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000
FXHW60 PHFO 211339
AFDHFO

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
339 AM HST MON APR 21 2014

.SYNOPSIS...
STRONG HIGH PRESSURE TO THE NORTH OF THE STATE WILL CREATE LOCALLY
WINDY TRADES TODAY. THE STRONG TRADES WILL CONTINUE TO BLOW PASSING
WINDWARD AND MAUKA SHOWERS OVER INTO LEEWARD AREAS AT TIMES TODAY
INTO TONIGHT. THE TRADES WILL GRADUALLY EASE TUESDAY THROUGH
WEDNESDAY AS HIGH PRESSURE MOVES FURTHER AWAY FROM THE STATE.
DRIER AIR AND FEWER SHOWERS ARE EXPECTED FROM TUESDAY THROUGH THE
REST OF THE WORK WEEK.

&&

.DISCUSSION...
RADAR LOOPS SHOW AN ACTIVE SHOWER PATTERN CONTINUING ACROSS
WINDWARD PORTIONS OF THE STATE DURING THE NIGHT...WITH SOME
SHOWER ACTIVITY SPILLING OVER INTO LEEWARD SECTIONS OF OAHU...
KAUAI AND MOLOKAI. RAIN GAUGES REPORT LIGHT TO LOCALLY MODERATE
ACCUMULATIONS AS THE SHOWERS ARE MOVING QUICKLY WITHIN RATHER
BRISK TRADE WIND FLOW. THE 12Z SOUNDINGS SHOW WEAK INVERSIONS
BASED FROM AROUND 6500 FEET AT LIHUE UP TO 9000 FEET AT HILO. AS
HAS BEEN THE CASE FOR THE PAST COUPLE OF DAYS...ABUNDANT MID/HIGH
LEVEL CLOUDINESS CONTINUES TO STREAM NORTHWARD ACROSS THE
STATE...TO THE EAST OF A STATIONARY MID/UPPER LEVEL TROUGH
CENTERED SEVERAL HUNDRED MILES TO THE SOUTHWEST. AT THE
SURFACE...A 1032 MB HIGH IS CENTERED ABOUT 1050 MILES DUE NORTH OF
THE BIG ISLAND...AND CONTINUES TO MOVE EASTWARD.

THE MAIN FORECAST ISSUE REMAINS GUSTY AND LOCALLY ADVISORY LEVEL
WINDS ACROSS SOME DOWNSLOPE AND EXPOSED HEADLAND/RIDGE AREAS. IN
ADDITION TO KAMUELA WHICH HAS REPORTED SUSTAINED WINDS OF 30 MPH
OR GREATER OFF AND ON FOR THE PAST 12 HOURS OR SO...A FEW OTHER
MESONET SITES ON OAHU...LANAI AND KAHOOLAWE HAVE REPORTED PEAK
WIND GUSTS AT OR JUST BELOW 50 MPH AS WELL. MODEL GUIDANCE...
INCLUDING THE HIGH RESOLUTION UNIVERSITY OF HAWAII WRF MODEL...
DOES STILL INDICATE BOUNDARY LAYER WINDS PEAKING TODAY...WITH 925
MB WINDS REACHING 35 KNOTS OR GREATER IN SOME AREAS. MODEL
SOUNDINGS ALSO SHOW SOME LOWERING AND STRENGTHENING OF THE
INVERSION DURING THIS TIME...ALTHOUGH THIS SEEMS SOMEWHAT
QUESTIONABLE GIVEN THE WEAK INVERSIONS OBSERVED BY THE 12Z
SOUNDINGS. WILL LEAVE THE WIND ADVISORY IN PLACE FOR TODAY WITH
NO COVERAGE CHANGES...ALTHOUGH IT SEEMS LIKELY THAT THE STRONGEST
WIND GUSTS OF 50 MPH OR GREATER WILL REMAIN FAIRLY ISOLATED.
IT SHOULD BE REITERATED THAT THE STRONGEST WINDS WILL NOT
AFFECT ENTIRE FORECAST ZONES...BUT INSTEAD ONLY SPECIFIC FAVORED
AREAS IMMEDIATELY DOWNSLOPE OF THE SMALLER MOUNTAIN RANGES AND
OVER SOME RIDGES AND HEADLANDS.

THE TRADES SHOULD GRADUALLY RELAX TO MORE MODERATE LEVELS TUESDAY
THROUGH WEDNESDAY AS THE SURFACE HIGH MOVES FURTHER NORTHEAST AND
AWAY FROM THE STATE. ANOTHER WEAKER HIGH WILL BUILD TO THE NORTH
OF OUR AREA WEDNESDAY THROUGH THURSDAY...BUT WOULD NOT EXPECT ANY
SIGNIFICANT WIND PROBLEMS. A STATIC PATTERN WILL THEN DEVELOP
ACROSS THE CENTRAL PACIFIC FOR THE LATE WEEK INTO THE WEEKEND...
WITH AN EAST-WEST HIGH PRESSURE RIDGE NORTH OF THE STATE AND
MODERATE TRADES PREVAILING ACROSS HAWAII.

AS FOR RAIN CHANCES...THE AREA OF HIGHER MOISTURE CURRENTLY ACROSS
HAWAII IS FORECAST TO SHIFT WEST OF THE STATE BY LATE TONIGHT
OR TUESDAY MORNING...WITH A DRIER AIRMASS THEN PREVAILING THROUGH
THE REST OF THE WEEK. THEREFORE WOULD EXPECT ANOTHER 24 HOURS OR
SO OF A MORE ACTIVE WINDWARD/MAUKA SHOWER PATTERN WITH SOME
LEEWARD SPILLOVER.. FOLLOWED BY MORE LIMITED SHOWER COVERAGE
FOCUSING ON WINDWARD AND MAUKA AREAS THEREAFTER.

&&

.AVIATION...
AIRMET TANGO WILL CONTINUE TODAY FOR THE MODERATE TO STRONG TRADES
ACROSS THE REGION...PRODUCING MECHANICAL TURBULENCE TO THE LEE OF
THE MOUNTAINS. AN UPPER LEVEL AIRMET CONTINUES ACROSS THE ISLANDS
DUE TO MODERATE TO STRONG SPEED AND DIRECTIONAL WIND SHEAR. THE
UPPER LEVEL CONDITIONS ARE EXPECTED TO IMPROVE AS THE DAY
PROGRESSES.

CLOUDS AND SHOWERS BEING CARRIED IN ON THE TRADES WILL BRING MVFR
AND ISOLATED IFR CONDITIONS TO WINDWARD AND MOUNTAIN AREAS. AIRMET
SIERRA HAS BEEN POSTED FOR MOUNTAIN OBSCURATION IN THESE AREAS.
IMPROVED CONDITIONS ARE POSSIBLE LATER TODAY.

&&

.MARINE...
THE SMALL CRAFT ADVISORY HAS BEEN EXTENDED THROUGH 6 AM TUESDAY
MORNING FOR ALL HAWAIIAN COASTAL WATERS. THE OVERNIGHT ASCAT PASS
MISSED THE COASTAL WATERS...BUT AVAILABLE LAND OBS AND MODEL DATA
INCLUDING THE UH-WRF SUGGEST THAT WINDS ARE LIKELY AROUND 25 KNOTS
ACROSS AT LEAST PARTS OF MOST ZONES. WINDS ARE FORECAST TO PEAK
JUST BELOW 30 KNOTS IN THE ALENUIHAHA CHANNEL TODAY. WINDS SHOULD
SLOWLY SUBSIDE TUESDAY THROUGH WEDNESDAY.

THE LATEST WAVEWATCH DATA CONTINUES TO SHOW BUILDING SHORT PERIOD
EASTERLY SWELL FOR TODAY...WHICH MAKES SENSE AS THE FETCH LENGTH
INTO HAWAII INCREASES DUE TO THE MOVEMENT OF THE STRONG HIGH TO
OUR NORTH. A HIGH SURF ADVISORY FOR EAST FACING SHORES REMAINS IN
EFFECT THROUGH TUESDAY. NO PROBLEMS THROUGH THE WEEK FOR THE OTHER
SHORES...WITH SMALL NORTHWEST SWELL THROUGH TUESDAY. THE NEXT
MODERATE NORTHWEST SWELL WILL ARRIVE WEDNESDAY AND CONTINUE
THROUGH FRIDAY...BUT THE RESULTING SURF ON NORTH/WEST FACING
SHORES WILL REMAIN WELL BELOW ADVISORY LEVELS.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 6 PM HST THIS EVENING FOR WAIANAE COAST-OAHU
KOOLAU-OLOMANA-WAIANAE MOUNTAINS-LANAI-KAHOOLAWE-MAUI WINDWARD
WEST-MAUI LEEWARD WEST-MAUI CENTRAL VALLEY-SOUTH BIG ISLAND-BIG
ISLAND NORTH AND EAST-KOHALA-BIG ISLAND INTERIOR.

HIGH SURF ADVISORY UNTIL 6 PM HST TUESDAY FOR KAUAI WINDWARD-
OAHU KOOLAU-OLOMANA-MOLOKAI WINDWARD-MAUI WINDWARD WEST-WINDWARD
HALEAKALA-SOUTH BIG ISLAND-BIG ISLAND NORTH AND EAST.

SMALL CRAFT ADVISORY UNTIL 6 AM HST TUESDAY FOR ALL HAWAIIAN
WATERS.

&&

$$

JACOBSON








000
FXHW60 PHFO 211339
AFDHFO

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
339 AM HST MON APR 21 2014

.SYNOPSIS...
STRONG HIGH PRESSURE TO THE NORTH OF THE STATE WILL CREATE LOCALLY
WINDY TRADES TODAY. THE STRONG TRADES WILL CONTINUE TO BLOW PASSING
WINDWARD AND MAUKA SHOWERS OVER INTO LEEWARD AREAS AT TIMES TODAY
INTO TONIGHT. THE TRADES WILL GRADUALLY EASE TUESDAY THROUGH
WEDNESDAY AS HIGH PRESSURE MOVES FURTHER AWAY FROM THE STATE.
DRIER AIR AND FEWER SHOWERS ARE EXPECTED FROM TUESDAY THROUGH THE
REST OF THE WORK WEEK.

&&

.DISCUSSION...
RADAR LOOPS SHOW AN ACTIVE SHOWER PATTERN CONTINUING ACROSS
WINDWARD PORTIONS OF THE STATE DURING THE NIGHT...WITH SOME
SHOWER ACTIVITY SPILLING OVER INTO LEEWARD SECTIONS OF OAHU...
KAUAI AND MOLOKAI. RAIN GAUGES REPORT LIGHT TO LOCALLY MODERATE
ACCUMULATIONS AS THE SHOWERS ARE MOVING QUICKLY WITHIN RATHER
BRISK TRADE WIND FLOW. THE 12Z SOUNDINGS SHOW WEAK INVERSIONS
BASED FROM AROUND 6500 FEET AT LIHUE UP TO 9000 FEET AT HILO. AS
HAS BEEN THE CASE FOR THE PAST COUPLE OF DAYS...ABUNDANT MID/HIGH
LEVEL CLOUDINESS CONTINUES TO STREAM NORTHWARD ACROSS THE
STATE...TO THE EAST OF A STATIONARY MID/UPPER LEVEL TROUGH
CENTERED SEVERAL HUNDRED MILES TO THE SOUTHWEST. AT THE
SURFACE...A 1032 MB HIGH IS CENTERED ABOUT 1050 MILES DUE NORTH OF
THE BIG ISLAND...AND CONTINUES TO MOVE EASTWARD.

THE MAIN FORECAST ISSUE REMAINS GUSTY AND LOCALLY ADVISORY LEVEL
WINDS ACROSS SOME DOWNSLOPE AND EXPOSED HEADLAND/RIDGE AREAS. IN
ADDITION TO KAMUELA WHICH HAS REPORTED SUSTAINED WINDS OF 30 MPH
OR GREATER OFF AND ON FOR THE PAST 12 HOURS OR SO...A FEW OTHER
MESONET SITES ON OAHU...LANAI AND KAHOOLAWE HAVE REPORTED PEAK
WIND GUSTS AT OR JUST BELOW 50 MPH AS WELL. MODEL GUIDANCE...
INCLUDING THE HIGH RESOLUTION UNIVERSITY OF HAWAII WRF MODEL...
DOES STILL INDICATE BOUNDARY LAYER WINDS PEAKING TODAY...WITH 925
MB WINDS REACHING 35 KNOTS OR GREATER IN SOME AREAS. MODEL
SOUNDINGS ALSO SHOW SOME LOWERING AND STRENGTHENING OF THE
INVERSION DURING THIS TIME...ALTHOUGH THIS SEEMS SOMEWHAT
QUESTIONABLE GIVEN THE WEAK INVERSIONS OBSERVED BY THE 12Z
SOUNDINGS. WILL LEAVE THE WIND ADVISORY IN PLACE FOR TODAY WITH
NO COVERAGE CHANGES...ALTHOUGH IT SEEMS LIKELY THAT THE STRONGEST
WIND GUSTS OF 50 MPH OR GREATER WILL REMAIN FAIRLY ISOLATED.
IT SHOULD BE REITERATED THAT THE STRONGEST WINDS WILL NOT
AFFECT ENTIRE FORECAST ZONES...BUT INSTEAD ONLY SPECIFIC FAVORED
AREAS IMMEDIATELY DOWNSLOPE OF THE SMALLER MOUNTAIN RANGES AND
OVER SOME RIDGES AND HEADLANDS.

THE TRADES SHOULD GRADUALLY RELAX TO MORE MODERATE LEVELS TUESDAY
THROUGH WEDNESDAY AS THE SURFACE HIGH MOVES FURTHER NORTHEAST AND
AWAY FROM THE STATE. ANOTHER WEAKER HIGH WILL BUILD TO THE NORTH
OF OUR AREA WEDNESDAY THROUGH THURSDAY...BUT WOULD NOT EXPECT ANY
SIGNIFICANT WIND PROBLEMS. A STATIC PATTERN WILL THEN DEVELOP
ACROSS THE CENTRAL PACIFIC FOR THE LATE WEEK INTO THE WEEKEND...
WITH AN EAST-WEST HIGH PRESSURE RIDGE NORTH OF THE STATE AND
MODERATE TRADES PREVAILING ACROSS HAWAII.

AS FOR RAIN CHANCES...THE AREA OF HIGHER MOISTURE CURRENTLY ACROSS
HAWAII IS FORECAST TO SHIFT WEST OF THE STATE BY LATE TONIGHT
OR TUESDAY MORNING...WITH A DRIER AIRMASS THEN PREVAILING THROUGH
THE REST OF THE WEEK. THEREFORE WOULD EXPECT ANOTHER 24 HOURS OR
SO OF A MORE ACTIVE WINDWARD/MAUKA SHOWER PATTERN WITH SOME
LEEWARD SPILLOVER.. FOLLOWED BY MORE LIMITED SHOWER COVERAGE
FOCUSING ON WINDWARD AND MAUKA AREAS THEREAFTER.

&&

.AVIATION...
AIRMET TANGO WILL CONTINUE TODAY FOR THE MODERATE TO STRONG TRADES
ACROSS THE REGION...PRODUCING MECHANICAL TURBULENCE TO THE LEE OF
THE MOUNTAINS. AN UPPER LEVEL AIRMET CONTINUES ACROSS THE ISLANDS
DUE TO MODERATE TO STRONG SPEED AND DIRECTIONAL WIND SHEAR. THE
UPPER LEVEL CONDITIONS ARE EXPECTED TO IMPROVE AS THE DAY
PROGRESSES.

CLOUDS AND SHOWERS BEING CARRIED IN ON THE TRADES WILL BRING MVFR
AND ISOLATED IFR CONDITIONS TO WINDWARD AND MOUNTAIN AREAS. AIRMET
SIERRA HAS BEEN POSTED FOR MOUNTAIN OBSCURATION IN THESE AREAS.
IMPROVED CONDITIONS ARE POSSIBLE LATER TODAY.

&&

.MARINE...
THE SMALL CRAFT ADVISORY HAS BEEN EXTENDED THROUGH 6 AM TUESDAY
MORNING FOR ALL HAWAIIAN COASTAL WATERS. THE OVERNIGHT ASCAT PASS
MISSED THE COASTAL WATERS...BUT AVAILABLE LAND OBS AND MODEL DATA
INCLUDING THE UH-WRF SUGGEST THAT WINDS ARE LIKELY AROUND 25 KNOTS
ACROSS AT LEAST PARTS OF MOST ZONES. WINDS ARE FORECAST TO PEAK
JUST BELOW 30 KNOTS IN THE ALENUIHAHA CHANNEL TODAY. WINDS SHOULD
SLOWLY SUBSIDE TUESDAY THROUGH WEDNESDAY.

THE LATEST WAVEWATCH DATA CONTINUES TO SHOW BUILDING SHORT PERIOD
EASTERLY SWELL FOR TODAY...WHICH MAKES SENSE AS THE FETCH LENGTH
INTO HAWAII INCREASES DUE TO THE MOVEMENT OF THE STRONG HIGH TO
OUR NORTH. A HIGH SURF ADVISORY FOR EAST FACING SHORES REMAINS IN
EFFECT THROUGH TUESDAY. NO PROBLEMS THROUGH THE WEEK FOR THE OTHER
SHORES...WITH SMALL NORTHWEST SWELL THROUGH TUESDAY. THE NEXT
MODERATE NORTHWEST SWELL WILL ARRIVE WEDNESDAY AND CONTINUE
THROUGH FRIDAY...BUT THE RESULTING SURF ON NORTH/WEST FACING
SHORES WILL REMAIN WELL BELOW ADVISORY LEVELS.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 6 PM HST THIS EVENING FOR WAIANAE COAST-OAHU
KOOLAU-OLOMANA-WAIANAE MOUNTAINS-LANAI-KAHOOLAWE-MAUI WINDWARD
WEST-MAUI LEEWARD WEST-MAUI CENTRAL VALLEY-SOUTH BIG ISLAND-BIG
ISLAND NORTH AND EAST-KOHALA-BIG ISLAND INTERIOR.

HIGH SURF ADVISORY UNTIL 6 PM HST TUESDAY FOR KAUAI WINDWARD-
OAHU KOOLAU-OLOMANA-MOLOKAI WINDWARD-MAUI WINDWARD WEST-WINDWARD
HALEAKALA-SOUTH BIG ISLAND-BIG ISLAND NORTH AND EAST.

SMALL CRAFT ADVISORY UNTIL 6 AM HST TUESDAY FOR ALL HAWAIIAN
WATERS.

&&

$$

JACOBSON









000
FXHW60 PHFO 210632
AFDHFO

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
832 PM HST SUN APR 20 2014

.SYNOPSIS...
STRONG HIGH PRESSURE TO THE NORTH OF THE STATE WILL CREATE LOCALLY
WINDY TRADES TONIGHT AND MONDAY. THE TRADES WILL EASE OFF A BIT AS
THE HIGH MOVES AWAY BY MIDWEEK. THE STRONG TRADES WILL CONTINUE TO
BLOW PASSING WINDWARD AND MAUKA SHOWERS OVER TO LEEWARD SIDES AT
TIMES THROUGH MONDAY OR MONDAY NIGHT. DRIER AIR AND FEWER SHOWERS
ARE EXPECTED FROM TUESDAY THROUGH THE REST OF THE WORK WEEK.

&&

.DISCUSSION...
RADAR LOOPS SHOW AN ACTIVE SHOWER PATTERN ACROSS WINDWARD PORTIONS
OF THE STATE DURING THE PAST SEVERAL HOURS...WITH SOME SHOWER
ACTIVITY SPILLING OVER INTO LEEWARD SECTIONS. RAIN GAUGES REPORT
MOSTLY LIGHT ACCUMULATIONS AS THE SHOWERS ARE MOVING QUICKLY
WITHIN RATHER BRISK TRADE WIND FLOW. THE 00Z SOUNDINGS SHOW WEAK
INVERSIONS BASED AROUND 7000 FEET...WITH AN OVERALL INCREASE IN
COLUMN MOISTURE DURING THE PREVIOUS 12 HOURS. PWATS HAVE INCREASED
TO AROUND THE 75TH PERCENTILE FOR THIS TIME OF YEAR. THIS IS
CONSISTENT WITH MIMIC-TPW SATELLITE IMAGERY...WHICH SHOWS AN AREA
OF RELATIVELY HIGHER MOISTURE MOVING WESTWARD THROUGH THE REGION.
AS HAS BEEN THE CASE FOR THE PAST COUPLE OF DAYS...ABUNDANT
MID/HIGH LEVEL CLOUDINESS CONTINUES TO STREAM NORTHWARD ACROSS THE
STATE...TO THE EAST OF A STATIONARY MID/UPPER LEVEL TROUGH
CENTERED SEVERAL HUNDRED MILES TO THE SOUTHWEST. AT THE
SURFACE...A 1032 MB HIGH IS NOW CENTERED ABOUT 1200 MILES DUE
NORTH OF THE BIG ISLAND...AND CONTINUES TO MOVE EASTWARD.

THE MAIN FORECAST ISSUE REMAINS THE POTENTIAL FOR GUSTY ADVISORY
LEVEL WINDS ACROSS SOME DOWNSLOPE AND EXPOSED HEADLAND AREAS. ONLY
KAMUELA IS REPORTING SUSTAINED WINDS OF 30 MPH OR GREATER AT THIS
TIME...ALTHOUGH SEVERAL OTHER SITES HAVE RECORDED WIND GUSTS IN THE
40S DURING THE PAST FEW HOURS. MODEL GUIDANCE...INCLUDING THE HIGH
RESOLUTION UNIVERSITY OF HAWAII WRF MODEL...DOES STILL INDICATE AN
INCREASE IN BOUNDARY LAYER WINDS LATE TONIGHT INTO MONDAY...WITH
925 MB WINDS REACHING AROUND 35 KNOTS IN SOME AREAS. MODEL
SOUNDINGS ALSO SHOW SOME LOWERING AND STRENGTHENING OF THE
INVERSION DURING THIS TIME...LIKELY IN RESPONSE TO A MID LEVEL
RIDGE BUILDING NORTH OF THE STATE. WILL LEAVE THE WIND ADVISORY
UNCHANGED AT THIS TIME. AGAIN...IT SHOULD BE REITERATED THAT
THE STRONGER WINDS WILL MAINLY AFFECT ONLY SPECIFIC AREAS
IMMEDIATELY DOWNWIND OF THE SMALLER MOUNTAIN RANGES AND OVER
HEADLANDS...WHILE MANY OTHER AREAS WILL SEE CONSIDERABLY LOWER
WIND SPEEDS.

THE TRADES SHOULD RELAX TO MORE MODERATE LEVELS TUESDAY AND
WEDNESDAY AS THE SURFACE HIGH MOVES FURTHER NORTHEAST AND AWAY
FROM THE STATE. ANOTHER WEAKER HIGH WILL BUILD TO THE NORTH OF
OUR AREA WEDNESDAY THROUGH THURSDAY...BUT WOULD NOT EXPECT ANY
SIGNIFICANT WIND PROBLEMS. A STATIC PATTERN WILL THEN DEVELOP
ACROSS THE CENTRAL PACIFIC FOR THE LATE WEEK INTO THE WEEKEND...
WITH AN EAST-WEST HIGH PRESSURE RIDGE NORTH OF THE STATE AND
MODERATE TRADES PREVAILING ACROSS HAWAII.

AS FOR RAIN CHANCES...THE AREA OF HIGHER MOISTURE IS FORECAST TO
SHIFT WEST OF THE STATE BY LATE MONDAY NIGHT OR TUESDAY...WITH A
DRIER AIRMASS THEN PREVAILING THROUGH THE REST OF THE WEEK.
THEREFORE WOULD EXPECT ANOTHER 24 TO 36 HOURS OF A MORE ACTIVE
WINDWARD/MAUKA SHOWER PATTERN WITH SOME LEEWARD SPILLOVER..
FOLLOWED BY MORE LIMITED SHOWER COVERAGE FOCUSING ON WINDWARD AND
MAUKA AREAS THEREAFTER.

&&

.AVIATION...
MODERATE TO STRONG TRADES CONTINUE...SO TO DOES AIRMET TANGO FOR
MECHANICAL TURBULENCE DOWNWIND OF THE MOUNTAINS. THE UPPER LEVEL
TROUGH PASSING OVER THE ISLANDS IS ALSO PRODUCING MODERATE
TURBULENCE AT THE UPPER LEVELS OVER THE ISLANDS. AN AIRMET FOR THIS
TURBULENCE OVER THE ISLANDS HAS BEEN POSTED AND WILL CONTINUE AT
LEAST THROUGH THE NIGHT.

CLOUDS AND SHOWERS BEING CARRIED IN ON THE TRADES WILL BRING MVFR
AND ISOLATED IFR CONDITIONS TO WINDWARD AND MOUNTAIN AREAS. AIRMET
SIERRA HAS BEEN POSTED FOR MOUNTAIN OBSCURATION IN THESE AREAS
OVERNIGHT.

&&

.MARINE...
A 2118Z ASCAT PASS REVEALED 25 KNOT WINDS PREVAILING IN THE
CHANNELS AND IN SOME OF THE OTHER TYPICALLY WINDIER AREAS AROUND
THE HAWAIIAN COASTAL WATERS. THE UH-WRF MODEL INDICATES THAT
WINDS HAVE LIKELY INCREASED FURTHER SINCE 21Z...AND THE SMALL
CRAFT ADVISORY REMAINS POSTED FOR ALL COASTAL WATERS. THE SCA WILL
VERY LIKELY NEED TO BE EXTENDED BEYOND THE CURRENT EXPIRATION TIME
OF 6 PM MONDAY. THERE IS A CHANCE THAT A GALE WARNING COULD BE
NEEDED ON MONDAY IN THE ALENUIHAHA CHANNEL...WITH THE 12Z WRF RUN
SHOWING SUSTAINED WINDS PEAKING AROUND 30 KNOTS IN THE AFTERNOON.
WILL AWAIT FURTHER 00Z CYCLE MODEL DATA BEFORE MAKING A DECISION
ON THIS WITH THE EARLY MONDAY MORNING FORECAST PACKAGE.

THE LATEST WAVEWATCH DATA CONTINUES TO SHOW INCREASING SHORT
PERIOD EASTERLY SWELL FOR TONIGHT AND MONDAY...WHICH MAKES SENSE
AS THE FETCH LENGTH INTO HAWAII INCREASES DUE TO THE MOVEMENT OF
THE STRONG HIGH TO OUR NORTH. A HIGH SURF ADVISORY FOR EAST FACING
SHORES WAS ISSUED EARLIER TODAY AND WILL REMAIN IN EFFECT THROUGH
TUESDAY. NO PROBLEMS THROUGH THE WEEK FOR THE OTHER SHORES...WITH
SMALL NORTHWEST SWELL THROUGH TUESDAY. THE NEXT MODERATE NORTHWEST
SWELL WILL ARRIVE WEDNESDAY AND CONTINUE THROUGH FRIDAY...BUT THE
RESULTING SURF ON NORTH/WEST FACING SHORES WILL REMAIN WELL BELOW
ADVISORY LEVELS.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 6 PM HST MONDAY FOR WAIANAE COAST-OAHU
KOOLAU-OLOMANA-WAIANAE MOUNTAINS-LANAI-KAHOOLAWE-MAUI WINDWARD
WEST-MAUI LEEWARD WEST-MAUI CENTRAL VALLEY-SOUTH BIG ISLAND-BIG
ISLAND NORTH AND EAST-KOHALA-BIG ISLAND INTERIOR.

HIGH SURF ADVISORY UNTIL 6 PM HST TUESDAY FOR KAUAI WINDWARD-
OAHU KOOLAU-OLOMANA-MOLOKAI WINDWARD-MAUI WINDWARD WEST-WINDWARD
HALEAKALA-SOUTH BIG ISLAND-BIG ISLAND NORTH AND EAST.

SMALL CRAFT ADVISORY UNTIL 6 PM HST MONDAY FOR ALL HAWAIIAN
WATERS.

&&

$$

DISCUSSION/MARINE...JACOBSON
AVIATION...M BALLARD









000
FXHW60 PHFO 210632
AFDHFO

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
832 PM HST SUN APR 20 2014

.SYNOPSIS...
STRONG HIGH PRESSURE TO THE NORTH OF THE STATE WILL CREATE LOCALLY
WINDY TRADES TONIGHT AND MONDAY. THE TRADES WILL EASE OFF A BIT AS
THE HIGH MOVES AWAY BY MIDWEEK. THE STRONG TRADES WILL CONTINUE TO
BLOW PASSING WINDWARD AND MAUKA SHOWERS OVER TO LEEWARD SIDES AT
TIMES THROUGH MONDAY OR MONDAY NIGHT. DRIER AIR AND FEWER SHOWERS
ARE EXPECTED FROM TUESDAY THROUGH THE REST OF THE WORK WEEK.

&&

.DISCUSSION...
RADAR LOOPS SHOW AN ACTIVE SHOWER PATTERN ACROSS WINDWARD PORTIONS
OF THE STATE DURING THE PAST SEVERAL HOURS...WITH SOME SHOWER
ACTIVITY SPILLING OVER INTO LEEWARD SECTIONS. RAIN GAUGES REPORT
MOSTLY LIGHT ACCUMULATIONS AS THE SHOWERS ARE MOVING QUICKLY
WITHIN RATHER BRISK TRADE WIND FLOW. THE 00Z SOUNDINGS SHOW WEAK
INVERSIONS BASED AROUND 7000 FEET...WITH AN OVERALL INCREASE IN
COLUMN MOISTURE DURING THE PREVIOUS 12 HOURS. PWATS HAVE INCREASED
TO AROUND THE 75TH PERCENTILE FOR THIS TIME OF YEAR. THIS IS
CONSISTENT WITH MIMIC-TPW SATELLITE IMAGERY...WHICH SHOWS AN AREA
OF RELATIVELY HIGHER MOISTURE MOVING WESTWARD THROUGH THE REGION.
AS HAS BEEN THE CASE FOR THE PAST COUPLE OF DAYS...ABUNDANT
MID/HIGH LEVEL CLOUDINESS CONTINUES TO STREAM NORTHWARD ACROSS THE
STATE...TO THE EAST OF A STATIONARY MID/UPPER LEVEL TROUGH
CENTERED SEVERAL HUNDRED MILES TO THE SOUTHWEST. AT THE
SURFACE...A 1032 MB HIGH IS NOW CENTERED ABOUT 1200 MILES DUE
NORTH OF THE BIG ISLAND...AND CONTINUES TO MOVE EASTWARD.

THE MAIN FORECAST ISSUE REMAINS THE POTENTIAL FOR GUSTY ADVISORY
LEVEL WINDS ACROSS SOME DOWNSLOPE AND EXPOSED HEADLAND AREAS. ONLY
KAMUELA IS REPORTING SUSTAINED WINDS OF 30 MPH OR GREATER AT THIS
TIME...ALTHOUGH SEVERAL OTHER SITES HAVE RECORDED WIND GUSTS IN THE
40S DURING THE PAST FEW HOURS. MODEL GUIDANCE...INCLUDING THE HIGH
RESOLUTION UNIVERSITY OF HAWAII WRF MODEL...DOES STILL INDICATE AN
INCREASE IN BOUNDARY LAYER WINDS LATE TONIGHT INTO MONDAY...WITH
925 MB WINDS REACHING AROUND 35 KNOTS IN SOME AREAS. MODEL
SOUNDINGS ALSO SHOW SOME LOWERING AND STRENGTHENING OF THE
INVERSION DURING THIS TIME...LIKELY IN RESPONSE TO A MID LEVEL
RIDGE BUILDING NORTH OF THE STATE. WILL LEAVE THE WIND ADVISORY
UNCHANGED AT THIS TIME. AGAIN...IT SHOULD BE REITERATED THAT
THE STRONGER WINDS WILL MAINLY AFFECT ONLY SPECIFIC AREAS
IMMEDIATELY DOWNWIND OF THE SMALLER MOUNTAIN RANGES AND OVER
HEADLANDS...WHILE MANY OTHER AREAS WILL SEE CONSIDERABLY LOWER
WIND SPEEDS.

THE TRADES SHOULD RELAX TO MORE MODERATE LEVELS TUESDAY AND
WEDNESDAY AS THE SURFACE HIGH MOVES FURTHER NORTHEAST AND AWAY
FROM THE STATE. ANOTHER WEAKER HIGH WILL BUILD TO THE NORTH OF
OUR AREA WEDNESDAY THROUGH THURSDAY...BUT WOULD NOT EXPECT ANY
SIGNIFICANT WIND PROBLEMS. A STATIC PATTERN WILL THEN DEVELOP
ACROSS THE CENTRAL PACIFIC FOR THE LATE WEEK INTO THE WEEKEND...
WITH AN EAST-WEST HIGH PRESSURE RIDGE NORTH OF THE STATE AND
MODERATE TRADES PREVAILING ACROSS HAWAII.

AS FOR RAIN CHANCES...THE AREA OF HIGHER MOISTURE IS FORECAST TO
SHIFT WEST OF THE STATE BY LATE MONDAY NIGHT OR TUESDAY...WITH A
DRIER AIRMASS THEN PREVAILING THROUGH THE REST OF THE WEEK.
THEREFORE WOULD EXPECT ANOTHER 24 TO 36 HOURS OF A MORE ACTIVE
WINDWARD/MAUKA SHOWER PATTERN WITH SOME LEEWARD SPILLOVER..
FOLLOWED BY MORE LIMITED SHOWER COVERAGE FOCUSING ON WINDWARD AND
MAUKA AREAS THEREAFTER.

&&

.AVIATION...
MODERATE TO STRONG TRADES CONTINUE...SO TO DOES AIRMET TANGO FOR
MECHANICAL TURBULENCE DOWNWIND OF THE MOUNTAINS. THE UPPER LEVEL
TROUGH PASSING OVER THE ISLANDS IS ALSO PRODUCING MODERATE
TURBULENCE AT THE UPPER LEVELS OVER THE ISLANDS. AN AIRMET FOR THIS
TURBULENCE OVER THE ISLANDS HAS BEEN POSTED AND WILL CONTINUE AT
LEAST THROUGH THE NIGHT.

CLOUDS AND SHOWERS BEING CARRIED IN ON THE TRADES WILL BRING MVFR
AND ISOLATED IFR CONDITIONS TO WINDWARD AND MOUNTAIN AREAS. AIRMET
SIERRA HAS BEEN POSTED FOR MOUNTAIN OBSCURATION IN THESE AREAS
OVERNIGHT.

&&

.MARINE...
A 2118Z ASCAT PASS REVEALED 25 KNOT WINDS PREVAILING IN THE
CHANNELS AND IN SOME OF THE OTHER TYPICALLY WINDIER AREAS AROUND
THE HAWAIIAN COASTAL WATERS. THE UH-WRF MODEL INDICATES THAT
WINDS HAVE LIKELY INCREASED FURTHER SINCE 21Z...AND THE SMALL
CRAFT ADVISORY REMAINS POSTED FOR ALL COASTAL WATERS. THE SCA WILL
VERY LIKELY NEED TO BE EXTENDED BEYOND THE CURRENT EXPIRATION TIME
OF 6 PM MONDAY. THERE IS A CHANCE THAT A GALE WARNING COULD BE
NEEDED ON MONDAY IN THE ALENUIHAHA CHANNEL...WITH THE 12Z WRF RUN
SHOWING SUSTAINED WINDS PEAKING AROUND 30 KNOTS IN THE AFTERNOON.
WILL AWAIT FURTHER 00Z CYCLE MODEL DATA BEFORE MAKING A DECISION
ON THIS WITH THE EARLY MONDAY MORNING FORECAST PACKAGE.

THE LATEST WAVEWATCH DATA CONTINUES TO SHOW INCREASING SHORT
PERIOD EASTERLY SWELL FOR TONIGHT AND MONDAY...WHICH MAKES SENSE
AS THE FETCH LENGTH INTO HAWAII INCREASES DUE TO THE MOVEMENT OF
THE STRONG HIGH TO OUR NORTH. A HIGH SURF ADVISORY FOR EAST FACING
SHORES WAS ISSUED EARLIER TODAY AND WILL REMAIN IN EFFECT THROUGH
TUESDAY. NO PROBLEMS THROUGH THE WEEK FOR THE OTHER SHORES...WITH
SMALL NORTHWEST SWELL THROUGH TUESDAY. THE NEXT MODERATE NORTHWEST
SWELL WILL ARRIVE WEDNESDAY AND CONTINUE THROUGH FRIDAY...BUT THE
RESULTING SURF ON NORTH/WEST FACING SHORES WILL REMAIN WELL BELOW
ADVISORY LEVELS.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 6 PM HST MONDAY FOR WAIANAE COAST-OAHU
KOOLAU-OLOMANA-WAIANAE MOUNTAINS-LANAI-KAHOOLAWE-MAUI WINDWARD
WEST-MAUI LEEWARD WEST-MAUI CENTRAL VALLEY-SOUTH BIG ISLAND-BIG
ISLAND NORTH AND EAST-KOHALA-BIG ISLAND INTERIOR.

HIGH SURF ADVISORY UNTIL 6 PM HST TUESDAY FOR KAUAI WINDWARD-
OAHU KOOLAU-OLOMANA-MOLOKAI WINDWARD-MAUI WINDWARD WEST-WINDWARD
HALEAKALA-SOUTH BIG ISLAND-BIG ISLAND NORTH AND EAST.

SMALL CRAFT ADVISORY UNTIL 6 PM HST MONDAY FOR ALL HAWAIIAN
WATERS.

&&

$$

DISCUSSION/MARINE...JACOBSON
AVIATION...M BALLARD








000
FXHW60 PHFO 210134
AFDHFO

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
334 PM HST SUN APR 20 2014

.SYNOPSIS...
STRONG HIGH PRESSURE TO THE NORTH OF THE STATE WILL CREATE LOCALLY
WINDY TRADES TONIGHT AND MONDAY. THE TRADES WILL EASE OFF A BIT AS
THE HIGH MOVES AWAY BY MIDWEEK. THE STRONG TRADES WILL CONTINUE TO
BLOW PASSING WINDWARD AND MAUKA SHOWERS OVER TO LEEWARD SIDES AT
TIMES THROUGH ABOUT MONDAY. DRIER AIR AND FEWER SHOWERS ARE
EXPECTED FOR MUCH OF THE WORK WEEK.

&&

.DISCUSSION...
SURFACE HIGH PRESSURE ANALYZED ABOUT 1000 MI ALMOST DUE N OF
PHNL AT 18Z KEEPING LOCALLY BREEZY TRADE WINDS BLOWING. THE HIGH
IS EXPECTED TO CONTINUE TO MOVE SLOWLY E OVER THE NEXT COUPLE OF
DAYS. AT THE SAME TIME...UPPER LEVEL RIDGING WILL BUILD OVER THE
SURFACE HIGH... HELPING TO LOWER AND STRENGTHEN THE RELATIVELY
WEAK SUBSIDENCE INVERSION CURRENTLY OVER THE ISLANDS. THIS SHOULD
HELP TO INCREASE WIND SPEEDS A BIT IN THE BOUNDARY LAYER TONIGHT
AND MON. SO FAR...ONLY KAMUELA HAS BEEN FLIRTING WITH ADVISORY
LEVEL WINDS... BUT A FEW MORE SPOTS COULD SEE WINDS NEAR OR AT
ADVISORY LEVEL LATER ON...THUS WILL LEAVE THE WIND ADVISORY IN
PLACE FOR NOW. IT IS WORTH REITERATING THAT THIS ADVISORY IS NOT
IN EFFECT FOR ALL PARTS OF ALL ISLANDS...BUT MAINLY FOR AREAS
IMMEDIATELY DOWNWIND OF THE SMALLER MOUNTAIN RANGES AND OVER
HEADLANDS.

THE TRADES WILL RELAX A BIT TUE AND WED AS THE HIGH TO THE
NE MOVES AWAY. ANOTHER HIGH WILL MOVE N OF THE ISLANDS WED NIGHT...
BUT THIS HIGH WILL BE A LITTLE WEAKER THAN THE CURRENT ONE. IT
WILL STALL OUT N OF THE ISLANDS...IN ALMOST SUMMERLIKE FASHION...
KEEPING LOCALLY BREEZY TRADES BLOWING ALL THE WAY INTO NEXT
WEEKEND.

AN AREA OF SOMEWHAT DEEPER MOISTURE IS SEEN ON THE MIMIC PRECIPITABLE
WATER ANIMATION RIDING IN ACROSS THE ISLANDS. THIS WILL CONTINUE
OVERNIGHT INTO MON...KEEPING SOME PASSING SHOWERS GOING FOR
WINDWARD AND MAUKA AREAS. THE BRISK TRADES WILL CONTINUE TO BE
STRONG ENOUGH TO PUSH SOME OF THESE SHOWERS OVER THE MOUNTAINS
BRIEFLY TO NEARBY LEEWARD LOCATIONS. THE AIRMASS SHOULD DRY OUT
AGAIN BY ABOUT TUESDAY... WITH FEWER SHOWERS EXPECTED FOR THE REST
OF THE WEEK.

&&

.AVIATION...
MODERATE TO STRONG TRADE WINDS FROM SFC TO ABOUT 10K WITH SUBSIDENCE
INVERSIONS BETWEEN 5K AND 8K ALOFT EXPECTED THROUGH 24 HOURS AND
BEYOND. WILL BE KEEPING AIRMET TANGO FOR MT WAVE TURB TO THE LEE OF
ALL ISLANDS IN EFFECT INDEFINITELY.

CLOUDS AND SHOWERS WILL FAVOR THE TYPICAL WINDWARD AND MOUNTAIN
AREAS TONIGHT WITH A FEW OF THESE SHOWERS DRIFTING INTO THE LEEWARD
PORTIONS OF THE SMALLER ISLANDS. MVFR CIGS IN SHOWERS ARE PRESENTLY
ISOLATED BUT CURRENT TREND IS FOR INCREASED MOISTURE IN THE LOWER
LEVELS. WILL LIKELY NEED AN AIRMET FOR MT OBSC OVERNIGHT FOR WINDWARD
SLOPES AND COASTS OF THE BIG ISLAND...AND POSSIBLY THE SMALLER ISLANDS
AS WELL.

FEW REPORTS OF MODERATE UPPER LEVEL TURBULENCE ACROSS THE STATE
TODAY BUT CONDITIONS ARE EXPECTED TO REMAIN ISOLATED. NO AIRMET
ISSUED OR ANTICIPATED...BUT WILL GIVE A NON-AIRMET MENTION IN THE
WA0HI.

&&

.MARINE...
THE UNIVERSITY OF HAWAII HIGH RESOLUTION WRF MODEL SHOWS WINDS
PEAKING JUST BELOW GALE FORCE IN THE ALENUIHAHA CHANNEL TOMORROW.
THERE IS A CHANCE WE COULD HAVE TO UPGRADE THE SMALL CRAFT
ADVISORY /SCA/ TO A WARNING IF THE MODELS ARE A BIT UNDERDONE ON
THE WINDS...BUT CONFIDENCE IS NOT HIGH ENOUGH YET TO JUSTIFY THAT.
WE HAVE ALSO ISSUED A HIGH SURF ADVISORY /HSA/ AS EAST FACING
SHORES ARE CONTINUING TO SEE SURF HEIGHTS INCREASE...AND MANY
AREAS WILL EXCEED THE 8 FEET FACE ADVISORY CRITERIA.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 6 PM HST MON FOR WAIANAE COAST-OAHU KOOLAU-
OLOMANA-WAIANAE MOUNTAINS-LANAI-KAHOOLAWE-MAUI WINDWARD WEST-MAUI
LEEWARD WEST-MAUI CENTRAL VALLEY-SOUTH BIG ISLAND-BIG ISLAND NORTH
AND EAST-KOHALA-BIG ISLAND INTERIOR.

HSA UNTIL 6 PM HST TUE FOR KAUAI WINDWARD- OAHU
KOOLAU-OLOMANA-MOLOKAI WINDWARD-MAUI WINDWARD WEST-WINDWARD
HALEAKALA-SOUTH BIG ISLAND-BIG ISLAND NORTH AND EAST.

SCA UNTIL 6 PM HST MON FOR ALL HAWAIIAN WATERS.

&&

$$
R BALLARD/ASB







000
FXHW60 PHFO 210134
AFDHFO

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
334 PM HST SUN APR 20 2014

.SYNOPSIS...
STRONG HIGH PRESSURE TO THE NORTH OF THE STATE WILL CREATE LOCALLY
WINDY TRADES TONIGHT AND MONDAY. THE TRADES WILL EASE OFF A BIT AS
THE HIGH MOVES AWAY BY MIDWEEK. THE STRONG TRADES WILL CONTINUE TO
BLOW PASSING WINDWARD AND MAUKA SHOWERS OVER TO LEEWARD SIDES AT
TIMES THROUGH ABOUT MONDAY. DRIER AIR AND FEWER SHOWERS ARE
EXPECTED FOR MUCH OF THE WORK WEEK.

&&

.DISCUSSION...
SURFACE HIGH PRESSURE ANALYZED ABOUT 1000 MI ALMOST DUE N OF
PHNL AT 18Z KEEPING LOCALLY BREEZY TRADE WINDS BLOWING. THE HIGH
IS EXPECTED TO CONTINUE TO MOVE SLOWLY E OVER THE NEXT COUPLE OF
DAYS. AT THE SAME TIME...UPPER LEVEL RIDGING WILL BUILD OVER THE
SURFACE HIGH... HELPING TO LOWER AND STRENGTHEN THE RELATIVELY
WEAK SUBSIDENCE INVERSION CURRENTLY OVER THE ISLANDS. THIS SHOULD
HELP TO INCREASE WIND SPEEDS A BIT IN THE BOUNDARY LAYER TONIGHT
AND MON. SO FAR...ONLY KAMUELA HAS BEEN FLIRTING WITH ADVISORY
LEVEL WINDS... BUT A FEW MORE SPOTS COULD SEE WINDS NEAR OR AT
ADVISORY LEVEL LATER ON...THUS WILL LEAVE THE WIND ADVISORY IN
PLACE FOR NOW. IT IS WORTH REITERATING THAT THIS ADVISORY IS NOT
IN EFFECT FOR ALL PARTS OF ALL ISLANDS...BUT MAINLY FOR AREAS
IMMEDIATELY DOWNWIND OF THE SMALLER MOUNTAIN RANGES AND OVER
HEADLANDS.

THE TRADES WILL RELAX A BIT TUE AND WED AS THE HIGH TO THE
NE MOVES AWAY. ANOTHER HIGH WILL MOVE N OF THE ISLANDS WED NIGHT...
BUT THIS HIGH WILL BE A LITTLE WEAKER THAN THE CURRENT ONE. IT
WILL STALL OUT N OF THE ISLANDS...IN ALMOST SUMMERLIKE FASHION...
KEEPING LOCALLY BREEZY TRADES BLOWING ALL THE WAY INTO NEXT
WEEKEND.

AN AREA OF SOMEWHAT DEEPER MOISTURE IS SEEN ON THE MIMIC PRECIPITABLE
WATER ANIMATION RIDING IN ACROSS THE ISLANDS. THIS WILL CONTINUE
OVERNIGHT INTO MON...KEEPING SOME PASSING SHOWERS GOING FOR
WINDWARD AND MAUKA AREAS. THE BRISK TRADES WILL CONTINUE TO BE
STRONG ENOUGH TO PUSH SOME OF THESE SHOWERS OVER THE MOUNTAINS
BRIEFLY TO NEARBY LEEWARD LOCATIONS. THE AIRMASS SHOULD DRY OUT
AGAIN BY ABOUT TUESDAY... WITH FEWER SHOWERS EXPECTED FOR THE REST
OF THE WEEK.

&&

.AVIATION...
MODERATE TO STRONG TRADE WINDS FROM SFC TO ABOUT 10K WITH SUBSIDENCE
INVERSIONS BETWEEN 5K AND 8K ALOFT EXPECTED THROUGH 24 HOURS AND
BEYOND. WILL BE KEEPING AIRMET TANGO FOR MT WAVE TURB TO THE LEE OF
ALL ISLANDS IN EFFECT INDEFINITELY.

CLOUDS AND SHOWERS WILL FAVOR THE TYPICAL WINDWARD AND MOUNTAIN
AREAS TONIGHT WITH A FEW OF THESE SHOWERS DRIFTING INTO THE LEEWARD
PORTIONS OF THE SMALLER ISLANDS. MVFR CIGS IN SHOWERS ARE PRESENTLY
ISOLATED BUT CURRENT TREND IS FOR INCREASED MOISTURE IN THE LOWER
LEVELS. WILL LIKELY NEED AN AIRMET FOR MT OBSC OVERNIGHT FOR WINDWARD
SLOPES AND COASTS OF THE BIG ISLAND...AND POSSIBLY THE SMALLER ISLANDS
AS WELL.

FEW REPORTS OF MODERATE UPPER LEVEL TURBULENCE ACROSS THE STATE
TODAY BUT CONDITIONS ARE EXPECTED TO REMAIN ISOLATED. NO AIRMET
ISSUED OR ANTICIPATED...BUT WILL GIVE A NON-AIRMET MENTION IN THE
WA0HI.

&&

.MARINE...
THE UNIVERSITY OF HAWAII HIGH RESOLUTION WRF MODEL SHOWS WINDS
PEAKING JUST BELOW GALE FORCE IN THE ALENUIHAHA CHANNEL TOMORROW.
THERE IS A CHANCE WE COULD HAVE TO UPGRADE THE SMALL CRAFT
ADVISORY /SCA/ TO A WARNING IF THE MODELS ARE A BIT UNDERDONE ON
THE WINDS...BUT CONFIDENCE IS NOT HIGH ENOUGH YET TO JUSTIFY THAT.
WE HAVE ALSO ISSUED A HIGH SURF ADVISORY /HSA/ AS EAST FACING
SHORES ARE CONTINUING TO SEE SURF HEIGHTS INCREASE...AND MANY
AREAS WILL EXCEED THE 8 FEET FACE ADVISORY CRITERIA.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 6 PM HST MON FOR WAIANAE COAST-OAHU KOOLAU-
OLOMANA-WAIANAE MOUNTAINS-LANAI-KAHOOLAWE-MAUI WINDWARD WEST-MAUI
LEEWARD WEST-MAUI CENTRAL VALLEY-SOUTH BIG ISLAND-BIG ISLAND NORTH
AND EAST-KOHALA-BIG ISLAND INTERIOR.

HSA UNTIL 6 PM HST TUE FOR KAUAI WINDWARD- OAHU
KOOLAU-OLOMANA-MOLOKAI WINDWARD-MAUI WINDWARD WEST-WINDWARD
HALEAKALA-SOUTH BIG ISLAND-BIG ISLAND NORTH AND EAST.

SCA UNTIL 6 PM HST MON FOR ALL HAWAIIAN WATERS.

&&

$$
R BALLARD/ASB






000
FXHW60 PHFO 202343
AFDHFO

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE HONOLULU HI
143 PM HST SUN APR 20 2014

.UPDATE...
UPDATED FOR HIGH SURF ADVISORY IN WWA BLOCK AT THE BOTTOM.

&&

.SYNOPSIS...
TRADE WINDS WILL INCREASE TODAY AND TONIGHT...THEN REMAIN STRONG
ON MONDAY...BEFORE DROPPING BACK TO MODERATE LEVELS BY MIDWEEK.
SHOWERS WILL CONTINUE TO FOCUS ACROSS WINDWARD AND MAUKA
AREAS...WITH SHOWERS SPILLING OVER INTO SOME LEEWARD AREAS AS
WELL.

&&

.DISCUSSION...
MAIN CONCERNS FOR THIS FORECAST CENTER ON STRENGTH OF THE TRADE
WINDS. ALTHOUGH MOST AREAS REMAIN WELL BELOW ADVISORY CRITERIA AS
OF MID-MORNING...KAMUELA AIRPORT DID REPORT A SUSTAINED WIND OF 26
KT EARLIER. A 1032 MB HIGH ANALYZED 850 MILES N OF KAUAI AT 12Z
IS FORECAST TO SLIDE SLOWLY ESE AND REMAIN NEAR ITS CURRENT
INTENSITY OVER THE NEXT COUPLE OF DAYS. AT THE SAME TIME...RIDGING
ALOFT IS EXPECTED TO BUILD OVER THE HIGH TONIGHT AND TOMORROW. THE
GUIDANCE RESPONDS TO THIS UPSTREAM RIDGING BY LOWERING AND
STRENGTHENING THE INVERSION A TAD OVER THE ISLANDS. MOS GUIDANCE
REFLECTS WINDS ABOUT 2 TO 4 KT STRONGER ACROSS THE STATE TONIGHT
AND MONDAY THAN TODAY...AND THE HIGH RES MODEL CROSS SECTIONS SHOW
STRONGER WINDS AT 925 MB AND 850 MB...SO CONFIDENCE IN REACHING
ADVISORY CRITERIA IN SELECT LOCATIONS IS A BIT HIGHER DURING THAT
TIME.

A FAIRLY TYPICAL DISTRIBUTION OF LOW CLOUDS AND SHOWERS IS SEEN
IN THE VISIBLE SATELLITE IMAGERY. THE GUIDANCE INDICATES WE WILL
CONTINUE TO SEE TYPICAL TRADE WIND SHOWERS OVER WINDWARD AND MAUKA
AREAS...EASILY SPILLING OVER TO ADJACENT AREAS TO THE LEE OF THE
SMALLER MOUNTAINS...FOR THE NEXT COUPLE OF DAYS. RAINFALL AMOUNTS
OVERALL WILL BE ON THE LIGHT SIDE...WITH SOMEWHAT HIGHER TOTALS
OVER WINDWARD BIG ISLAND WHERE OROGRAPHIC FORCING IS MAXIMIZED
DURING TRADES.

NOT MUCH CHANGE IS EXPECTED THIS WEEK. THE CURRENT HIGH WILL SLIDE
OFF TO THE EAST AWAY FROM THE ISLANDS AND THE WINDS WILL MODERATE
A BIT. A NEW HIGH...A BIT WEAKER THAN THE CURRENT ONE...WILL PASS
NORTH OF THE ISLANDS DURING THE MIDDLE OF THE WEEK...KEEPING THE
TRADES FAIRLY BREEZY. AFTER THE SLIGHTLY HIGHER INVERSION HEIGHTS
YIELDING EXTRA CLOUDS AND SHOWERS TODAY...THE MULTI-MODEL ENSEMBLE
IS SHOWING NEAR-NORMAL INVERSION HEIGHTS RETURNING AND SLIGHTLY
WARMER THAN NORMAL MID-LEVEL TEMPERATURES THROUGH THE WEEK...SO
SHOWERS SHOULD BECOME A LITTLE MORE SCARCE ONCE AGAIN.

&&

AVIATION...
MODERATE TO STRONG TRADE WINDS FROM SFC TO ABOUT 10 KFT WITH
SUBSIDENCE INVERSIONS BETWEEN 5 KFT AND 8 KFT ALOFT EXPECTED
THROUGH 24 HOURS AND BEYOND. WILL BE KEEPING AIRMET TANGO FOR MT
WAVE TURB TO THE LEE OF ALL ISLANDS IN EFFECT INDEFINITELY.

CLOUDS AND SHOWERS WILL FAVOR THE TYPICAL WINDWARD AND MOUNTAIN
AREAS TODAY AND TONIGHT WITH A FEW OF THESE SHOWERS DRIFTING INTO
THE LEEWARD PORTIONS OF THE SMALLER ISLANDS. MVFR CIGS IN SHOWERS
ARE PRESENTLY ISOLATED BUT TREND IS FOR INCREASED MOISTURE IN THE
LOWER LEVELS SO AN AIRMET FOR MT OBSC FOR NE SECTIONS OF ALL ISLANDS
COULD BECOME NECESSARY THIS AFTERNOON OR EVENING. WILL NEED TO
MONITOR CLOSELY.

WEAK SEA BREEZES...AND SEA BREEZE DRIVEN VFR CLOUDS AND SHOWERS...
ARE EXPECTED ALONG THE KONA COAST THIS AFTERNOON AND EARLY
EVENING.

&&

.MARINE...
WINDS ARE EXPECTED TO INCREASE TO SMALL CRAFT ADVISORY /SCA/
LEVELS EVERYWHERE LATER TODAY. THERE IS THE POSSIBILITY WINDS
COULD REACH GALE FORCE IN THE ALENUIHAHA CHANNEL TONIGHT OR
MONDAY...AND WE WILL BE KEEPING AN EYE ON THIS.

STRENGTHENING TRADE WINDS WILL PRODUCE SHORT PERIOD...CHOPPY SURF
ALONG EAST FACING SHORES...LIKELY REACHING ADVISORY LEVELS FOR
MONDAY THROUGH TUESDAY. OTHERWISE...A SMALL TO MODERATE NORTHWEST
SWELL WILL CONTINUE TODAY...THEN DECLINE TONIGHT AND MONDAY.
ANOTHER MODERATE NORTHWEST SWELL IS EXPECTED TO ARRIVE WEDNESDAY...
PEAK ON THURSDAY...THEN SLOWLY DECLINE ON FRIDAY. RESULTING SURF
ON NORTH AND WEST FACING SHORES WILL REMAIN WELL BELOW ADVISORY
LEVELS.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY TIL 6 PM HST MON FOR WAIANAE COAST-OAHU KOOLAU-
OLOMANA-WAIANAE MOUNTAINS-LANAI-KAHOOLAWE-MAUI WINDWARD WEST-MAUI
LEEWARD WEST-MAUI CENTRAL VALLEY-SOUTH BIG ISLAND-BIG ISLAND NORTH
AND EAST-KOHALA-BIG ISLAND INTERIOR.

SCA TIL 6 PM HST MON ALL HAWAIIAN WATERS.

HIGH SURF ADVISORY UNTIL 6 PM HST TUESDAY FOR EAST FACING SHORES OF
KAUAI-OAHU-MOLOKAI-MAUI-BIG ISLAND.

&&

$$

R BALLARD/ASB







000
FXHW60 PHFO 202343
AFDHFO

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE HONOLULU HI
143 PM HST SUN APR 20 2014

.UPDATE...
UPDATED FOR HIGH SURF ADVISORY IN WWA BLOCK AT THE BOTTOM.

&&

.SYNOPSIS...
TRADE WINDS WILL INCREASE TODAY AND TONIGHT...THEN REMAIN STRONG
ON MONDAY...BEFORE DROPPING BACK TO MODERATE LEVELS BY MIDWEEK.
SHOWERS WILL CONTINUE TO FOCUS ACROSS WINDWARD AND MAUKA
AREAS...WITH SHOWERS SPILLING OVER INTO SOME LEEWARD AREAS AS
WELL.

&&

.DISCUSSION...
MAIN CONCERNS FOR THIS FORECAST CENTER ON STRENGTH OF THE TRADE
WINDS. ALTHOUGH MOST AREAS REMAIN WELL BELOW ADVISORY CRITERIA AS
OF MID-MORNING...KAMUELA AIRPORT DID REPORT A SUSTAINED WIND OF 26
KT EARLIER. A 1032 MB HIGH ANALYZED 850 MILES N OF KAUAI AT 12Z
IS FORECAST TO SLIDE SLOWLY ESE AND REMAIN NEAR ITS CURRENT
INTENSITY OVER THE NEXT COUPLE OF DAYS. AT THE SAME TIME...RIDGING
ALOFT IS EXPECTED TO BUILD OVER THE HIGH TONIGHT AND TOMORROW. THE
GUIDANCE RESPONDS TO THIS UPSTREAM RIDGING BY LOWERING AND
STRENGTHENING THE INVERSION A TAD OVER THE ISLANDS. MOS GUIDANCE
REFLECTS WINDS ABOUT 2 TO 4 KT STRONGER ACROSS THE STATE TONIGHT
AND MONDAY THAN TODAY...AND THE HIGH RES MODEL CROSS SECTIONS SHOW
STRONGER WINDS AT 925 MB AND 850 MB...SO CONFIDENCE IN REACHING
ADVISORY CRITERIA IN SELECT LOCATIONS IS A BIT HIGHER DURING THAT
TIME.

A FAIRLY TYPICAL DISTRIBUTION OF LOW CLOUDS AND SHOWERS IS SEEN
IN THE VISIBLE SATELLITE IMAGERY. THE GUIDANCE INDICATES WE WILL
CONTINUE TO SEE TYPICAL TRADE WIND SHOWERS OVER WINDWARD AND MAUKA
AREAS...EASILY SPILLING OVER TO ADJACENT AREAS TO THE LEE OF THE
SMALLER MOUNTAINS...FOR THE NEXT COUPLE OF DAYS. RAINFALL AMOUNTS
OVERALL WILL BE ON THE LIGHT SIDE...WITH SOMEWHAT HIGHER TOTALS
OVER WINDWARD BIG ISLAND WHERE OROGRAPHIC FORCING IS MAXIMIZED
DURING TRADES.

NOT MUCH CHANGE IS EXPECTED THIS WEEK. THE CURRENT HIGH WILL SLIDE
OFF TO THE EAST AWAY FROM THE ISLANDS AND THE WINDS WILL MODERATE
A BIT. A NEW HIGH...A BIT WEAKER THAN THE CURRENT ONE...WILL PASS
NORTH OF THE ISLANDS DURING THE MIDDLE OF THE WEEK...KEEPING THE
TRADES FAIRLY BREEZY. AFTER THE SLIGHTLY HIGHER INVERSION HEIGHTS
YIELDING EXTRA CLOUDS AND SHOWERS TODAY...THE MULTI-MODEL ENSEMBLE
IS SHOWING NEAR-NORMAL INVERSION HEIGHTS RETURNING AND SLIGHTLY
WARMER THAN NORMAL MID-LEVEL TEMPERATURES THROUGH THE WEEK...SO
SHOWERS SHOULD BECOME A LITTLE MORE SCARCE ONCE AGAIN.

&&

AVIATION...
MODERATE TO STRONG TRADE WINDS FROM SFC TO ABOUT 10 KFT WITH
SUBSIDENCE INVERSIONS BETWEEN 5 KFT AND 8 KFT ALOFT EXPECTED
THROUGH 24 HOURS AND BEYOND. WILL BE KEEPING AIRMET TANGO FOR MT
WAVE TURB TO THE LEE OF ALL ISLANDS IN EFFECT INDEFINITELY.

CLOUDS AND SHOWERS WILL FAVOR THE TYPICAL WINDWARD AND MOUNTAIN
AREAS TODAY AND TONIGHT WITH A FEW OF THESE SHOWERS DRIFTING INTO
THE LEEWARD PORTIONS OF THE SMALLER ISLANDS. MVFR CIGS IN SHOWERS
ARE PRESENTLY ISOLATED BUT TREND IS FOR INCREASED MOISTURE IN THE
LOWER LEVELS SO AN AIRMET FOR MT OBSC FOR NE SECTIONS OF ALL ISLANDS
COULD BECOME NECESSARY THIS AFTERNOON OR EVENING. WILL NEED TO
MONITOR CLOSELY.

WEAK SEA BREEZES...AND SEA BREEZE DRIVEN VFR CLOUDS AND SHOWERS...
ARE EXPECTED ALONG THE KONA COAST THIS AFTERNOON AND EARLY
EVENING.

&&

.MARINE...
WINDS ARE EXPECTED TO INCREASE TO SMALL CRAFT ADVISORY /SCA/
LEVELS EVERYWHERE LATER TODAY. THERE IS THE POSSIBILITY WINDS
COULD REACH GALE FORCE IN THE ALENUIHAHA CHANNEL TONIGHT OR
MONDAY...AND WE WILL BE KEEPING AN EYE ON THIS.

STRENGTHENING TRADE WINDS WILL PRODUCE SHORT PERIOD...CHOPPY SURF
ALONG EAST FACING SHORES...LIKELY REACHING ADVISORY LEVELS FOR
MONDAY THROUGH TUESDAY. OTHERWISE...A SMALL TO MODERATE NORTHWEST
SWELL WILL CONTINUE TODAY...THEN DECLINE TONIGHT AND MONDAY.
ANOTHER MODERATE NORTHWEST SWELL IS EXPECTED TO ARRIVE WEDNESDAY...
PEAK ON THURSDAY...THEN SLOWLY DECLINE ON FRIDAY. RESULTING SURF
ON NORTH AND WEST FACING SHORES WILL REMAIN WELL BELOW ADVISORY
LEVELS.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY TIL 6 PM HST MON FOR WAIANAE COAST-OAHU KOOLAU-
OLOMANA-WAIANAE MOUNTAINS-LANAI-KAHOOLAWE-MAUI WINDWARD WEST-MAUI
LEEWARD WEST-MAUI CENTRAL VALLEY-SOUTH BIG ISLAND-BIG ISLAND NORTH
AND EAST-KOHALA-BIG ISLAND INTERIOR.

SCA TIL 6 PM HST MON ALL HAWAIIAN WATERS.

HIGH SURF ADVISORY UNTIL 6 PM HST TUESDAY FOR EAST FACING SHORES OF
KAUAI-OAHU-MOLOKAI-MAUI-BIG ISLAND.

&&

$$

R BALLARD/ASB






000
FXHW60 PHFO 201951
AFDHFO

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
951 AM HST SUN APR 20 2014

.SYNOPSIS...
TRADE WINDS WILL INCREASE TODAY AND TONIGHT...THEN REMAIN STRONG
ON MONDAY...BEFORE DROPPING BACK TO MODERATE LEVELS BY MIDWEEK.
SHOWERS WILL CONTINUE TO FOCUS ACROSS WINDWARD AND MAUKA
AREAS...WITH SHOWERS SPILLING OVER INTO SOME LEEWARD AREAS AS
WELL.

&&

.DISCUSSION...
MAIN CONCERNS FOR THIS FORECAST CENTER ON STRENGTH OF THE TRADE
WINDS. ALTHOUGH MOST AREAS REMAIN WELL BELOW ADVISORY CRITERIA AS
OF MID-MORNING...KAMUELA AIRPORT DID REPORT A SUSTAINED WIND OF 26
KT EARLIER. A 1032 MB HIGH ANALYZED 850 MILES N OF KAUAI AT 12Z
IS FORECAST TO SLIDE SLOWLY ESE AND REMAIN NEAR ITS CURRENT
INTENSITY OVER THE NEXT COUPLE OF DAYS. AT THE SAME TIME...RIDGING
ALOFT IS EXPECTED TO BUILD OVER THE HIGH TONIGHT AND TOMORROW. THE
GUIDANCE RESPONDS TO THIS UPSTREAM RIDGING BY LOWERING AND
STRENGTHENING THE INVERSION A TAD OVER THE ISLANDS. MOS GUIDANCE
REFLECTS WINDS ABOUT 2 TO 4 KT STRONGER ACROSS THE STATE TONIGHT
AND MONDAY THAN TODAY...AND THE HIGH RES MODEL CROSS SECTIONS SHOW
STRONGER WINDS AT 925 MB AND 850 MB...SO CONFIDENCE IN REACHING
ADVISORY CRITERIA IN SELECT LOCATIONS IS A BIT HIGHER DURING THAT
TIME.

A FAIRLY TYPICAL DISTRIBUTION OF LOW CLOUDS AND SHOWERS IS SEEN
IN THE VISIBLE SATELLITE IMAGERY. THE GUIDANCE INDICATES WE WILL
CONTINUE TO SEE TYPICAL TRADE WIND SHOWERS OVER WINDWARD AND MAUKA
AREAS...EASILY SPILLING OVER TO ADJACENT AREAS TO THE LEE OF THE
SMALLER MOUNTAINS...FOR THE NEXT COUPLE OF DAYS. RAINFALL AMOUNTS
OVERALL WILL BE ON THE LIGHT SIDE...WITH SOMEWHAT HIGHER TOTALS
OVER WINDWARD BIG ISLAND WHERE OROGRAPHIC FORCING IS MAXIMIZED
DURING TRADES.

NOT MUCH CHANGE IS EXPECTED THIS WEEK. THE CURRENT HIGH WILL SLIDE
OFF TO THE EAST AWAY FROM THE ISLANDS AND THE WINDS WILL MODERATE
A BIT. A NEW HIGH...A BIT WEAKER THAN THE CURRENT ONE...WILL PASS
NORTH OF THE ISLANDS DURING THE MIDDLE OF THE WEEK...KEEPING THE
TRADES FAIRLY BREEZY. AFTER THE SLIGHTLY HIGHER INVERSION HEIGHTS
YIELDING EXTRA CLOUDS AND SHOWERS TODAY...THE MULTI-MODEL ENSEMBLE
IS SHOWING NEAR-NORMAL INVERSION HEIGHTS RETURNING AND SLIGHTLY
WARMER THAN NORMAL MID-LEVEL TEMPERATURES THROUGH THE WEEK...SO
SHOWERS SHOULD BECOME A LITTLE MORE SCARCE ONCE AGAIN.

&&

AVIATION...
MODERATE TO STRONG TRADE WINDS FROM SFC TO ABOUT 10 KFT WITH
SUBSIDENCE INVERSIONS BETWEEN 5 KFT AND 8 KFT ALOFT EXPECTED
THROUGH 24 HOURS AND BEYOND. WILL BE KEEPING AIRMET TANGO FOR MT
WAVE TURB TO THE LEE OF ALL ISLANDS IN EFFECT INDEFINITELY.

CLOUDS AND SHOWERS WILL FAVOR THE TYPICAL WINDWARD AND MOUNTAIN
AREAS TODAY AND TONIGHT WITH A FEW OF THESE SHOWERS DRIFTING INTO
THE LEEWARD PORTIONS OF THE SMALLER ISLANDS. MVFR CIGS IN SHOWERS
ARE PRESENTLY ISOLATED BUT TREND IS FOR INCREASED MOISTURE IN THE
LOWER LEVELS SO AN AIRMET FOR MT OBSC FOR NE SECTIONS OF ALL ISLANDS
COULD BECOME NECESSARY THIS AFTERNOON OR EVENING. WILL NEED TO
MONITOR CLOSELY.

WEAK SEA BREEZES...AND SEA BREEZE DRIVEN VFR CLOUDS AND SHOWERS...
ARE EXPECTED ALONG THE KONA COAST THIS AFTERNOON AND EARLY
EVENING.

&&

.MARINE...
WINDS ARE EXPECTED TO INCREASE TO SMALL CRAFT ADVISORY /SCA/
LEVELS EVERYWHERE LATER TODAY. THERE IS THE POSSIBILITY WINDS
COULD REACH GALE FORCE IN THE ALENUIHAHA CHANNEL TONIGHT OR
MONDAY...AND WE WILL BE KEEPING AN EYE ON THIS.

STRENGTHENING TRADE WINDS WILL PRODUCE SHORT PERIOD...CHOPPY SURF
ALONG EAST FACING SHORES...LIKELY REACHING ADVISORY LEVELS FOR
MONDAY THROUGH TUESDAY. OTHERWISE...A SMALL TO MODERATE NORTHWEST
SWELL WILL CONTINUE TODAY...THEN DECLINE TONIGHT AND MONDAY.
ANOTHER MODERATE NORTHWEST SWELL IS EXPECTED TO ARRIVE WEDNESDAY...
PEAK ON THURSDAY...THEN SLOWLY DECLINE ON FRIDAY. RESULTING SURF
ON NORTH AND WEST FACING SHORES WILL REMAIN WELL BELOW ADVISORY
LEVELS.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY TIL 6 PM HST MON FOR WAIANAE COAST-OAHU KOOLAU-
OLOMANA-WAIANAE MOUNTAINS-LANAI-KAHOOLAWE-MAUI WINDWARD WEST-MAUI
LEEWARD WEST-MAUI CENTRAL VALLEY-SOUTH BIG ISLAND-BIG ISLAND NORTH
AND EAST-KOHALA-BIG ISLAND INTERIOR.

SCA TIL 6 PM HST MON ALL HAWAIIAN WATERS.

&&

$$

R BALLARD/ASB









000
FXHW60 PHFO 201951
AFDHFO

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
951 AM HST SUN APR 20 2014

.SYNOPSIS...
TRADE WINDS WILL INCREASE TODAY AND TONIGHT...THEN REMAIN STRONG
ON MONDAY...BEFORE DROPPING BACK TO MODERATE LEVELS BY MIDWEEK.
SHOWERS WILL CONTINUE TO FOCUS ACROSS WINDWARD AND MAUKA
AREAS...WITH SHOWERS SPILLING OVER INTO SOME LEEWARD AREAS AS
WELL.

&&

.DISCUSSION...
MAIN CONCERNS FOR THIS FORECAST CENTER ON STRENGTH OF THE TRADE
WINDS. ALTHOUGH MOST AREAS REMAIN WELL BELOW ADVISORY CRITERIA AS
OF MID-MORNING...KAMUELA AIRPORT DID REPORT A SUSTAINED WIND OF 26
KT EARLIER. A 1032 MB HIGH ANALYZED 850 MILES N OF KAUAI AT 12Z
IS FORECAST TO SLIDE SLOWLY ESE AND REMAIN NEAR ITS CURRENT
INTENSITY OVER THE NEXT COUPLE OF DAYS. AT THE SAME TIME...RIDGING
ALOFT IS EXPECTED TO BUILD OVER THE HIGH TONIGHT AND TOMORROW. THE
GUIDANCE RESPONDS TO THIS UPSTREAM RIDGING BY LOWERING AND
STRENGTHENING THE INVERSION A TAD OVER THE ISLANDS. MOS GUIDANCE
REFLECTS WINDS ABOUT 2 TO 4 KT STRONGER ACROSS THE STATE TONIGHT
AND MONDAY THAN TODAY...AND THE HIGH RES MODEL CROSS SECTIONS SHOW
STRONGER WINDS AT 925 MB AND 850 MB...SO CONFIDENCE IN REACHING
ADVISORY CRITERIA IN SELECT LOCATIONS IS A BIT HIGHER DURING THAT
TIME.

A FAIRLY TYPICAL DISTRIBUTION OF LOW CLOUDS AND SHOWERS IS SEEN
IN THE VISIBLE SATELLITE IMAGERY. THE GUIDANCE INDICATES WE WILL
CONTINUE TO SEE TYPICAL TRADE WIND SHOWERS OVER WINDWARD AND MAUKA
AREAS...EASILY SPILLING OVER TO ADJACENT AREAS TO THE LEE OF THE
SMALLER MOUNTAINS...FOR THE NEXT COUPLE OF DAYS. RAINFALL AMOUNTS
OVERALL WILL BE ON THE LIGHT SIDE...WITH SOMEWHAT HIGHER TOTALS
OVER WINDWARD BIG ISLAND WHERE OROGRAPHIC FORCING IS MAXIMIZED
DURING TRADES.

NOT MUCH CHANGE IS EXPECTED THIS WEEK. THE CURRENT HIGH WILL SLIDE
OFF TO THE EAST AWAY FROM THE ISLANDS AND THE WINDS WILL MODERATE
A BIT. A NEW HIGH...A BIT WEAKER THAN THE CURRENT ONE...WILL PASS
NORTH OF THE ISLANDS DURING THE MIDDLE OF THE WEEK...KEEPING THE
TRADES FAIRLY BREEZY. AFTER THE SLIGHTLY HIGHER INVERSION HEIGHTS
YIELDING EXTRA CLOUDS AND SHOWERS TODAY...THE MULTI-MODEL ENSEMBLE
IS SHOWING NEAR-NORMAL INVERSION HEIGHTS RETURNING AND SLIGHTLY
WARMER THAN NORMAL MID-LEVEL TEMPERATURES THROUGH THE WEEK...SO
SHOWERS SHOULD BECOME A LITTLE MORE SCARCE ONCE AGAIN.

&&

AVIATION...
MODERATE TO STRONG TRADE WINDS FROM SFC TO ABOUT 10 KFT WITH
SUBSIDENCE INVERSIONS BETWEEN 5 KFT AND 8 KFT ALOFT EXPECTED
THROUGH 24 HOURS AND BEYOND. WILL BE KEEPING AIRMET TANGO FOR MT
WAVE TURB TO THE LEE OF ALL ISLANDS IN EFFECT INDEFINITELY.

CLOUDS AND SHOWERS WILL FAVOR THE TYPICAL WINDWARD AND MOUNTAIN
AREAS TODAY AND TONIGHT WITH A FEW OF THESE SHOWERS DRIFTING INTO
THE LEEWARD PORTIONS OF THE SMALLER ISLANDS. MVFR CIGS IN SHOWERS
ARE PRESENTLY ISOLATED BUT TREND IS FOR INCREASED MOISTURE IN THE
LOWER LEVELS SO AN AIRMET FOR MT OBSC FOR NE SECTIONS OF ALL ISLANDS
COULD BECOME NECESSARY THIS AFTERNOON OR EVENING. WILL NEED TO
MONITOR CLOSELY.

WEAK SEA BREEZES...AND SEA BREEZE DRIVEN VFR CLOUDS AND SHOWERS...
ARE EXPECTED ALONG THE KONA COAST THIS AFTERNOON AND EARLY
EVENING.

&&

.MARINE...
WINDS ARE EXPECTED TO INCREASE TO SMALL CRAFT ADVISORY /SCA/
LEVELS EVERYWHERE LATER TODAY. THERE IS THE POSSIBILITY WINDS
COULD REACH GALE FORCE IN THE ALENUIHAHA CHANNEL TONIGHT OR
MONDAY...AND WE WILL BE KEEPING AN EYE ON THIS.

STRENGTHENING TRADE WINDS WILL PRODUCE SHORT PERIOD...CHOPPY SURF
ALONG EAST FACING SHORES...LIKELY REACHING ADVISORY LEVELS FOR
MONDAY THROUGH TUESDAY. OTHERWISE...A SMALL TO MODERATE NORTHWEST
SWELL WILL CONTINUE TODAY...THEN DECLINE TONIGHT AND MONDAY.
ANOTHER MODERATE NORTHWEST SWELL IS EXPECTED TO ARRIVE WEDNESDAY...
PEAK ON THURSDAY...THEN SLOWLY DECLINE ON FRIDAY. RESULTING SURF
ON NORTH AND WEST FACING SHORES WILL REMAIN WELL BELOW ADVISORY
LEVELS.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY TIL 6 PM HST MON FOR WAIANAE COAST-OAHU KOOLAU-
OLOMANA-WAIANAE MOUNTAINS-LANAI-KAHOOLAWE-MAUI WINDWARD WEST-MAUI
LEEWARD WEST-MAUI CENTRAL VALLEY-SOUTH BIG ISLAND-BIG ISLAND NORTH
AND EAST-KOHALA-BIG ISLAND INTERIOR.

SCA TIL 6 PM HST MON ALL HAWAIIAN WATERS.

&&

$$

R BALLARD/ASB








000
FXHW60 PHFO 201355
AFDHFO

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
355 AM HST SUN APR 20 2014

.SYNOPSIS...
TRADE WINDS WILL INCREASE TODAY AND TONIGHT...THEN REMAIN STRONG
ON MONDAY...BEFORE DROPPING BACK TO MODERATE LEVELS BY MIDWEEK.
SHOWERS WILL CONTINUE TO FOCUS ACROSS WINDWARD AND MAUKA
AREAS...WITH SHOWERS SPILLING OVER INTO SOME LEEWARD AREAS AS
WELL.

&&

.DISCUSSION...
RADAR LOOPS INDICATE INCREASED SHOWER ACTIVITY MOVING QUICKLY
WESTWARD ACROSS THE STATE DURING THE PAST FEW HOURS...BUT RAIN
GAUGES SHOW GENERALLY LIGHT ACCUMULATIONS OVER WINDWARD AREAS.
THE 12Z SOUNDINGS SHOW THE INVERSION BASED BETWEEN 5500 AND
8000 FEET...WITH WINDS AROUND 850 MB (JUST BELOW THE INVERSION)
INCREASING TO 23-27 KNOTS AT LIHUE. SATELLITE IMAGERY CONTINUES
TO SHOW ABUNDANT MID/HIGH LEVEL CLOUDINESS STREAMING NORTHWARD
ACROSS THE REGION...TO THE EAST OF A MID/UPPER LEVEL TROUGH
CENTERED SEVERAL HUNDRED MILES TO THE SOUTHWEST. AT THE
SURFACE...A 1031 MB HIGH IS CENTERED ABOUT 950 MILES NORTH OF
KAUAI AND IS BUILDING EASTWARD.

THE PRIMARY WEATHER CONCERN THROUGH THE SHORT TERM IS THE
POTENTIAL FOR GUSTY ADVISORY LEVEL TRADE WINDS...AS STRONG HIGH
PRESSURE PASSES BY TO THE NORTH OF THE STATE. THE 00Z UH-WRF RUN
CONTINUES TO SUGGEST THAT THE STRONGEST WINDS ARE LIKELY TO OCCUR
TONIGHT AND MONDAY...WITH 925 MB WINDS INCREASING TO 35 TO 40
KNOTS IN SOME AREAS. MODEL SOUNDINGS DO NOT SHOW QUITE AS STRONG
AN INVERSION AS ONE WOULD IDEALLY LIKE TO SEE IN ORDER TO MAXIMIZE
WIND PRODUCTION AT THE SURFACE...BUT STILL THINK THAT SOME OF THE
TYPICALLY FAVORED DOWNSLOPE AREAS WILL RECEIVE AT LEAST MINIMAL
ADVISORY CONDITIONS AT TIMES ESPECIALLY TONIGHT AND MONDAY.
EARLIER PUSHED BACK THE START TIME OF THE WIND ADVISORY TO 10 AM
THIS MORNING...AND WILL NOT MAKE ANY FURTHER CHANGES AT THIS
POINT. SEE THE LATEST ADVISORY PRODUCT FOR DETAILS ON AREAS
MOST LIKELY TO BE AFFECTED BY THIS EVENT.

OTHERWISE...MIMIC-TPW SATELLITE IMAGERY AND MODEL DATA CONTINUE
TO SUGGEST THAT AN AREA OF SOMEWHAT ENHANCED LOW LEVEL MOISTURE
WILL CONTINUE MOVING WESTWARD INTO THE STATE THIS MORNING. WOULD
EXPECT THIS ADDITIONAL MOISTURE WITHIN THE BUILDING TRADE FLOW TO
SUPPORT INCREASED SHOWER ACTIVITY ACROSS WINDWARD AND MAUKA
AREAS...WITH SOME SPILLOVER INTO LEEWARD SECTIONS.

STRONG TRADES WILL PREVAIL TONIGHT AND MONDAY AS THE HIGH PASSES
TO OUR NORTH...THEN TRADES SHOULD FALL BACK TO MODERATE LEVELS ON
TUESDAY WITH THE HIGH MOVING FURTHER AWAY TO THE NORTHEAST. THE
OTHER PLAYER IN OUR WEATHER DURING THE EARLY TO MID WEEK PERIOD
WILL BE A SLOW MOVING MID/UPPER TROUGH TO THE SOUTHWEST OF THE
STATE. GUIDANCE IS A BIT MORE EMPHATIC WITH MAINTAINING THIS
FEATURE IN THE MID LEVELS (500 MB) THAN IT WAS PREVIOUSLY... BUT
SHOWS BASICALLY NO REFLECTION IN THE LOWER LEVELS WITH A DISTINCT
DRY LAYER MAINTAINED BETWEEN THE MOISTURE ALOFT AND THE MOIST
TRADE FLOW AT LOW LEVELS. AT THIS POINT IT STILL APPEARS THAT
THERE WILL BE LITTLE IMPACT FROM THIS FEATURE ON SENSIBLE WEATHER
ASIDE FROM CONTINUED BOUTS OF MID/HIGH CLOUDINESS...BUT THIS IS
SOMETHING TO KEEP AN EYE ON THROUGH THE NEXT FEW DAYS. BARRING
ANY SURPRISES...EXPECT SHOWERS TO CONTINUE PRIMARILY ACROSS THE
TYPICAL WINDWARD AND MAUKA AREAS THROUGH MIDWEEK...WITH SOME
SPILLOVER INTO LEEWARD DUE TO THE STRENGTH OF THE TRADES.

LONGER RANGE GUIDANCE INDICATES A STATIC PATTERN ACROSS THE
CENTRAL PACIFIC THROUGH THE NEXT SEVERAL DAYS. MODERATE TRADES
WITH PRIMARILY WINDWARD AND MAUKA SHOWERS ARE LIKELY TO CONTINUE
ACROSS HAWAII FROM WEDNESDAY AT LEAST THROUGH THE END OF THE WEEK.

&&

.AVIATION...
TRADE WIND WILL BE STRENGTHENING THIS MORNING...BECOMING QUITE
WINDY AND GUSTY...AS THE SOURCE OF THE WIND...A STG SFC HIGH PASSES
ALMOST DUE N OF THE ISLAND THROUGH MONDAY. AIRMET TANGO FOR
TURBULENCE TO THE LEE OF THE ALL ISLANDS WILL CONT WELL INTO
TONIGHT AND MONDAY.

THE OTHER CONCERN IS FOR MTN OBSC ASSOCIATED WITH THE LOW CLOUDS AND
SHOWERS RIDING IN WITH THE TRADE WINDS. SO FAR...ALTHOUGH THE CLOUDS
AND SHOWERS HAVE INCREASED...THE CLD BASES ARE JUST ABV MVFR
CRITERIA OF 3K AND THE VIS STAYING ABV 5 MI. WE WILL CONT TO MONITOR
FOR WIDESPREAD MVFR CONDS AS THE DAY PROGRESSES. THESE SHOWERS WILL
BE FAVORING THE WINDWARD AND MTN AREAS WITH A FEW OF THESE SHOWERS
BLOWN DOWNWIND INTO LEEWARD SECTIONS OF THE SMALLER ISLANDS. LEEWARD
BIG ISLAND WILL SEE ITS NORMAL AFTERNOON CLOUDS AND ISOL SHOWERS.

AIRMET ZULU REMAINS IN EFFECT FOR LGT RIME IC DUE TO DENSE LAYERED
CLOUDS OVER THE BIG ISLAND 15K TO 35K. EXPECT THESE CLDS TO THIN OUT
BY 22Z.

OTHERWISE...VFR CONDS PREVAIL.

&&

.MARINE...
ALTHOUGH AN 08Z ASCAT PASS SHOWED WINDS BELOW 25 KNOTS ACROSS
A GOOD PORTION OF THE COASTAL WATERS...WINDS ARE EXPECTED TO
INCREASE TO ADVISORY LEVELS EVERYWHERE LATER TODAY AS HIGH
PRESSURE STRENGTHENS TO OUR NORTH. A SMALL CRAFT ADVISORY REMAINS
POSTED FOR ALL WATERS. WINDS MAY REACH NEAR GALE FORCE AT TIMES
TONIGHT AND MONDAY IN THE ALENUIHAHA CHANNEL.

STRENGTHENING TRADE WINDS WILL PRODUCE SHORT PERIOD...CHOPPY SURF
ALONG EAST FACING SHORES...POSSIBLY REACHING ADVISORY LEVELS
SOMETIME TONIGHT...AND LIKELY REACHING ADVISORY LEVELS FOR MONDAY
THROUGH TUESDAY. OTHERWISE...A SMALL TO MODERATE NORTHWEST SWELL
WILL CONTINUE TODAY...THEN DECLINE TONIGHT AND MONDAY. ANOTHER
MODERATE NORTHWEST SWELL IS EXPECTED TO ARRIVE WEDNESDAY...
PEAK ON THURSDAY...THEN SLOWLY DECLINE ON FRIDAY. RESULTING SURF
ON NORTH AND WEST FACING SHORES WILL REMAIN WELL BELOW ADVISORY
LEVELS.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY FROM 10 AM THIS MORNING TO 6 PM HST MONDAY FOR
WAIANAE COAST-OAHU KOOLAU-OLOMANA-WAIANAE MOUNTAINS-LANAI-
KAHOOLAWE-MAUI WINDWARD WEST-MAUI LEEWARD WEST-MAUI CENTRAL
VALLEY-SOUTH BIG ISLAND-BIG ISLAND NORTH AND EAST-KOHALA-BIG
ISLAND INTERIOR.

SMALL CRAFT ADVISORY UNTIL 6 PM HST MONDAY FOR ALL HAWAIIAN
WATERS.

&&

$$

DISCUSSION/MARINE...JACOBSON
AVIATION...LAU







000
FXHW60 PHFO 200643
AFDHFO

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
843 PM HST SAT APR 19 2014

.SYNOPSIS...
TRADE WINDS WILL INCREASE SUNDAY...THEN REMAIN STRONG SUNDAY
NIGHT AND MONDAY BEFORE DROPPING BACK TO MODERATE LEVELS TUESDAY.
SHOWERS WILL FOCUS OVER WINDWARD SLOPES WITH LEEWARD AREAS SEEING
ISOLATED SHOWERS.

&&

.DISCUSSION...
RADAR AND RAIN GAUGE DATA INDICATE VERY LITTLE SHOWER ACTIVITY
ACROSS THE STATE DURING THE PAST SEVERAL HOURS. THE 00Z SOUNDINGS
WERE NOT CHANGED MUCH FROM 12 HOURS EARLIER...WITH THE INVERSION
BASED BETWEEN 5500 AND 7500 FEET. MODERATE LOW LEVEL TRADE FLOW OF
AROUND 20 KNOTS PREVAILS AS PER THE LIHUE SOUNDING AND 88D VWP
DATA. SATELLITE IMAGERY CONTINUES TO SHOW ABUNDANT MID/HIGH LEVEL
CLOUDINESS STREAMING NORTHWARD ACROSS THE REGION...TO THE EAST OF
A MID/UPPER LEVEL TROUGH CENTERED SEVERAL HUNDRED MILES TO THE
SOUTHWEST. AT THE SURFACE...A 1030 MB HIGH IS CENTERED ABOUT 1000
MILES NNW OF KAUAI...AND IS BUILDING EASTWARD.

IN THE NEAR TERM...WILL BE PUSHING BACK THE START TIME OF THE
EXISTING WIND ADVISORY A FEW HOURS UNTIL 10 AM SUNDAY...AS THE
LATEST GUIDANCE AND EXTRAPOLATION FROM CURRENT SURFACE OBS
INDICATES THAT IT IS UNLIKELY THAT WE WILL SEE ADVISORY LEVEL
WINDS BEFORE THAT TIME. THE 12Z LOCAL WRF RUN SUGGESTS THAT THE
STRONGEST WINDS WILL LIKELY OCCUR SUNDAY NIGHT THROUGH MONDAY...
BUT THERE IS STILL THE POTENTIAL FOR AT LEAST ISOLATED ADVISORY
WINDS IN SOME AREAS SUNDAY AFTERNOON.

OTHERWISE...MIMIC-TPW SATELLITE IMAGERY AND MODEL DATA CONTINUE
TO SUGGEST THAT AN AREA OF SOMEWHAT ENHANCED MOISTURE WILL MOVE
WESTWARD INTO THE STATE LATE TONIGHT INTO SUNDAY MORNING. WOULD
EXPECT THIS ADDITIONAL MOISTURE WITHIN BUILDING TRADE FLOW TO
SUPPORT INCREASED SHOWER ACTIVITY ACROSS WINDWARD AND MAUKA
AREAS...WITH SPILLOVER OF AT LEAST ISOLATED SHOWERS INTO SOME
LEEWARD SECTIONS.

STRONG TRADES WILL PREVAIL SUNDAY NIGHT AND MONDAY AS HIGH
PRESSURE PASSES BY TO OUR NORTH...THEN TRADES SHOULD FALL BACK TO
MODERATE LEVELS ON TUESDAY WITH THE HIGH MOVING FURTHER AWAY TO
THE NORTHEAST. THE OTHER PLAYER IN OUR WEATHER DURING THE EARLY TO
MID WEEK PERIOD WILL BE A SLOW MOVING MID/UPPER TROUGH TO THE
SOUTHWEST OF THE STATE. GUIDANCE IS A BIT MORE EMPHATIC WITH
MAINTAINING THIS FEATURE IN THE MID LEVELS (500 MB) THAN IT WAS
YESTERDAY...BUT SHOWS LITTLE REFLECTION IN THE LOWER LEVELS WITH A
DISTINCT DRY LAYER MAINTAINED BETWEEN THE MOISTURE ALOFT AND THE
MOIST TRADE FLOW AT LOW LEVELS. AT THIS POINT IT STILL APPEARS
THAT THERE WILL BE LITTLE IMPACT FROM THIS FEATURE ON SENSIBLE
WEATHER ASIDE FROM CONTINUED MID/HIGH CLOUDINESS...BUT THIS IS
SOMETHING TO KEEP AN EYE ON THROUGH THE NEXT FEW DAYS.

LONGER RANGE GUIDANCE INDICATES A STATIC PATTERN ACROSS THE
CENTRAL PACIFIC. MODERATE TRADES WITH PRIMARILY WINDWARD AND
MAUKA SHOWERS ARE LIKELY TO CONTINUE ACROSS HAWAII FROM
WEDNESDAY AT LEAST THROUGH THE END OF NEXT WEEK.

&&

.AVIATION...
TRADE WIND FLOW CONTINUES...RESULTING IN AIRMET TANGO FOR TURBULENCE
TO THE LEE OF THE ALL ISLANDS. TRADES ARE EXPECTED TO CONTINUE
THROUGH THE WEEKEND...SO EXPECTING THE AIRMET TO ALSO CONTINUE.

SHOWER ACTIVITY MAY INCREASE AND BECOME WIDESPREAD TOWARDS DAYBREAK
SUNDAY WHERE AIRMET SIERRA FOR MTN OBSC MAY BE NEEDED. BUT BETWEEN
NOW AND THEN...VFR RULES WITH BRIEF MVFR CEILINGS AND VIS ASSOCIATED
WITH THE SHOWERS RIDING IN WITH THE TRADES. THESE SHOWERS WILL BE
FAVORING THE WINDWARD AND MTN AREAS...WITH A FEW OF THESE SHOWERS
DRIFTING INTO THE LEEWARD AREAS OF THE SMALLER ISLANDS.

&&

.MARINE...
A SMALL CRAFT ADVISORY REMAINS POSTED FOR ALL HAWAIIAN COASTAL
WATERS DUE TO GUSTY TRADE WINDS AND ROUGH SEAS. WINDS WILL
INCREASE FURTHER SUNDAY INTO MONDAY...AS HIGH PRESSURE STRENGTHENS
TO OUR NORTH. WINDS MAY REACH NEAR GALE FORCE AT TIMES SUNDAY
NIGHT THROUGH MONDAY IN THE ALENUIHAHA CHANNEL.

STRENGTHENING TRADE WINDS WILL PRODUCE SHORT PERIOD...CHOPPY SURF
ALONG EAST FACING SHORES...POSSIBLE REACHING ADVISORY LEVELS BY
SUNDAY EVENING...AND LIKELY REACHING ADVISORY LEVELS BY MONDAY.
OTHERWISE...A SMALL TO MODERATE NORTHWEST SWELL WILL CONTINUE
TONIGHT INTO SUNDAY...THEN DECLINE SUNDAY EVENING. ANOTHER
MODERATE NORTHWEST SWELL IS EXPECTED TO ARRIVE WEDNESDAY NIGHT AND
CONTINUE THROUGH FRIDAY. RESULTING SURF ON NORTH AND WEST FACING
SHORES WILL REMAIN WELL BELOW ADVISORY LEVELS.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY FROM 10 AM SUNDAY TO 6 PM HST MONDAY FOR WAIANAE
COAST-OAHU KOOLAU-OLOMANA-WAIANAE MOUNTAINS-LANAI-KAHOOLAWE-MAUI
WINDWARD WEST-MAUI LEEWARD WEST-MAUI CENTRAL VALLEY-SOUTH BIG
ISLAND-BIG ISLAND NORTH AND EAST-KOHALA-BIG ISLAND INTERIOR.

SMALL CRAFT ADVISORY UNTIL 6 PM HST MONDAY FOR ALL HAWAIIAN
WATERS.

&&

$$

DISCUSSION/MARINE...JACOBSON
AVIATION...LAU









000
FXHW60 PHFO 200153
AFDHFO

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
353 PM HST SAT APR 19 2014

.SYNOPSIS...
TRADE WINDS WILL INCREASE SUNDAY BRINGING WINDY CONDITIONS THROUGH
MONDAY...BEFORE DROPPING TO MODERATE LEVELS TUESDAY. SHOWERS WILL
FOCUS OVER WINDWARD SLOPES WITH LEEWARD AREAS SEEING ISOLATED
SHOWERS.

&&

.DISCUSSION...

HIGH PRESSURE NORTH OF THE STATE CONTINUES TO BRING ISLAND TRADE
WINDS THIS EVENING... WHILE SHOWERS BRING CLOUDS AND LIGHT
RAINFALL TO THE WINDWARD SLOPES. TRADE WINDS WILL CONTINUE THROUGH
THE FORECAST PERIOD WITH AN UPTICK IN WINDS AND SHOWERS EXPECTED
TONIGHT THROUGH TUESDAY.

HIGH PRESSURE MOVING IN FROM THE WEST WILL BUILD NORTH OF HAWAII
TONIGHT AND SUNDAY. THE PRESSURE GRADIENT WILL TIGHTEN FROM N TO S
ACROSS THE AREA AS THE HIGH BUILDS...AND WINDS WILL INCREASE IN
RESPONSE. A WIND ADVISORY HAS BEEN ISSUED ACROSS PARTS OF OAHU...
MAUI COUNTY... AND THE BIG ISLAND AS THE INCREASING WINDS
ACCELERATE AROUND AND OVER THE ISLAND TERRAIN. TUESDAY...THE HIGH
WILL PUSH TOWARD THE EAST PACIFIC AS A WEAK FRONT MOVES ACROSS THE
DATELINE. WINDS OVER THE STATE WILL DECREASE TO MODERATE TRADES AS
THE HIGH MOVES INTO THE EAST PACIFIC FOR THE SECOND HALF OF THE
WEEK.

CURRENT PRECIPITABLE WATER VALUES ARE BELOW NORMAL NEAR THE
ISLANDS AND SHOWERS HAVE BEEN LIMITED. THE MIMIC PRECIP WATER
FIELD SHOWS AN INCREASE IN MOISTURE UPSTREAM OF THE ISLANDS NEAR
152W AND 23N. THIS MOISTURE IS EXPECTED TO INCREASE WINDWARD
SHOWERS TONIGHT THROUGH TUESDAY NIGHT AS THE MOISTURE MOVES ACROSS
THE AREA.

&&

.AVIATION...
TRADE WIND FLOW CONTINUES...RESULTING IN AIRMET TANGO FOR TURBULENCE
TO THE LEE OF THE ALL ISLANDS. TRADES ARE EXPECTED TO INCREASE THROUGH
THE WEEKEND...SO EXPECTING THE AIRMET TO CONTINUE.

CLOUDS AND SHOWERS BEING CARRIED IN ON THE TRADES WILL BRING MVFR
CONDITIONS MAINLY TO WINDWARD AND MAUKA AREAS FROM TIME TO
TIME...AND ISOLATED IFR CONDITIONS ARE POSSIBLE. OTHERWISE VFR
CONDITIONS ARE EXPECTED TO PREVAIL OVER LEEWARD AREAS.


&&

.MARINE...
THE SMALL CRAFT ADVISORY COVERS ALL HAWAIIAN COASTAL WATERS DUE TO
SEAS AND WINDS. WINDS WILL INCREASE FURTHER SUNDAY AS HIGH PRESSURE
BUILDS TO OUR NORTH...AND THE SCA EXTENDS THROUGH MONDAY. WINDS
MAY REACH NEAR GALE FORCE AT TIMES SUNDAY THROUGH MONDAY IN THE
ALENUIHAHA CHANNEL.

A SMALL TO MODERATE NORTHWEST SWELL WILL BUILD TONIGHT...THEN
DECLINE SUNDAY EVENING. ANOTHER MODERATE NORTHWEST SWELL IS
EXPECTED NEXT WEDNESDAY NIGHT AND WILL CONTINUE THROUGH THE END OF
NEXT WEEK. STRENGTHENING TRADE WINDS WILL PRODUCE SHORT
PERIOD...CHOPPY SURF ALONG EAST FACING SHORES...LIKELY REACHING
ADVISORY LEVELS LATE SUNDAY OR MONDAY.


&&

.HFO WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY FROM 6 AM SUNDAY TO 6 PM HST MONDAY FOR WAIANAE
COAST-OAHU KOOLAU-OLOMANA-WAIANAE MOUNTAINS-LANAI-KAHOOLAWE-MAUI
WINDWARD WEST-MAUI LEEWARD WEST-MAUI CENTRAL VALLEY-SOUTH BIG
ISLAND-BIG ISLAND NORTH AND EAST-KOHALA-BIG ISLAND INTERIOR.

SMALL CRAFT ADVISORY UNTIL 6 PM HST MONDAY FOR ALL HAWAIIAN
WATERS-


&&

$$

MORRISON...DISCUSSION/MARINE
M BALLARD...AVIATION







000
FXHW60 PHFO 200153
AFDHFO

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
353 PM HST SAT APR 19 2014

.SYNOPSIS...
TRADE WINDS WILL INCREASE SUNDAY BRINGING WINDY CONDITIONS THROUGH
MONDAY...BEFORE DROPPING TO MODERATE LEVELS TUESDAY. SHOWERS WILL
FOCUS OVER WINDWARD SLOPES WITH LEEWARD AREAS SEEING ISOLATED
SHOWERS.

&&

.DISCUSSION...

HIGH PRESSURE NORTH OF THE STATE CONTINUES TO BRING ISLAND TRADE
WINDS THIS EVENING... WHILE SHOWERS BRING CLOUDS AND LIGHT
RAINFALL TO THE WINDWARD SLOPES. TRADE WINDS WILL CONTINUE THROUGH
THE FORECAST PERIOD WITH AN UPTICK IN WINDS AND SHOWERS EXPECTED
TONIGHT THROUGH TUESDAY.

HIGH PRESSURE MOVING IN FROM THE WEST WILL BUILD NORTH OF HAWAII
TONIGHT AND SUNDAY. THE PRESSURE GRADIENT WILL TIGHTEN FROM N TO S
ACROSS THE AREA AS THE HIGH BUILDS...AND WINDS WILL INCREASE IN
RESPONSE. A WIND ADVISORY HAS BEEN ISSUED ACROSS PARTS OF OAHU...
MAUI COUNTY... AND THE BIG ISLAND AS THE INCREASING WINDS
ACCELERATE AROUND AND OVER THE ISLAND TERRAIN. TUESDAY...THE HIGH
WILL PUSH TOWARD THE EAST PACIFIC AS A WEAK FRONT MOVES ACROSS THE
DATELINE. WINDS OVER THE STATE WILL DECREASE TO MODERATE TRADES AS
THE HIGH MOVES INTO THE EAST PACIFIC FOR THE SECOND HALF OF THE
WEEK.

CURRENT PRECIPITABLE WATER VALUES ARE BELOW NORMAL NEAR THE
ISLANDS AND SHOWERS HAVE BEEN LIMITED. THE MIMIC PRECIP WATER
FIELD SHOWS AN INCREASE IN MOISTURE UPSTREAM OF THE ISLANDS NEAR
152W AND 23N. THIS MOISTURE IS EXPECTED TO INCREASE WINDWARD
SHOWERS TONIGHT THROUGH TUESDAY NIGHT AS THE MOISTURE MOVES ACROSS
THE AREA.

&&

.AVIATION...
TRADE WIND FLOW CONTINUES...RESULTING IN AIRMET TANGO FOR TURBULENCE
TO THE LEE OF THE ALL ISLANDS. TRADES ARE EXPECTED TO INCREASE THROUGH
THE WEEKEND...SO EXPECTING THE AIRMET TO CONTINUE.

CLOUDS AND SHOWERS BEING CARRIED IN ON THE TRADES WILL BRING MVFR
CONDITIONS MAINLY TO WINDWARD AND MAUKA AREAS FROM TIME TO
TIME...AND ISOLATED IFR CONDITIONS ARE POSSIBLE. OTHERWISE VFR
CONDITIONS ARE EXPECTED TO PREVAIL OVER LEEWARD AREAS.


&&

.MARINE...
THE SMALL CRAFT ADVISORY COVERS ALL HAWAIIAN COASTAL WATERS DUE TO
SEAS AND WINDS. WINDS WILL INCREASE FURTHER SUNDAY AS HIGH PRESSURE
BUILDS TO OUR NORTH...AND THE SCA EXTENDS THROUGH MONDAY. WINDS
MAY REACH NEAR GALE FORCE AT TIMES SUNDAY THROUGH MONDAY IN THE
ALENUIHAHA CHANNEL.

A SMALL TO MODERATE NORTHWEST SWELL WILL BUILD TONIGHT...THEN
DECLINE SUNDAY EVENING. ANOTHER MODERATE NORTHWEST SWELL IS
EXPECTED NEXT WEDNESDAY NIGHT AND WILL CONTINUE THROUGH THE END OF
NEXT WEEK. STRENGTHENING TRADE WINDS WILL PRODUCE SHORT
PERIOD...CHOPPY SURF ALONG EAST FACING SHORES...LIKELY REACHING
ADVISORY LEVELS LATE SUNDAY OR MONDAY.


&&

.HFO WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY FROM 6 AM SUNDAY TO 6 PM HST MONDAY FOR WAIANAE
COAST-OAHU KOOLAU-OLOMANA-WAIANAE MOUNTAINS-LANAI-KAHOOLAWE-MAUI
WINDWARD WEST-MAUI LEEWARD WEST-MAUI CENTRAL VALLEY-SOUTH BIG
ISLAND-BIG ISLAND NORTH AND EAST-KOHALA-BIG ISLAND INTERIOR.

SMALL CRAFT ADVISORY UNTIL 6 PM HST MONDAY FOR ALL HAWAIIAN
WATERS-


&&

$$

MORRISON...DISCUSSION/MARINE
M BALLARD...AVIATION








000
FXHW60 PHFO 192019
AFDHFO

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
1019 AM HST SAT APR 19 2014

.SYNOPSIS...
BREEZY TRADE WINDS WILL CONTINUE THROUGH THE WEEK WITH SHOWERS
FOCUSING OVER THE WINDWARD SLOPES. LEEWARD AREAS OF THE SMALLER
ISLANDS WILL SEE A FEW SHOWERS IN THE EARLY MORNING AND LATE
AFTERNOON.

&&

.DISCUSSION...
HIGH PRESSURE NORTH OF THE STATE IS PROVIDING STEADY TRADE WINDS
ACROSS THE ISLANDS TODAY. WINDWARD SHOWERS ARE BRINGING CLOUDS AND
LIGHT RAINFALL ALONG THE WINDWARD SLOPES. TRADE WINDS WILL CONTINUE
THROUGH THE FORECAST PERIOD WITH AN UPTICK IN WINDS AND SHOWERS
EXPECTED SUNDAY THROUGH TUESDAY.

HIGH PRESSURE MOVING IN FROM THE WEST WILL BUILD NORTH OF HAWAII
TONIGHT AND SUNDAY. THE PRESSURE GRADIENT WILL TIGHTEN FROM N TO S
ACROSS THE AREA AS THE HIGH BUILDS...AND WINDS WILL INCREASE IN
RESPONSE. A WIND ADVISORY MAY BE NECESSARY ACROSS THE WINDIER
AREAS OF THE BIG ISLAND AND MAUI COUNTY SUNDAY AS THE WINDS
INCREASE. TUESDAY...THE HIGH WILL PUSH TOWARD THE EAST PACIFIC
AS A WEAK FRONT MOVES ACROSS THE DATELINE. WINDS OVER THE STATE
WILL DECREASE TO MODERATE TRADES AS THE HIGH MOVES INTO THE EAST
PACIFIC FOR THE SECOND HALF OF THE WEEK.

CURRENT PRECIPITABLE WATER VALUES ARE BELOW NORMAL NEAR THE
ISLANDS AND SHOWERS HAVE BEEN LIMITED. THE MIMIC PRECIP WATER
FIELD SHOWS AN INCREASE IN MOISTURE UPSTREAM OF THE ISLANDS NEAR
150W AND 24N. THIS MOISTURE IS EXPECTED TO INCREASE WINDWARD
SHOWERS TONIGHT THROUGH TUESDAY NIGHT AS THE MOISTURE MOVES ACROSS THE
AREA.


&&


.AVIATION...
TRADE WIND FLOW CONTINUES...RESULTING IN AIRMET TANGO FOR TURBULENCE
TO THE LEE OF THE ALL ISLANDS. TRADES ARE EXPECTED TO INCREASE THROUGH
THE WEEKEND...SO EXPECTING THE AIRMET TO CONTINUE.

CLOUDS AND SHOWERS BEING CARRIED IN ON THE TRADES WILL BRING MVFR
CONDITIONS MAINLY TO WINDWARD AND MAUKA AREAS FROM TIME TO
TIME...AND ISOLATED IFR CONDITIONS ARE POSSIBLE. OTHERWISE VFR
CONDITIONS ARE EXPECTED TO PREVAIL OVER LEEWARD AREAS.


&&

.MARINE...
THE SMALL CRAFT ADVISORY COVERS ALL HAWAIIAN COASTAL WATERS DUE TO
SEAS AND WINDS. WINDS SHOULD ONLY INCREASE FURTHER WITH TIME AS HIGH
PRESSURE BUILDS TO OUR NORTH...AND THE SCA EXTENDS THROUGH
MONDAY. WINDS MAY REACH NEAR GALE FORCE AT TIMES SUNDAY THROUGH
MONDAY IN THE ALENUIHAHA CHANNEL.

A SMALL TO MODERATE NORTHWEST SWELL WILL BUILD LATER TODAY AND
TONIGHT...THEN DECLINE SUNDAY EVENING. ANOTHER MODERATE NORTHWEST
SWELL IS EXPECTED NEXT WEDNESDAY NIGHT AND WILL CONTINUE THROUGH
THE END OF NEXT WEEK. STRENGTHENING TRADE WINDS WILL PRODUCE SHORT
PERIOD...CHOPPY SURF ALONG EAST FACING SHORES...LIKELY REACHING
ADVISORY LEVELS ON EAST FACING SHORES BY LATE SUNDAY OR MONDAY.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
SMALL CRAFT ADVISORY UNTIL 6 PM HST MONDAY FOR ALL HAWAIIAN
WATERS-


&&

$$

MORRISON...DISCUSSION/MARINE
M BALLARD...AVIATION







000
FXHW60 PHFO 192019
AFDHFO

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
1019 AM HST SAT APR 19 2014

.SYNOPSIS...
BREEZY TRADE WINDS WILL CONTINUE THROUGH THE WEEK WITH SHOWERS
FOCUSING OVER THE WINDWARD SLOPES. LEEWARD AREAS OF THE SMALLER
ISLANDS WILL SEE A FEW SHOWERS IN THE EARLY MORNING AND LATE
AFTERNOON.

&&

.DISCUSSION...
HIGH PRESSURE NORTH OF THE STATE IS PROVIDING STEADY TRADE WINDS
ACROSS THE ISLANDS TODAY. WINDWARD SHOWERS ARE BRINGING CLOUDS AND
LIGHT RAINFALL ALONG THE WINDWARD SLOPES. TRADE WINDS WILL CONTINUE
THROUGH THE FORECAST PERIOD WITH AN UPTICK IN WINDS AND SHOWERS
EXPECTED SUNDAY THROUGH TUESDAY.

HIGH PRESSURE MOVING IN FROM THE WEST WILL BUILD NORTH OF HAWAII
TONIGHT AND SUNDAY. THE PRESSURE GRADIENT WILL TIGHTEN FROM N TO S
ACROSS THE AREA AS THE HIGH BUILDS...AND WINDS WILL INCREASE IN
RESPONSE. A WIND ADVISORY MAY BE NECESSARY ACROSS THE WINDIER
AREAS OF THE BIG ISLAND AND MAUI COUNTY SUNDAY AS THE WINDS
INCREASE. TUESDAY...THE HIGH WILL PUSH TOWARD THE EAST PACIFIC
AS A WEAK FRONT MOVES ACROSS THE DATELINE. WINDS OVER THE STATE
WILL DECREASE TO MODERATE TRADES AS THE HIGH MOVES INTO THE EAST
PACIFIC FOR THE SECOND HALF OF THE WEEK.

CURRENT PRECIPITABLE WATER VALUES ARE BELOW NORMAL NEAR THE
ISLANDS AND SHOWERS HAVE BEEN LIMITED. THE MIMIC PRECIP WATER
FIELD SHOWS AN INCREASE IN MOISTURE UPSTREAM OF THE ISLANDS NEAR
150W AND 24N. THIS MOISTURE IS EXPECTED TO INCREASE WINDWARD
SHOWERS TONIGHT THROUGH TUESDAY NIGHT AS THE MOISTURE MOVES ACROSS THE
AREA.


&&


.AVIATION...
TRADE WIND FLOW CONTINUES...RESULTING IN AIRMET TANGO FOR TURBULENCE
TO THE LEE OF THE ALL ISLANDS. TRADES ARE EXPECTED TO INCREASE THROUGH
THE WEEKEND...SO EXPECTING THE AIRMET TO CONTINUE.

CLOUDS AND SHOWERS BEING CARRIED IN ON THE TRADES WILL BRING MVFR
CONDITIONS MAINLY TO WINDWARD AND MAUKA AREAS FROM TIME TO
TIME...AND ISOLATED IFR CONDITIONS ARE POSSIBLE. OTHERWISE VFR
CONDITIONS ARE EXPECTED TO PREVAIL OVER LEEWARD AREAS.


&&

.MARINE...
THE SMALL CRAFT ADVISORY COVERS ALL HAWAIIAN COASTAL WATERS DUE TO
SEAS AND WINDS. WINDS SHOULD ONLY INCREASE FURTHER WITH TIME AS HIGH
PRESSURE BUILDS TO OUR NORTH...AND THE SCA EXTENDS THROUGH
MONDAY. WINDS MAY REACH NEAR GALE FORCE AT TIMES SUNDAY THROUGH
MONDAY IN THE ALENUIHAHA CHANNEL.

A SMALL TO MODERATE NORTHWEST SWELL WILL BUILD LATER TODAY AND
TONIGHT...THEN DECLINE SUNDAY EVENING. ANOTHER MODERATE NORTHWEST
SWELL IS EXPECTED NEXT WEDNESDAY NIGHT AND WILL CONTINUE THROUGH
THE END OF NEXT WEEK. STRENGTHENING TRADE WINDS WILL PRODUCE SHORT
PERIOD...CHOPPY SURF ALONG EAST FACING SHORES...LIKELY REACHING
ADVISORY LEVELS ON EAST FACING SHORES BY LATE SUNDAY OR MONDAY.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
SMALL CRAFT ADVISORY UNTIL 6 PM HST MONDAY FOR ALL HAWAIIAN
WATERS-


&&

$$

MORRISON...DISCUSSION/MARINE
M BALLARD...AVIATION








000
FXHW60 PHFO 191340
AFDHFO

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
340 AM HST SAT APR 19 2014

.SYNOPSIS...
A TRADE WIND WEATHER PATTERN WILL CONTINUE THROUGH THE NEXT
SEVERAL DAYS ACROSS HAWAII...THANKS TO HIGH PRESSURE NORTH OF THE
STATE. SHOWERS WILL FAVOR WINDWARD AND MAUKA AREAS WITH A FEW
SHOWERS POSSIBLE OVER SOME LEEWARD LOCATIONS.

&&

.DISCUSSION...
SHOWERS HAVE BECOME RATHER SPARSE OVER THE STATE DURING THE PAST
SEVERAL HOURS...WITH RADAR AND RAIN GAUGE DATA SHOWING ONLY VERY
LIGHT RAINFALL AMOUNTS ACROSS SOME WINDWARD AREAS. THE 12Z
SOUNDINGS SHOW A LOWERING OF THE INVERSION AS EXPECTED...WITH THE
BASE DOWN TO BETWEEN 5700 AND 6700 FEET...FROM ABOUT 9000 FEET 12
HOURS EARLIER. THIS IS CONSISTENT WITH MIMIC-TPW SATELLITE DATA
WHICH INDICATE A DRIER AIRMASS SPREADING INTO THE STATE FROM THE
EAST. EARLIER MODEL DATA SUGGESTED THAT THIS DRYING WOULD TAKE
PLACE PRIMARILY IN THE 850-700 MB LAYER...AGAIN CONSISTENT WITH
THE 12Z RAOB DATA. SATELLITE IMAGERY DEPICTS ABUNDANT HIGH
LEVEL CLOUDINESS STREAMING NORTHWARD ACROSS THE STATE...TO THE
EAST OF A MID/UPPER LEVEL TROUGH CENTERED SEVERAL HUNDRED MILES
TO THE SOUTHWEST. AT THE SURFACE...A 1023 MB HIGH IS CENTERED WELL
NORTHEAST OF THE STATE...WITH A STRONGER 1028 MB HIGH BUILDING
EASTWARD FROM THE DATELINE NORTH OF 30N.

FOR TODAY...EXPECT SHOWER COVERAGE TO REMAIN FAIRLY SPARSE WITH
LIGHT RAINFALL AMOUNTS EVEN ACROSS WINDWARD SECTIONS...AS STABLE
AND DRY CONDITIONS CONTINUE. TONIGHT...SATELLITE AND MODEL DATA
INDICATE THAT ANOTHER AREA OF HIGHER MOISTURE WILL BE MOVING INTO
THE STATE...ALTHOUGH MODEL SOUNDINGS SHOW THE INVERSION REMAINING
FAIRLY LOW. WITH BRISK TRADES IN PLACE...THE INFLUX OF ADDITIONAL
LOW LEVEL MOISTURE SHOULD BE SUFFICIENT TO INCREASE SHOWER
ACTIVITY ONCE AGAIN ACROSS WINDWARD/MAUKA AREAS...WITH SOME
SPILLOVER INTO LEEWARD.

SUNDAY THROUGH MONDAY NIGHT...RATHER STRONG HIGH PRESSURE WILL
PASS NORTH OF THE STATE...CAUSING TRADES TO INCREASE FURTHER.
ALOFT...GUIDANCE INDICATES THAT THE MID/UPPER TROUGH TO OUR
SOUTHWEST WILL SHEAR APART...WITH THE MID LEVEL TROUGH MOVING TO
THE WEST SOUTHWEST AND AWAY FROM OUR AREA...WHILE THE WEAKENING
UPPER LEVEL TROUGH DRIFTS SLOWLY TO THE EAST NORTHEAST. A DEEP DRY
LAYER WILL PERSIST ACROSS THE STATE IN THE MID LEVELS...WITH A MID
LEVEL RIDGE BUILDING JUST TO OUR NORTH. THEREFORE WOULD EXPECT
THE ONLY IMPACT TO OUR SENSIBLE WEATHER FROM THE UPPER TROUGH TO
BE PERIODS OF HIGH LEVEL CLOUDINESS. ACTIVE TRADE SHOWERS WILL
CONTINUE ACROSS WINDWARD/MAUKA...WITH SOME SPILLOVER TO LEEWARD
DUE TO THE STRENGTH OF THE TRADES.

TRADES SHOULD RETURN TO MORE MODERATE LEVELS TUESDAY THROUGH
THURSDAY...AS THE FIRST SURFACE HIGH SHIFTS FURTHER TO THE
NORTHEAST AND IS REPLACED BY A SECOND SLIGHTLY WEAKER HIGH TO OUR
NORTH. WOULD EXPECT LITTLE CHANGE IN THE WEATHER PATTERN ACROSS
HAWAII WITH SHOWERS CONTINUING MAINLY ACROSS WINDWARD SECTIONS.

&&

.AVIATION...
A TRADE WIND FLOW CONTINUES WITH EMBEDDED SHOWERS FAVORING THE
WINDWARD AND MTN AREAS. BUT IT APPEARS THIS FLOW HAS BECOME DRIER AS
THE NIGHT PROGRESSES. FIRST IS THE MARINE LAYER WHICH HAS LOWERED
FROM 10K EARLY IN THE EVENING TO THE CURRENT...BETWEEN 6 AND 7K
FEET. SECOND...RADAR RETURNS ARE NOT AS ACTIVE AS AT THE START OF
THE EVENING. THE SHOWERS HAVE TURNED LIGHTER TO PERHAPS MORE OF A
DRIZZLE. THIRD...SFC OBS FROM AROUND THE STATE SUGGEST THE LO CLD
COVER ESPECIALLY FROM THE WINDWARD STATIONS...HAS BECOME LESS.
CLOUD BASES THOUGH REMAINS AS LOW AS 2K FEET. MODELS SUGGESTS THIS
DRIER AIR MASS TO PERSISTS THROUGH ALL OF TODAY. HENCE...VFR
CONDITION RULES. ANY MVFR DUE TO CEILINGS AND VIS WILL BE BRIEF
AND ISOLATED AND FAVORING THE WINDWARD AND MTN AREAS.

LITTLE CHANGE TO THE STRENGTH OF THE TRADE WINDS WHICH WILL BE IN
THE MODERATE TO STRONG RANGE. GIVEN A DECENT INVERSION...AIRMET
TANGO FOR MOD MECHANICAL TURB WILL CONT TO WELL BEYOND 04Z SUNDAY.

&&

.MARINE...
AN 0830Z ASCAT PASS ONLY CAUGHT THE WESTERN EDGE OF THE COASTAL
WATERS...BUT DID SHOW SIGNIFICANT COVERAGE OF 23-25 KT WINDS WEST
AND SOUTH OF KAUAI. THESE WINDS ARE SEVERAL KNOTS ABOVE GUIDANCE...
BUT THIS DATA COMBINED WITH AVAILABLE LAND STATION OBS SUPPORT
EXPANDING THE SMALL CRAFT ADVISORY TO COVER ALL HAWAIIAN COASTAL
WATERS. WINDS SHOULD ONLY INCREASE FURTHER WITH TIME AS HIGH
PRESSURE BUILDS TO OUR NORTH...AND HAVE ALSO EXTENDED THE SCA
IN TIME OUT THROUGH MONDAY. WINDS MAY REACH NEAR GALE FORCE AT
TIMES SUNDAY THROUGH MONDAY IN THE ALENUIHAHA CHANNEL.

ANOTHER SMALL NORTHWEST SWELL IS EXPECTED TO ARRIVE LATER TODAY
AND LINGER THROUGH SUNDAY...BUT THE RESULTING SURF WILL REMAIN
WELL BELOW ADVISORY LEVELS FOR NORTH AND WEST FACING SHORES. TRADE
WINDS WILL CONTINUE TO PRODUCE SHORT PERIOD CHOPPY SURF ALONG EAST
FACING SHORES...AND HIGH SURF ADVISORIES WILL PROBABLY BE NEEDED
BY SUNDAY AS THE FETCH LENGTH INCREASES DUE TO THE BUILDING HIGH
TO OUR NORTH.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
SMALL CRAFT ADVISORY UNTIL 6 PM HST MONDAY FOR ALL HAWAIIAN
WATERS.

&&

$$

DISCUSSION/MARINE...JACOBSON
AVIATION...LAU








000
FXHW60 PHFO 191340
AFDHFO

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
340 AM HST SAT APR 19 2014

.SYNOPSIS...
A TRADE WIND WEATHER PATTERN WILL CONTINUE THROUGH THE NEXT
SEVERAL DAYS ACROSS HAWAII...THANKS TO HIGH PRESSURE NORTH OF THE
STATE. SHOWERS WILL FAVOR WINDWARD AND MAUKA AREAS WITH A FEW
SHOWERS POSSIBLE OVER SOME LEEWARD LOCATIONS.

&&

.DISCUSSION...
SHOWERS HAVE BECOME RATHER SPARSE OVER THE STATE DURING THE PAST
SEVERAL HOURS...WITH RADAR AND RAIN GAUGE DATA SHOWING ONLY VERY
LIGHT RAINFALL AMOUNTS ACROSS SOME WINDWARD AREAS. THE 12Z
SOUNDINGS SHOW A LOWERING OF THE INVERSION AS EXPECTED...WITH THE
BASE DOWN TO BETWEEN 5700 AND 6700 FEET...FROM ABOUT 9000 FEET 12
HOURS EARLIER. THIS IS CONSISTENT WITH MIMIC-TPW SATELLITE DATA
WHICH INDICATE A DRIER AIRMASS SPREADING INTO THE STATE FROM THE
EAST. EARLIER MODEL DATA SUGGESTED THAT THIS DRYING WOULD TAKE
PLACE PRIMARILY IN THE 850-700 MB LAYER...AGAIN CONSISTENT WITH
THE 12Z RAOB DATA. SATELLITE IMAGERY DEPICTS ABUNDANT HIGH
LEVEL CLOUDINESS STREAMING NORTHWARD ACROSS THE STATE...TO THE
EAST OF A MID/UPPER LEVEL TROUGH CENTERED SEVERAL HUNDRED MILES
TO THE SOUTHWEST. AT THE SURFACE...A 1023 MB HIGH IS CENTERED WELL
NORTHEAST OF THE STATE...WITH A STRONGER 1028 MB HIGH BUILDING
EASTWARD FROM THE DATELINE NORTH OF 30N.

FOR TODAY...EXPECT SHOWER COVERAGE TO REMAIN FAIRLY SPARSE WITH
LIGHT RAINFALL AMOUNTS EVEN ACROSS WINDWARD SECTIONS...AS STABLE
AND DRY CONDITIONS CONTINUE. TONIGHT...SATELLITE AND MODEL DATA
INDICATE THAT ANOTHER AREA OF HIGHER MOISTURE WILL BE MOVING INTO
THE STATE...ALTHOUGH MODEL SOUNDINGS SHOW THE INVERSION REMAINING
FAIRLY LOW. WITH BRISK TRADES IN PLACE...THE INFLUX OF ADDITIONAL
LOW LEVEL MOISTURE SHOULD BE SUFFICIENT TO INCREASE SHOWER
ACTIVITY ONCE AGAIN ACROSS WINDWARD/MAUKA AREAS...WITH SOME
SPILLOVER INTO LEEWARD.

SUNDAY THROUGH MONDAY NIGHT...RATHER STRONG HIGH PRESSURE WILL
PASS NORTH OF THE STATE...CAUSING TRADES TO INCREASE FURTHER.
ALOFT...GUIDANCE INDICATES THAT THE MID/UPPER TROUGH TO OUR
SOUTHWEST WILL SHEAR APART...WITH THE MID LEVEL TROUGH MOVING TO
THE WEST SOUTHWEST AND AWAY FROM OUR AREA...WHILE THE WEAKENING
UPPER LEVEL TROUGH DRIFTS SLOWLY TO THE EAST NORTHEAST. A DEEP DRY
LAYER WILL PERSIST ACROSS THE STATE IN THE MID LEVELS...WITH A MID
LEVEL RIDGE BUILDING JUST TO OUR NORTH. THEREFORE WOULD EXPECT
THE ONLY IMPACT TO OUR SENSIBLE WEATHER FROM THE UPPER TROUGH TO
BE PERIODS OF HIGH LEVEL CLOUDINESS. ACTIVE TRADE SHOWERS WILL
CONTINUE ACROSS WINDWARD/MAUKA...WITH SOME SPILLOVER TO LEEWARD
DUE TO THE STRENGTH OF THE TRADES.

TRADES SHOULD RETURN TO MORE MODERATE LEVELS TUESDAY THROUGH
THURSDAY...AS THE FIRST SURFACE HIGH SHIFTS FURTHER TO THE
NORTHEAST AND IS REPLACED BY A SECOND SLIGHTLY WEAKER HIGH TO OUR
NORTH. WOULD EXPECT LITTLE CHANGE IN THE WEATHER PATTERN ACROSS
HAWAII WITH SHOWERS CONTINUING MAINLY ACROSS WINDWARD SECTIONS.

&&

.AVIATION...
A TRADE WIND FLOW CONTINUES WITH EMBEDDED SHOWERS FAVORING THE
WINDWARD AND MTN AREAS. BUT IT APPEARS THIS FLOW HAS BECOME DRIER AS
THE NIGHT PROGRESSES. FIRST IS THE MARINE LAYER WHICH HAS LOWERED
FROM 10K EARLY IN THE EVENING TO THE CURRENT...BETWEEN 6 AND 7K
FEET. SECOND...RADAR RETURNS ARE NOT AS ACTIVE AS AT THE START OF
THE EVENING. THE SHOWERS HAVE TURNED LIGHTER TO PERHAPS MORE OF A
DRIZZLE. THIRD...SFC OBS FROM AROUND THE STATE SUGGEST THE LO CLD
COVER ESPECIALLY FROM THE WINDWARD STATIONS...HAS BECOME LESS.
CLOUD BASES THOUGH REMAINS AS LOW AS 2K FEET. MODELS SUGGESTS THIS
DRIER AIR MASS TO PERSISTS THROUGH ALL OF TODAY. HENCE...VFR
CONDITION RULES. ANY MVFR DUE TO CEILINGS AND VIS WILL BE BRIEF
AND ISOLATED AND FAVORING THE WINDWARD AND MTN AREAS.

LITTLE CHANGE TO THE STRENGTH OF THE TRADE WINDS WHICH WILL BE IN
THE MODERATE TO STRONG RANGE. GIVEN A DECENT INVERSION...AIRMET
TANGO FOR MOD MECHANICAL TURB WILL CONT TO WELL BEYOND 04Z SUNDAY.

&&

.MARINE...
AN 0830Z ASCAT PASS ONLY CAUGHT THE WESTERN EDGE OF THE COASTAL
WATERS...BUT DID SHOW SIGNIFICANT COVERAGE OF 23-25 KT WINDS WEST
AND SOUTH OF KAUAI. THESE WINDS ARE SEVERAL KNOTS ABOVE GUIDANCE...
BUT THIS DATA COMBINED WITH AVAILABLE LAND STATION OBS SUPPORT
EXPANDING THE SMALL CRAFT ADVISORY TO COVER ALL HAWAIIAN COASTAL
WATERS. WINDS SHOULD ONLY INCREASE FURTHER WITH TIME AS HIGH
PRESSURE BUILDS TO OUR NORTH...AND HAVE ALSO EXTENDED THE SCA
IN TIME OUT THROUGH MONDAY. WINDS MAY REACH NEAR GALE FORCE AT
TIMES SUNDAY THROUGH MONDAY IN THE ALENUIHAHA CHANNEL.

ANOTHER SMALL NORTHWEST SWELL IS EXPECTED TO ARRIVE LATER TODAY
AND LINGER THROUGH SUNDAY...BUT THE RESULTING SURF WILL REMAIN
WELL BELOW ADVISORY LEVELS FOR NORTH AND WEST FACING SHORES. TRADE
WINDS WILL CONTINUE TO PRODUCE SHORT PERIOD CHOPPY SURF ALONG EAST
FACING SHORES...AND HIGH SURF ADVISORIES WILL PROBABLY BE NEEDED
BY SUNDAY AS THE FETCH LENGTH INCREASES DUE TO THE BUILDING HIGH
TO OUR NORTH.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
SMALL CRAFT ADVISORY UNTIL 6 PM HST MONDAY FOR ALL HAWAIIAN
WATERS.

&&

$$

DISCUSSION/MARINE...JACOBSON
AVIATION...LAU









000
FXHW60 PHFO 190630
AFDHFO

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
830 PM HST FRI APR 18 2014

.SYNOPSIS...
A TRADE WIND WEATHER PATTERN WILL CONTINUE THROUGH THE NEXT
SEVERAL DAYS ACROSS HAWAII...THANKS TO HIGH PRESSURE NORTH OF THE
STATE. CLOUDS AND PASSING SHOWERS WILL FAVOR WINDWARD AND MAUKA
AREAS WITH A FEW SHOWERS POSSIBLE OVER SOME LEEWARD LOCATIONS.

&&

.DISCUSSION...
RADAR AND RAIN GAUGE DATA INDICATE THAT SHOWER ACTIVITY HAS
REMAINED FOCUSED PRIMARILY ACROSS THE TYPICALLY WETTER WINDWARD
AND MAUKA AREAS DURING THE PAST SEVERAL HOURS...BUT LIGHT RAINFALL
AMOUNTS HAVE OCCURRED AT SOME LEEWARD SPOTS. THE 00Z SOUNDINGS
SHOW A RATHER HIGH INVERSION BASED NEAR 9000 FEET. THE DEEPER
MOIST LAYER BENEATH THE INVERSION ALLOWS FOR PWATS TO BE NEAR OR
ABOVE NORMAL...WITH THE LIHUE PWAT JUST ABOVE THE 75TH PERCENTILE
FOR THIS TIME OF YEAR. SATELLITE IMAGERY DEPICTS ABUNDANT HIGH
LEVEL CLOUDINESS STREAMING NORTHWARD ACROSS THE STATE...TO THE
EAST OF A MID/UPPER LEVEL TROUGH CENTERED SEVERAL HUNDRED MILES
TO THE SOUTHWEST. AT THE SURFACE...A 1024 MB HIGH IS CENTERED WELL
NORTHEAST OF THE STATE...WITH A SLIGHTLY STRONGER HIGH WELL TO OUR
NORTHWEST.

FOR THE OVERNIGHT PERIOD INTO SATURDAY MORNING...MIMIC-TPW
SATELLITE IMAGERY AND MODEL DATA SUGGEST THAT A SLIGHTLY DRIER
LOWER/MID LEVEL (850-700 MB) AIRMASS WILL SPREAD ACROSS THE STATE
FROM THE EAST. MODEL SOUNDINGS SHOW A LOWERING OF THE INVERSION
DURING THIS TIME AS WELL. THEREFORE IN THE NEAR TERM WOULD EXPECT
TRADE SHOWERS TO REMAIN SOMEWHAT ACTIVE THROUGH THE REST OF THIS
EVENING AND INTO THE OVERNIGHT...THEN BECOME MORE LIMITED IN EXTENT
WITH LIGHTER RAINFALL AMOUNTS TOWARD SUNRISE AND INTO SATURDAY.

THROUGH THE REST OF THE WEEKEND AND INTO EARLY NEXT WEEK...HIGH
PRESSURE WILL STRENGTHEN TO THE NORTH OF THE STATE...CAUSING AN
UPTICK IN THE TRADE WIND FLOW FROM SUNDAY THROUGH MONDAY. 850-700
MB LAYER MOISTURE IS FORECAST TO INCREASE ONCE AGAIN DURING THAT
TIME AS WELL. ALOFT...GUIDANCE INDICATES THAT THE MID/UPPER
TROUGH TO OUR SOUTHWEST WILL SHEAR APART...WITH THE MID LEVEL
TROUGH MOVING TO THE WEST SOUTHWEST AND AWAY FROM OUR AREA...WHILE
THE WEAKENING UPPER LEVEL TROUGH DRIFTS SLOWLY TO THE EAST
NORTHEAST. A DEEP DRY LAYER WILL PERSIST ACROSS THE STATE IN THE
MID LEVELS...WITH A MID LEVEL RIDGE BUILDING JUST TO OUR NORTH
MONDAY THROUGH TUESDAY. THEREFORE WOULD EXPECT THE ONLY IMPACT TO
OUR SENSIBLE WEATHER FROM THE UPPER TROUGH TO BE CONTINUED HIGH
LEVEL CLOUDINESS...WITH SHOWERS FAVORING WINDWARD/MAUKA AREAS.
TRADE SHOWERS MAY BE ENHANCED SOMEWHAT FROM SUNDAY THROUGH EARLY
MONDAY DUE TO THE INCREASING TRADES AND DEEPENING MOISTURE.

LITTLE CHANGE IS EXPECTED DURING THE MIDDLE OF NEXT WEEK...WITH
RIDGING AT THE SURFACE AND ALOFT REMAINING NORTH OF THE STATE AND
TRADES CONTINUING. CONTINUED WEAKENING OF THE NEARBY UPPER TROUGH
AND THE PROXIMITY OF THE MID LEVEL RIDGE MAY LOWER THE INVERSION
SOMEWHAT AND PRODUCE A SLIGHTLY DRIER PATTERN...WITH LIMITED
SHOWERS CONTINUING WINDWARD AND MAUKA.

&&

.AVIATION...
A TRADE WIND FLOW CONTINUES WITH EMBEDDED SHOWERS FAVORING THE WINDWARD
AND MTN AREAS. THUS WE WILL BE MONITORING CLOSELY FOR WIDESPREAD MTN
OBSC DUE TO THESE SHOWER BEARING CLOUDS THAT MAY WARRANT AN AIRMET
SIERRA. CLOUD BASES ARE DOWN TO AS LOW AS 1500 FEET.

A FEW OF THESE SHOWERS WILL DRIFT OVER ONTO THE LEEWARD SECTIONS OF
THE SMALLER ISLANDS BUT THEY SHOULD NOT WARRANT ANY AIRMETS.

AIRMET TANGO FOR LOW LEVEL MECHANICAL TURBULENCE WILL CONT THROUGH
AT LEAST 16Z SATURDAY.

OTHERWISE...VFR IS THE PREVAILING FLYING COND.

&&

.MARINE...
A SMALL CRAFT ADVISORY REMAINS POSTED THROUGH SUNDAY AFTERNOON FOR
THE TYPICALLY WINDY WATERS AROUND MAUI AND THE BIG ISLAND. THIS
ADVISORY WILL LIKELY NEED TO BE EXTENDED INTO EARLY NEXT WEEK AS
MODERATE TO FRESH TRADE WINDS ARE EXPECTED TO CONTINUE INTO THE
FORESEEABLE FUTURE. IT IS POSSIBLE THAT SOME OF THE OTHER CHANNELS
MAY NEED TO BE INCLUDED IN THE ADVISORY AS WELL FROM SUNDAY
THROUGH MONDAY WHEN TRADES ARE FORECAST TO INCREASE SLIGHTLY.

THE CURRENT SMALL NORTHWEST SWELL WILL CONTINUE TO LOWER OVERNIGHT.
ANOTHER SMALL NORTHWEST SWELL IS EXPECTED TO FILL IN DURING THE
WEEKEND...BUT THE RESULTING SURF WILL REMAIN WELL BELOW ADVISORY
LEVELS. TRADE WINDS WILL CONTINUE TO PRODUCE SHORT PERIOD CHOPPY
SURF ALONG EAST FACING SHORES...AND THERE IS SOME POTENTIAL FOR
MINIMAL ADVISORY LEVEL SURF ON THOSE SHORES BY MONDAY.

&&

.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...JACOBSON
AVIATION...LAU








000
FXHW60 PHFO 190133
AFDHFO

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
400 PM HST FRI APR 18 2014

.SYNOPSIS...
A TRADE WIND WEATHER PATTERN IS EXPECTED OVER THE NEXT SEVERAL DAYS
THANKS TO HIGH PRESSURE NORTH OF THE STATE. CLOUDS AND PASSING
SHOWERS WILL FAVOR WINDWARD AND MAUKA AREAS WITH A FEW SHOWERS
POSSIBLE OVER SOME LEEWARD LOCATIONS.

&&

.DISCUSSION...
A 1024 MB SURFACE HIGH IS CENTERED FAR TO THE NORTHEAST OF THE STATE
WITH A RIDGE EXTENDING WESTWARD TO A 1026 MB HIGH FAR TO THE
NORTHWEST OF THE STATE. THIS PLACES THE ISLANDS IN A MODERATE TRADE
WIND ENVIRONMENT. THE HIGH TO THE NORTHEAST IS EXPECTED TO WEAKEN
WHILE THE HIGH TO THE NORTHWEST STRENGTHENS A BIT AND MOVES EASTWARD
OVER THE WEEKEND AND ON INTO EARLY NEXT WEEK. AS THE HIGH
STRENGTHENS TO OUR NORTH...WE EXPECT A SLIGHT UPTICK IN TRADE WINDS
SPEEDS DURING THE SUNDAY AND MONDAY TIME PERIOD. THE HIGH WILL
CONTINUE MOVING EASTWARD TO A POSITION FAR TO OUR NORTHEAST BY THE
MIDDLE OF NEXT WEEK AND WEAKEN A BIT AS WELL. THUS TRADE WINDS WILL
LIKELY DROP BACK DOWN TO PRESENT LEVELS.

MOISTURE EMBEDDED IN THE TRADES IS PROVIDING FOR PASSING SHOWERS FOR
WINDWARD AND MAUKA AREAS WITH A FEW SHOWERS SPREADING OVER TO SELECT
LEEWARD AREAS AT TIMES. AN UPPER TROUGH SEEN ON SATELLITE IMAGERY
JUST TO THE SOUTHWEST OF THE STATE HAS RAISED INVERSION LEVELS A BIT
ALLOWING FOR SLIGHTLY HIGHER CLOUD DEVELOPMENT. THE 00Z SOUNDINGS
SHOW THAT THE INVERSION IS NEAR 9000 FEET. THE UPPER TROUGH IS
FORECAST TO LINGER NEAR THE AREA OVER THE NEXT SEVERAL DAYS. THUS
SHOWERS WILL CONTINUE TO FAVOR WINDWARD AND MAUKA AREAS AND WILL BE
HIGHLY DEPENDENT ON INCOMING MOISTURE AVAILABILITY. THE UPPER TROUGH
IS EXPECTED TO WEAKEN DURING THE SECOND HALF OF THE WEEK WITH A
SLIGHTLY DRIER WINDWARD AND MAUKA SHOWER PATTERN EXPECTED.

&&

.AVIATION...
AIRMET TANGO CONTINUES FOR LOW LEVEL TURBULENCE TO THE LEE OF THE
ISLANDS. THIS AIRMET IS EXPECTED TO CONTINUE THROUGH AT LEAST
SATURDAY.

CLOUDS AND SHOWERS ARE FOCUSED OVER WINDWARD AND MAUKA AREAS...WHICH
AT TIMES WILL BRING MVFR CONDITIONS TO THOSE AREAS. OTHERWISE...VFR
CONDITIONS ARE EXPECTED...WITH PASSING HIGH CLOUDS.

&&

.MARINE...
A SMALL CRAFT ADVISORY REMAINS POSTED THROUGH SUNDAY AFTERNOON FOR
THE TYPICALLY WINDY WATERS AROUND MAUI AND THE BIG ISLAND. THIS WILL
LIKELY HAVE TO BE EXTENDED INTO EARLY NEXT WEEK AS MODERATE TO FRESH
TRADE WINDS ARE EXPECTED TO CONTINUE INTO THE FORESEEABLE FUTURE.

THE CURRENT SMALL NORTHWEST SWELL WILL CONTINUE TO LOWER OVERNIGHT.
ANOTHER SMALL NORTHWEST SWELL IS EXPECTED TO FILL IN OVER THE
WEEKEND. 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.

&&

$$

SYNOPSIS/DISCUSSION/MARINE...BURKE
AVIATION...M BALLARD







000
FXHW60 PHFO 190133
AFDHFO

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
400 PM HST FRI APR 18 2014

.SYNOPSIS...
A TRADE WIND WEATHER PATTERN IS EXPECTED OVER THE NEXT SEVERAL DAYS
THANKS TO HIGH PRESSURE NORTH OF THE STATE. CLOUDS AND PASSING
SHOWERS WILL FAVOR WINDWARD AND MAUKA AREAS WITH A FEW SHOWERS
POSSIBLE OVER SOME LEEWARD LOCATIONS.

&&

.DISCUSSION...
A 1024 MB SURFACE HIGH IS CENTERED FAR TO THE NORTHEAST OF THE STATE
WITH A RIDGE EXTENDING WESTWARD TO A 1026 MB HIGH FAR TO THE
NORTHWEST OF THE STATE. THIS PLACES THE ISLANDS IN A MODERATE TRADE
WIND ENVIRONMENT. THE HIGH TO THE NORTHEAST IS EXPECTED TO WEAKEN
WHILE THE HIGH TO THE NORTHWEST STRENGTHENS A BIT AND MOVES EASTWARD
OVER THE WEEKEND AND ON INTO EARLY NEXT WEEK. AS THE HIGH
STRENGTHENS TO OUR NORTH...WE EXPECT A SLIGHT UPTICK IN TRADE WINDS
SPEEDS DURING THE SUNDAY AND MONDAY TIME PERIOD. THE HIGH WILL
CONTINUE MOVING EASTWARD TO A POSITION FAR TO OUR NORTHEAST BY THE
MIDDLE OF NEXT WEEK AND WEAKEN A BIT AS WELL. THUS TRADE WINDS WILL
LIKELY DROP BACK DOWN TO PRESENT LEVELS.

MOISTURE EMBEDDED IN THE TRADES IS PROVIDING FOR PASSING SHOWERS FOR
WINDWARD AND MAUKA AREAS WITH A FEW SHOWERS SPREADING OVER TO SELECT
LEEWARD AREAS AT TIMES. AN UPPER TROUGH SEEN ON SATELLITE IMAGERY
JUST TO THE SOUTHWEST OF THE STATE HAS RAISED INVERSION LEVELS A BIT
ALLOWING FOR SLIGHTLY HIGHER CLOUD DEVELOPMENT. THE 00Z SOUNDINGS
SHOW THAT THE INVERSION IS NEAR 9000 FEET. THE UPPER TROUGH IS
FORECAST TO LINGER NEAR THE AREA OVER THE NEXT SEVERAL DAYS. THUS
SHOWERS WILL CONTINUE TO FAVOR WINDWARD AND MAUKA AREAS AND WILL BE
HIGHLY DEPENDENT ON INCOMING MOISTURE AVAILABILITY. THE UPPER TROUGH
IS EXPECTED TO WEAKEN DURING THE SECOND HALF OF THE WEEK WITH A
SLIGHTLY DRIER WINDWARD AND MAUKA SHOWER PATTERN EXPECTED.

&&

.AVIATION...
AIRMET TANGO CONTINUES FOR LOW LEVEL TURBULENCE TO THE LEE OF THE
ISLANDS. THIS AIRMET IS EXPECTED TO CONTINUE THROUGH AT LEAST
SATURDAY.

CLOUDS AND SHOWERS ARE FOCUSED OVER WINDWARD AND MAUKA AREAS...WHICH
AT TIMES WILL BRING MVFR CONDITIONS TO THOSE AREAS. OTHERWISE...VFR
CONDITIONS ARE EXPECTED...WITH PASSING HIGH CLOUDS.

&&

.MARINE...
A SMALL CRAFT ADVISORY REMAINS POSTED THROUGH SUNDAY AFTERNOON FOR
THE TYPICALLY WINDY WATERS AROUND MAUI AND THE BIG ISLAND. THIS WILL
LIKELY HAVE TO BE EXTENDED INTO EARLY NEXT WEEK AS MODERATE TO FRESH
TRADE WINDS ARE EXPECTED TO CONTINUE INTO THE FORESEEABLE FUTURE.

THE CURRENT SMALL NORTHWEST SWELL WILL CONTINUE TO LOWER OVERNIGHT.
ANOTHER SMALL NORTHWEST SWELL IS EXPECTED TO FILL IN OVER THE
WEEKEND. 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.

&&

$$

SYNOPSIS/DISCUSSION/MARINE...BURKE
AVIATION...M BALLARD






000
FXHW60 PHFO 182008
AFDHFO

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
1000 AM HST FRI APR 18 2014

.SYNOPSIS...
A TRADE WIND WEATHER PATTERN IS EXPECTED OVER THE NEXT SEVERAL DAYS
THANKS TO HIGH PRESSURE NORTH OF THE STATE. CLOUDS AND PASSING
SHOWERS WILL FAVOR WINDWARD AND MAUKA AREAS WITH A FEW SHOWERS
POSSIBLE OVER SOME LEEWARD LOCATIONS.

&&

.DISCUSSION...
A 1025 MB SURFACE HIGH IS CENTERED FAR TO THE NORTHEAST OF THE STATE
WITH A RIDGE EXTENDING WESTWARD TO ANOTHER 1025 MB HIGH FAR TO THE
NORTHWEST OF THE STATE. THIS PLACES THE ISLANDS IN A MODERATE TRADE
WIND ENVIRONMENT. THE HIGH TO THE NORTHEAST IS EXPECTED TO WEAKEN
WHILE THE HIGH TO THE NORTHWEST STRENGTHENS A BIT AND MOVES EASTWARD
OVER THE WEEKEND AND ON INTO EARLY NEXT WEEK. AS THE HIGH
STRENGTHENS TO OUR NORTH...WE EXPECT A SLIGHT UPTICK IN TRADE WINDS
SPEEDS DURING THE SUNDAY AND MONDAY TIME PERIOD. THE HIGH WILL
CONTINUE MOVING EASTWARD TO A POSITION FAR TO OUR NORTHEAST BY THE
MIDDLE OF NEXT WEEK AND WEAKEN A BIT AS WELL. THUS TRADE WINDS WILL
LIKELY DROP BACK DOWN TO PRESENT LEVELS.

MOISTURE EMBEDDED IN THE TRADES IS PROVIDING FOR PASSING SHOWERS FOR
WINDWARD AND MAUKA AREAS WITH A FEW SHOWERS SPREADING OVER TO SELECT
LEEWARD AREAS AT TIMES. AN UPPER TROUGH SEEN ON SATELLITE IMAGERY
JUST TO THE SOUTHWEST OF THE STATE HAS RAISED INVERSION LEVELS A BIT
ALLOWING FOR SLIGHTLY HIGHER CLOUD DEVELOPMENT. A FEW WINDWARD AND
MAUKA GAUGES HAVE RECEIVED OVER AN INCH OF RAIN OVER THE PAST 12
HOURS. THE UPPER TROUGH IS FORECAST TO LINGER NEAR THE AREA OVER
THE NEXT SEVERAL DAYS. THUS SHOWERS WILL CONTINUE TO FAVOR WINDWARD
AND MAUKA AREAS AND WILL BE HIGHLY DEPENDENT ON INCOMING MOISTURE
AVAILABILITY.

&&

.AVIATION...
AIRMET TANGO CONTINUES FOR LOW LEVEL TURBULENCE TO THE LEE OF THE
ISLANDS. UPPER LEVEL WINDS OVER THE ISLANDS ARE SUFFICIENT ENOUGH TO
CONTINUE AN UPPER LEVEL TURBULENCE AIRMET AS WELL.

CLOUDS AND SHOWERS ARE FOCUSED OVER WINDWARD AND MAUKA AREAS...WHICH
AT TIMES WILL BRING MVFR CONDITIONS TO THOSE AREAS. OTHERWISE...VFR
CONDITIONS ARE EXPECTED...WITH PASSING HIGH CLOUDS.

&&

.MARINE...
A SMALL CRAFT ADVISORY REMAINS POSTED THROUGH SATURDAY AFTERNOON FOR
THE TYPICALLY WINDY WATERS AROUND MAUI AND THE BIG ISLAND. THIS WILL
LIKELY HAVE TO BE EXTENDED INTO EARLY NEXT WEEK AS MODERATE TO FRESH
TRADE WINDS ARE EXPECTED TO CONTINUE INTO THE FORESEEABLE FUTURE.

THE CURRENT SMALL NORTHWEST SWELL WILL CONTINUE TO LOWER TODAY.
ANOTHER SMALL NORTHWEST SWELL IS EXPECTED TO FILL IN OVER THE
WEEKEND. 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 SATURDAY FOR MAALAEA BAY-
PAILOLO CHANNEL-ALENUIHAHA CHANNEL-BIG ISLAND LEEWARD WATERS-BIG
ISLAND SOUTHEAST WATERS.

&&

$$

SYNOPSIS/DISCUSSION/MARINE...BURKE
AVIATION...M BALLARD






000
FXHW60 PHFO 182008
AFDHFO

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
1000 AM HST FRI APR 18 2014

.SYNOPSIS...
A TRADE WIND WEATHER PATTERN IS EXPECTED OVER THE NEXT SEVERAL DAYS
THANKS TO HIGH PRESSURE NORTH OF THE STATE. CLOUDS AND PASSING
SHOWERS WILL FAVOR WINDWARD AND MAUKA AREAS WITH A FEW SHOWERS
POSSIBLE OVER SOME LEEWARD LOCATIONS.

&&

.DISCUSSION...
A 1025 MB SURFACE HIGH IS CENTERED FAR TO THE NORTHEAST OF THE STATE
WITH A RIDGE EXTENDING WESTWARD TO ANOTHER 1025 MB HIGH FAR TO THE
NORTHWEST OF THE STATE. THIS PLACES THE ISLANDS IN A MODERATE TRADE
WIND ENVIRONMENT. THE HIGH TO THE NORTHEAST IS EXPECTED TO WEAKEN
WHILE THE HIGH TO THE NORTHWEST STRENGTHENS A BIT AND MOVES EASTWARD
OVER THE WEEKEND AND ON INTO EARLY NEXT WEEK. AS THE HIGH
STRENGTHENS TO OUR NORTH...WE EXPECT A SLIGHT UPTICK IN TRADE WINDS
SPEEDS DURING THE SUNDAY AND MONDAY TIME PERIOD. THE HIGH WILL
CONTINUE MOVING EASTWARD TO A POSITION FAR TO OUR NORTHEAST BY THE
MIDDLE OF NEXT WEEK AND WEAKEN A BIT AS WELL. THUS TRADE WINDS WILL
LIKELY DROP BACK DOWN TO PRESENT LEVELS.

MOISTURE EMBEDDED IN THE TRADES IS PROVIDING FOR PASSING SHOWERS FOR
WINDWARD AND MAUKA AREAS WITH A FEW SHOWERS SPREADING OVER TO SELECT
LEEWARD AREAS AT TIMES. AN UPPER TROUGH SEEN ON SATELLITE IMAGERY
JUST TO THE SOUTHWEST OF THE STATE HAS RAISED INVERSION LEVELS A BIT
ALLOWING FOR SLIGHTLY HIGHER CLOUD DEVELOPMENT. A FEW WINDWARD AND
MAUKA GAUGES HAVE RECEIVED OVER AN INCH OF RAIN OVER THE PAST 12
HOURS. THE UPPER TROUGH IS FORECAST TO LINGER NEAR THE AREA OVER
THE NEXT SEVERAL DAYS. THUS SHOWERS WILL CONTINUE TO FAVOR WINDWARD
AND MAUKA AREAS AND WILL BE HIGHLY DEPENDENT ON INCOMING MOISTURE
AVAILABILITY.

&&

.AVIATION...
AIRMET TANGO CONTINUES FOR LOW LEVEL TURBULENCE TO THE LEE OF THE
ISLANDS. UPPER LEVEL WINDS OVER THE ISLANDS ARE SUFFICIENT ENOUGH TO
CONTINUE AN UPPER LEVEL TURBULENCE AIRMET AS WELL.

CLOUDS AND SHOWERS ARE FOCUSED OVER WINDWARD AND MAUKA AREAS...WHICH
AT TIMES WILL BRING MVFR CONDITIONS TO THOSE AREAS. OTHERWISE...VFR
CONDITIONS ARE EXPECTED...WITH PASSING HIGH CLOUDS.

&&

.MARINE...
A SMALL CRAFT ADVISORY REMAINS POSTED THROUGH SATURDAY AFTERNOON FOR
THE TYPICALLY WINDY WATERS AROUND MAUI AND THE BIG ISLAND. THIS WILL
LIKELY HAVE TO BE EXTENDED INTO EARLY NEXT WEEK AS MODERATE TO FRESH
TRADE WINDS ARE EXPECTED TO CONTINUE INTO THE FORESEEABLE FUTURE.

THE CURRENT SMALL NORTHWEST SWELL WILL CONTINUE TO LOWER TODAY.
ANOTHER SMALL NORTHWEST SWELL IS EXPECTED TO FILL IN OVER THE
WEEKEND. 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 SATURDAY FOR MAALAEA BAY-
PAILOLO CHANNEL-ALENUIHAHA CHANNEL-BIG ISLAND LEEWARD WATERS-BIG
ISLAND SOUTHEAST WATERS.

&&

$$

SYNOPSIS/DISCUSSION/MARINE...BURKE
AVIATION...M BALLARD







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