Marine forecast
Florida Straits: Seven Mile Bridge–Halfmoon Shoal
- current wind
- 12 kt NE
- Gusts
- 14 kt
- Seas
- 2.0 ft
- Period
- 5 sec
- Air
- 84°F
Observed Tue 3:10 PM | GMZ054
- Gusts now
- 14 kt
- Seas now
- 2.0 ft · 5 sec
- Air
- 84°F
- 72-hr peak
- 15 kt
- Peak seas
- 4 ft
In brief
At 3:10 pm EDT on Oct 13, 2026, NDBC station SANF1 (Sand Key, FL, 22 miles away) measured wind from the NE at 12 kt, gusting to 14 kt; buoy 42095 measured seas of 2.0 ft. The NWS forecast for Florida Straits: Seven Mile Bridge–Halfmoon Shoal, FL issued at 10:19 am EDT on Oct 13, 2026 reads, for this afternoon: “Northeast winds near 15 knots. Seas 2 to 3 feet, building to 2 to 4 feet, occasionally to 5 feet.”
Source: National Weather Service Key West FL forecast; NDBC observations
Wind forecast · ktPeak 15 kt
Seas forecast · ftPeak 4 ft
NWS marine forecast
| Period | Forecast |
|---|---|
| This Afternoon | Northeast winds near 15 knots. Seas 2 to 3 feet, building to 2 to 4 feet, occasionally to 5 feet. Wave Detail: North 3 feet at 5 seconds. A chance of showers with a slight chance of thunderstorms. |
| Tonight | Northeast to east winds near 15 knots. Seas 3 to 4 feet, occasionally to 5 feet. Wave Detail: Northeast to east 4 feet at 5 seconds. Showers likely with a slight chance of thunderstorms. |
| Wednesday | Northeast to east winds near 15 knots. Seas 3 to 4 feet, occasionally to 5 feet. Wave Detail: Northeast to east 3 feet at 5 seconds. A chance of showers with a slight chance of thunderstorms. |
| Wednesday Night | East winds near 15 knots. Seas 3 to 4 feet, occasionally to 5 feet. A chance of showers with a slight chance of thunderstorms. |
| Thursday | East winds 10 to 15 knots. Seas 2 to 4 feet, occasionally to 5 feet. A chance of showers with a slight chance of thunderstorms. |
| Thursday Night | East winds near 15 knots. Seas 3 to 4 feet, occasionally to 5 feet. A chance of showers with a slight chance of thunderstorms. |
| Friday | East winds 10 to 15 knots, decreasing to near 10 knots. Seas 3 to 4 feet, occasionally to 5 feet, subsiding to 2 to 3 feet. A chance of showers with a slight chance of thunderstorms. |
| Friday Night | Northeast to east winds 5 to 10 knots, increasing to near 10 knots. Seas 1 to 2 feet. A chance of showers and thunderstorms. |
| Saturday | Northeast to east winds 10 to 15 knots. Seas 1 to 2 feet. Showers with a chance of thunderstorms. |
| Saturday Night | Northeast to east winds increasing to 15 to 20 knots. Seas building to 2 to 4 feet, occasionally to 5 feet. A chance of thunderstorms. Showers. |
Issued Tue 10:19 AM by Key West FL (product CWFKEY).
Synopsis
High pressure is centered over the Southeast U.S. and the northern Gulf. An Atlantic ridge continues to weaken and retreat east towards the central Atlantic. In between these two features lies a weak cold front which is in the process of stalling along and parallel or just south of the Florida Keys this morning. This will promote gentle to moderate northeast to east breezes over the next several days. There will be chances for showers and a few thunderstorms over the next few days as this weak and diffuse front remains in the area. Late in the week, a strong cold front could develop and move towards the Florida Keys by the weekend. Currently, there are low chances that the front will make it to the Florida Keys waters. We will continue monitoring this system. The Approximate Shoreward Edge of the Gulf Stream as of October 9, 2026... 53 NM south-southeast of Dry Tortugas Light, on Loggerhead Key 33 NM south-southeast of Cosgrove Shoal Light, off the Marquesas Keys 24 NM south-southeast of Sand Key Light, off Key West 19 NM south-southeast of Looe Key, off Big Pine Key 13 NM south-southeast of Sombrero Key Light, off Marathon 5 NM south-southeast of Alligator Reef Light, off Islamorada 2 NM east of Molasses Reef Light, off Key Largo 2 NM east of Carysfort Reef Light, off Ocean Reef Gulf Stream Information Courtesy of the Naval Oceanographic Office.
Recent buoy conditions
| Time | Wind | Gust | Seas | Water |
|---|---|---|---|---|
| Tue 3:10 PM | 12 kt NE | 14 kt | — | — |
| Tue 2:50 PM | 12 kt NE | 14 kt | — | — |
| Tue 1:50 PM | 12 kt NE | 14 kt | — | — |
| Tue 12:50 PM | 14 kt ENE | 16 kt | — | — |
| Tue 11:50 AM | 14 kt NE | 16 kt | — | — |
| Tue 10:50 AM | 15 kt NE | 18 kt | — | — |
| Tue 9:50 AM | 12 kt NE | 14 kt | — | — |
| Tue 8:50 AM | 7 kt N | 9 kt | — | — |
| Tue 7:50 AM | 11 kt NE | 15 kt | — | — |
| Tue 6:50 AM | 10 kt ENE | 13 kt | — | — |
| Tue 5:50 AM | 7 kt ENE | 10 kt | — | — |
| Tue 4:50 AM | 9 kt E | 12 kt | — | — |
Observed Tue 3:10 PM at NDBC buoy SANF1 (Sand Key, FL), 22.3 miles away. Seas from buoy 42095 (Satan Shoal, FL (244)), 26.5 miles away, at Tue 3:00 PM.
Frequently asked questions
What is the marine forecast for Florida Straits: Seven Mile Bridge–Halfmoon Shoal today?
This Afternoon: Northeast winds near 15 knots. Seas 2 to 3 feet, building to 2 to 4 feet, occasionally to 5 feet. Wave Detail: North 3 feet at 5 seconds. A chance of showers with a slight chance of thunderstorms.
Is there a small craft advisory for Florida Straits: Seven Mile Bridge–Halfmoon Shoal?
No advisories, warnings or watches are in effect for NWS zone GMZ054 as of the last update on this page. Advisories can be issued at any time; check the current bulletin before leaving the dock.
How high are the waves at Florida Straits: Seven Mile Bridge–Halfmoon Shoal right now?
Seas are running 2.0 ft at a 5-second period, measured at NDBC buoy SANF1 Tue 3:10 PM, 22.3 miles from this zone. The forecast peaks at 4.0 ft Wed 2 AM.
What do the wind speeds in knots mean?
One knot is 1.15 mph. The National Weather Service issues a small craft advisory for sustained winds of roughly 22–33 knots or hazardous seas, a gale warning at 34–47 knots, and a storm warning at 48 knots and above. Exact advisory thresholds vary by forecast office and by water body — a bay reaches dangerous chop at a lower wind speed than open ocean.
Where does this forecast come from?
The forecast text is the National Weather Service's own marine bulletin for zone GMZ054, issued by Key West FL, reproduced in full. The wind and seas charts are drawn from the NWS gridded forecast for a point inside the zone. Observations come from the nearest reporting NDBC buoy. We are not affiliated with NOAA or the National Weather Service.
Forecast: NOAA/NWS product CWFKEY, issued Tue 10:19 AM. Observations: NOAA National Data Buoy Center station SANF1, read Tue 3:10 PM. Retrieved Oct 13, 3:42 PM. Conditions offshore change faster than any page can be rebuilt, so check the current NWS bulletin and your own instruments before going out.