A series of storms originating from the Gulf of Mexico has inundated South Florida with flash floods, stalling vehicles, canceling dozens of flights, and causing widespread disruptions for tens of thousands of residents.

Why is Florida Prone to Flooding?

Florida’s flat terrain makes it susceptible to flooding, even during sunny days when king tides surge in coastal areas. Tropical storms and hurricanes can exacerbate the situation, leading to river flooding and overwhelming the region’s drainage systems and canals.

How Much Rain Has Fallen?

The National Weather Service reports that from Tuesday through Wednesday, approximately 20 inches (50 centimeters) of rain fell in the hardest-hit areas, including Hallandale Beach, Hollywood (near Fort Lauderdale), and North Miami. Miami Beach, known for flooding during less severe storms, received about 13 inches (33 centimeters). More rain is expected on Thursday, likely causing additional flooding due to the already saturated ground.

How Unusual Is This?

June is typically the wettest month in Miami, with an average annual rainfall of over 10 inches (25 centimeters), according to Alex DaSilva, AccuWeather’s lead hurricane forecaster. The unusual aspect is the volume of rain South Florida has experienced in such a short period. For instance, Fort Lauderdale recorded unprecedented rainfall in April 2023, with totals ranging from 15 inches (38 centimeters) to 26 inches (66 centimeters), resulting in significant flooding for homes and businesses, some of which are facing similar conditions again.

What Weather Patterns Are Causing the Repeated Rains?

Two persistent weather systems are responsible for the ongoing floods in Florida. One is a high-pressure area off the southeastern coast, spinning clockwise. The other is a “Central American gyre,” a low-pressure area of storms spinning counterclockwise in the western Caribbean Sea, which appears every spring. These systems have created a channel funneling moisture from the Caribbean into Florida, acting like a fire hose on jet mode. Additionally, a stalled front across Florida has enhanced precipitation.

What Are Flash Floods in Florida?

Unlike other regions prone to flash floods with dry riverbeds or gullies that become raging torrents, Florida’s flat terrain leads to flooding that overwhelms drainage and pumping systems. This can quickly transform a few inches of water on roadways into a couple of feet, enough to stall and float cars. On Wednesday, the National Weather Service in Miami issued a rare flash flood emergency, highlighting imminent life-threatening conditions and potential property damage, primarily due to vehicles stuck on flooded roads. Approximately half of flood-related deaths occur in vehicles.

Is There Any Silver Lining?

Before these storms, many parts of Florida, particularly the Gulf Coast from Tampa Bay to Fort Myers and Naples, experienced drought conditions. Sarasota even declared a drought emergency, urging water conservation. However, the recent rains have significantly alleviated these conditions. Some areas in Sarasota received 8 inches (20 centimeters) of rain in a single hour, a 500-year event. This rainfall is expected to eliminate most, if not all, drought conditions across South Florida, according to DaSilva.