ORLANDO — Residents of South Florida woke up to heavy rain and flooding in some areas on Saturday as a rapidly growing weather system moved into the region. Although the tropical system did not turn into a named storm as it washed ashore on Friday night, it was expected to bring more than a foot of rain to some areas, including the Florida Keys, the Bahamas and Cuba, meteorologists said.
In Miami, drivers faced slashing rains and flooded streets in the early hours of Saturday morning. The city’s fire department responded to several people caught in cars amid the rising waters. Six high-water vehicles deployed in the city, the department said on Twitter. Winds of 40 miles per hour did not meet the threshold necessary for the system to be classified as Tropical Storm Alex, but they did slosh water into the downtown area, including in parking areas of condominiums.
Miami recorded 9.7 inches of rain as of Saturday morning, according to AccuWeather, but other areas, including Key Largo (11 inches) and Biscayne Park (11.6), saw higher totals. There was also reported flooding in communities outside Miami including Hialeah, Sweetwater and Hollywood, as well as in Naples, Fla., on the Gulf Coast.
Power outages did not soar overnight, however. As of 9 a.m. on Saturday, Miami-Dade County had 4,083 outages according to PowerOutage.us, while the surrounding counties of Broward and Palm Beach reported 781 and 227, respectively. To the west, Collier County, home of well-populated Naples, had 226 outages reported.
Although meteorologists said the storm never fully organized as it traveled from the Gulf of Mexico toward the Keys, it does not take much rain to cause mayhem in Miami — especially on a weekend night when many are out. Warnings about continued possible weather risks remained for the weekend.
“The main threat right now is the potential for heavy rainfall and flash flooding,” said Maria Torres, a spokeswoman for the National Hurricane Center in Miami, on Friday.
Early Saturday, the center warned of “considerable flash and urban flooding” in South Florida.
Rainfall totals associated with the storm were expected to be wide-ranging. Western Cuba could see up to 14 inches of rain with the possibility of life-threatening flash flooding and mudslides, forecasters said. Some areas in the northwestern Bahamas could see up to 10 inches.
The forecast for Florida included the possibility of tornadoes over the southern portion of the state through Saturday. South Florida could see six to 10 inches of rain, with isolated totals of up to 15 inches, while the Keys could see four to eight inches, with isolated totals of up to 10 inches. The Hurricane Center said that some cities could see a storm surge of up to three feet.
People who live in parts of South Florida that are prone to floods should identify a safe place to go to if waters begin to rise, and be careful not to drive through standing water, Ms. Torres said on Friday.
“Turn around, don’t drown,” she said.
Officials in Miami, Fort Lauderdale and other cities were distributing free sandbags on Friday. Miami’s zoo said on Friday that it would be closed through Saturday to allow staff members to prepare the facility for the storm. In Key West, an L.G.B.T.Q. street festival to kick off Pride Month was canceled.
In Palmetto Bay, an incorporated suburb about 15 miles south of Miami, officials were particularly concerned on Friday about the possibility of heavy rains, given that almost all of the village’s eight square miles were in a flood zone.
“We’re encouraging residents to keep their storm drains clear of debris,” Mayor Karyn Cunningham said. She noted that the village had increased its yearly budget for drain clearing but urged its 25,000 residents to play their part, including by keeping roads clear of obstructions and drains free of landscape clippings.
“We’ve been preparing for months for the upcoming hurricane season and take emergency response seriously,” Ms. Cunningham said. “We have to focus people’s minds around the fact that it’s hurricane season.”
Caroline Horn, the manager of a group that fights against flood insurance price hikes in the Florida Keys, said the warnings began early.
“I’m already getting notices on my phone to watch out for standing water,” Ms. Horn said. “We check the radar, every day, multiple times a day.”
Hurricane Agatha, the first named storm in the eastern Pacific region, roared into Mexico this week as a Category 2 storm with heavy rains and damaging winds. It killed at least nine people and left five others missing, the governor of the southern state of Oaxaca, Alejandro Murat, said on Friday morning.
Concerns about dangerous weather in the Atlantic began this week when forecasters said a large area of disturbed weather, related to the remnants of Hurricane Agatha, had formed near the Yucatán Peninsula and had interacted with an upper-level trough over the Gulf of Mexico.
Meteorologists expect an “above normal” Atlantic hurricane season, which runs through Nov. 30, with 14 to 21 named storms considered likely. Up to 10 of those are expected to reach hurricane strength.
Roman Gastesi, the county administrator in the Florida Keys, said he took his boat out of the water but did not go so far as to put up hurricane shutters. The county warned that some coastal residents might see flooding of up to two feet.
“It’s a good time to dust off your hurricane plans,” Mr. Gastesi said. “Here we go, it’s hurricane season. It’s certainly not the big one, but it puts us on alert.”
Alanis Thames, Nick Madigan and Jesus Jiménez contributed reporting.
