Summer Rains Are On Way to Parched Polk

After the driest May in more than a half-century, the weather forecast is changing quickly.

Florida's rain machine, which results in almost daily afternoon and evening thunderstorms during the summer months, is cranking up, according to forecasters.

Residents in parts of southern Polk County got a taste of that Sunday and Monday as huge clouds with anvil-shaped heads boomed their way into existence and then unloaded. Between one and three inches fell in East Polk on Monday evening, with the heaviest rains near the Osceola County line, according to Brian McClure of Bay News 9. About 1 1/4 inches fell in Lake Wales.

"We are starting to get into the early pattern," said Rick Davis of the National Weather Service. He said the forecast for the next few days includes a 30 percent chance of afternoon and evening thunderstorms, increasing to 40 percent by the weekend.

"It looks like we're under way," agreed Mike Clay of Bay News 9. "Enjoy the storms - they're on the way."

It is summertime and it is Florida. The forecast for the next few months involves heat, humidity and rain. Once the pattern is fully developed, colliding sea breezes and rising heat from the inland will result in almost-daily rainfall chances of between 50 percent and 60 percent.

While the summer pattern generally begins about June 1, forecasters say that's an average. It can begin in May, but in some years it hasn't developed until late June.

This year, the on-time arrival is appreciated by officials who hope to see the drought index begin to drop and lake levels begin to rise.

The drought index for Polk County, which measures the dryness in the soil, stood at 563 before Sunday's rains. While much of Polk County received no rain Sunday, the south Polk rain had enough impact to reduce the average for Polk County to 549.

Florida Division of Forestry officials use the index to gauge the threat of wildfires. Officials expect problems any time the index exceeds the 400 mark. The index ranges from a soggy zero to a bone-dry 800.

Sunday's storms generated lightning strikes that caused at least one small fire in the phosphate area of southwest Polk, according to Division of Forestry spokeswoman Chris Kintner.

Kintner said lightning strikes are the main concern as the rainy season begins, because it will take time to saturate the soil and to turn vegetation green.

In Lakeland, May rainfall totaled just 0.37 inches, compared with an average for the month of 3.81 inches. It was the second-driest May ever, surpassed only by 1953 when rainfall totaled 0.13 inches. That all compares with 16.03 inches recorded in 1979, which was the wettest May ever.

For the year to date, 15.44 inches has been recorded in Lakeland, compared with an average of 14.41 inches. While that's above average for the year so far, it has not been enough to offset the impact of 2007, when rainfall was far below normal in most of Polk County.

However, Sunday's rains, and the prospect for more, were enough to at least forestall implementation of a county burn ban, which had been expected this week. Heather McClanahan, spokeswoman for Polk County Fire Services, said the ban has been placed on hold.

[ Bill Bair can be reached at bill.bair@theledger.com or 863-676-7118. ]