Slow-moving Gulf storm threatening Florida with heavy rains and flooding

A storm rolling across the Gulf of Mexico and threatening to ruin Memorial Day plans is now expected to become a depression by late Saturday, National Hurricane Center forecasters said Thursday morning.

In an 8 a.m. advisory, forecasters gave the system a 40 percent chance of forming over the next two days and an 80 percent chance in five days. Gradual development is expected over the next two days with a tropical, or subtropical, depression forming over the southeastern Gulf of Mexico.

Because the system lacks an organized core, it’s difficult to forecast a storm track, said AccuWeather senior meteorologist Dan Kottlowski, but models so far show it nearing land near the Florida Panhandle or Louisiana coast.

Read more: So it’s going to rain all Memorial Day Weekend – here’s why we’re super happy about that.

Flooding is possible because the area has already received so much rain, he said.

“The grounds are fairly saturated right now. I wouldn’t say they’re extremely saturated, but they are fairly saturated so areas that receive heavy rainfall we could see some flooding issues.”

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Southwest Florida could begin to see rain from the system by Friday. Source: NOAA Climate Prediction Center

The slow-moving low pressure system began drawing meteorologists attention last week when computer models began to suggest possible development, Kottlowski said. While the official hurricane season doesn’t start until next Friday, Gulf waters are already warm enough to fuel a tropical cyclone if atmospheric conditions are favorable.

The system’s proximity to the Belize coast and wind shear have so far kept it in check. But by Friday or Saturday, upper level winds are expected to move east, forcing the low pressure system to the north.

“As the low pressure moves away from land, then it will have nothing but the open part of the Gulf to move over,” Kottlowski said.

If a subtropical system forms, stronger winds will occur around the storm’s edges rather than the center. Subtropical systems are similar to tropical systems and produce the same hazards — wind and heavy rain — but don’t have the warm center, he said.

Heavy rain appears to be the system’s biggest threat to land and a concern for South Florida, which has been hammered by rain over the last month. In some places, rainfall is more than three times the monthly average, a dramatic leap from April when totals fell well below average, left the region abnormally dry and fueled wildfires across the Big Cypress National Preserve.

The Gulf Coast should also lookout for heavy rip currents, forecasters said.