Marine Weather and Tide Forecast for Stock Island, FL

FXUS62 KKEY 071950 AFDKEY

Area Forecast Discussion National Weather Service Key West FL 250 PM EST Sat Dec 7 2024

New DISCUSSION, MARINE, AVIATION

DISCUSSION
Issued at 245 PM EST Sat Dec 7 2024 A GORGEOUS early December afternoon is ongoing across the Florida Keys. While much of the Island Chain is basking in sunshine, GOES 16 Visible satellite imagery shows some of the cumulus and stratocumulus over the eastern Straits and eastern Hawk Channel starting to encroach on the Upper Keys. This is in conjunction with winds starting to ever subtly shift to the northeast direction. KBYX radar has shown persistent showers along the Gulf Stream throughout the day with this activity barely moving from where it was earlier this morning. Temperatures along the Island Chain are quite comfortable in the lower 70s with dew points in the lower 60s. Surface high pressure continues to slowly move eastward across the Southeast U.S. As a result, marine platforms are observing north to northeast breezes of 5 to 10 knots north of the Chain with 15 to 20 knots south of the Chain. Island Chain communities are observing 5 to 10 mph along the Middle and Upper Keys with 10 to 15 mph for the Lower Keys.

FORECAST
The aforementioned high pressure will continue to dominate the weather across the Keys for the next few days. As the high continues to slide across the Southeast U.S., north to northeast breezes tonight will shift to the northeast for Sunday and Sunday night before shifting to the east Monday and Monday night.
However, the cooler water to the north of the Chain may cause the Island Chain and the nearshore waters to the north to maintain the northeast breezes a little longer than anticipated.
Therefore, breezes may remain northeast to start the new work week. We will continue to fine tune over subsequent updates and as observations come in. Moisture is expected to remain quite scant over the next few days resulting in near nil rain chances through Monday night. The best place and chances for rain will remain across the Straits of Florida where the greater moisture content is as well as warmer water. Cooler air aloft moving over warm water creates some instability along with evaporation which can condense into clouds and develop some isolated showers.

The Keys remain under upper level ridging for Tuesday and Tuesday night. In conjunction, the aforementioned surface high pressure continues to slide further into the western North Atlantic resulting in an east to southeast flow. This will help to send increasing moisture towards the Keys. Therefore, slight chance of rain creep into the forecast at this juncture.

Then around mid week, a potent upper level trough is expected to deepen and swing across the Southeast U.S. in the Wednesday/Wednesday night time frame. Most deterministic and ensemble guidance are in great agreement on another frontal passage during this time period. The main difference remains on the exact strength of the front and the resulting breezes that come behind it. Nevertheless, another period of breezy to windy conditions is anticipated. It remains to be seen exactly how much moisture will be present ahead of and when the front passes through the Keys. For now, maintained 30% for Wednesday.
Statistical guidance suggests higher chances, therefore, there may be changes in subsequent updates.

Late week into the first half of next weekend, high pressure builds into the ARK-LA-TEX region. This high continues to strengthen as it moves northeastward becoming centered somewhere over New England by next weekend. As a result, a prolonged period of breezy to windy conditions is expected again for the Keys. Most of the deterministic and ensemble guidance are in agreement on the movement and placement of this high. Guidance dries out the mid to upper levels, but 850 mb is anticipated to remain quite moist. Therefore, slight chances of rain were maintained through the extended.
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