Marine Weather Net

Hawk Channel from Seven Mile Bridge to Halfmoon Shoal out to the reef Marine Forecast


OVERNIGHT

SE
WINDS
10 - 15
KNOTS

TUESDAY

SE
WINDS
10 - 15
KNOTS

TUESDAY NIGHT AND WEDNESDAY

ESE
WINDS
10
KNOTS

WEDNESDAY NIGHT

E
WINDS
10 - 15
KNOTS

The Marine Weather Forecast In Detail:
GMZ044 Forecast Issued: 1027 PM EDT Mon Jun 21 2021

Overnight...Southeast Winds 10 To 15 Knots Early, Increasing To Near 15 Knots. Seas 1 To 3 Feet, Building To 2 To 3 Feet. Nearshore Waters A Light To Moderate Chop, Becoming A Moderate Chop. Isolated Showers.
Tuesday...Southeast Winds 10 To 15 Knots. Seas 1 To 3 Feet. Nearshore Waters A Light To Moderate Chop. Isolated Showers And Thunderstorms.
Tuesday Night And Wednesday...East To Southeast Winds Near 10 Knots. Seas 1 To 2 Feet. Nearshore Waters A Light Chop. Scattered Showers And Isolated Thunderstorms.
Wednesday Night...East Winds Increasing To 10 To 15 Knots. Seas Building To 1 To 3 Feet. Nearshore Waters Becoming A Light To Moderate Chop. Scattered Showers And Isolated Thunderstorms.
Thursday...East Winds 10 To 15 Knots. Seas 1 To 3 Feet. Nearshore Waters A Light To Moderate Chop. Scattered Showers And Isolated Thunderstorms.
Thursday Night...East Winds Near 15 Knots. Seas 2 To 3 Feet. Nearshore Waters A Moderate Chop. Scattered Showers And Isolated Thunderstorms.
Friday And Friday Night...East Winds Near 15 Knots. Seas 2 To 3 Feet. Nearshore Waters A Moderate Chop. Scattered Showers And Isolated Thunderstorms.
Saturday...East Winds 10 To 15 Knots. Seas 1 To 3 Feet. Nearshore Waters A Light To Moderate Chop. Scattered Showers And Isolated Thunderstorms.
Saturday Night...East To Southeast Winds Near 15 Knots. Seas 2 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
1027 PM EDT Mon Jun 21 2021

The ridge axis across South Florida will continue to drift slowly northward. However, the ridge will erode Tuesday night and Wednesday as a longwave trough approaches the Florida Peninsula. The east to southeast moderate breezes will slacken Wednesday and Wednesday night. The ridge will once again build over the Western Atlantic Thursday and Friday, resulting in freshening east to southeast breezes. Rain and thunder chances will remain low through Tuesday night, then increase to higher than normal Wednesday through the end of the week. The highest rain and thunder chances will be Wednesday night through Thursday night.

Gulf Stream
The Approximate Shoreward Edge of the Gulf Stream as of June 17...
- 21 NM South of Dry Tortugas Light...on Loggerhead Key.
- 8 NM South of Cosgrove Shoal Light...off the Marquesas Keys.
- 8 NM South of Sand Key Light...off Key West.
- 11 NM South of Looe Key...off Big Pine Key.
- 12 NM South of Sombrero Key Light...off Marathon.
- 10 NM Southeast of Alligator Reef Light...off Islamorada.
- 8 NM Southeast of Molasses Reef Light...off Key Largo.
- 8 NM East of Carysfort Reef Light...off Ocean Reef.
Area Forecast Discussion
National Weather Service Key West FL
1025pm EDT Monday Jun 21 2021

The Florida Keys remain in the western periphery of a large subtropical ridge positioned over the central Atlantic. This synoptic pattern allows for light to moderate southeasterly breezes. The KBYX radar is showing chaff over the southeast Gulf waters and a few showers west of Andros. The storm activity that developed in the afternoon hours over the mainland remained well north of the island chain, while the storms over Cuba only produced weak outflows that dissipated after entering the Straits. The satellite imagery also showed passing cirrus clouds moving on a general southerly direction. Temperatures in the island communities are in the lower to mid 80s and the dew point values are in the mid 70s.

The 00Z KEY sounding made a couple of interesting observations. The sounding reported a temperature gradient near the surface, between 960 and 910 mb, which is helping to suppress the development of showers and thunderstorms. Also, the precipitable water value was 1.42 inches, a significant decrease from 2.10 inches the night before. Overall, the forecast is on track and no changes are necessary. Temperatures are forecast to settle into the lower 80s across the archipelago. Rain chances are retained at 10 percent, well below normal for late June. Forecast soundings indicate that the temperature inversion is likely to erode during the overnight hours, which may allow for some low-level convergence and isolated showers, especially over the Straits. Lastly, an ASCAT pass arrived around 02Z depicting east to southeast winds at 10 to 15 knots across most of the coastal waters of the Florida Keys. Guidance continues to support another wind surge occurring during the early overnight hours. Winds are expected to increase to near 15 knots across most of our marine sectors.

Marine
There are no watches, warnings, or advisories currently in effect for the coastal waters of the Florida Keys. From synopsis, the ridge axis across South Florida will continue to drift slowly northward. However, the ridge will erode Tuesday night and Wednesday. The east to southeast moderate breezes will slacken Wednesday and Wednesday night. The ridge will once again build over the Western Atlantic Thursday and Friday, resulting in freshening east to southeast breezes. Rain and thunder chances will increase to higher than normal Wednesday through the end of the week. The highest rain and thunder chances will be Wednesday night through Thursday night.

Climate
On June 21, 1860, the U.S. Army created its Signal Corps, which would be tasked 10 years later with creating a national weather service.

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