March 15, 2012

With La Niña breaking up, Florida growers can expect a warm, dry spring

This chart shows the weather pattern that predominated the United States this winter, with a La Nina affect over the Pacific Ocean bringing warmer, drier weather to the south and cooler, wetter weather to the north.

After two years of freezing temperatures and other abnormal climate conditions, Florida growers can content themselves with the knowledge that the La Niña weather pattern responsible for recent weather extremes is expected to resolve some time this spring.

In the early season, that may be little comfort to growers, according to Daniel Noah of the National Weather Service in Ruskin, FL.

“I am not sure how moisture conditions will impact crops, but we are dry and the March-April-May seasonal forecast calls for a greater than 50 percent chance of below-normal precipitation,” Mr. Noah told The Produce News March 8. “The spring is usually dry in Florida and drought conditions are not uncommon. However, we are drier than normal and extreme drought conditions are beginning to spread across parts of the state.”

The area from Tampa Bay south to Immokalee is in severe drought, while a dozen north-central Florida counties are experiencing extreme drought conditions. South Florida is in better shape, with normal conditions for most of the area except the southeast coast – home to much of the state’s vegetable production – which is abnormally dry but not drought-stricken.

The good news is, “Basically, La Niña is forecast to go away within the next 3 months with neutral conditions expected,” Mr. Noah said.

Scott Spratt of the National Weather Service Forecast Office in Melbourne, FL, agreed with Mr. Noah. “The La Niña pattern of colder than normal Pacific Ocean temperatures appears to be breaking down over the past few weeks,” he said. “ It appears the Pacific may be beginning to transition out of the La Niña pattern towards neutral conditions — a prolonged period of near normal water temperatures, and a state between the extremes of La Niña and El Niño. The consensus of El Niño climate models also suggests a return to neutral conditions soon, which are expected to persist through the summer.”

That does not mean Florida growers can count on the weather in the interim.

“There typically is a lag time between the change of the state of the La Niña/El Niño Pacific Ocean temperatures and the associated atmospheric conditions over the southern United States, including Florida,” Mr. Spratt said. “We expect La Niña-like atmospheric conditions to persist through the remainder of the central Florida dry season, through April; warmer than normal temperatures and drier than normal precipitation. The typical onset of the central Florida wet season occurs during late May or early June. It is too early to tell if the wet season may begin on time, or perhaps earlier. A recent statistical forecast based on expected La Niña conditions and past La Niña relationship on our local temperature and rainfall records indicates a 65-67 percent probability of above normal temperatures during the February-April period for central Florida and a 73-85 percent probability of below normal rainfall.”

NWS Melbourne Climate Program Leader Derrick Weitlich noted that the forecast applies to the entire state of Florida, despite climate difference between the north and south regions of the state.

“This forecast does hold true for the entire state of Florida,” he said. “The dry season outlook actually covers the entire state of Florida and the latest three month outlook from the Climate Prediction Center continues greater chances for drier than normal conditions and warmer than normal temperatures into the spring.”

By Chip Carter / Published March 14, 2012

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