Marine Weather Net

Straits of Florida from Craig Key to West End of Seven Mile Bridge Out 20 NM Marine Forecast


THIS AFTERNOON

E
WINDS
15 - 20
KNOTS

TONIGHT

E
WINDS
15 - 20
KNOTS

THURSDAY AND THURSDAY NIGHT

E
WINDS
15 - 20
KNOTS

FRIDAY

E
WINDS
15
KNOTS

The Marine Weather Forecast In Detail:
GMZ053 Forecast Issued: 1124 AM EDT Wed Oct 21 2020

SMALL CRAFT SHOULD EXERCISE CAUTION ...SMALL CRAFT ADVISORY MAY BE REQUIRED TONIGHT...
This Afternoon...East Winds 15 To 20 Knots. Seas 3 To 5 Feet. Numerous Showers And Isolated Thunderstorms.
Tonight...East Winds 15 To 20 Knots. Seas 4 To 5 Feet. Scattered To Numerous Showers And Isolated Thunderstorms.
Thursday And Thursday Night...East Winds 15 To 20 Knots. Seas 4 To 5 Feet. Scattered Showers And Isolated Thunderstorms.
Friday...East Winds Near 15 Knots. Seas 3 To 5 Feet. Scattered Showers And Isolated Thunderstorms.
Friday Night...East Winds Near 15 Knots. Seas 3 To 5 Feet. Scattered Showers And Isolated Thunderstorms.
Saturday And Saturday Night...East To Southeast Winds 10 To 15 Knots. Seas 3 To 4 Feet. Scattered Showers And Isolated Thunderstorms.
Sunday...East To Southeast Winds Near 15 Knots. Seas 3 To 4 Feet. Scattered Showers And Isolated Thunderstorms.
Sunday Night...East To Southeast Winds 10 To 15 Knots. Seas 2 To 3 Feet. Scattered Showers And Isolated Thunderstorms.
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Synopsis for Keys coastal waters from Ocean Reef to Dry Tortugas: GMZ005
1124 AM EDT Wed Oct 21 2020

The Keys waters lie between a weak area of low pressure over the northeast Yucatan Peninsula and a large area of high pressure near the U.S. Mid-Atlantic coast, bringing fresh to to occasional strong east breezes this morning and again tonight, with peaks and lulls for Thursday through Friday. For this weekend, winds will slacken.

Gulf Stream
The Approximate Shoreward Edge of the Gulf Stream as of October 20...
- 44 NM South of Dry Tortugas Light...on Loggerhead Key.
- 48 NM South of Cosgrove Shoal Light...off the Marquesas Keys.
- 53 NM South of Sand Key Light...off Key West.
- 45 NM South of Looe Key...off Big Pine Key.
- 15 NM South of Sombrero Key Light...off Marathon.
- 12 NM Southeast of Alligator Reef Light...off Islamorada.
- 6 NM Southeast of Molasses Reef Light...off Key Largo.
- 4 NM East of Carysfort Reef Light...off Ocean Reef.
Area Forecast Discussion
National Weather Service Key West FL
1152am EDT Wednesday Oct 21 2020

Currently - Showers and isolated thunderstorms continue to move across the Florida Keys this morning, though the activity has shifted more over the Middle and Upper Keys the last few hours. These showers are thanks to a robust and dynamic pattern the Keys remain under. Aloft we have a weak upper level trough parked over and just west of the Florida Peninsula, while at the surface the island chain is pinched between a low over the Yucatan Peninsula, a high over the eastern U.S. and Hurricane Epsilon east of Bermuda. This surface pattern is promoting a tightened gradient across the area with a east southeast wind that is transporting ample moisture into the region. All of this equals widespread showers with localized flooding as ample moisture in the low levels continues to pump in.

Otherwise, some sun is breaking through for at least the Lower Keys. Where it has been raining, temperatures are hovering in the middle 70s, while the Lower Keys are in the lower 80s.

Short Term Update
Made quite a bit of changes this morning to the going forecast, mainly on the coastal waters forecast. Winds are a bit stronger than previously anticipated and as such, Small Craft Advisories had to be added for our eastern waters. Meanwhile, winds have come down over the western waters, however they have not fallen as low as previously forecasted. It has been a very complicated forecast this morning trying to separate gradient winds from convective winds, but it appears that the picture is becoming clearer as to what winds will do this afternoon and evening. Regarding rain chances, chances will remain likely through tonight and gradually decrease into the weekend, while remaining above normal.

Marine
Breezes are fresh to strong just off the Upper Keys and as such Small Craft Advisories (SCA) are in effect for these waters. Meanwhile, winds have come down across the western waters and SCA have been taken down. Aside from the Upper Keys, winds have entered a lull but will increase this evening and overnight and additional SCA (Small Craft Advisory) may be required. Typical peaks and lulls will be expected again tomorrow. For this weekend, gentle to moderate breezes are expected, before light to gentle winds are anticipated by Sunday night.

NOAA Key West FL Office: Watches - Warnings - Advisories
FL...Coastal Flood Advisory for FLZ076.

GM...Small Craft Advisory for GMZ042-052- 072.