NWS Marine Forecast


   AMZ400-131630-  Synopsis for Altamaha Sound GA to Flagler Beach FL out to 60 nm-  922 PM EDT Sat Sep 12 2026      .SYNOPSIS...    Showers and thunderstorms over the offshore waters should dissipate  towards midnight tonight. Otherwise, weakening high pressure  stretching across south Florida and a trough progressing across the  southeastern states will create a prevailing west-northwesterly wind  flow across our local waters through Sunday morning, with the  afternoon sea breeze shifting winds to onshore across the near shore  waters. Scattered afternoon and early evening thunderstorms will be  possible on Sunday, mainly across the near shore waters. A few  strong storms could develop, containing strong wind gusts, frequent  lightning strikes, and torrential downpours. Coverage of afternoon  showers and thunderstorms will briefly shift south of St. Augustine  on Monday. Strengthening high pressure over New England on Tuesday  will then send a surge northeasterly winds southward across our  local waters, with Small Craft Advisory conditions and building seas  overspreading the waters during the afternoon hours and likely  continuing through Thursday. These strong onshore winds are expected  to develop waves of scattered to numerous showers and embedded  thunderstorms throughout our local waters from Tuesday through at  least Thursday.      .GULF STREAM...    The approximate location of the west wall of the Gulf Stream as of  Sep 12, 2026 at 0000 UTC...    50 nautical miles east of Flagler Beach.  58 nautical miles east of Saint Augustine Beach.  64 nautical miles east southeast of Jacksonville Beach.  76 nautical miles east southeast of St Simons Island.    This data derived from NCEP Global RTOFS model.    $$
   AMZ450-452-454-131630-  Coastal waters from Altamaha Sound to Fernandina Beach FL out  20 NM-  Coastal waters from Fernandina Beach to St. Augustine FL out  20 NM-  Coastal waters from St. Augustine to Flagler Beach FL out 20 NM-  922 PM EDT Sat Sep 12 2026    REST OF TONIGHT  Southwest winds 10 to 15 knots, becoming west  5 to 10 knots after midnight. Seas 2 to 3 feet. Wave Detail:  Southeast 2 feet at 4 seconds and east 2 feet at 8 seconds.  Intracoastal waters becoming mostly smooth.  SUNDAY  West northwest winds around 10 knots, becoming  east northeast 10 to 15 knots in the afternoon. Seas around 2  feet. Wave Detail: South 2 feet at 4 seconds and east 2 feet at 8  seconds. Intracoastal waters a light chop. A chance of showers  and thunderstorms in the afternoon. A few strong storms will be  possible late in the afternoon, with strong wind gusts, frequent  lightning strikes, and torrential downpours.  SUNDAY NIGHT  South winds 10 to 15 knots, becoming west 5 to  10 knots after midnight. Seas 2 to 3 feet. Wave Detail: Southeast  3 feet at 9 seconds and southeast 2 feet at 4 seconds.  Intracoastal waters becoming mostly smooth. A chance of showers  and thunderstorms in the evening.  MONDAY  Northwest winds 5 to 10 knots, becoming east northeast  around 10 knots in the afternoon. Seas around 2 feet. Wave  Detail: Southeast 2 feet at 9 seconds. Intracoastal waters  becoming a light chop. A slight chance of showers and  thunderstorms late in the afternoon.  MONDAY NIGHT  Southeast winds around 5 knots, becoming northeast  around 10 knots after midnight. Seas around 2 feet. Wave Detail:  East 2 feet at 9 seconds. Intracoastal waters mostly smooth.  TUESDAY  Northeast winds 15 to 20 knots, increasing to 20 to 25  knots in the afternoon. Seas 2 to 3 feet, building to 4 to 6 feet,  occasionally to 8 feet in the afternoon. Wave Detail:  Northeast 3 feet at 7 seconds and east 2 feet at 9 seconds,  becoming northeast 6 feet at 5 seconds and east 2 feet at 9  seconds. Intracoastal waters becoming rough. A chance of showers  with a slight chance of thunderstorms in the morning, then showers  likely with a chance of thunderstorms in the afternoon.  TUESDAY NIGHT  Northeast winds 20 to 25 knots. Seas 6 to 8  feet, occasionally to 10 feet. Intracoastal waters rough. A  chance of showers with a slight chance of thunderstorms.  WEDNESDAY  Northeast winds 20 to 25 knots. Seas 6 to 9 feet,  occasionally to 11 feet. Intracoastal waters rough. A chance of  showers. and thunderstorms after midnight.  WEDNESDAY NIGHT AND THURSDAY  Northeast winds around 20 knots,  becoming east 15 to 20 knots during the afternoon. Seas 5 to 7  feet, occasionally to 9 feet. Intracoastal waters becoming choppy.  Showers likely with a chance of thunderstorms.    Winds and waves higher in and near thunderstorms.    $$