Waterspouts spotted near Lower Keys, more possible through afternoon

Mariners in the Lower Keys were warned to move fast Monday after a National Weather Service staff member reported an observed waterspout about 1 mile south of Boca Chica at 11:28 a.m. EDT. The alert covered Key West, Boca Chica, Big Coppitt and Sugarloaf Key, with forecasters saying more waterspouts were possible through the afternoon over nearshore waters from the west end of Seven Mile Bridge to Halfmoon Shoal and across Hawk Channel to the reef.

The Marine Weather Statement warned of thunderstorms with wind gusts near 30 knots, rough and confused seas, occasional lightning strikes and potentially blinding downpours. It told mariners to seek safe port quickly and to report waterspouts to NWS Key West at 305-295-1316 ext. 3. Forecasters said the spouts were most likely to appear beneath a dark, flat-bottomed building cumulus line at the hint of rain, a familiar setup for the Lower Keys during the rainy season.

KBYX radar was showing only a few isolated showers, mainly northwest of the Lower Keys, and the broader marine forecast called for gentle to moderate east to southeasterly breezes across Florida Keys waters through the first half of the week. Even so, the weather office said rain and thunder chances would peak Wednesday through Thursday. No marine watches, warnings or advisories were in effect for the Florida Keys coastal waters in the morning forecast discussion, making the waterspout threat a fast-moving hazard rather than part of a larger widespread marine warning.

Waterspouts are common in the Florida Keys, especially the non-supercell or fair-weather variety that forms along cumulus cloud lines. The National Weather Service says mature waterspouts can produce spray rings that indicate winds above 40 knots, or 46 mph, turning what may look like a narrow funnel into a serious threat for boaters, charter operators and anyone running across open water near the reef tract.

The pattern is well known in Monroe County. The Lower Keys Waterspout Project, run from May through September 1969, recorded 390 waterspouts and funnel clouds within 50 nautical miles of Key West. The Key West office also points to major outbreaks closer to home, including 14 waterspouts near Key West on March 28, 2017, and 12 more on November 4, 2022. For the Lower Keys, the message remained the same Monday: conditions can turn quickly, and waterspouts can form with little warning just off the islands.