Coastal Flooding Potential
- A COASTAL FLOOD WARNING is in effect for the Upper Florida Keys, particularly for the Sounds and the Bayside of Key Largo. Numerous streets, especially in low-lying neighborhoods along the Bayside of Key Largo, may be impassible to smaller vehicles.
- A COASTAL FLOOD ADVISORY is in effect for the remainder of the Florida Keys for moderate saltwater flooding of low elevation streets and lots, overflowing storm drains, and overtopped docks.
- This Monday morning, tides are running around 1 foot higher than lunar/astronomical tide prediction charts indicate.
- Minor to moderate saltwater flooding is expected to continue throughout much of this week.
- The higher high tide is transitioning to the late evening/early pre-dawn hours this week.
- Tides are expected to continue up to around 1 foot above normal predicted values, with the peak tides are expected to reach between 3 and 12 inches deep in the lowest streets and lots in areas prone to King Tide flooding.
Rainfall Outlook
- The chances for rainfall exceeding one inch during overnight tonight ranges from 5 to 20 percent. The chances of exceeding one inch of rainfall overnight Wednesday night and Thursday night during the times of the higher high tide are currently around 5 percent. For the Upper Keys, where Bayside water levels will remain consistently at moderate to major flood levels day and night, the chances for receiving an inch of rain or more during the daytime Wednesday and Thursday could be as high as 15 percent. The NWS will continue to monitor heavy rainfall potential this week, as any downpours near one inch of rain or more can greatly exacerbate flooding in poor drainage areas around the times of the higher high tide each night.
- The return to above-normal rain chances will occur from a combination of a stationary front weakening over the Straits of Florida, and a high altitude trough of low pressure across the eastern Gulf bringing deep tropical moisture back northward over the Florida Keys.
Next Briefing: Wednesday, Sep 30, 2026
9:30 AM EDT