Marine Weather and Tide Forecast for Marathon, FL

November 29, 2023 6:50 AM EST (11:50 UTC)
Sunrise 6:51AM Sunset 5:39PM Moonrise 7:36PM Moonset 9:05AM
GMZ053 Expires:202311291530;;591994 Fzus52 Kkey 290928 Cwfkey
coastal waters forecast for the florida keys national weather service key west fl 428 am est Wed nov 29 2023
florida bay, hawk channel and straits of florida from ocean reef to south of dry tortugas, and the extreme southeastern gulf of mexico, including the florida keys national marine sanctuary
seas are given as significant wave height, which is the average height of the highest 1/3 of the waves. Individual waves may be more than twice the significant wave height.
gmz052>055-072>075-291530- straits of florida from ocean reef to craig key out 20 nm- straits of florida from craig key to west end of seven mile bridge out 20 nm- straits of florida from west end of seven mile bridge to south of halfmoon shoal out 20 nm- straits of florida from halfmoon shoal to 20 nm west of dry tortugas out 20 nm- straits of florida from ocean reef to craig key 20 to 60 nm out- straits of florida from craig key to west end of seven mile bridge 20 to 60 nm out- straits of florida from west end of seven mile bridge to south of halfmoon shoal 20 to 60 nm out- straits of florida from halfmoon shoal to 20 nm west of dry tortugas 20 to 60 nm out- 428 am est Wed nov 29 2023
.small craft should exercise caution...
Today..North to northeast winds 15 to 20 knots, becoming northeast. Seas 3 to 6 feet. Isolated showers.
Tonight..Northeast to east winds 15 to 20 knots. Seas 3 to 6 feet. Isolated showers.
Thursday..Northeast to east winds 15 to 20 knots, becoming east. Seas 3 to 6 feet. Isolated showers.
Thursday night..East winds 15 to 20 knots, decreasing to near 15 knots. Seas 3 to 6 feet. Isolated showers.
Friday..East to southeast winds near 15 knots. Seas 3 to 5 feet. Isolated showers.
Friday night..East to southeast winds 15 to 20 knots, decreasing to near 15 knots. Seas 3 to 5 feet. Isolated showers.
Saturday..East to southeast winds near 15 knots, decreasing to 10 to 15 knots. Seas 2 to 4 feet. Isolated showers.
Saturday night..East to southeast winds 10 to 15 knots. Seas 2 to 4 feet. Isolated showers.
Sunday..Southeast winds near 10 knots, decreasing to 5 to 10 knots. Seas 2 to 3 feet, subsiding to around 2 feet. Isolated showers.
Sunday night..Variable winds 5 to 10 knots. Seas 1 to 2 feet. Isolated showers.
coastal waters forecast for the florida keys national weather service key west fl 428 am est Wed nov 29 2023
florida bay, hawk channel and straits of florida from ocean reef to south of dry tortugas, and the extreme southeastern gulf of mexico, including the florida keys national marine sanctuary
seas are given as significant wave height, which is the average height of the highest 1/3 of the waves. Individual waves may be more than twice the significant wave height.
gmz052>055-072>075-291530- straits of florida from ocean reef to craig key out 20 nm- straits of florida from craig key to west end of seven mile bridge out 20 nm- straits of florida from west end of seven mile bridge to south of halfmoon shoal out 20 nm- straits of florida from halfmoon shoal to 20 nm west of dry tortugas out 20 nm- straits of florida from ocean reef to craig key 20 to 60 nm out- straits of florida from craig key to west end of seven mile bridge 20 to 60 nm out- straits of florida from west end of seven mile bridge to south of halfmoon shoal 20 to 60 nm out- straits of florida from halfmoon shoal to 20 nm west of dry tortugas 20 to 60 nm out- 428 am est Wed nov 29 2023
.small craft should exercise caution...
Today..North to northeast winds 15 to 20 knots, becoming northeast. Seas 3 to 6 feet. Isolated showers.
Tonight..Northeast to east winds 15 to 20 knots. Seas 3 to 6 feet. Isolated showers.
Thursday..Northeast to east winds 15 to 20 knots, becoming east. Seas 3 to 6 feet. Isolated showers.
Thursday night..East winds 15 to 20 knots, decreasing to near 15 knots. Seas 3 to 6 feet. Isolated showers.
Friday..East to southeast winds near 15 knots. Seas 3 to 5 feet. Isolated showers.
Friday night..East to southeast winds 15 to 20 knots, decreasing to near 15 knots. Seas 3 to 5 feet. Isolated showers.
Saturday..East to southeast winds near 15 knots, decreasing to 10 to 15 knots. Seas 2 to 4 feet. Isolated showers.
Saturday night..East to southeast winds 10 to 15 knots. Seas 2 to 4 feet. Isolated showers.
Sunday..Southeast winds near 10 knots, decreasing to 5 to 10 knots. Seas 2 to 3 feet, subsiding to around 2 feet. Isolated showers.
Sunday night..Variable winds 5 to 10 knots. Seas 1 to 2 feet. Isolated showers.
GMZ005 Synopsis For Keys Coastal Waters From Ocean Reef To Dry Tortugas 428 Am Est Wed Nov 29 2023
Synopsis..High pressure initially over the appalachians will shift east across the southeast united states into the western north atlantic over the next several days. Moderate to fresh north to northeast breezes will clock to the east to southeast and diminish as the high moves into the atlantic by the end of the week.
the approximate shoreward edge of the gulf stream as of november 25...
39 nm south of dry tortugas light...on loggerhead key. 11 nm south of cosgrove shoal light...off the marquesas keys. 7 nm south of sand key light...off key west. 14 nm south of looe key...off big pine key. 28 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.
gulf stream information courtesy of the naval oceanographic office.
Synopsis..High pressure initially over the appalachians will shift east across the southeast united states into the western north atlantic over the next several days. Moderate to fresh north to northeast breezes will clock to the east to southeast and diminish as the high moves into the atlantic by the end of the week.
the approximate shoreward edge of the gulf stream as of november 25...
39 nm south of dry tortugas light...on loggerhead key. 11 nm south of cosgrove shoal light...off the marquesas keys. 7 nm south of sand key light...off key west. 14 nm south of looe key...off big pine key. 28 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.
gulf stream information courtesy of the naval oceanographic office.

Area Discussion for - Key West, FL
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FXUS62 KKEY 290940 AFDKEY
Area Forecast Discussion National Weather Service Key West FL 440 AM EST Wed Nov 29 2023
New DISCUSSION, MARINE, AVIATION
DISCUSSION
Issued at 440 AM EST Wed Nov 29 2023
The coolest night since last spring is currently ongoing across the Florida Keys, with temperatures in the mid to upper 60s. The drier air behind Monday's frontal passage filtered into the area yesterday, and dew points dropped as low the mid 50s yesterday, but have since gained a few degrees and are generally near 60 degrees. Atmospheric moisture content has also dropped as the drier air moved in, and shower activity has shutdown all night.
High pressure across the Appalachians has kept a tightened gradient across the region, and marine observations platforms along the Reef recording winds between 15 and 20 knots.
A relatively routine late November forecast is on tap for the Florida Keys. Modified continental air will continue to be pumped into the region though at least the first part of Thursday, and dew points will remain in the 60s, with temperatures in the mid to upper 70s during this period. The aforementioned area of high pressure will maintain moderate elevated breezes through the end of the week as it slowly moves eastward over the next few days. As this high treks across the Southeast, winds across the region will quickly veer to the east to southeast. The Keys will find themselves in a very different airmass than we are currently experiencing, with MOS guidance indicating temperatures will likely peak in the mid to possibly upper 80s by the weekend. Dew points will also spike into the mid 70s at this time, leading to a pretty muggy start to December. Rain chances will remain near nil for the island chain through tomorrow night. PoPs will return back closer to climatology by Friday as moisture rounds the western periphery of the high, which will be centered in the western North Atlantic by this time.
Heading into the latter half of the weekend, global models have been consistent in bringing another front through the forecast area. There are some inconsistencies with timing and strength of this front, but regardless of the exact details, steering flow will finally shift from the southeast to the northwest by Monday afternoon/night. This will give the Keys a good reprieve from the tropical airmass that will be firmly in place over the area through at least Sunday night. Details of this front will be refined over the next few forecast cycles.
MARINE
Issued at 440 AM EST Wed Nov 29 2023
Small Craft Should Exercise Caution in all Florida Keys coastal waters this morning. From synopsis, High pressure initially over the Appalachians will shift east across the Southeast United States into the western North Atlantic over the next several days.
Moderate to fresh north to northeast breezes will clock to the east to southeast and diminish as the high moves into the Atlantic by the end of the week.
AVIATION
(06Z TAFS)
Issued at 440 AM EST Wed Nov 29 2023
VFR and dry conditions will prevail at both island terminals through the TAF period. Near surface winds will be mostly north to northeast at near 10 knots with occasional gusts of up to 20 knots (mostly at EYW) through this afternoon.
CLIMATE
On this day in 1968, the daily record rainfall of 2.55" was recorded in Key West. Rainfall records date back to 1871.
PRELIMINARY POINT TEMPS/POPS
Key West 76 70 79 74 / 10 10 10 10 Marathon 75 70 80 74 / 10 10 0 10
KEY WATCHES/WARNINGS/ADVISORIES
FL...None.
GM...None.
Area Forecast Discussion National Weather Service Key West FL 440 AM EST Wed Nov 29 2023
New DISCUSSION, MARINE, AVIATION
DISCUSSION
Issued at 440 AM EST Wed Nov 29 2023
The coolest night since last spring is currently ongoing across the Florida Keys, with temperatures in the mid to upper 60s. The drier air behind Monday's frontal passage filtered into the area yesterday, and dew points dropped as low the mid 50s yesterday, but have since gained a few degrees and are generally near 60 degrees. Atmospheric moisture content has also dropped as the drier air moved in, and shower activity has shutdown all night.
High pressure across the Appalachians has kept a tightened gradient across the region, and marine observations platforms along the Reef recording winds between 15 and 20 knots.
A relatively routine late November forecast is on tap for the Florida Keys. Modified continental air will continue to be pumped into the region though at least the first part of Thursday, and dew points will remain in the 60s, with temperatures in the mid to upper 70s during this period. The aforementioned area of high pressure will maintain moderate elevated breezes through the end of the week as it slowly moves eastward over the next few days. As this high treks across the Southeast, winds across the region will quickly veer to the east to southeast. The Keys will find themselves in a very different airmass than we are currently experiencing, with MOS guidance indicating temperatures will likely peak in the mid to possibly upper 80s by the weekend. Dew points will also spike into the mid 70s at this time, leading to a pretty muggy start to December. Rain chances will remain near nil for the island chain through tomorrow night. PoPs will return back closer to climatology by Friday as moisture rounds the western periphery of the high, which will be centered in the western North Atlantic by this time.
Heading into the latter half of the weekend, global models have been consistent in bringing another front through the forecast area. There are some inconsistencies with timing and strength of this front, but regardless of the exact details, steering flow will finally shift from the southeast to the northwest by Monday afternoon/night. This will give the Keys a good reprieve from the tropical airmass that will be firmly in place over the area through at least Sunday night. Details of this front will be refined over the next few forecast cycles.
MARINE
Issued at 440 AM EST Wed Nov 29 2023
Small Craft Should Exercise Caution in all Florida Keys coastal waters this morning. From synopsis, High pressure initially over the Appalachians will shift east across the Southeast United States into the western North Atlantic over the next several days.
Moderate to fresh north to northeast breezes will clock to the east to southeast and diminish as the high moves into the Atlantic by the end of the week.
AVIATION
(06Z TAFS)
Issued at 440 AM EST Wed Nov 29 2023
VFR and dry conditions will prevail at both island terminals through the TAF period. Near surface winds will be mostly north to northeast at near 10 knots with occasional gusts of up to 20 knots (mostly at EYW) through this afternoon.
CLIMATE
On this day in 1968, the daily record rainfall of 2.55" was recorded in Key West. Rainfall records date back to 1871.
PRELIMINARY POINT TEMPS/POPS
Key West 76 70 79 74 / 10 10 10 10 Marathon 75 70 80 74 / 10 10 0 10
KEY WATCHES/WARNINGS/ADVISORIES
FL...None.
GM...None.
toggle option: (graph/table)
Airport Reports
EDIT (on/off)  Help Click EDIT to display multiple airports. Follow links for more data.Airport | Dist | Age | Wind kt | Vis | Sky | Weather | Temp | DewPt | RH | inHg |
KMTH THE FLORIDA KEYS MARATHON INTL,FL | 1 sm | 57 min | NNE 12G18 | 10 sm | Clear | 64°F | 61°F | 88% | 30.07 |
Wind History from MTH
(wind in knots)Tide / Current for Vaca Key-Fat Deer Key bridge, Florida
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Vaca Key-Fat Deer Key bridge
Click for Map
Wed -- 04:19 AM EST -0.11 feet Low Tide
Wed -- 06:49 AM EST Sunrise
Wed -- 09:05 AM EST Moonset
Wed -- 10:28 AM EST 1.23 feet High Tide
Wed -- 03:19 PM EST 0.50 feet Low Tide
Wed -- 05:34 PM EST Sunset
Wed -- 07:36 PM EST Moonrise
Wed -- 09:21 PM EST 2.16 feet High Tide
Tide / Current data from XTide NOT FOR NAVIGATION
Click for Map
Wed -- 04:19 AM EST -0.11 feet Low Tide
Wed -- 06:49 AM EST Sunrise
Wed -- 09:05 AM EST Moonset
Wed -- 10:28 AM EST 1.23 feet High Tide
Wed -- 03:19 PM EST 0.50 feet Low Tide
Wed -- 05:34 PM EST Sunset
Wed -- 07:36 PM EST Moonrise
Wed -- 09:21 PM EST 2.16 feet High Tide
Tide / Current data from XTide NOT FOR NAVIGATION
Vaca Key-Fat Deer Key bridge, Florida, Tide feet
12 am |
1.4 |
1 am |
0.9 |
2 am |
0.4 |
3 am |
0.1 |
4 am |
-0.1 |
5 am |
-0.1 |
6 am |
0.2 |
7 am |
0.5 |
8 am |
0.8 |
9 am |
1.1 |
10 am |
1.2 |
11 am |
1.2 |
12 pm |
1.1 |
1 pm |
0.9 |
2 pm |
0.6 |
3 pm |
0.5 |
4 pm |
0.6 |
5 pm |
0.8 |
6 pm |
1.2 |
7 pm |
1.6 |
8 pm |
2 |
9 pm |
2.1 |
10 pm |
2.1 |
11 pm |
2 |
Moser Channel (swingbridge)
Click for Map
Wed -- 03:29 AM EST -2.33 knots Max Ebb
Wed -- 06:50 AM EST Sunrise
Wed -- 06:58 AM EST 0.00 knots Slack
Wed -- 09:05 AM EST Moonset
Wed -- 09:58 AM EST 1.85 knots Max Flood
Wed -- 01:27 PM EST -0.00 knots Slack
Wed -- 04:17 PM EST -1.58 knots Max Ebb
Wed -- 05:35 PM EST Sunset
Wed -- 07:29 PM EST 0.00 knots Slack
Wed -- 07:36 PM EST Moonrise
Wed -- 09:47 PM EST 1.02 knots Max Flood
Tide / Current data from XTide NOT FOR NAVIGATION
Click for Map
Wed -- 03:29 AM EST -2.33 knots Max Ebb
Wed -- 06:50 AM EST Sunrise
Wed -- 06:58 AM EST 0.00 knots Slack
Wed -- 09:05 AM EST Moonset
Wed -- 09:58 AM EST 1.85 knots Max Flood
Wed -- 01:27 PM EST -0.00 knots Slack
Wed -- 04:17 PM EST -1.58 knots Max Ebb
Wed -- 05:35 PM EST Sunset
Wed -- 07:29 PM EST 0.00 knots Slack
Wed -- 07:36 PM EST Moonrise
Wed -- 09:47 PM EST 1.02 knots Max Flood
Tide / Current data from XTide NOT FOR NAVIGATION
Moser Channel (swingbridge), Florida Current, knots
12 am |
-0.1 |
1 am |
-0.9 |
2 am |
-1.8 |
3 am |
-2.3 |
4 am |
-2.3 |
5 am |
-1.8 |
6 am |
-1 |
7 am |
0 |
8 am |
1 |
9 am |
1.7 |
10 am |
1.9 |
11 am |
1.7 |
12 pm |
1.2 |
1 pm |
0.4 |
2 pm |
-0.5 |
3 pm |
-1.2 |
4 pm |
-1.6 |
5 pm |
-1.5 |
6 pm |
-1.1 |
7 pm |
-0.4 |
8 pm |
0.4 |
9 pm |
0.9 |
10 pm |
1 |
11 pm |
0.8 |
Key West, FL,

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