02/02/2024
Here is a Florida Keys marine weather update:
Strong to severe storms will be possible Sunday as a thundery squall line strafes the Florida Keys
Small Craft Advisory conditions are expected Sunday through at least Tuesday night
Sustained winds will peak at 25 to 30 knots Monday morning through Tuesday morning, with frequent gusts approaching 35 to 40 knots
A potent branch of the Pacific jet stream will build east-southeast across the Rio Grande on Saturday. In response to the changes aloft, a complex low-pressure system will form over the Gulf of Mexico on Saturday night. A broad convergence zone on the leading edge of the low-pressure system will spread east-southeast across the southeastern Gulf early Sunday morning. The Storm Prediction Center placed the Florida Keys in a Marginal Risk (level 1 of 5) for severe thunderstorms on Sunday as the thundery squall line strafes through the Keys. There likely will be a lull in breezes behind the squall line as the tapped atmosphere recharges. However, westerly breezes will freshen in earnest late Sunday night/early Monday morning as the low-pressure system consolidates and broadens over northern Florida. Near-gale breezes (28-33 knots) will be possible Monday morning through Monday evening, with winds greater than 20 knots possible through Tuesday night. Significant wave heights will build to greater than 9 feet across the Straits of Florida on Monday evening (attached).
Squall Line: The most potent squall lines feature a 'Goldilocks' mixture of wind shear and fuel. Typically, during winter squall lines we are well within the warm and moist sector and have plenty of fuel. The best wind shear typically remains well to our north as the buckles in the jet stream pivot through the southeastern United States. Given the displacement of the jet stream well into the Gulf of Mexico, our guidance suggests we will have plenty of wind shear and adequate fuel for a potent squall line. There is the potential for damaging wind gusts near 60 knots and isolated tornadoes. The Storm Prediction Center left the door open for an upgrade to Level 2 of 5 if conditions warrant. Stay tuned. Our best estimate for time of arrival is near Key West Sunday morning, then clear of the Upper Keys Sunday afternoon.
Westerly Blow: Westerly winds will increase to 25 to 30 knots Monday around sunrise, then shift to the northwest Monday evening. Western-facing harbors (Key West Mooring field/Harbor, Boca Chica Marina, Boot Key Harbor) will take the brunt of this westerly blow with full exposure to the near-gale breezes. Any preparations for the westerly blow (chafing gear, beefed-up bumpers and fenders, secure holding power from ground tackle) should be complete on Saturday due to the Sunday squall line.