFT IS ALSO PRODUCING HIGH CLOUDS THAT MAY BE
THICK AT TIMES...BUT WON/T BRING ANY RAIN. THE ATMOSPHERE WILL START
TO STABILIZE TUESDAY NIGHT AS THE LOW ALOFT MOVES AWAY TO THE WEST
AND RIDGING ALOFT BUILDS OVER THE ISLANDS. MEANWHILE...THE SURFACE
HIGH WILL MOVE AWAY TO THE NORTHWEST. THE TRADE WINDS WILL WEAKEN
AND THE WEATHER WILL BECOME QUITE DRY FROM THURSDAY THROUGH NEXT
WEEKEND.

&&

.DISCUSSION...
A 1029 MB SURFACE HIGH ABOUT 1100 MILES NORTH OF KAUAI WILL MOVE
NORTHWEST AND STRENGTHEN OVER THE NEXT FEW DAYS. THIS HIGH WILL
PRODUCE LOCALLY BREEZY TRADE WINDS OVER THE ISLANDS THROUGH TUESDAY
MORNING. THE TRADES ARE CARRYING SHOWERY LOW CLOUDS OVER THE ISLANDS.

UPPER AIR ANALYSES AND WATER VAPOR IMAGERY SHOW A LOW ALOFT 250
MILES NORTH NORTHEAST OF KAUAI NEAR 25N158W. THIS LOW IS FORECAST
TO MOVE WEST SOUTHWEST AND DEEPEN. THE LOW KEEP THE ATMOSPHERE OVER
THE ISLANDS A BIT UNSTABLE...SO SHOWERS ARE LIKELY TO BE MORE ACTIVE
AND WIDESPREAD THROUGH TUESDAY.

RIDGING ALOFT WILL BUILD OVER THE ISLANDS FROM THE SOUTHEAST ON
WEDNESDAY. THE ATMOSPHERE OVER THE ISLANDS WILL BECOME DRIER AND
MORE STABLE AND RAINFALL WILL BECOME SPARSE. AS THE SURFACE HIGH
CONTINUES TO MOVE NORTHWEST...THE SURFACE PRESSURE BETWEEN THE HIGH
AND THE ISLANDS WILL DROP...AND A SURFACE LOW MAY FORM NORTHWEST OF
KAUAI TUESDAY NIGHT. THIS PATTERN WILL DECREASE THE PRESSURE
GRADIENT OVER THE ISLANDS AND THE TRADE WINDS WILL WEAKEN. IN THE
SECOND HALF OF THE WEEK WE SHOULD HAVE GENTLE TO MODERATE TRADE
WINDS AND RATHER WARM DRY WEATHER.

&&

.MARINE...
THE SMALL CRAFT ADVISORY REMAINS UP FOR THE USUAL WINDY AREAS AROUND
MAUI AND THE BIG ISLAND. WINDS ARE LIKELY TO DROP BELOW THE ADVISORY
THRESHOLD TOMORROW AND REMAIN BELOW THE ADVISORY LEVEL THROUGH NEXT
WEEKEND. NO LARGE SWELLS ARE EXPECTED.

&&

.AVIATION...
AIRMET TANGO FOR MODERATE LOW LEVEL TURBULENCE IS IN EFFECT DUE TO
STRONG TRADE WINDS. THIS AIRMET MAY REMAIN UP THROUGH TUESDAY
MORNING.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
SMALL CRAFT ADVISORY UNTIL 600 AM TUESDAY.

&&

$$
DONALDSON