030
FXHW60 PHFO 021318
AFDHFO
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
318 AM HST FRI OCT 2 2026
SYNOPSIS
THE SUBTROPICAL RIDGE WILL SLOWLY BUILD BACK IN OVER THE HAWAIIAN
ISLANDS AS TROPICAL STORM NOLO CONTINUES TO DRIFT WESTWARD AWAY
FROM THE HAWAII REGION. HIGHER PRESSURE RETURNING TO THE ISLANDS
FROM WILL PRODUCE EASTERLY TRADE WINDS, INCREASING ATMOSPHERIC
STABILITY, LOWERING HUMIDITY LEVELS AND DECREASING SHOWER TRENDS
THROUGH THE WEEKEND. BRIEF PASSING SHOWERS WILL FAVOR WINDWARD
MOUNTAIN AREAS IN THE OVERNIGHT TO EARLY MORNING HOURS. INCREASING
CLOUD COVER AND SHOWER TRENDS MAY RETURN FROM MONDAY NIGHT INTO
THURSDAY MORNING DUE TO A PASSING DISTURBANCE.
DISCUSSION
SOUTHERLY WINDS ACROSS THE WESTERN ISLANDS LAST NIGHT PRODUCED
BANDS OF MODERATE TO HEAVY SHOWERS AFFECTING THE ISLANDS OF
NIIHAU, KAUAI, AND PORTIONS OF OAHU. HIGH WATER LEVELS IN LOCAL
STREAMS BRIEFLY EXCEEDED FLASH FLOOD THRESHOLDS OVER NORTHERN
KAUAI TRIGGERING FLOOD ADVISORY AND FLASH FLOOD WARNING ISSUANCE.
NO REPORTS OF FLOODING WERE RECEIVED DURING LAST NIGHTS EVENT.
TODAY WE BEGIN TO TRANSITION BACK TO MORE TYPICAL DRIER EASTERLY
TRADE WIND WEATHER JUST IN TIME FOR THE WEEKEND. LOWER HUMIDITY
LEVELS AND MOSTLY SUNNY SKIES WILL PREVAIL FROM SATURDAY THROUGH
MONDAY AFTERNOON.
A WEAK DISTURBANCE IN THE FORCE MAY BRING ANOTHER ROUND OF
ENHANCED SHOWERS TO ALL ISLANDS FROM MONDAY NIGHT INTO THURSDAY
MORNING. TRADE WIND TEMPERATURE INVERSION HEIGHTS RISE INTO THE
8,000 TO 10,000 FOOT RANGE, WHICH ALLOWS FOR SCATTERED TO NUMEROUS
SHOWER ACTIVITY STATEWIDE. NORTHEASTERN TO EASTERN WINDWARD
MOUNTAIN SLOPES WOULD LIKELY SEE THE HIGHER RAINFALL AMOUNTS DUE
TO EASTERLY WIND FORCING IN THIS EVOLVING WEATHER PATTERN FOR THE
MIDDLE OF NEXT WEEK. INCREASED WET TRADE WIND RAINFALL COVERAGE FOR
THIS TIME PERIOD IN THE LATEST FORECAST GRIDS, WITH DRYING TRENDS
FORECAST BY THE END OF NEXT WEEK.
AVIATION
MODERATE SOUTHEAST WINDS WILL CONTINUE TODAY ACROSS THE STATE AS
TROPICAL STORM NOLO MOVES AWAY. SHOWERS LOOSELY ASSOCIATED WITH
NOLO WILL CONTINUE TO TRACK OVER KAUAI AND OAHU TODAY WITH MVFR
CONDITIONS LIKELY WITH BRIEF PERIODS OF IFR CONDITIONS POSSIBLE.
TRADE WINDS WILL PUSH IN A DRIER AIR MASS TONIGHT.
AIRMET SIERRA IS IN EFFECT FOR MOUNTAIN OBSCURATION ABOVE 2000
FEET OVER KAUAI, OAHU AND ABOVE 2500 FEET ON BIG ISLAND, THOUGH
CONDITIONS WILL IMPROVE OVER BIG ISLAND THIS MORNING. CLOUD BUILD
UPS LIKELY BY AFTERNOON ACROSS MAUI COUNTY AND BIG ISLAND BEFORE
DISSIPATING TONIGHT.
MARINE
MODERATE TO FRESH EAST TO SOUTHEASTERLY WINDS WILL PREVAIL ACROSS
THE REGION TODAY AS TROPICAL STORM NOLO LINGERS AMONGST THE
NORTHWESTERN HAWAIIAN ISLANDS. NOLO WILL BEGIN TO ACCELERATE
WESTWARD AWAY FROM THE HAWAIIAN ISLANDS TODAY, WHICH WILL DIMINISH
ITS INFLUENCE ON HAWAIIAN WATERS. GENTLE TO FRESH EAST TO
NORTHEAST TRADES FILL BACK IN ACROSS THE WATERS THIS WEEKEND INTO
EARLY NEXT WEEK. A SMALL CRAFT ADVISORY MAY BE NEEDED FOR THE
TYPICALLY WINDY CHANNELS LATE THIS WEEKEND FOR LOCALLY STRONG
TRADES. BY MID-NEXT WEEK, TROUGHING DEVELOPING NORTHWEST OF THE
ISLANDS MAY CAUSE THE TRADE WINDS TO WEAKEN AND VEER OUT OF THE
SOUTHEAST ONCE AGAIN.
A MODERATE, MEDIUM-PERIOD WEST TO SOUTHWEST SWELL ORIGINATING
FROM TROPICAL STORM NOLO WILL CONTINUE FOR NIIHAU AND KAUAI
TODAY BEFORE QUICKLY FADING TONIGHT. MEANWHILE, A SMALL,
BACKGROUND SOUTH SWELL CONTINUES FOR OTHER ISLANDS, HOLDING SURF
MOSTLY STEADY ALONG SOUTH FACING SHORES THROUGH THE WEEKEND. A NEW
SMALL, LONG-PERIOD SOUTH SWELL, ORIGINATING FROM A LARGE FETCH OF
GALE FORCE WINDS SOUTHEAST OF NEW ZEALAND EARLIER THIS WEEK, IS
FORECAST TO ARRIVE BEGINNING SUNDAY AND PEAK MONDAY THROUGH
WEDNESDAY.
SURF ALONG NORTH-FACING SHORES WILL SEE A TINY BUMP TODAY INTO TONIGHT
AS A SMALL, SHORT-PERIOD NORTHERLY SWELL MOVES THROUGH THE REGION.
SMALL SURF IS POSSIBLE EARLY NEXT WEEK AS A SMALL, MEDIUM-PERIOD
NORTHWEST SWELL ARRIVES THIS WEEKEND AND PEAKS ON MONDAY, FOLLOWED BY
A SLIGHTLY LARGER NORTHWEST SWELL PEAKING ON WEDNESDAY. SURF ALONG
EAST FACING SHORES WILL SEE A SLIGHT BOOST AND BECOME MORE CHOPPY AS
EASTERLY TRADES BUILD BACK INTO THE REGION THIS WEEKEND.
FIRE WEATHER
FIRE WEATHER CONDITIONS WILL REMAIN BELOW CRITICAL THRESHOLD THIS
WEEK FOR BOTH WIND AND HUMIDITY LEVELS. TEMPERATURE INVERSION
HEIGHTS NEAR MAUI AND THE BIG ISLAND TODAY WILL RANGE FROM 6,000
TO 7,000 FEET ELEVATION.
HFO WATCHES/WARNINGS/ADVISORIES
NONE.
DISCUSSION...BOHLIN
AVIATION...FOSTER
MARINE...QUESADA
FIRE WEATHER...BOHLIN
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