Super soaker storms doused West Palm Beach with more than 8 inches of rain Thursday, erasing a 51-year-old record of 3.75 inches for Dec. 14, set in 1955.

The rainfall turned streets in West Palm Beach into fast-moving canals by lunchtime and knocked out power to about 2,200 FPL customers from Sebastian to Boca Raton.

Some roads in downtown West Palm Beach were so flooded they were blocked off to traffic, which added to the horn-honking gridlock at intersections.

Sidewalks were impassible except to those wearing knee-high rubber boots or bare feet.

"Every time a car passed, a wave would wash across the sidewalk up to our door," said Neal Chanda, owner of Atrio Restaurant on Olive Street.

"Doormats and some sandwich signs got washed away."

December is usually a dry month for South Florida, but a low-pressure trough combined with flows of moisture from the Caribbean and the Pacific Ocean created the squally weather, said meteorologist Pablo Santos of the National Weather Service in Miami.

"All those ingredients are coming together to produce this rain," he said.

"It's a rather unusual wet pattern for this time of year."

By 2 p.m., West Palm Beach activated a "Code Red" system, which called residents and businesses suggesting motorists should avoid unnecessary travel.

Police closed Parker Avenue between Okeechobee and Southern boulevards because of the flooding.

The lowest point of town, Pineapple Park, couldn't escape the deluge even as the city began pumping water from its plant, Assistant City Administrator Ken Reardon said.

Water backed up into the immediate neighborhood and city streets.

Other eastern Palm Beach County areas also were flooded, said the weather service, which issued a flash flood warning for most of the afternoon.

The Red Cross opened a 200-bed urban flood shelter at the Westgate Community Center gymnasium west of West Palm Beach, where five people had sought help by 9 p.m.

Storms also were to blame for the closing of Christmas in the Village at the South Florida Fairgrounds, where electrical wires running through puddles caused a safety concern. The Village should reopen today.

Three pumping stations ran throughout the night to keep dumping water from canals, the South Florida Water Management District said.

Despite the soaking, the water district asked residents to continue voluntarily conserving water. Because surface water levels were raised, residents should turn off their lawn sprinklers for a while, district spokesman Randy Smith said.

"You have to remember that we were facing a deficit of 15 to 20 inches in some areas," he said.

"This one particular rain system won't ease our water shortage."

Today's forecast calls for a 60 percent chance of rain, including possible thunderstorms, the weather service said.

"Saturday night right now looks decent," Santos said. "There's a slight chance of rain at best."

Staff Writers Ken Kaye, Josh Hafenbrack, Stephanie Horvath and Erika Slife contributed to this report.

Chrystian Tejedor can be reached at ctejedor@sun-sentinel.com or 561-243-6645.