Current Conditions
Temp3.8 C
RH11 %
WindSSE 10 mph
RoadOpen
Menu of Text Products for the Hawaiian Islands and the Tropical Pacific/Atlantic Oceans:
Narrow the Menu List
Select Time Limit: 12 hours | 24 hours | 48 hours | 72 hours | No time limit
Select Product Type: All | Routine Bulletins/FCSTS | Warnings/Watches/Advisories | HAWN Weather | Tropical | Marine | Aviation | Daily Obs | Special
Hawaiian Islands Synoptic Discussion and Guidance

316
FXHW60 PHFO 010117
AFDHFO

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
330 PM HST THU JUL 31 2014

.SYNOPSIS...
HIGH PRESSURE FAR NORTH OF THE STATE WILL KEEP TRADE WINDS BLOWING
THROUGH THE WEEKEND AND INTO NEXT WEEK. MOISTURE MOVING ACROSS THE
ISLANDS BEGINNING TONIGHT THROUGH SATURDAY WILL RESULT IN AN
INCREASE IN SHOWERS. DRIER AND MORE STABLE WEATHER IS EXPECTED
THROUGH THE MIDDLE OF NEXT WEEK.

&&

.DISCUSSION...
THE SUBTROPICAL RIDGE FAR NORTH NORTHEAST OF FORECAST AREA REMAINS
IN PLACE THIS AFTERNOON. A STABLE TRADE WIND PATTERN OVER THE MAIN
HAWAIIAN ISLANDS IS RESULTING IN DRY CONDITIONS FOR ALL BUT THE
WETTEST MOUNTAIN SPOTS.

IN THE SHORT TERM FORECAST...THE LEADING EDGE OF AN AREA OF
MOISTURE IS LOCATED JUST EAST OF THE BIG ISLAND THIS AFTERNOON. THIS
MOISTURE IS POISED TO DRIFT UP ACROSS THE WINDWARD BIG ISLAND THIS
EVENING AND OVERNIGHT BRINGING INCREASING CLOUDS AND SHOWERS.
ELSEWHERE ACROSS THE STATE...THE TRADE WINDS WILL REMAIN LARGELY
SHOWER FREE THIS EVENING...DO EXPECT A BUMP IN ISOLATED OR
SCATTERED SHOWER ACTIVITY WINDWARD AREAS...DUE TO DIURNAL EFFECTS.

LOOKING AT FRIDAY...EXPECT HUMIDITY WILL INCREASE DURING THE
DAY FRIDAY ACROSS THE STATE AS THE SLUG OF MOISTURE CONTINUES TO
MOVE IN FROM THE EAST. ALONG WITH THE MUGGIER WEATHER ON
FRIDAY...THERE WILL TEND TO BE MORE CLOUDS AND SHOWERS ALONG
WINDWARD AND MOUNTAIN AREAS. THE WINDWARD BIG ISLAND WILL BE THE
WETTEST AREA...WITH LOCALLY HEAVY SHOWERS A POSSIBILITY
TOMORROW...AS MOISTURE VALUES CLIMB HIGHER THROUGH THE DAY.

FOR FRIDAY NIGHT AND SATURDAY...THE MOISTURE VALUES WILL PEAK OUT
LATE FRIDAY EVENING ON THE BIG ISLAND...AND SATURDAY MORNING ACROSS
THE SMALLER ISLANDS...AND THIS TIMING SHOULD MATCH WITH THE BEST
CHANCES FOR APPRECIABLE RAINFALL. THERE IS MODEST INSTABILITY
FRIDAY NIGHT ACROSS THE STATE...ENOUGH TO MENTION LOCALLY HEAVY
RAINFALL FOR MAINLY WINDWARD AREAS...BUT NOT UNSTABLE ENOUGH FOR A
THREAT OF THUNDERSTORMS. THE THREAT OF FLASH FLOODING LOOKS MINIMAL
AS WELL.

EXPECTED TOTAL RAINFALL AMOUNTS FOR TONIGHT THROUGH
SATURDAY...WINDWARD AREAS OF THE BIG ISLAND 1-3 INCHES...AND
WINDWARD AND MAUKA AREAS OF THE SMALLER ISLANDS GENERALLY AROUND A
HALF AN INCH TO POSSIBLY AS MUCH AS 2 INCHES. OTHER AREAS OF THE
STATE...GENERALLY LESS THAN HALF AN INCH.

FOR NEXT WEEK...DRIER AND MORE STABLE AIR WILL INVADE FROM THE EAST
BY LATE IN THE WEEKEND AS RIDGING ALOFT MOVES OVERHEAD...LIMITING
TRADE SHOWERS. THE MAJORITY OF MODEL GUIDANCE SHOWS A CONTINUED
STABLE TRADE WIND PATTERN FOR THE STATE THROUGH THE MIDDLE OF NEXT
WEEK...KEEPING TROPICAL MOISTURE SOUTH OF THE MAIN HAWAIIAN ISLANDS.

&&

.AVIATION...
VFR CONDITIONS WILL PREVAIL ACROSS THE SMALLER ISLANDS TONIGHT.
ISOLATED MVFR CONDITIONS WILL BE POSSIBLE ACROSS WINDWARD SLOPES OF
THE SMALLER ISLANDS. INCREASING TROPICAL MOISTURE IS FORECAST TO
MOVE INTO THE BIG ISLAND LATER TONIGHT FROM THE EAST...BRINGING THE
POTENTIAL FOR SHOWERS...REDUCED VISIBILITY AND MOUNTAIN
OBSCURATIONS. AIRMET SIERRA MAY BE NEEDED FOR PARTS OF THE BIG
ISLAND AT THAT TIME.

DUE TO CONTINUED MODERATE TO LOCALLY BREEZY TRADE WINDS...AIRMET
TANGO FOR LOW LEVEL TURBULENCE REMAINS IN EFFECT...COVERING THE
AREAS OVER AND IMMEDIATELY SOUTH THROUGH WEST OF THE HIGHER TERRAIN.

&&

.MARINE...
LOCALLY STRONG TRADES WILL CONTINUE TO BRING SMALL CRAFT ADVISORY
CONDITIONS...25 KNOT WINDS AND ROUGH...CHOPPY SEAS...TO THE WATERS
AROUND MAUI COUNTY AND THE BIG ISLAND THROUGH AT LEAST THE WEEKEND.

A SMALL TO MODERATELY LARGE SWELL FROM THE SOUTH-SOUTHWEST SHOULD
ARRIVE OVER THE WEEKEND. OTHERWISE...A SERIES OF SMALL SOUTH SWELLS
WILL KEEP ARRIVING THROUGH NEXT WEEK. PREVAILING TRADE WINDS WILL
CONTINUE TO PRODUCE SHORT-PERIOD...CHOPPY SURF ALONG EAST-FACING
SHORES.


&&

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

&&

$$

DISCUSSION/MARINE...BRENCHLEY
AVIATION...FOSTER



Bulletins, Forecasts and Observations are courtesy of Honolulu National Weather Service Forecast Office