A gulp of tropical moisture is forecast to sweep into South Florida this weekend, dousing Mother’s Day and heralding a seasonal shift as punctual as the tides.
The rainy season, a faucet that brings Palm Beach, Broward and Miami-Dade counties up to 70 percent of their annual rainfall, could make its 2018 debut with widespread showers dumping up to 4 inches of rain Saturday through Tuesday.
While the wettest weather is expected Sunday, the sky may open late Saturday as a slowpoke area of storminess forms in the eastern Gulf of Mexico. The system’s counterclockwise spin will pull soggy air into the Peninsula. At the same time, the front that brought rain to South Florida on Sunday will move north from where it’s been stalled in the Florida Straits.
“No one escapes this one. Everybody is going to get wet,” said Kevin Scharfenberg, a meteorologist with the National Weather Service in Miami. “The question will be where the heaviest pockets of rain will be, but we are looking at an average between late Saturday to Tuesday of 2 to 4 inches.”
That means anyone with outdoor plans for Mother’s Day may want a contingency.
Ashley Koecheler, a manager at the popular Guanabanas waterfront restaurant and bar in Jupiter, said they’ve been watching the forecast expecting a crush of customers Sunday. The restaurant has some covered seating, but is largely open.
“We’re pretty used to the weather in South Florida and dealing with the rain,” she said. “It would put a damper on the day, but we would work around it to make sure everyone was covered.”
The Weather Prediction Center has the far reaches of southeast Florida under a marginal threat for excessive rainfall Saturday through Sunday. That means there is between a 5 to 10 percent chance of rains heavy enough to cause flooding in low-lying areas, ditches and areas that drain slowly.
Scharfenberg said if there is flooding, it would more likely occur late Sunday into Monday as water begins to pile up.
“Since we will have 2 to 4 inches across the whole area, once you get those kinds of rates, we might be talking about some potential for the usual urban flooding,” he said. “It’s a little too early to issue a flood watch because we are talking a few days away.”
Parts of South Florida are experiencing moderate to severe drought with Thursday’s report from the U.S. Drought Monitor showing Palm Beach County with mostly “abnormally dry conditions.” Areas of Broward, Miami-Dade and Collier counties are feeling a deeper dry spell as recent rains focused more heavily to the north.
April was the first month since October to have normal to slightly above normal rainfall in the 16-county region overseen by the South Florida Water Management District. That’s left the area, which runs from Orlando to the Keys, with a 4.4-inch deficit of rain for the year.
“We are running about 60 percent of average for the last several months dating back to November,” said district chief engineer John Mitnik during a governing board meeting Thursday. “The upper east coast saw the majority of rain, while what will stand out is the southwest coast didn’t get a whole lot.”
About 10.6 inches of rain has fallen for the year in coastal Palm Beach County, which is 2.8 inches less than normal. Areas closer to Lake Okeechobee are down 3.5 inches of rain.
The parched winter lowered Lake Okeechobee to a Thursday height of 12.9 feet above sea level, within the Army Corps of Engineers comfort zone of between 12.5 and 15.5 feet above sea level.
Saturday’s forecast is for a 30 percent chance of rain early in the day increasing to 60 percent after 2 p.m. and up to 70 percent at night. The high temperature Saturday is will be near 85 with an overnight low of 72. Sunday’s temperatures will hover closer to 80 degrees for a high.
Last week, the NWS in Miami announced it was setting hard dates for the rainy season, declaring a May 15 through Oct. 15 as the wettest part of the year. Before, the rainy season was based on dew points and a pattern of consistent rainfall.
“I don’t see any dry weather for a while,” Scharfenberg said. “We are now calling the wet season to be static every year and the timing looks pretty right.”