Marine Weather Net

Bayside and Gulf side from Craig Key to West End of Seven Mile Bridge Marine Forecast


OVERNIGHT

N
WINDS
5
KNOTS

MONDAY AND MONDAY NIGHT

SE
WINDS
5 - 10
KNOTS

TUESDAY

S
WINDS
10
KNOTS

TUESDAY NIGHT

SW
WINDS
5 - 10
KNOTS

The Marine Weather Forecast In Detail:
GMZ032 Forecast Issued: 1009 PM EDT Sun Sep 27 2020

Overnight...North Winds Near 5 Knots, Becoming East. Seas 1 Foot Or Less. Nearshore Waters Smooth. Scattered Showers And Isolated Thunderstorms.
Monday And Monday Night...Southeast Winds 5 To 10 Knots. Seas 1 Foot Or Less. Nearshore Waters Smooth To A Light Chop. Scattered Showers And Thunderstorms.
Tuesday...Southeast To South Winds Near 10 Knots. Seas Around 1 Foot. Nearshore Waters A Light Chop. Scattered Showers And Isolated Thunderstorms In The Morning, Then Isolated Showers In The Afternoon.
Tuesday Night...Southwest Winds 5 To 10 Knots. Seas 1 Foot Or Less. Nearshore Waters Smooth To A Light Chop. Scattered Showers And Isolated Thunderstorms.
Wednesday...Southwest To West Winds 5 To 10 Knots, Becoming North And Increasing To 10 To 15 Knots. Seas Building To 1 To 3 Feet. West Of The Marquesas Keys, Seas Building To 2 To 4 Feet Due To Northwest Swell. Nearshore Waters Smooth To A Light Chop, Becoming A Light To Moderate Chop. Scattered Showers And Isolated Thunderstorms.
Wednesday Night...North To Northeast Winds 10 To 15 Knots. Seas 1 To 3 Feet, Except 3 To 4 Feet West Of The Marquesas Keys Due To Northwest Swell. Nearshore Waters A Light To Moderate Chop. Scattered Showers And Isolated Thunderstorms.
Thursday...Northeast Winds 10 To 15 Knots. Seas 1 To 3 Feet. Nearshore Waters A Light To Moderate Chop. Scattered Showers And Isolated Thunderstorms.
Thursday Night...Northeast To East Winds 10 To 15 Knots. Seas 1 To 3 Feet. Nearshore Waters A Light To Moderate Chop. Scattered Showers And Isolated Thunderstorms.
Friday...Northeast Winds 10 To 15 Knots. Seas 1 To 3 Feet. Nearshore Waters A Light To Moderate Chop. Scattered Showers And Isolated Thunderstorms.
Friday Night...Northeast Winds Near 15 Knots. Seas 1 To 3 Feet. Nearshore Waters A Moderate Chop. Scattered Showers And Isolated Thunderstorms.
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Synopsis for Keys coastal waters from Ocean Reef to Dry Tortugas: GMZ005
1009 PM EDT Sun Sep 27 2020

Gentle, mostly southeast breezes will prevail late tonight through Tuesday morning, becoming southerly Tuesday afternoon and Tuesday night as a cold front approaches from the Gulf of Mexico. This front will slide southeast through the Keys Wednesday and Wednesday evening, with freshening north to northeast breezes. Moderate to occasionally fresh northeast breezes are expected Thursday through Friday night.

Gulf Stream
The Approximate Shoreward Edge of the Gulf Stream as of September 26...
- 51 NM South of Dry Tortugas Light...on Loggerhead Key.
- 33 NM South of Cosgrove Shoal Light...off the Marquesas Keys.
- 26 NM South of Sand Key Light...off Key West.
- 19 NM South of Looe Key...off Big Pine Key.
- 18 NM South of Sombrero Key Light...off Marathon.
- 11 NM Southeast of Alligator Reef Light...off Islamorada.
- 6 NM Southeast of Molasses Reef Light...off Key Largo.
- 6 NM East of Carysfort Reef Light...off Ocean Reef.
Area Forecast Discussion
National Weather Service Key West FL
1054pm EDT Sunday September 27 2020

Little overall change in the weather is expected through Tuesday. A low-mid level ridge axis will extend east-west across South Florida, with weak flow in close proximity over the Keys. A very moist and moderately unstable air mass remains in place, but the light-flow regime means that convective cells take on a short- lived pulse mode and move slowly. We must rely on differential heating to fire off any convection, which comes most notably with daytime heating over the islands. On Tuesday, a turn to southerly flow will introduce the convectively inhibiting effect of the downwind shadow off Cuba during the afternoon hours.

Latest guidance continues on track in showing an uncommonly early season cold front spreading southeast across the forecast domain on Wednesday and Wednesday evening. It will be followed by a turn to a fresh northerly breeze. Dewpoints may very well fall into the upper 60s by Thursday morning. This represents a modest drying of the air mass and will decrease the feeling of mugginess in the air.

This evening's Tropical Weather Outlook from NHC introduced a low-chance area over the Northwest Caribbean for tropical cyclone development late this week. As we head into October, this is an area that we watch closely based on historic tracks of past storms. It is way too early to project what may happen beyond the possible development area. As at any time during hurricane season, would urge folks to review your hurricane plan and make sure you have supplies on hand. Will be watching the outlooks with interest in the days ahead.

Marine
Gentle southeast breezes will develop on the waters on Monday morning, as a weak high pressure ridge nudges westward across South Florida. Breezes will become more southerly on Tuesday and Tuesday night, in advance of an early season cold front that will spread southeast across the waters on Wednesday and Wednesday evening. Fresh northerly breezes will follow the front, with a turn to northeast breezes on Thursday and continuing Friday.

NOAA Key West FL Office: Watches - Warnings - Advisories
FL...None. GM...None.