Straits of Florida from Ocean Reef to Craig Key out 20 - 60 NM Marine Forecast
|Tonight...Southeast To South Winds 15 To 20 Knots. Seas 2 To 4 Feet. Scattered Showers And Isolated Thunderstorms Developing.|
|Sunday...South To Southwest Winds 15 To 20 Knots, Decreasing To 5 To 10 Knots In The Afternoon. Seas Subsiding To 1 To 3 Feet. Isolated Showers In The Morning, Then Scattered Showers And Isolated Thunderstorms Developing.|
|Sunday Night...South To Southwest Winds 10 To 15 Knots. Seas 1 To 3 Feet. Scattered Showers And Isolated Thunderstorms.|
|Monday...Southwest To West Winds 5 To 10 Knots, Becoming West To Northwest And Increasing To Near 10 Knots. Seas 1 To 2 Feet. Scattered Showers And Isolated Thunderstorms.|
|Monday Night...Northwest To North Winds 5 To 10 Knots, Becoming Northeast To East And Increasing To 10 To 15 Knots. Seas Building To Around 2 Feet. Isolated Showers.|
|Tuesday...East Winds 10 To 15 Knots. Seas 2 To 4 Feet. Isolated Showers.|
|Tuesday Night...East To Southeast Winds 10 To 15 Knots. Seas 2 To 3 Feet.|
|Wednesday...Southeast Winds 10 To 15 Knots. Seas 2 To 3 Feet.|
|Wednesday Night...East To Southeast Winds Near 10 Knots, Becoming Variable Less Than 5 Knots. Seas 1 To 2 Feet.|
|Thursday...South To Southwest Winds 5 To 10 Knots, Becoming West To Northwest. Seas 1 To 2 Feet.|
|Thursday Night...Northwest To North Winds 5 To 10 Knots, Becoming Variable Less Than 5 Knots. Seas 1 To 2 Feet.|
| Synopsis for Keys coastal waters from Ocean Reef to Dry Tortugas: GMZ005|
418 PM EDT Sat Apr 10 2021
High pressure centered near Bermuda will continue to slide eastward for the remainder of the weekend, as a trough of low pressure pivots towards the Eastern Seaboard. Moderate southeast breezes will freshen briefly overnight, then will become south to southwest and slacken to light to gentle by Sunday afternoon. A round of showers and thunderstorms is possible tonight, with a more likely period of unsettled weather expected Sunday afternoon through at least Monday morning. An extended period of dry weather and gentle to moderate east to southeast breezes is expected Tuesday through the end of the week.
The Approximate Shoreward Edge of the Gulf Stream as of April 10...
- 57 NM South of Dry Tortugas Light...on Loggerhead Key.
- 12 NM South of Cosgrove Shoal Light...off the Marquesas Keys.
- 5 NM South of Sand Key Light...off Key West.
- 6 NM South of Looe Key...off Big Pine Key.
- 6 NM South of Sombrero Key Light...off Marathon.
- 10 NM Southeast of Alligator Reef Light...off Islamorada.
- 2 NM Southeast of Molasses Reef Light...off Key Largo.
- 2 NM East of Carysfort Reef Light...off Ocean Reef.
| Area Forecast Discussion|
National Weather Service Key West FL
358pm EDT Sat April 10 2021
The cuban shadow has largely dominated our weather this afternoon, with mostly sunny skies across the island chain. Available Doppler radar data indicates convection over Cuba has had a tough time of firing so far, with only harmless popcorn-like clouds over the island thus far. That being said, there are still several hours of available daytime heating to fuel these storms. Any convection that is able to develop over Cuba will quickly propagate northward. This still has a chance to interact with a decaying MCS that continues to march southeastward to toward the Florida Keys. Although there is quite a bit of uncertainty regarding the ability of this line to survive its trek, there remains a decent shot of shower and even possible thunderstorm activity for the overnight period. Choosing to maintain 30% Probability of Precipitation for this period.
Thereafter, both global and CAM model guidance is in pretty good agreement that there will be a lull in convection for much of tomorrow morning. As a trough of low pressure edges closer to the Florida Peninsula, all indications are there will be sufficient instability, moisture, and lift necessary to fire off convection late Sunday afternoon through at least early Monday morning. There is a larger amount of uncertainty in convective evolution for Monday. Outside of a line of showers and possible thunderstorms expected as the trough finally pushes through the area Monday afternoon and evening, ahead of this passage, there may be a sufficient duration of southeasterly flow to produce a reverse cloud line for portions of the island chain in the late morning or early afternoon hours. This will need to be monitored, as any cloud line will likely be supportive of waterspouts in the vicinity of the island chain.
After the trough pushes through, dry air will penetrate the Keys for the remainder of the week. Near-nil rain chances are expected, with a return to east to southeasterly flow through Friday.
High pressure centered near the island of Bermuda will continue to push eastward through Sunday, as a vigorous trough pivots towards the Eastern Seaboard. Moderate southeast to south breezes will freshen briefly overnight, then will become south to southwest and slacken to light to gentle levels by Sunday afternoon. A period of showers and thunderstorms is possible overnight, with a more likely period of unsettled weather anticipated for Sunday afternoon through at least Monday morning. Thereafter, dry weather and gentle to moderate east to southeast breezes will prevail Tuesday through the end of the week.
NOAA Key West FL Office: Watches - Warnings - Advisories