516
FXHW60 PHFO 231402 CCA
AFDHFO
AREA FORECAST DISCUSSION...CORRECTED
NATIONAL WEATHER SERVICE HONOLULU HI
402 AM HST SAT AUG 23 2025
SYNOPSIS
THE ISLANDS WILL REMAIN UNDER THE INFLUENCE OF HIGH PRESSURE
RIDGING TO THE NORTH AND EAST WITH A TROUGH LINGERING FAR
NORTHWEST OF THE STATE. THIS WILL RESULT IN LIGHT TO LOCALLY
BREEZY TRADE WINDS THIS WEEKEND. THERE WILL BE A SLIGHT DROP OFF
IN WIND SPEEDS EARLY NEXT WEEK IN RESPONSE TO THE TROUGH SLIGHTLY
SAGGING SOUTH AND WEAKENING THE DOWNSTREAM PRESSURE GRADIENT. A
DRY AND STABLE WEATHER PATTERN WINS OUT IN THE NEAR FUTURE WITH
ONLY OCCASIONAL LIGHT WINDWARD MAUKA TRADE SHOWERS.
DISCUSSION
EARLY MORNING SATELLITE TRENDS VERIFY STABLE CONDITIONS WITH ONLY
SCATTERED WARM LOW TOPPED CLOUDS MOVING IN ON MODERATE EAST TRADE
FLOW. OTHER THAN A FEW LIGHT SHOWERS COMING ONSHORE IN BIG
ISLAND'S PUNA REGION, THE MAJORITY OF THE STATE REMAINS DRY. 12Z
LOCAL SOUNDINGS DEPICT A CONTINUED 5-6K FT TRADE INVERSION HEIGHT
AND MUCH BELOW NORMAL NEAR ONE INCH PRECIPITABLE WATERS. WITH
LITTLE VARIANCE IN THE CENTRAL PACIFIC SYNOPTIC PATTERN FOR THE
FORESEEABLE FUTURE, THESE SUMMERTIME CONDITIONS WILL BE THE
GENERAL THEME THROUGH THE REMAINDER OF AUGUST.
MID TO UPPER LEVEL RIDGING CENTERED NORTH AND EAST OF THE ISLANDS
WILL BE THE MAIN CONTROL TO PERSISTENT DRY SUMMER WEATHER. THE
ONLY CAVEAT WILL BE SOUTHERN APPROACH OF A NORTHERN TROUGH AXIS
THAT MAY REACH OUR NORTHERN OFFSHORE WATERS MONDAY AND TUESDAY.
THIS WILL WEAKEN THE NORTHEAST-TO-EAST RIDGE ENOUGH TO CAUSE A
BRIEF INTERRUPTION IN MODERATE TO LOCALLY STRONG (OCEANIC) TRADE
FLOW. MONDAY THROUGH WEDNESDAY'S WINDS WILL VEER A BIT MORE TO THE
EAST-SOUTHEAST AND WEAKEN A TOUCH. SHORTWAVE ENERGY DIVING DOWN
AROUND THE BASE OF THE TROUGH LATER NEXT WEEK WILL ASSIST IN
KEEPING STRONGER TRADES AT BAY INTO THE LAST FEW DAYS OF THE
MONTH. WEAKER TRADE FLOW WITHIN A DRIER SCENARIO SUGGESTS THAT
LOCAL BREEZES WILL BECOME MORE DOMINANT. THUS, EARLY SUN WILL
LIKELY LEAD TO MID-LATE AFTERNOON INTO EARLY EVENING CLOUD BUILD
UP AND SCATTERED SHOWERS OVER BIG ISLAND KONA AND UPSLOPE LEEWARD
ON OAHU. MOISTURE LEVELS UNDERGO LITTLE TO NO CHANGE SO, OTHER
THAN LOCALIZED AFTERNOON BREEZE ACTIVITY, THE ONLY OTHER RAIN
SOURCE WILL BE FROM THE TYPICAL BRIEF TOPO-ENHANCED WINDWARD AND
MAUKA SHOWERS.
AVIATION
MODERATE TO BREEZY EASTERLY TRADE WINDS WILL PERSIST THROUGH THE
FORECAST PERIOD. CLOUDS AND SHOWERS WILL REMAIN PRIMARILY FOCUSED
TO THE WINDWARD MAUKA SLOPES, PARTICULARLY DURING THE NOCTURNAL
HOURS. BRIEF MVFR CONDITIONS WILL BE POSSIBLE WITHIN HEAVIER
SHOWERS, OTHERWISE VFR WILL LIKELY PREVAIL.
NO AIRMETS ARE CURRENTLY IN EFFECT.
MARINE
A HIGH PRESSURE RIDGE NORTH OF THE HAWAIIAN ISLANDS CONTINUES TO
PRODUCE FRESH TO LOCALLY STRONG TRADES THROUGH EARLY NEXT WEEK. A
SMALL CRAFT ADVISORY (SCA) REMAINS IN EFFECT FOR THE WINDIER
WATERS OF MAUI COUNTY AND THE BIG ISLAND. THIS SCA WILL LIKELY
CONTINUE INTO THE FIRST HALF OF NEXT WEEK.
SMALL OVERLAPPING MEDIUM AND LONG PERIOD SOUTH SWELLS WILL CONTINUE
TODAY, THIS SWELL ENERGY WILL FADE INTO BACKGROUND LEVELS BY
SUNDAY. SURF HEIGHTS WILL CONTINUE TO DECLINE INTO MONDAY.
ANOTHER SMALL LONG PERIOD SOUTH SWELL WILL ARRIVE BY TUESDAY,
BOOSTING SOUTH SHORE SURF HEIGHTS THROUGH THURSDAY.
SURF ALONG NORTH AND WEST FACING SHORES REMAINS NEARLY FLAT. WHILE
SMALL TRADE WIND DRIVEN WAVE CHOP LINGERS OUT EAST.
FIRE WEATHER
THE LACK OF RAIN AND LOWER HUMIDITY WILL MAINTAIN ELEVATED FIRE
WEATHER CONCERNS THIS WEEKEND. OTHER THAN THE TYPICAL HIGH TERRAIN
CHANNELED WINDS, MANY LOCATIONS WILL EXPERIENCE LIGHT TO LOW END
MODERATE TRADES OR AFTERNOON SEA BREEZES/OVERNIGHT LAND BREEZES.
WHILE MANY WILL EXPERIENCE AFTERNOON HUMIDITIES FALLING UNDER 50
PERCENT, LIGHTER WINDS SHOULD HOLD RED FLAG WARNING (RFW) CONDITIONS
AT BAY. THESE DRY CONDITIONS HAVE PLACED THE MAJORITY OF THE
STATE IN A MODERATE TO SEVERE DROUGHT. THUS, REGIONAL SCALE WINDS
WILL NEED TO BE THE PARAMETER THAT IS MOST CLOSELY MONITORED IN A
POTENTIAL RFW SITUATION. INVERSION HEIGHTS WILL UNDERGO LITTLE
CHANGE SO THE MAIN DRIVER OF WIND WILL BE SUPPORTED IN THE LARGE
SCALE. WIND SPEEDS ARE EXPECTED TO FALL OFF EARLY NEXT WEEK IN
RESPONSE TO A NORTHERN TROUGH WEAKENING THE GRADIENT PRODUCED BY
EASTERN HIGH PRESSURE. AS THIS TROUGH PULLS BACK FURTHER NORTH AT
MID WEEK, TRADES MAY SLIGHTLY INCREASE TO MORE TYPICAL MODERATE
SPEEDS WEDNESDAY.
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...BLOOD
AVIATION...BLOOD
MARINE...BOHLIN
FIRE WEATHER...BLOOD
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