Cars drive through a flooded street in Dania Beach, Florida, April 12
Joe Raedle/Getty Images
Heavy rains hit parts of southern Florida, forcing the U.S. National Weather Service to declare a flash flood emergency and permanently shut down Fort Lauderdale Airport. Road, rail and air connections were cut, and emergency services worked overnight to rescue those stranded in the rising waters.
Meteorologists say the rainfall likely broke local records, likely caused in part by increasing climate change.
Here’s what we know about what happened and whether such events can be predicted.
How much rain has it rained in Florida?
According to the US National Weather Service, on April 12, Fort Lauderdale in southern Florida received more than 50 cm of rain in just six hours.
Total daily precipitation can be higher. His WeatherSTEM station at the Fort Lauderdale airport showed he had about 66 cm of rain on the station in the 24 hours ending at 7 a.m. on April 13, local time.
Heavy downpours come after several days of wet weather in Florida. Florida should still have an eight month dry season with an average monthly rainfall of about 7.6 cm.
Niklas Boers of Germany’s Potsdam Institute for Climate Impact Research said the extreme rain was “a very, very, very extraordinary event. [for Florida], especially in the dry season. ”
What areas were affected by the rains in Florida?
Heavy rains quickly overwhelmed urban drainage systems in the region, turning roads into rivers and flooding homes. At some point on April 12, approximately 22,000 residents lost power.
The hardest-hit area was around Fort Lauderdale, where transportation was effectively shut down. The Fort Lauderdale airport has been closed since the afternoon of his April 12th, and at least he will be closed until noon on April 13th local time. Meanwhile, South Florida’s high-speed commuter rail service Brightline is also closed.
About 330 schools in Broward County, which covers parts of Fort Lauderdale and Miami, closed April 13 due to unsafe conditions.
According to the National Weather Service, more showers and thunderstorms are expected on April 13, with an additional 5 to 10 cm of rain possible.
When a huge storm like this hits a city, there’s little city officials can do to minimize disruption, says Boers. and it becomes very difficult for that amount of water to penetrate the soil,” he says. “It’s a nightmare for climate adaptation planners because there is basically nothing that can be done.”
Why does it rain so much in an area with such concentration of rain?
The rain was caused by a slow cluster of thunderstorms that gathered in Florida on April 12th. Such extreme storms are becoming increasingly common as the climate changes. In 2021, Germany and Belgium experienced two days of severe storms that caused devastating flooding. China, Italy and New York have also experienced similar flooding due to extreme rainfall in recent years.
The increase in rainfall intensity is due to climate-induced warming, says Hayley Fowler of the University of Newcastle, UK. A warmer atmosphere holds more moisture, increasing the frequency and intensity of storms. “The ability to have these larger downpours is there in terms of the increased ability of the atmosphere to hold moisture,” she says.
There is also some evidence to suggest that climate change will make storms more likely to “stall,” bringing more rain to concentrated areas and increasing the risk of flash flooding.
Can these events be predicted?
The potential for extreme rainfall is one of the most difficult weather phenomena to predict for climate scientists and meteorologists. One problem is that climate models seem to underestimate the potential for more severe precipitation as the climate warms.
Researchers modeling the impact of climate change on precipitation rely on the Clausius-Clapeyron equation. This formula calculates that for every degree increase in atmospheric temperature, there should be a 7% increase in precipitation.
But recent extreme rainfall events seem to have released more water than that, says Fowler, suggesting something is wrong with climate modeling in the region.
For example, a 2022 study found that climate change increased precipitation by 11% during the heaviest period of the 2020 North Atlantic hurricanes.
“The kind of downpours we’re seeing seem to represent a much bigger change than that. [the Clausius-Clapeyron equation], potentially,” says Fowler. “So there’s something going on that our weather and climate models don’t capture.”
Fowler is one of a team of scientists currently researching how to fine-tune climate models to avoid underestimating the potential severity of future storms. “I think I’m missing something important,” she says.
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