Marine Weather and Tide Forecast for Big Pine Key, FL

DISCUSSION
Issued at 1030 AM EDT Wed Jul 29 2026 The 12z morning sounding at KEY on this first day of the 2026 lobster sport season sampled a well-mixed adiabatically layer from the surface up to around 940 mb, capped by a weak temperature inversion, and then relatively dry air above. GOES-19 visible satellite imagery is only detecting isolated to scattered cumuli streaming across the Florida Keys and the adjacent marine zones in the mean moderate to southwesterlies. These southwesterlies are a response to the interaction of a stationary front draped across the Mid- Atlantic and a 1024 mb surface high pressure system centered northeast of the Leeward Islands. Under ample solar insolation, land-based surface observations across the Keys are reporting temperatures near 90F already at this early afternoon hour.

For this afternoon and evening, skies should remain generally mostly sunny across the Keys, with temperatures nudging up another few degrees. We will need to monitor the potential for broken cumulus cloud line development across portions of the Keys.
However, given the mean wind speeds and the aforementioned dry air above 950 mb, current reasoning suggests any cloud streamer forming along the Island Chain will be weak and quickly dissipating. No changes to the inherited short-term forecast proposed.

MARINE
Issued at 1030 AM EDT Wed Jul 29 2026 Small Craft Should Exercise Caution headlines are posted for the eastern marine zones south of the Upper Keys, including Hawk Channel and the Straits of Florida. In addition, a broken cloud line will also be possible along portions of the Florida Keys.
Any developing cloud line will support possible waterspout formation. From synopsis, troughing combined with the western periphery of an Atlantic surface ridge will support moderate to fresh southwest to west breezes across the Keys marine zones, especially over the adjacent nearshore and offshore waters off the Upper Keys. Breezes will gradually slacken overnight through Thursday night, as weak nebulous flow takes over. A col region will set up for late week into the weekend, resulting in a potential period of variable breezes.

AVIATION
(15Z TAFS)
Issued at 1030 AM EDT Wed Jul 29 2026 While a broken cloud line will be possible over portions of the Lower and Middle Keys this afternoon, moderate southwesterly low- level steering flow will likely prevent any well-defined cloud line. This will be monitored throughout the afternoon. Otherwise, VFR conditions will prevail across the EYW and MTH island terminals through 12z Thursday morning.

KEY WATCHES/WARNINGS/ADVISORIES
FL...None.
GM...None.