499 FZNT02 KNHC 150348 HSFAT2 HIGH SEAS FORECAST NWS NATIONAL HURRICANE CENTER MIAMI FL 0430 UTC SAT SEP 15 2018 SUPERSEDED BY NEXT ISSUANCE IN 6 HOURS SEAS GIVEN AS SIGNIFICANT WAVE HEIGHT...WHICH IS THE AVERAGE HEIGHT OF THE HIGHEST 1/3 OF THE WAVES.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. SECURITE ATLANTIC FROM 07N TO 31N W OF 35W INCLUDING CARIBBEAN SEA AND GULF OF MEXICO SYNOPSIS VALID 0000 UTC SAT SEP 15. 24 HOUR FORECAST VALID 0000 UTC SUN SEP 16. 48 HOUR FORECAST VALID 0000 UTC MON SEP 17. .WARNINGS. ...TROPICAL STORM WARNING... .TROPICAL STORM HELENE NEAR 35.8N 35.8W 988 MB AT 0300 UTC SEP 15 MOVING NNE OR 030 DEG AT 16 KT. MAXIMUM SUSTAINED WINDS 60 KT GUSTS 75 KT. TROPICAL STORM FORCE WINDS WITHIN 140 NM E SEMICIRCLE...70 NM SW QUADRANT AND 120 NM NW QUADRANT. SEAS 12 FT OR GREATER WITHIN 240 NM NE QUADRANT...300 NM SE QUADRANT... 210 NM SW QUADRANT...AND 180 NM NW QUADRANT WITH SEAS TO 34 FT. OVER FORECAST WATERS N OF 28N E OF 41W WINDS 20 KT OR LESS. SEAS 8 TO 11 FT IN MIXED SWELL. .24 HOUR FORECAST TROPICAL STORM HELENE NEAR 40.3N 31.2W. MAXIMUM SUSTAINED WINDS 55 KT GUSTS 65 KT. TROPICAL STORM FORCE WINDS WITHIN 120 NM NE AND SW QUADRANTS...130 NM NW QUADRANT AND 150 NM SE QUADRANT. SEAS 12 FT OR GREATER N OF AREA. OVER FORECAST WATERS WINDS 20 KT OR LESS. SEAS LESS THAN 8 FT. .48 HOUR FORECAST POST-TROPICAL EXTRATROPICAL HELENE NEAR 45.0N 21.5W. MAXIMUM SUSTAINED WINDS 50 KT GUSTS 60 KT. TROPICAL STORM FORCE WINDS WITHIN 140 NM N SEMICIRCLE AND 160 NM S SEMICIRCLE. SEAS 12 FT OR GREATER N OF AREA. OVER FORECAST WATERS WINDS 20 KT OR LESS. SEAS LESS THAN 8 FT. .72 HOUR FORECAST POST-TROPICAL EXTRATROPICAL HELENE NEAR 51.5N 9.0W. MAXIMUM SUSTAINED WINDS 50 KT GUSTS 60 KT. EXTENDED OUTLOOK...USE FOR GUIDANCE ONLY...ERRORS MAY BE LARGE. .96 HOUR FORECAST...DISSIPATED. ...TROPICAL STORM WARNING... .TROPICAL STORM JOYCE NEAR 31.6N 43.6W 997 MB AT 0300 UTC SEP 15 MOVING E OR 090 DEG AT 5 KT. MAXIMUM SUSTAINED WINDS 45 KT GUSTS 55 KT. TROPICAL STORM FORCE WINDS WITHIN 30 NM E SEMICIRCLE AND 0 NM W SEMICIRCLE. SEAS 12 FT OR GREATER WITHIN 60 NM OF CENTER EXCEPT 0 NM SW QUADRANT WITH SEAS TO 14 FT. OVER FORECAST WATERS WITHIN 240 NM SE AND 180 NM SW QUADRANTS WINDS 20 TO 30 KT. SEAS 9 TO 11 FT. ELSEWHERE N OF 25N BETWEEN 41W AND 55W WINDS 20 KT OR LESS. SEAS TO 10 FT IN MIXED SWELL. .24 HOUR FORECAST TROPICAL STORM JOYCE NEAR 33.2N 39.8W. MAXIMUM SUSTAINED WINDS 50 KT GUSTS 60 KT. TROPICAL STORM FORCE WINDS WITHIN 40 NM E SEMICIRCLE AND 30 NM W SEMICIRCLE. OVER FORECAST WATERS N OF 29N BETWEEN 36W AND 41W SW WINDS 20 TO 25 KT. SEAS TO 9 FT. .48 HOUR FORECAST TROPICAL STORM JOYCE NEAR 35.1N 33.6W. MAXIMUM SUSTAINED WINDS 40 KT GUSTS 50 KT. TROPICAL STORM FORCE WINDS WITHIN 30 NM E SEMICIRCLE AND 0 NM W SEMICIRCLE. OVER FORECAST WATERS WINDS 20 KT OR LESS. SEAS LESS THAN 8 FT. .72 HOUR FORECAST TROPICAL STORM JOYCE NEAR 34.0N 28.4W. MAXIMUM SUSTAINED WINDS 35 KT GUSTS 45 KT. EXTENDED OUTLOOK...USE FOR GUIDANCE ONLY...ERRORS MAY BE LARGE. .96 HOUR FORECAST...DISSIPATED. ...TROPICAL STORM WARNING... .TROPICAL STORM ISAAC NEAR 15.4N 69.5W 1002 MB AT 0300 UTC SEP 15 MOVING W OR 275 DEG AT 13 KT. MAXIMUM SUSTAINED WINDS 35 KT GUSTS 45 KT. TROPICAL STORM FORCE WINDS WITHIN 40 NM E SEMICIRCLE...0 NM SW QUADRANT AND 30 NM NW QUADRANT. SEAS TO 11 FT N OF 15N BETWEEN 66W AND 72W. SCATTERED TSTMS WITHIN 150 NM SW QUADRANT OF ISAAC AND N OF 14N BETWEEN 63W AND 68W. .24 HOUR FORECAST TROPICAL STORM ISAAC NEAR 15.7N 73.3W. MAXIMUM SUSTAINED WINDS 35 KT GUSTS 45 KT. LITTLE CHANGE IN RADIUS OF TROPICAL STORM FORCE WINDS. SEAS 8 TO 11 FT WITHIN 90 NM NE QUADRANT. ELSEWHERE WINDS 20 TO 33 KT WITHIN 300 NM N SEMICIRCLE. SEAS TO 8 FT. SCATTERED TSTMS WITHIN 150 NM N OF CENTER. .48 HOUR FORECAST TROPICAL DEPRESSION ISAAC NEAR 16.7N 77.4W. MAXIMUM SUSTAINED WINDS 30 KT GUSTS 40 KT. WINDS 20 TO 30 KT WITHIN 180 NM NE SEMICIRCLE. SEAS TO 9 FT. .72 HOUR FORECAST TROPICAL DEPRESSION ISAAC NEAR 18.7N 81.4W. MAXIMUM SUSTAINED WINDS 30 KT GUSTS 40 KT. EXTENDED OUTLOOK...USE FOR GUIDANCE ONLY...ERRORS MAY BE LARGE. .96 HOUR FORECAST...DISSIPATED. FORECAST WINDS IN AND NEAR ACTIVE TROPICAL CYCLONES SHOULD BE USED WITH CAUTION DUE TO UNCERTAINTY IN FORECAST TRACK...SIZE AND INTENSITY. .SYNOPSIS AND FORECAST. .ATLC N OF 30N BETWEEN 68W AND 80W WINDS 20 KT OR LESS. SEAS TO 9 FT IN MIXED SWELL. ELSEWHERE N OF 17.5N BETWEEN 55W AND 74W WINDS 20 KT OR LESS. SEAS TO 10 FT IN MIXED SWELL. .24 HOUR FORECAST N OF 30N W OF 74W WINDS 20 KT OR LESS. SEAS TO 9 FT IN MIXED SW AND SE SWELL. .48 HOUR FORECAST WINDS 20 KT OR LESS. SEAS LESS THAN 8 FT. .REMAINDER OF AREA WINDS 20 KT OR LESS. SEAS LESS THAN 8 FT. $$ .FORECASTER STRIPLING. NATIONAL HURRICANE CENTER.