UPDATE 2-Wisconsin flooding prompts state of emergency

(Recasts with state of emergency)

By John Rondy

MILWAUKEE, July 23 (Reuters) - Wisconsin's governor declared a state of emergency on Friday after torrential rains flooded homes and opened sinkholes in Milwaukee and closed the city's main airport.

Runways were inundated at General Mitchell International Airport and the facility shut down temporarily on Friday.

The airport, which handled nearly 8 million passengers last year, shut on Thursday night as storms dumped 5-1/2 inches (14 cm) of rain on the city. One rain gauge in the suburb of Shorewood recorded nearly a foot (30 cm) of water.

"Yesterday, Milwaukee saw what may be record rainfall," Governor Jim Doyle said.

"(Milwaukee) Mayor (Tom) Barrett called to update me on the damage this morning and I assured him that the state will do everything we can to help people in Milwaukee," he said.

Cars were submerged, streets and highways were flooded, and one sinkhole swallowed a sport-utility vehicle and its driver, who was rescued by a passerby.

The 20-foot-deep (6 metres), 40-foot-wide (12 metres) sinkhole formed at an intersection when a manhole collapsed, and will require several weeks to repair, a city spokesman said.

Another sinkhole damaged a home. Officials warned that heavy rains the past few weeks threatened to create more.

A flash flood watch remained in effect through Saturday morning, the National Weather Service said in an advisory, warning of possible widespread flooding. Also under flood watch were parts of northern Illinois and western Iowa.

In the eastern half of the United States, hot, humid air pumped up from the South by a high pressure ridge prompted the Weather Service to issue heat advisories in 17 states.

Milwaukee residents could not turn to Lake Michigan for relief from the heat because its beaches were ordered closed through Sunday because the deluge forced the city to open floodgates, sending runoff and untreated sewage into the lake.

Even the rain-stricken region's farmers needed relief.

"The rains across Iowa, southern Wisconsin and northern Illinois are more than what the guys want," said Roy Huckabay, a grains market analyst in Chicago for The Linn Group.

(Writing by Andrew Stern and Jerry Norton; Editing by Greg McCune and Will Dunham)