Marine Weather Net

Straits of Florida from Craig Key to West End of Seven Mile Bridge out 20 - 60 NM Marine Forecast


OVERNIGHT

ESE
WINDS
20
KNOTS

SUNDAY

ESE
WINDS
15 - 20
KNOTS

SUNDAY NIGHT

ESE
WINDS
15 - 20
KNOTS

MONDAY

E
WINDS
15
KNOTS

The Marine Weather Forecast In Detail:
GMZ073 Forecast Issued: 933 PM EDT Sat Mar 28 2020

SMALL CRAFT ADVISORY IN EFFECT
Overnight...East To Southeast Winds Near 20 Knots. Seas 4 To 7 Feet.
Sunday...East To Southeast Winds 15 To 20 Knots. Seas 4 To 5 Feet.
Sunday Night...East To Southeast Winds 15 To 20 Knots. Seas 4 To 6 Feet.
Monday...East To Southeast Winds Near 15 Knots. Seas Subsiding To 3 To 4 Feet.
Monday Night...Southeast Winds 10 To 15 Knots. Seas 2 To 3 Feet.
Tuesday...South To Southwest Winds 5 To 10 Knots. Seas 1 To 3 Feet.
Tuesday Night...Variable Winds 5 To 10 Knots. Seas 1 To 2 Feet.
Wednesday...West Winds Increasing To 15 To 20 Knots. Seas Building To 3 To 6 Feet Feet. Isolated Showers.
Wednesday Night...Northwest To North Winds Near 15 Knots. Seas 3 To 5 Feet. Isolated Showers.
Thursday...North To Northeast Winds Near 10 Knots, Becoming East. Seas Subsiding To 2 To 3 Feet. Isolated Showers.
Thursday Night...East To Southeast Winds 5 To 10 Knots. Seas 1 To 3 Feet.
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Synopsis for Keys coastal waters from Ocean Reef to Dry Tortugas: GMZ005
440 AM EDT Sun Mar 29 2020

High pressure centered between the Bahamas and Bermuda will lumber a bit to the southeast over the next few days. Moderate to fresh east to southeast breezes are expected across the coastal waters of the Florida Keys through Monday. Breezes will turn to the south Tuesday and Tuesday night as the high pressure system recedes east into the Atlantic. A weakening cold front may push through the island chain Wednesday or Wednesday night. Strong westerly breezes are possible Wednesday evening adjacent to the Florida Peninsula, followed by broadly easterly breezes Thursday and Thursday night.

Gulf Stream
The Approximate Shoreward Edge of the Gulf Stream as of March 28...
- 33 NM South of Dry Tortugas Light...on Loggerhead Key.
- 45 NM South of Cosgrove Shoal Light...off the Marquesas Keys.
- 35 NM South of Sand Key Light...off Key West.
- 29 NM South of Looe Key...off Big Pine Key.
- 30 NM South of Sombrero Key Light...off Marathon.
- 18 NM Southeast of Alligator Reef Light...off Islamorada.
- 18 NM Southeast of Molasses Reef Light...off Key Largo.
- 16 NM East of Carysfort Reef Light...off Ocean Reef.
Area Forecast Discussion
National Weather Service Key West FL
435am EDT Sunday Mar 29 2020

Currently - A high pressure system centered between the Bahamas and Bermuda extends a ridge across Florida in to the Gulf of Mexico. Winds picked up across Keys waters, becoming occasionally breezy earlier last evening. Winds have been gradually easing back and are now gentle to moderate out of the east to southeast. The warm flow has kept temperatures in the mid 70s with dew points near 70. Very stable conditions are in place with strong deep layered ridging aloft and a stunning subsidence inversion based around 940 mb with incredibly dry air above. Despite this, there is enough moisture to allow for the development of scattered thin stratocumulus.

Short Term Update
The high pressure system off the coast will gradually slide southeastwards over the next couple of days as the upper level ridge pivots more zonally. As a result, winds will gradually trend downwards, remaining out of the east to southeast. Expect continued warm conditions with a moderate amount of humidity (~70 dew points). Stable conditions will prevail with skies mostly sunny or sunny during the day and becoming partly cloudy overnight.

A mid latitude low will roll off the North Atlantic coast in the Monday night and Tuesday time frame. In response, the previously mentioned high will gradually shift further southwards. Winds will slacken further and shift more southerly, becoming briefly variable late Tuesday. Winds will then steadily strengthen out of the southwest to west Tuesday night and early Wednesday as a prefrontal trough begins to swing southeastward through Florida and the eastern Gulf of Mexico. Convective parameters are not impressive, and only slight chance probability of precipitation are expected head of a cold front passage on Wednesday. Winds will swing north in wake of the cold front, but will continue to quickly shift northeast then east through the back half of the week as the a lobe of a high cell over the eastern United States builds southeastwards into the Atlantic. The warm nearshore waters and lack of much in the way of cold air advection will mean temperatures will only fall to near or slightly below normal.

Beyond this time frame, run to run and model to run inconsistency has been considerable higher than normal.

Marine
A ridge across Florida will shift southeastward then southwards through the first half of this week. As a result, winds will trend downwards, however expect the usual wind surges in the evening and overnight hours. A small craft advisory may be required for portions of the Florida Straits tonight. Winds will relax in earnest on Tuesday and transition to a prevailing southwest to west flow. A cold front is expected to move through the Keys on Wednesday. Expect winds to briefly surge out of the north then quickly clock northeast then next over the following couple of days.

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

Small Craft Advisory until 5am EDT early this morning for GMZ044-052>055-072>075.