Marine Weather Net

Florida Bay including Blackwater and Buttonwood Sounds Marine Forecast


TODAY

ESE
WINDS
10
KNOTS

TONIGHT

ESE
WINDS
10
KNOTS

TUESDAY

SE
WINDS
5 - 10
KNOTS

TUESDAY NIGHT

SE
WINDS
5 - 10
KNOTS

The Marine Weather Forecast In Detail:
GMZ031 Forecast Issued: 431 AM EDT Mon Jun 29 2026

Today...East To Southeast Winds Near 10 Knots. Bay Waters A Light Chop. A Slight Chance Of Showers And Thunderstorms.
Tonight...East To Southeast Winds Near 10 Knots, Decreasing To 5 To 10 Knots. Bay Waters A Light Chop, Becoming Smooth To A Light Chop. A Slight Chance Of Showers And Thunderstorms.
Tuesday...Southeast Winds 5 To 10 Knots. Bay Waters Smooth To A Light Chop. A Chance Of Showers With A Slight Chance Of Thunderstorms.
Tuesday Night...Southeast Winds 5 To 10 Knots. Bay Waters Smooth To A Light Chop. A Slight Chance Of Showers And Thunderstorms.
Wednesday...East To Southeast Winds Near 5 Knots. Bay Waters Smooth. A Slight Chance Of Showers And Thunderstorms.
Wednesday Night...East To Southeast Winds 5 To 10 Knots. Bay Waters Smooth To A Light Chop. A Slight Chance Of Showers And Thunderstorms.
Thursday...East To Southeast Winds 5 To 10 Knots. Bay Waters Smooth To A Light Chop. A Chance Of Showers And Thunderstorms.
Thursday Night...East To Southeast Winds Near 10 Knots. Bay Waters A Light Chop. A Chance Of Showers And Thunderstorms.
Friday...East To Southeast Winds 5 To 10 Knots. Bay Waters Smooth To A Light Chop. A Chance Of Showers And Thunderstorms.
Friday Night...East To Southeast Winds 5 To 10 Knots. Bay Waters Smooth To A Light Chop. A Chance Of Showers And Thunderstorms.
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Area Forecast Discussion
National Weather Service Key West FL
1032pm EDT Sunday Jun 28 2026

Issued at 1028pm EDT Sunday Jun 28 2026 CIMSS products shows the beginning of what will be quite an amplified pattern across the lower 48. A deep mean layer ridge is currently strengthening and building across the ARK-LA-TEX region along with deep mean layer troughing across the Intermountain West. However, there is another subtly feature undercutting the ridge across the Keys and Cuba currently. In order to see this feature, we need to look at the GOES 19 Mid-level water vapor imagery. While looping the last few hours, we notice a weak cyclonic flow in the imagery or a weak tropical wave/trough moving slowly westward. This may be one of the factors attributed to the increased shower and thunderstorm activity today across the Keys as well as across the Southwest Florida mainland. KBYX radar has remained slightly active this evening with a couple showers, occasionally a thunderstorm, across the SE Gulf waters and the eastern Straits of Florida. Temperatures along the Island Chain are in the mid 80s and dew points are in the mid 70s. At the surface, an Atlantic ridge extends westward through the Keys and into the Gulf. Marine observation platforms surrounding the Keys are observing east to southeast breezes near 10 knots as a result.

Short Term - Tonight Through Friday
CAST... The 00z evening sounding shows a mostly dry vertical profile. The PWAT (Precipitable Water) value measured was 2.01 inches which is a little below the 90th percentile for the date. There is also plenty of instability (CAPE) in the profile with a value measured of 3251 J/kg. This is a very high value and most likely one of the reasons why most of the activity today became thunderstorms. The cells were feeding off the instability and didn't need much to make them become a thunderstorm. We expect it to remain fairly quiet overnight since we are lacking some of the ingredients to really get storm activity going. However, any shower that does develop will be capable of becoming a thunderstorm quite easily due to the impeccable amount of instability across the area. No changes to the ongoing forecast as a result.

Marine
Issued at 1028pm EDT Sunday Jun 28 2026 There are currently no watches, warnings, or advisories in effect across the Florida Keys coastal waters. From synopsis, a broad high pressure system centered over the North Atlantic will continue to extend westward to the Florida Peninsula through early week. This will support bouts of light to gentle breezes that may freshen to gentle to moderate at times, mainly in the overnight hours. Starting late Monday, a frontal boundary will press south across the Florida Peninsula and stall across central Florida. This will act to weaken the high and allow for slackening breezes through Thursday. Thereafter, breezes will resume a cycle of overnight peaks and daytime lulls.

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