102
FXHW60 PHFO 170650
AFDHFO
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
850 PM HST WED APR 16 2025
SYNOPSIS
A CONVECTIVE PATTERN WITH MOSTLY LIGHT WINDS WILL HOLD IN PLACE
DURING THE NEXT COUPLE DAYS, WITH SHOWERS FAVORING AREAS NEAR THE
COAST AT NIGHT AND THE ISLAND INTERIORS DURING THE AFTERNOON AND
EVENING HOURS. LIGHT TO MODERATE TRADE WINDS WILL RETURN OVER THE
WEEKEND INTO EARLY NEXT WEEK, HOWEVER LINGERING MOISTURE WILL
LIKELY KEEP THE PATTERN RATHER SHOWERY, EVEN IN LEEWARD AREAS AT
TIMES. A NEW STORM SYSTEM DEVELOPING WEST OF THE STATE COULD BRING
SOUTHERLY WINDS ALONG WITH ANOTHER CHANCE FOR HEAVY RAINFALL AND
THUNDERSTORMS TO THE ISLANDS TUESDAY AND NEXT WEDNESDAY.
DISCUSSION
CURRENTLY AT THE SURFACE, A WEAKENING STATIONARY FRONT IS LOCATED
AROUND 350 MILES NORTHWEST OF KAUAI, WITH BROAD TROUGHING NOW
PRESENT OVER THE ISLAND CHAIN. MEANWHILE, A 1029 MB HIGH IS
CENTERED TO THE DISTANT NORTH-NORTHEAST. WINDS ARE LIGHT AND
VARIABLE ACROSS THE WESTERN ISLANDS, WHILE LIGHT TO MODERATE
EAST- SOUTHEASTERLIES ARE PRESENT IN UNSHELTERED SECTIONS OF MAUI
COUNTY AND THE BIG ISLAND. INFRARED SATELLITE IMAGERY SHOWS MOSTLY
CLOUDY CONDITIONS IN PLACE, WITH RADAR IMAGERY SHOWING MOST OF THE
DAYTIME HEATING DRIVEN SHOWER ACTIVITY FIZZLING OUT. MAIN SHORT
TERM FOCUS REVOLVES AROUND THE POTENTIAL FOR HEAVY RAIN AND
THUNDERSTORMS DURING THE NEXT COUPLE DAYS.
BROAD TROUGHING WILL HOLD IN PLACE DURING THE NEXT COUPLE DAYS,
KEEPING LAND AND SEA BREEZES COMMON OVER THE WESTERN END OF THE
STATE. LIGHT TO MODERATE EAST-SOUTHEAST WINDS WILL PERSIST OVER
THE EASTERN ISLANDS, WITH LAND AND SEA BREEZES COMMON IN THE MORE
TERRAIN SHELTERED AREAS. THE BROAD TROUGHING WILL DAMPEN OUT BY
LATE FRIDAY, ALLOWING LIGHT TO MODERATE TRADE WINDS TO FILL BACK
IN ACROSS THE STATE FRIDAY NIGHT AND PERSIST THROUGH EARLY NEXT
WEEK. A DEVELOPING STORM SYSTEM WEST OF THE ISLANDS COULD BRING
MODERATE SOUTHERLY WINDS TO THE AREAS TUESDAY AND NEXT WEDNESDAY.
AS FOR THE REMAINING WEATHER DETAILS, A CONVECTIVE PATTERN IS
EXPECTED TO CONTINUE THROUGH FRIDAY, WITH SHOWERS FAVORING AREAS
NEAR THE COAST AND NIGHT AND THE ISLAND INTERIORS DURING THE
AFTERNOON AND EVENING HOURS. AN UPPER LEVEL TROUGH WILL MOVE
SLOWLY EASTWARD ACROSS THE STATE TONIGHT THROUGH FRIDAY, WITH 500
MB TEMPERATURES OF -12 TO -14C AND PRECIPITABLE WATER VALUES
HOVERING AROUND 1.5 INCHES. THIS IS EXPECTED TO BRING SOME
HEAVIER SHOWERS TO THE AREA DURING THE AFTERNOON AND EVENING
HOURS. IN ADDITION, ISOLATED THUNDERSTORMS WILL REMAIN POSSIBLE
AS THE COLD POOL ALOFT MOVES EASTWARD ACROSS THE STATE. IN FACT,
THE LINGERS NEAR THE BIG ISLAND THROUGH THE WEEKEND, SO A
THUNDERSTORM OR TWO COULD DEVELOP HERE EACH AFTERNOON. ELSEWHERE,
WE SHOULD SEE A HYBRID TRADE WIND PATTERN RETURN OVER THE WEEKEND
INTO EARLY NEXT WEEK. PRECIPITABLE WATER VALUES CONTINUE TO HOLD
CLOSE TO 1.5 INCHES AND THE LATEST MODEL TRENDS HAVE BEEN FOR
WEAKER TRADES. AS A RESULT, THE PATTERN LOOKS A BIT SHOWERY
THROUGH THE WEEKEND, WITH CHANCES FOR SHOWERS EACH AFTERNOON AND
EVENING IN MOST LEEWARD AREAS AS WELL. A NEW STORM SYSTEM MAY
BRING ANOTHER ROUND OF HEAVY RAIN AND THUNDERSTORMS TO THE ISLANDS
TUESDAY AND NEXT WEDNESDAY.
AVIATION
A FRONT WILL STALL NORTHWEST OF THE STATE TONIGHT AND BRING LIGHT
AND VARIABLE WINDS FOR KAUAI AND OAHU, WITH LIGHT TO MODERATE
SOUTHEAST FLOW PREVAILING ACROSS THE REMAINING ISLANDS. CONDITIONS
WILL BECOME SLIGHTLY MORE UNSTABLE ALOFT AS THE NIGHT PROGRESSES
WITH SCATTERED SHOWERS DEVELOPING AREAWIDE AND A SLIGHT CHANCE OF
THUNDERSTORMS OVER OAHU AND KAUAI. LOCALIZED IFR CIG/VIS IN
+TSRA/+SHRA MAY ACCOMPANY ANY OF THE HEAVIER ACTIVITY.
BEYOND THURSDAY MORNING, LIGHT FLOW WILL LEAD TO A SEA
BREEZE/LAND BREEZE PATTERN WITH PERIODIC HEAVIER SHOWERS AND A
SLIGHT CHANCE OF THUNDERSTORMS ACROSS ALL ISLANDS.
MARINE
LIGHT TO MODERATE EAST-SOUTHEAST WINDS WILL PERSIST INTO FRIDAY
AS A FRONT REMAINS STALLED AND SLOWLY DIMINISHES TO THE WEST. OVER
THE WESTERN END OF THE ISLANDS, THE LIGHT WINDS WILL ALLOW A LAND
AND SEA BREEZE PATTERN TO DEVELOP NEAR THE COASTS, WHICH WILL
PERSIST INTO FRIDAY. FOR THE EASTERN END, LIGHT TO MODERATE EAST
TO SOUTHEAST BREEZES, WITH LOCALIZED FRESH POCKETS, WILL LIKELY
PERSIST, PARTICULARLY AROUND THE BIG ISLAND. A RETURN TO FRESH TO
STRONG EASTERLY TRADES IS POSSIBLE BY THE WEEKEND AS HIGH PRESSURE
BUILDS TO THE NORTH.
HEAVY SHOWERS AND THUNDERSTORMS WILL REMAIN POSSIBLE, MAINLY OVER
THE WESTERN END OF THE STATE TONIGHT, WITH CHANCES INCREASING
STATEWIDE THURSDAY INTO FRIDAY. CONDITIONS SHOULD BEGIN TO
IMPROVE THIS WEEKEND.
SURF ALONG EXPOSED NORTH AND WEST FACING SHORES WILL TREND UP
THURSDAY AS A FRESH NORTH-NORTHWEST ARRIVES AND BUILDS DOWN THE
ISLAND CHAIN. SURF MAY NEAR THE ADVISORY LEVELS FOR EXPOSED NORTH
AND WEST FACING SHORES THURSDAY NIGHT INTO FRIDAY AS THIS SWELL
PEAKS. A DOWNWARD TREND IS THEN EXPECTED OVER THE WEEKEND, WITH
THE SWELL SHIFTING OUT OF NORTH.
SURF ALONG EAST FACING SHORES WILL REMAIN BELOW THE APRIL AVERAGE
THROUGH AT LEAST SATURDAY, THEN STEADILY RISE TO AROUND AVERAGE
BY EARLY NEXT WEEK.
SURF ALONG SOUTH FACING SHORES WILL REMAIN SMALL, WITH MAINLY
OVERLAPPING BACKGROUND SOUTH SWELLS MOVING THROUGH. A LARGER PULSE
OF SOUTH-SOUTHWEST SWELL MAY ARRIVE TUESDAY.
HFO WATCHES/WARNINGS/ADVISORIES
NONE.
DISCUSSION...JELSEMA
AVIATION...THOMAS
MARINE...GIBBS
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