Marine Weather Net

Straits of Florida from Halfmoon Shoal to 20 NM west of Dry Tortugas out 20 to 60 NM Marine Forecast


REST OF TODAY

E
WINDS
20
KNOTS

TONIGHT AND THURSDAY

E
WINDS
20
KNOTS

THURSDAY NIGHT AND FRIDAY

ESE
WINDS
15 - 20
KNOTS

FRIDAY NIGHT

ESE
WINDS
15
KNOTS

The Marine Weather Forecast In Detail:
GMZ075 Forecast Issued: 949 AM EDT Wed Oct 21 2020

SMALL CRAFT ADVISORY IN EFFECT
Rest Of Today...East Winds Near 20 Knots, Decreasing To 15 To 20 Knots. Seas 4 To 6 Feet. Numerous Showers And Isolated Thunderstorms.
Tonight And Thursday...East Winds Near 20 Knots. Seas 4 To 7 Feet. Scattered To Numerous Showers And Isolated Thunderstorms.
Thursday Night And Friday...East To Southeast Winds 15 To 20 Knots. Seas 3 To 6 Feet. Scattered To Numerous Showers And Isolated Thunderstorms.
Friday Night...East To Southeast Winds Near 15 Knots. Seas 3 To 4 Feet. Scattered Showers And Isolated Thunderstorms.
Saturday And Saturday Night...East To Southeast Winds 10 To 15 Ts. Seas 2 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 4 Feet. Scattered Showers And Isolated Thunderstorms.
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Synopsis for Keys coastal waters from Ocean Reef to Dry Tortugas: GMZ005
949 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
451am EDT Wednesday Oct 21 2020

Under mostly cloudy skies, mainly east winds of 5 to 15 mph along with showers passing through, temperatures are in the mid to upper 70s along the Florida Keys. Meanwhile, local radars are detecting scattered showers and an occasional thunderstorm tracking west northwest across our region. Due to episodes of rainfall, winds are mainly east ranging from 12 to 20 knots across our entire marine district.

Short Term - Today Through Friday Night
A mid and upper level trough will lie in the Southeast Gulf of Mexico through tonight, before exiting offshore of the east coast of the Florida Peninsula on Thursday. Hence, periodic spells of ascent will persist through tonight. Meanwhile, a low level trough extending from the Yucatan Peninsula and into the extreme Southeast Gulf of Mexico, will maintain a confluent and very moist easterly trajectory. Subsequently, well above normal likely probability of precipitation will be inserted through tonight. For the balance of this week, pockets of drier air, an evolving decoupled flow and little if any lift will result in high chance probability of precipitation taping off to low chance beginning Friday.

Long Term
(Saturday through Tuesday) Another low level trough lying from the Northwest Caribbean Sea northeastward into the Bahamas, will track northwestward and cross our entire region late Saturday night and Sunday. With that, ample low level moisture and subtle low level confluence will prompt 30 to 40 percent rain chances. Beyond that, a weak Western Atlantic ridge will extend across the Sunshine State, resulting in much drier air to seep in. Hence, isolated climo 20 percent probability of precipitation along with daytime highs in the upper 80s and overnight lows near 80 degrees.

Marine
Moderate to occasionally strong east breezes are anticipated, but with typical peaks and lulls expected today through the balance of this week. For this weekend, gentle to moderate breezes are expected, before light to gentle winds are anticipated by Sunday night.

Climate
In 1964, the daily record low temperature of 64 degrees was last recorded in Key West. Temperature records date back to 1872.

NOAA Key West FL Office: Watches - Warnings - Advisories
FL...None. GM...Small Craft Advisory until 11am EDT this morning for GMZ033-034- 055-075.