685
FXHW60 PHFO 171952
AFDHFO
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
952 AM HST TUE MAR 17 2026
SYNOPSIS
CLOUDY SKIES WITH GENERALLY LIGHT WINDS AND PERIODS OF SHOWERS
WILL PERSIST THROUGH MIDWEEK. ALTHOUGH WIDESPREAD HEAVY RAIN IS
NOT EXPECTED DURING THIS TIME, DEEP TROPICAL MOISTURE WILL REMAIN
IN PLACE, PARTICULARLY OVER THE EASTERN END OF THE STATE.
CONDITIONS ARE EXPECTED TO DETERIORATE AGAIN BY FRIDAY AS ANOTHER
UPPER-LEVEL DISTURBANCE AND SURFACE LOW APPROACH FROM THE WEST,
BRINGING INCREASING CHANCES FOR WIDESPREAD RAINFALL AND MODERATE
KONA WINDS. WITH SOILS ALREADY SATURATED FROM THIS PAST WEEKEND,
ADDITIONAL RAINFALL COULD QUICKLY LEAD TO RUNOFF AND FLOODING
IMPACTS.
SHORT TERM UPDATE
ISSUED AT 952 AM HST TUE MAR 17 2026
AN AREA OF LIGHT SHOWERS WAS MOVING ENE OVER THE KAUAI CHANNEL
THIS MORNING, AND THERE WERE ALSO A FEW SHOWERS OVER MAUI.
SCATTERED SHOWERS ARE FORECAST TO CONTINUE TODAY, MOST NUMEROUS
OVER THE EASTERN ISLANDS. RAINFALL AMOUNTS WILL BE LOW TO PERHAPS
MODERATE. OTHERWISE, EXPECT MOSTLY CLOUDY SKIES AND RELATIVELY
LIGHT WINDS, GENERALLY 5-15 MPH. NO UPDATES ARE NEEDED AT THIS
TIME.
PREV DISCUSSION
ISSUED AT 305 AM HST TUE MAR 17 2026
IN THE WAKE OF THE SIGNIFICANT KONA LOW THAT IMPACTED THE STATE
OVER THE PAST SEVERAL DAYS, A BROAD AND PERSISTENT UPPER-LEVEL
TROUGH REMAINS ANCHORED OVER THE REGION. WHILE THE KONA LOW HAS
WEAKENED AND LIFTED AWAY, THE LARGER-SCALE PATTERN REMAINS LARGELY
UNCHANGED, WITH DEEP TROPICAL MOISTURE CONTINUING TO STREAM
NORTHWARD OVER PORTIONS OF THE STATE. PRECIPITABLE WATER VALUES
REMAIN ANOMALOUSLY HIGH, MAINTAINING A MOIST AIR MASS ACROSS THE
REGION.
MODEL GUIDANCE CONTINUES TO INDICATE A RELATIVE DECREASE IN
WIDESPREAD HEAVY RAINFALL THROUGH THE NEXT COUPLE OF DAYS,
PARTICULARLY OVER THE WESTERN END OF THE STATE. HOWEVER, THIS
SHOULD NOT BE INTERPRETED AS A RETURN TO BENIGN CONDITIONS.
PERIODS OF SHOWERS WILL PERSIST, WITH THE BEST CHANCES EXPECTED
ACROSS MAUI COUNTY AND THE BIG ISLAND, WHERE THE AXIS OF DEEPEST
MOISTURE IS FORECAST TO REMAIN FOCUSED THROUGH MIDWEEK.
BY THE LATTER HALF OF THE WEEK, THE UPPER-LEVEL TROUGH IS
FORECAST TO DEEPEN WEST OF THE STATE. THIS FEATURE IS EXPECTED TO
RE-EXPAND THE AXIS OF ANOMALOUS MOISTURE BACK ACROSS THE ENTIRE
ISLAND CHAIN WHILE INCREASING LARGE-SCALE ASCENT. AT THE SURFACE,
LOW PRESSURE IS FORECAST TO DEVELOP AND APPROACH THE ISLANDS, WITH
MODERATE KONA WINDS RETURNING AND DEWPOINTS CLIMBING BACK TOWARD
70 DEGREES.
THIS EVOLVING PATTERN WILL SUPPORT A RENEWED INCREASE IN SHOWER
COVERAGE AND INTENSITY FROM LATE WEEK INTO THE WEEKEND, WITH MODEL
CONSENSUS SUGGESTING AN ADDITIONAL SEVERAL INCHES OF RAINFALL
POSSIBLE OVER PORTIONS OF THE STATE DURING THIS PERIOD. WHILE
THIS NEXT SYSTEM DOES NOT CURRENTLY APPEAR TO BE AS INTENSE AS
THE RECENT EVENT, IT WILL IMPACT AN ALREADY HIGHLY SATURATED
ENVIRONMENT.
GIVEN THE ANTECEDENT CONDITIONS, INCLUDING ELEVATED STREAMS AND
SATURATED SOILS, EVEN MODERATE RAINFALL RATES MAY QUICKLY LEAD TO
RUNOFF ISSUES. THE THREAT FOR FLASH FLOODING WILL BECOME ELEVATED
STATEWIDE BY FRIDAY, WITH THE POTENTIAL FOR MORE SIGNIFICANT
IMPACTS PERSISTING THROUGH THE WEEKEND.
AVIATION
ISSUED AT 305 AM HST TUE MAR 17 2026
PASSING SHOWERS CONTINUE OVER THE ENTIRE STATE EARLY THIS MORNING
AS A SURFACE TROUGH MOVES INTO THE STATE WITH INTERMITTENT MVFR
AND IFR CONDITIONS AT SELECT TAF SITES ACROSS MAUI COUNTY AND THE
BIG ISLAND. CONDITIONS LOOK TO IMPROVE OVER KAUAI AND OAHU THIS
AFTERNOON AS THE TROUGH PUSHES EAST TO MAUI COUNTY. THE TROUGH
WILL KEEP SOME SHOWERS AND MVFR CIGS/VSBYS AROUND MAUI COUNTY AND
THE BIG ISLAND WITH ISOLATED PERIODS OF IFR CONDITIONS THROUGH THE
FORECAST PERIOD.
AIRMET SIERRA IS IN EFFECT FOR MTN OBSC FOR KAUAI, MAUI, LANAI,
AND THE BIG ISLAND AND WILL LIKELY BE EXTENDED THIS MORNING. KAUAI
WILL LIKELY BE CLEAR OF MTN OBSC BY THIS AFTERNOON. NO OTHER
AIRMETS ARE CURRENTLY IN EFFECT.
MARINE
ISSUED AT 305 AM HST TUE MAR 17 2026
LIGHT AND VARIABLE WINDS WILL PREVAILING THROUGH MIDWEEK, WITH
DAYTIME SEA BREEZES AND OVERNIGHT LAND BREEZES NEAR THE COASTS. A
BRIEF PERIOD OF LIGHT TRADES WILL BE POSSIBLE BY MIDWEEK AS A WEAK
RIDGE BUILDS NORTH OF THE STATE, FOLLOWED BY LIGHT TO MODERATE S
WINDS LATE IN THE WEEK AS A NEW SYSTEM APPROACHES FROM THE WEST.
SURF ALONG EXPOSED NORTH AND WEST FACING SHORES ARE TRENDING UP
THIS MORNING AS A FRESH NORTH-NORTHWEST SWELL BUILDS DOWN THE
ISLAND CHAIN. THIS SOURCE SHOULD PEAK TODAY THROUGH WEDNESDAY
(OVERHEAD TO DOUBLE OVERHEAD AT PEAK SPOTS), THEN EASE INTO THE
SECOND HALF OF THE WEEK AS IT SHIFTS OUT OF THE NORTH-NORTHEAST.
SURF ALONG S SHORES WILL TREND UP LATER TODAY THROUGH MIDWEEK AS
A FRESH LONG PERIOD SOUTH SWELL ARRIVES. THIS SWELL WILL PEAK
WEDNESDAY THROUGH THURSDAY (HEAD HIGH), THEN EASE INTO THE
WEEKEND.
SURF ALONG EAST FACING SHORES WILL REMAIN WELL BELOW AVERAGE DUE
TO THE LACK OF TRADES LOCALLY AND UPSTREAM. THE EXCEPTION WILL BE
FOR EAST FACING SHORES EXPOSED TO NORTH-NORTHEAST SWELLS EXPECTED
LATER THIS WEEK/WEEKEND.
HFO WATCHES/WARNINGS/ADVISORIES
NONE.
UPDATE...PARKER
DISCUSSION...GIBBS
AVIATION...SHIGESATO
MARINE...GIBBS
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