The National Weather Service has placed central and southern portions of the Florida peninsula at Level 2 of 4 for a slight risk of flash flooding and excessive precipitation Tuesday through Friday. Flood warnings could be issued on Tuesday ahead of heavy rain.
Much of the area expected to receive torrential rains is facing severe drought of late, with parched lawns and an increased risk of fire. Precipitation will reduce or eliminate much of it by Saturday.
The same system could then concentrate a band of intense rain toward the Florida peninsula or southern Alabama around Mobile by the weekend or early next week, but confidence in this outcome remains quite low .
When will these rains come?
A few isolated late day thunderstorms are possible Monday across central and south Florida, with more scattered or scattered storms Tuesday afternoon, particularly along the Gulf Coast. From Tuesday evening to Wednesday morning, the heaviest will work on land, with intermittent showers until Friday. Precipitation rates of 2 to 3 inches per hour are likely during the heaviest downpours.
Showers could ease a bit Friday and Saturday and perhaps diminish in South Florida, but the axis of heaviest humidity could then head north into Florida’s Big Bend or in the Panhandle.
Rain totals and potential flooding
Widespread totals of 10 to 14 inches are expected in South Florida through Friday, primarily from Punta Gorda and Fort Myers to Lake Okeechobee and Palm Beach. Weather models depict about a foot of rain falling in Miami and Fort Lauderdale, which will likely lead to urban flooding.
A general level of 5 to 10 inches is forecast for Tampa, the Space Coast – including Cape Canaveral – and Orlando. In North Florida, amounts are decreasing pretty quickly, with a best bet of 3 to 5 inches.
Flooding aside, precipitation is exactly what Florida needs. According to the U.S. Drought Monitor, most of South Florida is facing moderate or severe drought.
Stagnating high pressure and warm, sinking air during May led to increased sunshine and decreased precipitation. Hot weather also evaporates more moisture from the soil, leading to increasing drought. This May was the hottest on record in the state of Florida.
At first glance, this may not be the case look as if Florida was facing a drought. Miami is just 2.5 inches below average for the year to date, so it is, for all intents and purposes, about where it should be. Naples is also above average. But Fort Myers is more than 7 inches behind.
But much of that rain fell early in the year. The last month has been relatively dry. Fort Myers is just under 3 inches behind over the past month, and Naples is about 3.5 inches behind.
This appears to be the first significant rain event of the summer rainy season, but it could be a little more than many expected.
The configuration for these conditions
Florida will find itself in a classic “squeeze play” pattern, meaning the state will fall between two weather systems that will feed a rich tongue of moisture to the northeast.
An area of high pressure is rotating clockwise over the western Atlantic Ocean. A counterclockwise-circling “shortwave” low will approach the Southern Plains on Tuesday, then stall over Texas, Louisiana, and the northwest Gulf of Mexico from here Wednesday.
The two opposingly rotating systems will behave somewhat like interlocking gears, entraining rich tropical moisture from the Caribbean Sea and Cuba region and transporting it north-northeast. For days, Florida will be in the crosshairs of this humidity, which will fuel showers and thunderstorms. These showers will form along a stationary front, or stagnant frontal boundary, which will remain draped across the state. This means they will move through the same areas repeatedly, resulting in higher totals.