Small Craft Advisory 33, NWS Honolulu, HI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
830 PM HST SAT JUL 26 2014

.SYNOPSIS...
HIGH PRESSURE RIDGE NORTH OF THE ISLANDS WILL MAINTAIN MODERATE
TRADE WINDS TO THE ISLANDS. SHOWERS CARRIED BY THE WINDS WILL AFFECT
MAINLY WINDWARD AND MAUKA AREAS. WINDS MAY STRENGTHEN SOMEWHAT BY
EARLY NEXT WEEK.

&&

.DISCUSSION...
THE AREA OF MOISTURE THAT IS SUPPOSED TO SPREAD ACROSS THE ISLANDS
THIS EVENING TOOK A PATH FURTHER NORTH EARLIER THIS AFTERNOON.
THEREFORE THE BULK OF THE MOISTURE WILL NOW PASS NORTH MISSING THE
STATE. BUT THEN LATEST SATELLITE IMAGERY STILL SHOWS SOME PART OF
THIS MOISTURE REACHING THE CENTRAL ISLANDS THIS EVENING...AFFECTING
MAINLY OAHU. RADAR DATA ALSO SHOWED A LINE OF SHOWERS MOVING ACROSS
WINDWARD OAHU AT TIME...WHILE MORE SHOWERS WILL REACH OAHU IN THE
NEXT FEW HOURS. IT CERTAINLY FELT A LITTLE MORE MUGGY IN THE OUTDOOR
TODAY...AS DEW POINTS ONCE AGAIN EDGED UP WITH THE INCREASING
MOISTURE. THERE IS AN UPPER LEVEL TROUGH IN THE ISLAND VICINITY THIS
EVENING. THIS RESULTS IN THE AIR MASS BECOMING A LITTLE MORE
UNSTABLE OVER THE STATE. AS SUCH...ATMOSPHERIC CONDITIONS ARE
FAVORABLE FOR WETTING RAIN TO DEVELOP. EXPECT PASSING SHOWERS TO
AFFECT THE ISLANDS THROUGH REST OF THE EVENING INTO EARLY SUNDAY
MORNING...ESPECIALLY FOR OAHU THIS EVENING...THEN KAUAI OVERNIGHT.

A SURFACE HIGH PRESSURE RIDGE WILL REMAIN NORTH OF THE STATE PRETTY
MUCH THROUGH THE COMING WEEK. ALTHOUGH THE RIDGE IS NOT VERY
STRONG...PRESSURE GRADIENT ACROSS THE STATE REMAINS SOMEWHAT TIGHT
AS LOW PRESSURE SYSTEMS PASSING SOUTH OF THE ISLANDS WILL HELP
MAINTAINING THE GRADIENT. REGARDLESS...MODERATE TRADE WINDS WILL
PREVAIL THROUGH NEXT WEEK...AND WILL FLUCTUATE A BIT AT TIMES.
OVERALL...TRADE WIND WEATHER IS TO PREVAIL THROUGH NEXT WEEK...WITH
PASSING SHOWERS AFFECTING MAINLY WINDWARD AND MAUKA AREAS.

LATEST MODEL GUIDANCE STILL SHOWS A DRIER AIR MASS ACROSS THE STATE
BY THE MIDDLE OF NEXT WEEK. THIS WILL BE SHORT-LIVED AS ANOTHER
SURGE OF TROPICAL MOISTURE FROM THE SOUTHEAST IS EXPECTED TOWARDS
THE NEXT WEEKEND. THEREFORE THE STATE MAY SEE MORE STICKY WEATHER
WITH INCREASING SHOWERS.

&&

.AVIATION...
AN AIRMET FOR MOUNTAIN OBSCURATION HAS BEEN ISSUED FOR WINDWARD
OAHU...WHERE A PLUME OF SHOWERS STREAMING OFF MOLOKAI WILL PRODUCE
PERIODS OF MVFR CONDITIONS INTO THE OVERNIGHT PERIOD. ELSEWHERE...
SCATTERED SHOWERS AND ISOLATED MVFR CONDITIONS WILL AFFECT WINDWARD
SLOPES OVERNIGHT AND SUNDAY MORNING. VFR CONDITIONS WILL PREVAIL
ELSEWHERE INCLUDING MOST OF THE TERMINALS. AN AIRMET FOR LOW LEVEL
TURBULENCE MAY BECOME NECESSARY ON SUNDAY...WHEN THE INVERSION IS
FORECAST TO STRENGTHEN ALONG WITH A SLIGHT INCREASE IN THE TRADE
WIND FLOW.

&&

.MARINE...
WINDS MAY INCREASE TO SMALL CRAFT ADVISORY LEVELS BY SUNDAY OR
SUNDAY EVENING ACROSS THE TYPICALLY WINDIER AREAS AROUND MAUI COUNTY
AND THE BIG ISLAND. SMALL CRAFT ADVISORY WIND CONDITIONS MAY PREVAIL
IN THOSE AREAS POSSIBLY THROUGH MUCH OF NEXT WEEK.

A SMALL SSW SWELL MAY PRODUCE A MINOR BUMP ON SOUTH FACING SHORES
THROUGH SUNDAY. SHORT PERIOD TRADE WIND SWELL WILL CONTINUE ACROSS
EAST FACING SHORES...POSSIBLY INCREASING A BIT EARLY NEXT
WEEK IF TRADES STRENGTHEN. NO OTHER SIGNIFICANT SWELLS ARE EXPECTED
THROUGH THE NEXT SEVERAL DAYS.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

AVIATION...JACOBSON
REST...HUI