


High Seas Forecast
Issued by NWS
Issued by NWS
879 FZPN40 PHFO 182218 HSFNP HIGH SEAS FORECAST NATIONAL WEATHER SERVICE HONOLULU HI 2300 UTC FRI JUL 18 2025 SUPERSEDED BY NEXT ISSUANCE IN 6 HOURS SEAS GIVEN AS SIGNIFICANT WAVE HEIGHT...WHICH IS THE AVERAGE HEIGHT OF THE HIGHEST 1/3 OF THE WAVES. INDIVIDUAL WAVES MAY BE MORE THAN TWICE THE SIGNIFICANT WAVE HEIGHT. THIS HIGH SEAS FORECAST USES 1-MINUTE AVERAGE WINDS WHICH MAY BE HIGHER THAN 10-MINUTE AVERAGE WINDS. SECURITE NORTH PACIFIC EQUATOR TO 30N BETWEEN 140W AND 160E SYNOPSIS VALID 1800 UTC JUL 18 2025. 24 HOUR FORECAST VALID 1800 UTC JUL 19 2025. 48 HOUR FORECAST VALID 1800 UTC JUL 20 2025. .WARNINGS. .NONE. .SYNOPSIS AND FORECAST. .TROUGH 29N165E 27N161E 25N160E MOVING W 10 KT. SCATTERED MODERATE TSTMS FROM 20N TO 27N BETWEEN 174E AND TROUGH. .24 HOUR FORECAST TROUGH MOVED W OF AREA. .TROUGH 17N162E 11N160E MOVING W 10 KT. SCATTERED MODERATE TSTMS WITHIN 270 NM E OF TROUGH. .24 HOUR FORECAST TROUGH MOVED W OF AREA. .24 HOUR FORECAST E WINDS 20 TO 25 KT FROM 10N TO 16N BETWEEN 173W AND 170E. .48 HOUR FORECAST E WINDS 20 TO 25 KT S OF 06N BETWEEN 164W AND 171W. .WINDS 20 KT OR LESS OVER REMAINDER OF FORECAST AREA. .SEAS 2.5 M OR LOWER OVER REMAINDER OF FORECAST AREA. .MONSOON TROUGH 10N140W 11N147W. ISOLATED MODERATE TSTMS WITHIN 210 NM OF TROUGH . .ITCZ 11N148W 09N154W 08N163W 06N172E. ISOLATED MODERATE TSTMS WITHIN 210 NM OF ITCZ W OF 177W. .ISOLATED MODERATE TSTMS FROM 01N TO 15N W OF 176W. $$ .FORECASTER TSAMOUS. HONOLULU HI.