June 4, 2009

May's record rainfall soaks South Florida drought

The wet season arrived with a historically soggy splash and erased most drought impacts.

In a swift and soggy reversal, South Florida's weather has gone from historically dry to historically wet in the space of a month.

It was the rainiest May on record for the South Florida Water Management District, which recorded just over nines inches overall in the 16 counties it oversees, including Miami-Dade, Broward and Monroe.

That's more than double the average, replenishing lakes and ground-water supplies that had been drained dangerously low by one of the driest dry seasons ever.

''I think for all intents and purposes the drought is over,'' said Robert Molleda, warning coordination meteorologist for the National Weather Service in Miami.

Water managers weren't quite ready to go that far.

South Florida gets about 70 percent of its annual rainfall, normally 35 to 45 inches, during the rainy season.

Annual Rainfall in South Florida, 1951 to 1980 (See map below)

But as the last year has shown, average rainfall in the subtropical lower peninsula is often the point between two extremes.

Spokesman Randy Smith said the district was reviewing the improving conditions but with the six-month rainy season less than a month old, it was too early to declare the drought over.

But it was the rainiest May in West Palm Beach in 119 years, with a gauge at Palm Beach International Airport collecting 15.69 inches.

Moore Haven, on the southern shore of Lake Okeechobee, recorded 11.52 inches, less than a half-inch short of the two wettest Mays in 1923 and 1954.

Miami and Fort Lauderdale were almost above normal but far short of records. Miami International Airport recorded 7.53 inches -- nearly a foot short of the 18.66 record of Miami 1925. Fort Lauderdale-Hollywood International saw 7.80 inches -- 10 inches short of the 17.85 that fell in 2003.

The district's broader array of gauges across the counties showed coastal Miami-Dade, Broward and Palm Beach counties all at or near 10 inches for the month, close to double the normal amount of rainfall.

The upper basin of the Kissimmee River, which feeds Lake Okeechobee, recorded a stunning 14.16 inches -- more than four times the average.

The lake, which serves as the region's water barrel, has rebounded as well, rising three-quarters of a foot in the last few weeks and erasing evaporation losses from the last month.

The lake still remains seven-tenths of a foot below where water managers would like to see it at this time of year.

Even the driest region, Naples and Southwest Florida, recorded well above average rainfall.

Because the rainfall deficit between November and April was so deep -- with Miami about a foot below average and Fort Lauderdale and Palm Beach more than 16 inches below normal -- groundwater and lake levels were at extreme low levels only a few weeks ago.

Much of Homestead, Florida City and the Keys remain on once-weekly watering restrictions because of concerns that encroaching salt water could taint well fields.

Forecasters expect the patterns of afternoon thunderstorms to continue into the week.


No comments:

Post a Comment