420
FXHW60 PHFO 250200
AFDHFO
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
400 PM HST SUN AUG 24 2025
SYNOPSIS
STABLE, MOSTLY DRY CONDITIONS WILL CONTINUE INTO THE FIRST HALF
OF THE WORK WEEK. TRADE WINDS WILL VEER SLIGHTLY EAST
SOUTHEASTERLY AND WEAKEN A BIT INTO THE MODERATE RANGE. TRADE WIND
SHOWERS WILL BE FEW AND FAR BETWEEN. THE ONE EXCEPTION WILL BE
THE BIG ISLAND, WHICH COULD SEE INCREASED SHOWERS OVER THE KONA
SLOPES THROUGH MID-WEEK. MORE TYPICAL EASTERLY TRADES LOOK TO
RETURN DURING THE SECOND HALF OF THIS WEEK.
DISCUSSION
THIS AFTERNOON, VERY DRY CONDITIONS ARE PREVAILING ACROSS THE
MAIN HAWAIIAN ISLANDS. RIDGING BOTH AT THE SURFACE AND ALOFT
NORTHEAST OF THE ISLAND CHAIN IS THE MAIN INFLUENCE OF WEATHER
ACROSS THE REGION, MAINTAINING PERSISTENT WARM, STABLE, AND DRY
CONDITIONS. LATEST SATELLITE IMAGERY SHOWS MOST AREAS ARE CLOUD
AND SHOWER-FREE THIS AFTERNOON, WITH THE EXCEPTION OF DAYTIME
SEA-BREEZE INDUCED CLOUD BUILDUPS ALONG THE KONA SLOPES OF THE BIG
ISLAND. THERE ARE ALSO A FEW CLOUDS OVER INTERIOR KAUAI, WHICH IS
LOCATED CLOSER TO A TROUGH PASSING NORTH OF THE STATE. SURFACE
OBSERVATIONS AND AN ASCAT PASS SHOW THAT WIND SPEEDS ARE GENERALLY
IN THE MODERATE RANGE WITH SOME LOCALLY BREEZY GUSTS.
LITTLE CHANGE IS EXPECTED OVER THE NEXT FEW DAYS. A LOW PRESSURE
SYSTEM WILL PUSH EASTWARD ACROSS THE NORTH PACIFIC THROUGH
WEDNESDAY. AS THIS OCCURS, A TROUGH WILL ALLOW THE PRESSURE
GRADIENT OVER THE ISLAND CHAIN TO RELAX SLIGHTLY. WIND SPEEDS
ACROSS THE ISLANDS WILL FOLLOW SUIT, EASING SLIGHTLY WHEN
COMPARED TO THOSE OBSERVED TODAY, AND VEERING EAST SOUTHEAST. THE
LIGHTER WINDS WILL ALSO BE CONDUCIVE TO SEA-BREEZE DEVELOPMENT
ACROSS TERRAIN-SHELTERED AREAS. MODEL GUIDANCE CONTINUES TO SHOW A
MINOR INCREASE IN MOISTURE APPROACHING FROM THE SOUTHEAST AND
PASSING ACROSS BIG ISLAND LATE MONDAY THROUGH TUESDAY NIGHT. THIS
MOISTURE MAY ENHANCE AFTERNOON SHOWERS OVER THE KONA SLOPES
THROUGH MID-WEEK. HOWEVER, VERY DRY AIR ALOFT ACROSS THE REMAINDER
OF STATE WILL REMAIN FIRMLY IN PLACE. THEREFORE, OTHER THAN
LOCALIZED AFTERNOON BREEZE ACTIVITY, VERY FEW SHOWERS ARE
EXPECTED, ASIDE FROM BRIEF TERRAIN-ENHANCED WINDWARD UPSLOPE MAUKA
SHOWERS.
A NEW HIGH FAR NORTH-NORTHEAST OF THE STATE WILL BECOME
ESTABLISHED DURING THE SECOND HALF OF THE WEEK, ALLOWING MORE
TYPICAL EASTERLY TRADE WINDS TO RETURN.
AVIATION
STABLE, MODERATE TO BREEZY TRADES WILL CONTINUE TO DELIVER CLOUDS
AND SHOWERS TO WINDWARD AND MOUNTAIN AREAS THROUGH THE PERIOD,
PARTICULARLY OVERNIGHT AND DURING THE EARLY MORNING HOURS.
ISOLATED MVFR WILL BE POSSIBLE WITHIN SHOWERS. OTHERWISE, VFR
WILL PREVAIL.
NO AIRMETS ARE IN EFFECT AND NONE ARE ANTICIPATED TO BE NEEDED
THROUGH TOMORROW.
MARINE
HIGH PRESSURE NORTH OF THE HAWAIIAN ISLANDS MAINTAINS MODERATE TO
FRESH TRADES THROUGH THE WEEK. SMALL SWELL ENERGY EMANATING FROM
THE SOUTHERLY QUADRANT SLOWLY DECLINES INTO MONDAY. A SERIES OF
SMALL LONGER PERIOD S SWELLS THEN ARRIVE BY TUESDAY PROVIDING A
MODEST BOOST TO S SHORE SURF THROUGH FRIDAY. SURF ALONG N AND W
FACING SHORES REMAINS NEARLY FLAT WHILE SURF ALONG E SHORES WILL
REMAIN CHARACTERIZED BY SHORT PERIOD CHOP.
FIRE WEATHER
ELEVATED FIRE WEATHER CONDITIONS WILL CONTINUE FOR THE NEXT
COUPLE OF DAYS DUE TO THE LOW RELATIVE HUMIDITY VALUES. VERY DRY
CONDITIONS WERE OBSERVED ACROSS THE STATE TODAY, WITH RH DROPPING
INTO THE 30S AND 40S THIS AFTERNOON. THIS IS EXPECTED TO BE THE
CASE AGAIN THROUGH TUESDAY WITH DRY AIR REMAINING IN PLACE.
DESPITE THESE DRY CONDITIONS, HOWEVER, MARGINAL WIND SPEEDS HAVE
KEPT THE NEED FOR FIRE WEATHER HEADLINES AT BAY. WITH THE WINDS
EXPECTED TO EASE FURTHER MONDAY THROUGH TUESDAY, NOT ANTICIPATING
THE NEED FOR ANY FIRE WEATHER HEADLINES AT THIS TIME.
HFO WATCHES/WARNINGS/ADVISORIES
NONE.
DISCUSSION...VAUGHAN
AVIATION...FARRIS
MARINE...JVC
FIRE WEATHER...VAUGHAN
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